Merge tag 'arm-drivers-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM SoC driver updates from Arnd Bergmann:
 "A couple of subsystems have their own subsystem maintainers but choose
  to have the code merged through the soc tree as upstream, as the code
  tends to be used across multiple SoCs or has SoC specific drivers
  itself:

   - memory controllers:

     Krzysztof Kozlowski takes ownership of the drivers/memory subsystem
     and its drivers, starting out with a set of cleanup patches.

     A larger driver for the Tegra memory controller that was
     accidentally missed for v5.8 is now added.

   - reset controllers:

     Only minor updates to drivers/reset this time

   - firmware:

     The "turris mox" firmware driver gains support for signed firmware
     blobs The tegra firmware driver gets extended to export some debug
     information Various updates to i.MX firmware drivers, mostly
     cosmetic

   - ARM SCMI/SCPI:

     A new mechanism for platform notifications is added, among a number
     of minor changes.

   - optee:

     Probing of the TEE bus is rewritten to better support detection of
     devices that depend on the tee-supplicant user space. A new
     firmware based trusted platform module (fTPM) driver is added based
     on OP-TEE

   - SoC attributes:

     A new driver is added to provide a generic soc_device for
     identifying a machine through the SMCCC ARCH_SOC_ID firmware
     interface rather than by probing SoC family specific registers.

     The series also contains some cleanups to the common soc_device
     code.

  There are also a number of updates to SoC specific drivers, the main
  ones are:

   - Mediatek cmdq driver gains a few in-kernel interfaces

   - Minor updates to Qualcomm RPMh, socinfo, rpm drivers, mostly adding
     support for additional SoC variants

   - The Qualcomm GENI core code gains interconnect path voting and
     performance level support, and integrating this into a number of
     device drivers.

   - A new driver for Samsung Exynos5800 voltage coupler for

   - Renesas RZ/G2H (R8A774E1) SoC support gets added to a couple of SoC
     specific device drivers

   - Updates to the TI K3 Ring Accelerator driver"

* tag 'arm-drivers-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (164 commits)
  soc: qcom: geni: Fix unused label warning
  soc: qcom: smd-rpm: Fix kerneldoc
  memory: jz4780_nemc: Only request IO memory the driver will use
  soc: qcom: pdr: Reorder the PD state indication ack
  MAINTAINERS: Add Git repository for memory controller drivers
  memory: brcmstb_dpfe: Fix language typo
  memory: samsung: exynos5422-dmc: Correct white space issues
  memory: samsung: exynos-srom: Correct alignment
  memory: pl172: Enclose macro argument usage in parenthesis
  memory: of: Correct kerneldoc
  memory: omap-gpmc: Fix language typo
  memory: omap-gpmc: Correct white space issues
  memory: omap-gpmc: Use 'unsigned int' for consistency
  memory: omap-gpmc: Enclose macro argument usage in parenthesis
  memory: omap-gpmc: Correct kerneldoc
  memory: mvebu-devbus: Align with open parenthesis
  memory: mvebu-devbus: Add missing braces to all arms of if statement
  memory: bt1-l2-ctl: Add blank lines after declarations
  soc: TI knav_qmss: make symbol 'knav_acc_range_ops' static
  firmware: ti_sci: Replace HTTP links with HTTPS ones
  ...

28 files changed, 3029 insertions, 86 deletions

diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 1cad32b38b29..6f9cbc4aef22 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -1,9 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-y	= scmi-bus.o scmi-driver.o scmi-protocols.o scmi-transport.o
 scmi-bus-y = bus.o
-scmi-driver-y = driver.o
+scmi-driver-y = driver.o notify.o
 scmi-transport-y = shmem.o
 scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
-scmi-transport-$(CONFIG_ARM_PSCI_FW) += smc.o
+scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o
 scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o
 obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o
diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index ce7d9203e41b..9853bd3c4d45 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -5,7 +5,15 @@
  * Copyright (C) 2018 ARM Ltd.
  */
 
+#define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
+
+#include <linux/scmi_protocol.h>
+
 #include "common.h"
+#include "notify.h"
+
+#define SCMI_BASE_NUM_SOURCES		1
+#define SCMI_BASE_MAX_CMD_ERR_COUNT	1024
 
 enum scmi_base_protocol_cmd {
 	BASE_DISCOVER_VENDOR = 0x3,
@@ -19,16 +27,25 @@ enum scmi_base_protocol_cmd {
 	BASE_RESET_AGENT_CONFIGURATION = 0xb,
 };
 
-enum scmi_base_protocol_notify {
-	BASE_ERROR_EVENT = 0x0,
-};
-
 struct scmi_msg_resp_base_attributes {
 	u8 num_protocols;
 	u8 num_agents;
 	__le16 reserved;
 };
 
+struct scmi_msg_base_error_notify {
+	__le32 event_control;
+#define BASE_TP_NOTIFY_ALL	BIT(0)
+};
+
+struct scmi_base_error_notify_payld {
+	__le32 agent_id;
+	__le32 error_status;
+#define IS_FATAL_ERROR(x)	((x) & BIT(31))
+#define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
+	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
+};
+
 /**
  * scmi_base_attributes_get() - gets the implementation details
  *	that are associated with the base protocol.
@@ -222,6 +239,83 @@ static int scmi_base_discover_agent_get(const struct scmi_handle *handle,
 	return ret;
 }
 
+static int scmi_base_error_notify(const struct scmi_handle *handle, bool enable)
+{
+	int ret;
+	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
+	struct scmi_xfer *t;
+	struct scmi_msg_base_error_notify *cfg;
+
+	ret = scmi_xfer_get_init(handle, BASE_NOTIFY_ERRORS,
+				 SCMI_PROTOCOL_BASE, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->event_control = cpu_to_le32(evt_cntl);
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_base_set_notify_enabled(const struct scmi_handle *handle,
+					u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_base_error_notify(handle, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
+
+	return ret;
+}
+
+static void *scmi_base_fill_custom_report(const struct scmi_handle *handle,
+					  u8 evt_id, ktime_t timestamp,
+					  const void *payld, size_t payld_sz,
+					  void *report, u32 *src_id)
+{
+	int i;
+	const struct scmi_base_error_notify_payld *p = payld;
+	struct scmi_base_error_report *r = report;
+
+	/*
+	 * BaseError notification payload is variable in size but
+	 * up to a maximum length determined by the struct ponted by p.
+	 * Instead payld_sz is the effective length of this notification
+	 * payload so cannot be greater of the maximum allowed size as
+	 * pointed by p.
+	 */
+	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
+	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
+	for (i = 0; i < r->cmd_count; i++)
+		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
+	*src_id = 0;
+
+	return r;
+}
+
+static const struct scmi_event base_events[] = {
+	{
+		.id = SCMI_EVENT_BASE_ERROR_EVENT,
+		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
+		.max_report_sz = sizeof(struct scmi_base_error_report) +
+				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
+	},
+};
+
+static const struct scmi_event_ops base_event_ops = {
+	.set_notify_enabled = scmi_base_set_notify_enabled,
+	.fill_custom_report = scmi_base_fill_custom_report,
+};
+
 int scmi_base_protocol_init(struct scmi_handle *h)
 {
 	int id, ret;
@@ -256,6 +350,12 @@ int scmi_base_protocol_init(struct scmi_handle *h)
 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
 		rev->num_agents);
 
+	scmi_register_protocol_events(handle, SCMI_PROTOCOL_BASE,
+				      (4 * SCMI_PROTO_QUEUE_SZ),
+				      &base_event_ops, base_events,
+				      ARRAY_SIZE(base_events),
+				      SCMI_BASE_NUM_SOURCES);
+
 	for (id = 0; id < rev->num_agents; id++) {
 		scmi_base_discover_agent_get(handle, id, name);
 		dev_dbg(dev, "Agent %d: %s\n", id, name);
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 4c2227662b26..75e39882746e 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -5,6 +5,8 @@
  * Copyright (C) 2018 ARM Ltd.
  */
 
+#include <linux/sort.h>
+
 #include "common.h"
 
 enum scmi_clock_protocol_cmd {
@@ -121,11 +123,23 @@ static int scmi_clock_attributes_get(const struct scmi_handle *handle,
 	return ret;
 }
 
+static int rate_cmp_func(const void *_r1, const void *_r2)
+{
+	const u64 *r1 = _r1, *r2 = _r2;
+
+	if (*r1 < *r2)
+		return -1;
+	else if (*r1 == *r2)
+		return 0;
+	else
+		return 1;
+}
+
 static int
 scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 			      struct scmi_clock_info *clk)
 {
-	u64 *rate;
+	u64 *rate = NULL;
 	int ret, cnt;
 	bool rate_discrete = false;
 	u32 tot_rate_cnt = 0, rates_flag;
@@ -184,8 +198,10 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 		 */
 	} while (num_returned && num_remaining);
 
-	if (rate_discrete)
+	if (rate_discrete && rate) {
 		clk->list.num_rates = tot_rate_cnt;
+		sort(rate, tot_rate_cnt, sizeof(*rate), rate_cmp_func, NULL);
+	}
 
 	clk->rate_discrete = rate_discrete;
 
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 31fe5a22a011..c113e578cc6c 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -6,6 +6,8 @@
  *
  * Copyright (C) 2018 ARM Ltd.
  */
+#ifndef _SCMI_COMMON_H
+#define _SCMI_COMMON_H
 
 #include <linux/bitfield.h>
 #include <linux/completion.h>
@@ -235,3 +237,5 @@ void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
 void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
 		     struct scmi_xfer *xfer);
+
+#endif /* _SCMI_COMMON_H */
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 7483cacf63f9..03ec74242c14 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -26,6 +26,7 @@
 #include <linux/slab.h>
 
 #include "common.h"
+#include "notify.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/scmi.h>
@@ -208,7 +209,9 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
 	struct device *dev = cinfo->dev;
 	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
 	struct scmi_xfers_info *minfo = &info->rx_minfo;
+	ktime_t ts;
 
+	ts = ktime_get_boottime();
 	xfer = scmi_xfer_get(cinfo->handle, minfo);
 	if (IS_ERR(xfer)) {
 		dev_err(dev, "failed to get free message slot (%ld)\n",
@@ -221,6 +224,8 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
 	scmi_dump_header_dbg(dev, &xfer->hdr);
 	info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size,
 					    xfer);
+	scmi_notify(cinfo->handle, xfer->hdr.protocol_id,
+		    xfer->hdr.id, xfer->rx.buf, xfer->rx.len, ts);
 
 	trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id,
 			   xfer->hdr.protocol_id, xfer->hdr.seq,
@@ -392,8 +397,7 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
 		info->desc->ops->mark_txdone(cinfo, ret);
 
 	trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id,
-			    xfer->hdr.protocol_id, xfer->hdr.seq,
-			    xfer->hdr.status);
+			    xfer->hdr.protocol_id, xfer->hdr.seq, ret);
 
 	return ret;
 }
@@ -789,6 +793,9 @@ static int scmi_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	if (scmi_notification_init(handle))
+		dev_err(dev, "SCMI Notifications NOT available.\n");
+
 	ret = scmi_base_protocol_init(handle);
 	if (ret) {
 		dev_err(dev, "unable to communicate with SCMI(%d)\n", ret);
@@ -831,6 +838,8 @@ static int scmi_remove(struct platform_device *pdev)
 	struct scmi_info *info = platform_get_drvdata(pdev);
 	struct idr *idr = &info->tx_idr;
 
+	scmi_notification_exit(&info->handle);
+
 	mutex_lock(&scmi_list_mutex);
 	if (info->users)
 		ret = -EBUSY;
@@ -901,7 +910,7 @@ ATTRIBUTE_GROUPS(versions);
 /* Each compatible listed below must have descriptor associated with it */
 static const struct of_device_id scmi_of_match[] = {
 	{ .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
-#ifdef CONFIG_ARM_PSCI_FW
+#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
 	{ .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
 #endif
 	{ /* Sentinel */ },
diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
new file mode 100644
index 000000000000..4731daaacd19
--- /dev/null
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -0,0 +1,1526 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Notification support
+ *
+ * Copyright (C) 2020 ARM Ltd.
+ */
+/**
+ * DOC: Theory of operation
+ *
+ * SCMI Protocol specification allows the platform to signal events to
+ * interested agents via notification messages: this is an implementation
+ * of the dispatch and delivery of such notifications to the interested users
+ * inside the Linux kernel.
+ *
+ * An SCMI Notification core instance is initialized for each active platform
+ * instance identified by the means of the usual &struct scmi_handle.
+ *
+ * Each SCMI Protocol implementation, during its initialization, registers with
+ * this core its set of supported events using scmi_register_protocol_events():
+ * all the needed descriptors are stored in the &struct registered_protocols and
+ * &struct registered_events arrays.
+ *
+ * Kernel users interested in some specific event can register their callbacks
+ * providing the usual notifier_block descriptor, since this core implements
+ * events' delivery using the standard Kernel notification chains machinery.
+ *
+ * Given the number of possible events defined by SCMI and the extensibility
+ * of the SCMI Protocol itself, the underlying notification chains are created
+ * and destroyed dynamically on demand depending on the number of users
+ * effectively registered for an event, so that no support structures or chains
+ * are allocated until at least one user has registered a notifier_block for
+ * such event. Similarly, events' generation itself is enabled at the platform
+ * level only after at least one user has registered, and it is shutdown after
+ * the last user for that event has gone.
+ *
+ * All users provided callbacks and allocated notification-chains are stored in
+ * the @registered_events_handlers hashtable. Callbacks' registration requests
+ * for still to be registered events are instead kept in the dedicated common
+ * hashtable @pending_events_handlers.
+ *
+ * An event is identified univocally by the tuple (proto_id, evt_id, src_id)
+ * and is served by its own dedicated notification chain; information contained
+ * in such tuples is used, in a few different ways, to generate the needed
+ * hash-keys.
+ *
+ * Here proto_id and evt_id are simply the protocol_id and message_id numbers
+ * as described in the SCMI Protocol specification, while src_id represents an
+ * optional, protocol dependent, source identifier (like domain_id, perf_id
+ * or sensor_id and so forth).
+ *
+ * Upon reception of a notification message from the platform the SCMI RX ISR
+ * passes the received message payload and some ancillary information (including
+ * an arrival timestamp in nanoseconds) to the core via @scmi_notify() which
+ * pushes the event-data itself on a protocol-dedicated kfifo queue for further
+ * deferred processing as specified in @scmi_events_dispatcher().
+ *
+ * Each protocol has it own dedicated work_struct and worker which, once kicked
+ * by the ISR, takes care to empty its own dedicated queue, deliverying the
+ * queued items into the proper notification-chain: notifications processing can
+ * proceed concurrently on distinct workers only between events belonging to
+ * different protocols while delivery of events within the same protocol is
+ * still strictly sequentially ordered by time of arrival.
+ *
+ * Events' information is then extracted from the SCMI Notification messages and
+ * conveyed, converted into a custom per-event report struct, as the void *data
+ * param to the user callback provided by the registered notifier_block, so that
+ * from the user perspective his callback will look invoked like:
+ *
+ * int user_cb(struct notifier_block *nb, unsigned long event_id, void *report)
+ *
+ */
+
+#define dev_fmt(fmt) "SCMI Notifications - " fmt
+#define pr_fmt(fmt) "SCMI Notifications - " fmt
+
+#include <linux/bitfield.h>
+#include <linux/bug.h>
+#include <linux/compiler.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hashtable.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/kfifo.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/refcount.h>
+#include <linux/scmi_protocol.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include "notify.h"
+
+#define SCMI_MAX_PROTO		256
+
+#define PROTO_ID_MASK		GENMASK(31, 24)
+#define EVT_ID_MASK		GENMASK(23, 16)
+#define SRC_ID_MASK		GENMASK(15, 0)
+
+/*
+ * Builds an unsigned 32bit key from the given input tuple to be used
+ * as a key in hashtables.
+ */
+#define MAKE_HASH_KEY(p, e, s)			\
+	(FIELD_PREP(PROTO_ID_MASK, (p)) |	\
+	   FIELD_PREP(EVT_ID_MASK, (e)) |	\
+	   FIELD_PREP(SRC_ID_MASK, (s)))
+
+#define MAKE_ALL_SRCS_KEY(p, e)		MAKE_HASH_KEY((p), (e), SRC_ID_MASK)
+
+/*
+ * Assumes that the stored obj includes its own hash-key in a field named 'key':
+ * with this simplification this macro can be equally used for all the objects'
+ * types hashed by this implementation.
+ *
+ * @__ht: The hashtable name
+ * @__obj: A pointer to the object type to be retrieved from the hashtable;
+ *	   it will be used as a cursor while scanning the hastable and it will
+ *	   be possibly left as NULL when @__k is not found
+ * @__k: The key to search for
+ */
+#define KEY_FIND(__ht, __obj, __k)				\
+({								\
+	typeof(__k) k_ = __k;					\
+	typeof(__obj) obj_;					\
+								\
+	hash_for_each_possible((__ht), obj_, hash, k_)		\
+		if (obj_->key == k_)				\
+			break;					\
+	__obj = obj_;						\
+})
+
+#define KEY_XTRACT_PROTO_ID(key)	FIELD_GET(PROTO_ID_MASK, (key))
+#define KEY_XTRACT_EVT_ID(key)		FIELD_GET(EVT_ID_MASK, (key))
+#define KEY_XTRACT_SRC_ID(key)		FIELD_GET(SRC_ID_MASK, (key))
+
+/*
+ * A set of macros used to access safely @registered_protocols and
+ * @registered_events arrays; these are fixed in size and each entry is possibly
+ * populated at protocols' registration time and then only read but NEVER
+ * modified or removed.
+ */
+#define SCMI_GET_PROTO(__ni, __pid)					\
+({									\
+	typeof(__ni) ni_ = __ni;					\
+	struct scmi_registered_events_desc *__pd = NULL;		\
+									\
+	if (ni_)							\
+		__pd = READ_ONCE(ni_->registered_protocols[(__pid)]);	\
+	__pd;								\
+})
+
+#define SCMI_GET_REVT_FROM_PD(__pd, __eid)				\
+({									\
+	typeof(__pd) pd_ = __pd;					\
+	typeof(__eid) eid_ = __eid;					\
+	struct scmi_registered_event *__revt = NULL;			\
+									\
+	if (pd_ && eid_ < pd_->num_events)				\
+		__revt = READ_ONCE(pd_->registered_events[eid_]);	\
+	__revt;								\
+})
+
+#define SCMI_GET_REVT(__ni, __pid, __eid)				\
+({									\
+	struct scmi_registered_event *__revt;				\
+	struct scmi_registered_events_desc *__pd;			\
+									\
+	__pd = SCMI_GET_PROTO((__ni), (__pid));				\
+	__revt = SCMI_GET_REVT_FROM_PD(__pd, (__eid));			\
+	__revt;								\
+})
+
+/* A couple of utility macros to limit cruft when calling protocols' helpers */
+#define REVT_NOTIFY_SET_STATUS(revt, eid, sid, state)		\
+({								\
+	typeof(revt) r = revt;					\
+	r->proto->ops->set_notify_enabled(r->proto->ni->handle,	\
+					(eid), (sid), (state));	\
+})
+
+#define REVT_NOTIFY_ENABLE(revt, eid, sid)			\
+	REVT_NOTIFY_SET_STATUS((revt), (eid), (sid), true)
+
+#define REVT_NOTIFY_DISABLE(revt, eid, sid)			\
+	REVT_NOTIFY_SET_STATUS((revt), (eid), (sid), false)
+
+#define REVT_FILL_REPORT(revt, ...)				\
+({								\
+	typeof(revt) r = revt;					\
+	r->proto->ops->fill_custom_report(r->proto->ni->handle,	\
+					  __VA_ARGS__);		\
+})
+
+#define SCMI_PENDING_HASH_SZ		4
+#define SCMI_REGISTERED_HASH_SZ		6
+
+struct scmi_registered_events_desc;
+
+/**
+ * struct scmi_notify_instance  - Represents an instance of the notification
+ * core
+ * @gid: GroupID used for devres
+ * @handle: A reference to the platform instance
+ * @init_work: A work item to perform final initializations of pending handlers
+ * @notify_wq: A reference to the allocated Kernel cmwq
+ * @pending_mtx: A mutex to protect @pending_events_handlers
+ * @registered_protocols: A statically allocated array containing pointers to
+ *			  all the registered protocol-level specific information
+ *			  related to events' handling
+ * @pending_events_handlers: An hashtable containing all pending events'
+ *			     handlers descriptors
+ *
+ * Each platform instance, represented by a handle, has its own instance of
+ * the notification subsystem represented by this structure.
+ */
+struct scmi_notify_instance {
+	void			*gid;
+	struct scmi_handle	*handle;
+	struct work_struct	init_work;
+	struct workqueue_struct	*notify_wq;
+	/* lock to protect pending_events_handlers */
+	struct mutex		pending_mtx;
+	struct scmi_registered_events_desc	**registered_protocols;
+	DECLARE_HASHTABLE(pending_events_handlers, SCMI_PENDING_HASH_SZ);
+};
+
+/**
+ * struct events_queue  - Describes a queue and its associated worker
+ * @sz: Size in bytes of the related kfifo
+ * @kfifo: A dedicated Kernel kfifo descriptor
+ * @notify_work: A custom work item bound to this queue
+ * @wq: A reference to the associated workqueue
+ *
+ * Each protocol has its own dedicated events_queue descriptor.
+ */
+struct events_queue {
+	size_t			sz;
+	struct kfifo		kfifo;
+	struct work_struct	notify_work;
+	struct workqueue_struct	*wq;
+};
+
+/**
+ * struct scmi_event_header  - A utility header
+ * @timestamp: The timestamp, in nanoseconds (boottime), which was associated
+ *	       to this event as soon as it entered the SCMI RX ISR
+ * @payld_sz: Effective size of the embedded message payload which follows
+ * @evt_id: Event ID (corresponds to the Event MsgID for this Protocol)
+ * @payld: A reference to the embedded event payload
+ *
+ * This header is prepended to each received event message payload before
+ * queueing it on the related &struct events_queue.
+ */
+struct scmi_event_header {
+	ktime_t timestamp;
+	size_t payld_sz;
+	unsigned char evt_id;
+	unsigned char payld[];
+};
+
+struct scmi_registered_event;
+
+/**
+ * struct scmi_registered_events_desc  - Protocol Specific information
+ * @id: Protocol ID
+ * @ops: Protocol specific and event-related operations
+ * @equeue: The embedded per-protocol events_queue
+ * @ni: A reference to the initialized instance descriptor
+ * @eh: A reference to pre-allocated buffer to be used as a scratch area by the
+ *	deferred worker when fetching data from the kfifo
+ * @eh_sz: Size of the pre-allocated buffer @eh
+ * @in_flight: A reference to an in flight &struct scmi_registered_event
+ * @num_events: Number of events in @registered_events
+ * @registered_events: A dynamically allocated array holding all the registered
+ *		       events' descriptors, whose fixed-size is determined at
+ *		       compile time.
+ * @registered_mtx: A mutex to protect @registered_events_handlers
+ * @registered_events_handlers: An hashtable containing all events' handlers
+ *				descriptors registered for this protocol
+ *
+ * All protocols that register at least one event have their protocol-specific
+ * information stored here, together with the embedded allocated events_queue.
+ * These descriptors are stored in the @registered_protocols array at protocol
+ * registration time.
+ *
+ * Once these descriptors are successfully registered, they are NEVER again
+ * removed or modified since protocols do not unregister ever, so that, once
+ * we safely grab a NON-NULL reference from the array we can keep it and use it.
+ */
+struct scmi_registered_events_desc {
+	u8				id;
+	const struct scmi_event_ops	*ops;
+	struct events_queue		equeue;
+	struct scmi_notify_instance	*ni;
+	struct scmi_event_header	*eh;
+	size_t				eh_sz;
+	void				*in_flight;
+	int				num_events;
+	struct scmi_registered_event	**registered_events;
+	/* mutex to protect registered_events_handlers */
+	struct mutex			registered_mtx;
+	DECLARE_HASHTABLE(registered_events_handlers, SCMI_REGISTERED_HASH_SZ);
+};
+
+/**
+ * struct scmi_registered_event  - Event Specific Information
+ * @proto: A reference to the associated protocol descriptor
+ * @evt: A reference to the associated event descriptor (as provided at
+ *       registration time)
+ * @report: A pre-allocated buffer used by the deferred worker to fill a
+ *	    customized event report
+ * @num_sources: The number of possible sources for this event as stated at
+ *		 events' registration time
+ * @sources: A reference to a dynamically allocated array used to refcount the
+ *	     events' enable requests for all the existing sources
+ * @sources_mtx: A mutex to serialize the access to @sources
+ *
+ * All registered events are represented by one of these structures that are
+ * stored in the @registered_events array at protocol registration time.
+ *
+ * Once these descriptors are successfully registered, they are NEVER again
+ * removed or modified since protocols do not unregister ever, so that once we
+ * safely grab a NON-NULL reference from the table we can keep it and use it.
+ */
+struct scmi_registered_event {
+	struct scmi_registered_events_desc *proto;
+	const struct scmi_event	*evt;
+	void		*report;
+	u32		num_sources;
+	refcount_t	*sources;
+	/* locking to serialize the access to sources */
+	struct mutex	sources_mtx;
+};
+
+/**
+ * struct scmi_event_handler  - Event handler information
+ * @key: The used hashkey
+ * @users: A reference count for number of active users for this handler
+ * @r_evt: A reference to the associated registered event; when this is NULL
+ *	   this handler is pending, which means that identifies a set of
+ *	   callbacks intended to be attached to an event which is still not
+ *	   known nor registered by any protocol at that point in time
+ * @chain: The notification chain dedicated to this specific event tuple
+ * @hash: The hlist_node used for collision handling
+ * @enabled: A boolean which records if event's generation has been already
+ *	     enabled for this handler as a whole
+ *
+ * This structure collects all the information needed to process a received
+ * event identified by the tuple (proto_id, evt_id, src_id).
+ * These descriptors are stored in a per-protocol @registered_events_handlers
+ * table using as a key a value derived from that tuple.
+ */
+struct scmi_event_handler {
+	u32				key;
+	refcount_t			users;
+	struct scmi_registered_event	*r_evt;
+	struct blocking_notifier_head	chain;
+	struct hlist_node		hash;
+	bool				enabled;
+};
+
+#define IS_HNDL_PENDING(hndl)	(!(hndl)->r_evt)
+
+static struct scmi_event_handler *
+scmi_get_active_handler(struct scmi_notify_instance *ni, u32 evt_key);
+static void scmi_put_active_handler(struct scmi_notify_instance *ni,
+				    struct scmi_event_handler *hndl);
+static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
+				      struct scmi_event_handler *hndl);
+
+/**
+ * scmi_lookup_and_call_event_chain()  - Lookup the proper chain and call it
+ * @ni: A reference to the notification instance to use
+ * @evt_key: The key to use to lookup the related notification chain
+ * @report: The customized event-specific report to pass down to the callbacks
+ *	    as their *data parameter.
+ */
+static inline void
+scmi_lookup_and_call_event_chain(struct scmi_notify_instance *ni,
+				 u32 evt_key, void *report)
+{
+	int ret;
+	struct scmi_event_handler *hndl;
+
+	/*
+	 * Here ensure the event handler cannot vanish while using it.
+	 * It is legitimate, though, for an handler not to be found at all here,
+	 * e.g. when it has been unregistered by the user after some events had
+	 * already been queued.
+	 */
+	hndl = scmi_get_active_handler(ni, evt_key);
+	if (!hndl)
+		return;
+
+	ret = blocking_notifier_call_chain(&hndl->chain,
+					   KEY_XTRACT_EVT_ID(evt_key),
+					   report);
+	/* Notifiers are NOT supposed to cut the chain ... */
+	WARN_ON_ONCE(ret & NOTIFY_STOP_MASK);
+
+	scmi_put_active_handler(ni, hndl);
+}
+
+/**
+ * scmi_process_event_header()  - Dequeue and process an event header
+ * @eq: The queue to use
+ * @pd: The protocol descriptor to use
+ *
+ * Read an event header from the protocol queue into the dedicated scratch
+ * buffer and looks for a matching registered event; in case an anomalously
+ * sized read is detected just flush the queue.
+ *
+ * Return:
+ * * a reference to the matching registered event when found
+ * * ERR_PTR(-EINVAL) when NO registered event could be found
+ * * NULL when the queue is empty
+ */
+static inline struct scmi_registered_event *
+scmi_process_event_header(struct events_queue *eq,
+			  struct scmi_registered_events_desc *pd)
+{
+	unsigned int outs;
+	struct scmi_registered_event *r_evt;
+
+	outs = kfifo_out(&eq->kfifo, pd->eh,
+			 sizeof(struct scmi_event_header));
+	if (!outs)
+		return NULL;
+	if (outs != sizeof(struct scmi_event_header)) {
+		dev_err(pd->ni->handle->dev, "corrupted EVT header. Flush.\n");
+		kfifo_reset_out(&eq->kfifo);
+		return NULL;
+	}
+
+	r_evt = SCMI_GET_REVT_FROM_PD(pd, pd->eh->evt_id);
+	if (!r_evt)
+		r_evt = ERR_PTR(-EINVAL);
+
+	return r_evt;
+}
+
+/**
+ * scmi_process_event_payload()  - Dequeue and process an event payload
+ * @eq: The queue to use
+ * @pd: The protocol descriptor to use
+ * @r_evt: The registered event descriptor to use
+ *
+ * Read an event payload from the protocol queue into the dedicated scratch
+ * buffer, fills a custom report and then look for matching event handlers and
+ * call them; skip any unknown event (as marked by scmi_process_event_header())
+ * and in case an anomalously sized read is detected just flush the queue.
+ *
+ * Return: False when the queue is empty
+ */
+static inline bool
+scmi_process_event_payload(struct events_queue *eq,
+			   struct scmi_registered_events_desc *pd,
+			   struct scmi_registered_event *r_evt)
+{
+	u32 src_id, key;
+	unsigned int outs;
+	void *report = NULL;
+
+	outs = kfifo_out(&eq->kfifo, pd->eh->payld, pd->eh->payld_sz);
+	if (!outs)
+		return false;
+
+	/* Any in-flight event has now been officially processed */
+	pd->in_flight = NULL;
+
+	if (outs != pd->eh->payld_sz) {
+		dev_err(pd->ni->handle->dev, "corrupted EVT Payload. Flush.\n");
+		kfifo_reset_out(&eq->kfifo);
+		return false;
+	}
+
+	if (IS_ERR(r_evt)) {
+		dev_warn(pd->ni->handle->dev,
+			 "SKIP UNKNOWN EVT - proto:%X  evt:%d\n",
+			 pd->id, pd->eh->evt_id);
+		return true;
+	}
+
+	report = REVT_FILL_REPORT(r_evt, pd->eh->evt_id, pd->eh->timestamp,
+				  pd->eh->payld, pd->eh->payld_sz,
+				  r_evt->report, &src_id);
+	if (!report) {
+		dev_err(pd->ni->handle->dev,
+			"report not available - proto:%X  evt:%d\n",
+			pd->id, pd->eh->evt_id);
+		return true;
+	}
+
+	/* At first search for a generic ALL src_ids handler... */
+	key = MAKE_ALL_SRCS_KEY(pd->id, pd->eh->evt_id);
+	scmi_lookup_and_call_event_chain(pd->ni, key, report);
+
+	/* ...then search for any specific src_id */
+	key = MAKE_HASH_KEY(pd->id, pd->eh->evt_id, src_id);
+	scmi_lookup_and_call_event_chain(pd->ni, key, report);
+
+	return true;
+}
+
+/**
+ * scmi_events_dispatcher()  - Common worker logic for all work items.
+ * @work: The work item to use, which is associated to a dedicated events_queue
+ *
+ * Logic:
+ *  1. dequeue one pending RX notification (queued in SCMI RX ISR context)
+ *  2. generate a custom event report from the received event message
+ *  3. lookup for any registered ALL_SRC_IDs handler:
+ *    - > call the related notification chain passing in the report
+ *  4. lookup for any registered specific SRC_ID handler:
+ *    - > call the related notification chain passing in the report
+ *
+ * Note that:
+ * * a dedicated per-protocol kfifo queue is used: in this way an anomalous
+ *   flood of events cannot saturate other protocols' queues.
+ * * each per-protocol queue is associated to a distinct work_item, which
+ *   means, in turn, that:
+ *   + all protocols can process their dedicated queues concurrently
+ *     (since notify_wq:max_active != 1)
+ *   + anyway at most one worker instance is allowed to run on the same queue
+ *     concurrently: this ensures that we can have only one concurrent
+ *     reader/writer on the associated kfifo, so that we can use it lock-less
+ *
+ * Context: Process context.
+ */
+static void scmi_events_dispatcher(struct work_struct *work)
+{
+	struct events_queue *eq;
+	struct scmi_registered_events_desc *pd;
+	struct scmi_registered_event *r_evt;
+
+	eq = container_of(work, struct events_queue, notify_work);
+	pd = container_of(eq, struct scmi_registered_events_desc, equeue);
+	/*
+	 * In order to keep the queue lock-less and the number of memcopies
+	 * to the bare minimum needed, the dispatcher accounts for the
+	 * possibility of per-protocol in-flight events: i.e. an event whose
+	 * reception could end up being split across two subsequent runs of this
+	 * worker, first the header, then the payload.
+	 */
+	do {
+		if (!pd->in_flight) {
+			r_evt = scmi_process_event_header(eq, pd);
+			if (!r_evt)
+				break;
+			pd->in_flight = r_evt;
+		} else {
+			r_evt = pd->in_flight;
+		}
+	} while (scmi_process_event_payload(eq, pd, r_evt));
+}
+
+/**
+ * scmi_notify()  - Queues a notification for further deferred processing
+ * @handle: The handle identifying the platform instance from which the
+ *	    dispatched event is generated
+ * @proto_id: Protocol ID
+ * @evt_id: Event ID (msgID)
+ * @buf: Event Message Payload (without the header)
+ * @len: Event Message Payload size
+ * @ts: RX Timestamp in nanoseconds (boottime)
+ *
+ * Context: Called in interrupt context to queue a received event for
+ * deferred processing.
+ *
+ * Return: 0 on Success
+ */
+int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
+		const void *buf, size_t len, ktime_t ts)
+{
+	struct scmi_registered_event *r_evt;
+	struct scmi_event_header eh;
+	struct scmi_notify_instance *ni;
+
+	/* Ensure notify_priv is updated */
+	smp_rmb();
+	if (!handle->notify_priv)
+		return 0;
+	ni = handle->notify_priv;
+
+	r_evt = SCMI_GET_REVT(ni, proto_id, evt_id);
+	if (!r_evt)
+		return -EINVAL;
+
+	if (len > r_evt->evt->max_payld_sz) {
+		dev_err(handle->dev, "discard badly sized message\n");
+		return -EINVAL;
+	}
+	if (kfifo_avail(&r_evt->proto->equeue.kfifo) < sizeof(eh) + len) {
+		dev_warn(handle->dev,
+			 "queue full, dropping proto_id:%d  evt_id:%d  ts:%lld\n",
+			 proto_id, evt_id, ktime_to_ns(ts));
+		return -ENOMEM;
+	}
+
+	eh.timestamp = ts;
+	eh.evt_id = evt_id;
+	eh.payld_sz = len;
+	/*
+	 * Header and payload are enqueued with two distinct kfifo_in() (so non
+	 * atomic), but this situation is handled properly on the consumer side
+	 * with in-flight events tracking.
+	 */
+	kfifo_in(&r_evt->proto->equeue.kfifo, &eh, sizeof(eh));
+	kfifo_in(&r_evt->proto->equeue.kfifo, buf, len);
+	/*
+	 * Don't care about return value here since we just want to ensure that
+	 * a work is queued all the times whenever some items have been pushed
+	 * on the kfifo:
+	 * - if work was already queued it will simply fail to queue a new one
+	 *   since it is not needed
+	 * - if work was not queued already it will be now, even in case work
+	 *   was in fact already running: this behavior avoids any possible race
+	 *   when this function pushes new items onto the kfifos after the
+	 *   related executing worker had already determined the kfifo to be
+	 *   empty and it was terminating.
+	 */
+	queue_work(r_evt->proto->equeue.wq,
+		   &r_evt->proto->equeue.notify_work);
+
+	return 0;
+}
+
+/**
+ * scmi_kfifo_free()  - Devres action helper to free the kfifo
+ * @kfifo: The kfifo to free
+ */
+static void scmi_kfifo_free(void *kfifo)
+{
+	kfifo_free((struct kfifo *)kfifo);
+}
+
+/**
+ * scmi_initialize_events_queue()  - Allocate/Initialize a kfifo buffer
+ * @ni: A reference to the notification instance to use
+ * @equeue: The events_queue to initialize
+ * @sz: Size of the kfifo buffer to allocate
+ *
+ * Allocate a buffer for the kfifo and initialize it.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_initialize_events_queue(struct scmi_notify_instance *ni,
+					struct events_queue *equeue, size_t sz)
+{
+	int ret;
+
+	if (kfifo_alloc(&equeue->kfifo, sz, GFP_KERNEL))
+		return -ENOMEM;
+	/* Size could have been roundup to power-of-two */
+	equeue->sz = kfifo_size(&equeue->kfifo);
+
+	ret = devm_add_action_or_reset(ni->handle->dev, scmi_kfifo_free,
+				       &equeue->kfifo);
+	if (ret)
+		return ret;
+
+	INIT_WORK(&equeue->notify_work, scmi_events_dispatcher);
+	equeue->wq = ni->notify_wq;
+
+	return ret;
+}
+
+/**
+ * scmi_allocate_registered_events_desc()  - Allocate a registered events'
+ * descriptor
+ * @ni: A reference to the &struct scmi_notify_instance notification instance
+ *	to use
+ * @proto_id: Protocol ID
+ * @queue_sz: Size of the associated queue to allocate
+ * @eh_sz: Size of the event header scratch area to pre-allocate
+ * @num_events: Number of events to support (size of @registered_events)
+ * @ops: Pointer to a struct holding references to protocol specific helpers
+ *	 needed during events handling
+ *
+ * It is supposed to be called only once for each protocol at protocol
+ * initialization time, so it warns if the requested protocol is found already
+ * registered.
+ *
+ * Return: The allocated and registered descriptor on Success
+ */
+static struct scmi_registered_events_desc *
+scmi_allocate_registered_events_desc(struct scmi_notify_instance *ni,
+				     u8 proto_id, size_t queue_sz, size_t eh_sz,
+				     int num_events,
+				     const struct scmi_event_ops *ops)
+{
+	int ret;
+	struct scmi_registered_events_desc *pd;
+
+	/* Ensure protocols are up to date */
+	smp_rmb();
+	if (WARN_ON(ni->registered_protocols[proto_id]))
+		return ERR_PTR(-EINVAL);
+
+	pd = devm_kzalloc(ni->handle->dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return ERR_PTR(-ENOMEM);
+	pd->id = proto_id;
+	pd->ops = ops;
+	pd->ni = ni;
+
+	ret = scmi_initialize_events_queue(ni, &pd->equeue, queue_sz);
+	if (ret)
+		return ERR_PTR(ret);
+
+	pd->eh = devm_kzalloc(ni->handle->dev, eh_sz, GFP_KERNEL);
+	if (!pd->eh)
+		return ERR_PTR(-ENOMEM);
+	pd->eh_sz = eh_sz;
+
+	pd->registered_events = devm_kcalloc(ni->handle->dev, num_events,
+					     sizeof(char *), GFP_KERNEL);
+	if (!pd->registered_events)
+		return ERR_PTR(-ENOMEM);
+	pd->num_events = num_events;
+
+	/* Initialize per protocol handlers table */
+	mutex_init(&pd->registered_mtx);
+	hash_init(pd->registered_events_handlers);
+
+	return pd;
+}
+
+/**
+ * scmi_register_protocol_events()  - Register Protocol Events with the core
+ * @handle: The handle identifying the platform instance against which the
+ *	    the protocol's events are registered
+ * @proto_id: Protocol ID
+ * @queue_sz: Size in bytes of the associated queue to be allocated
+ * @ops: Protocol specific event-related operations
+ * @evt: Event descriptor array
+ * @num_events: Number of events in @evt array
+ * @num_sources: Number of possible sources for this protocol on this
+ *		 platform.
+ *
+ * Used by SCMI Protocols initialization code to register with the notification
+ * core the list of supported events and their descriptors: takes care to
+ * pre-allocate and store all needed descriptors, scratch buffers and event
+ * queues.
+ *
+ * Return: 0 on Success
+ */
+int scmi_register_protocol_events(const struct scmi_handle *handle,
+				  u8 proto_id, size_t queue_sz,
+				  const struct scmi_event_ops *ops,
+				  const struct scmi_event *evt, int num_events,
+				  int num_sources)
+{
+	int i;
+	size_t payld_sz = 0;
+	struct scmi_registered_events_desc *pd;
+	struct scmi_notify_instance *ni;
+
+	if (!ops || !evt)
+		return -EINVAL;
+
+	/* Ensure notify_priv is updated */
+	smp_rmb();
+	if (!handle->notify_priv)
+		return -ENOMEM;
+	ni = handle->notify_priv;
+
+	/* Attach to the notification main devres group */
+	if (!devres_open_group(ni->handle->dev, ni->gid, GFP_KERNEL))
+		return -ENOMEM;
+
+	for (i = 0; i < num_events; i++)
+		payld_sz = max_t(size_t, payld_sz, evt[i].max_payld_sz);
+	payld_sz += sizeof(struct scmi_event_header);
+
+	pd = scmi_allocate_registered_events_desc(ni, proto_id, queue_sz,
+						  payld_sz, num_events, ops);
+	if (IS_ERR(pd))
+		goto err;
+
+	for (i = 0; i < num_events; i++, evt++) {
+		struct scmi_registered_event *r_evt;
+
+		r_evt = devm_kzalloc(ni->handle->dev, sizeof(*r_evt),
+				     GFP_KERNEL);
+		if (!r_evt)
+			goto err;
+		r_evt->proto = pd;
+		r_evt->evt = evt;
+
+		r_evt->sources = devm_kcalloc(ni->handle->dev, num_sources,
+					      sizeof(refcount_t), GFP_KERNEL);
+		if (!r_evt->sources)
+			goto err;
+		r_evt->num_sources = num_sources;
+		mutex_init(&r_evt->sources_mtx);
+
+		r_evt->report = devm_kzalloc(ni->handle->dev,
+					     evt->max_report_sz, GFP_KERNEL);
+		if (!r_evt->report)
+			goto err;
+
+		pd->registered_events[i] = r_evt;
+		/* Ensure events are updated */
+		smp_wmb();
+		dev_dbg(handle->dev, "registered event - %lX\n",
+			MAKE_ALL_SRCS_KEY(r_evt->proto->id, r_evt->evt->id));
+	}
+
+	/* Register protocol and events...it will never be removed */
+	ni->registered_protocols[proto_id] = pd;
+	/* Ensure protocols are updated */
+	smp_wmb();
+
+	devres_close_group(ni->handle->dev, ni->gid);
+
+	/*
+	 * Finalize any pending events' handler which could have been waiting
+	 * for this protocol's events registration.
+	 */
+	schedule_work(&ni->init_work);
+
+	return 0;
+
+err:
+	dev_warn(handle->dev, "Proto:%X - Registration Failed !\n", proto_id);
+	/* A failing protocol registration does not trigger full failure */
+	devres_close_group(ni->handle->dev, ni->gid);
+
+	return -ENOMEM;
+}
+
+/**
+ * scmi_allocate_event_handler()  - Allocate Event handler
+ * @ni: A reference to the notification instance to use
+ * @evt_key: 32bit key uniquely bind to the event identified by the tuple
+ *	     (proto_id, evt_id, src_id)
+ *
+ * Allocate an event handler and related notification chain associated with
+ * the provided event handler key.
+ * Note that, at this point, a related registered_event is still to be
+ * associated to this handler descriptor (hndl->r_evt == NULL), so the handler
+ * is initialized as pending.
+ *
+ * Context: Assumes to be called with @pending_mtx already acquired.
+ * Return: the freshly allocated structure on Success
+ */
+static struct scmi_event_handler *
+scmi_allocate_event_handler(struct scmi_notify_instance *ni, u32 evt_key)
+{
+	struct scmi_event_handler *hndl;
+
+	hndl = kzalloc(sizeof(*hndl), GFP_KERNEL);
+	if (!hndl)
+		return NULL;
+	hndl->key = evt_key;
+	BLOCKING_INIT_NOTIFIER_HEAD(&hndl->chain);
+	refcount_set(&hndl->users, 1);
+	/* New handlers are created pending */
+	hash_add(ni->pending_events_handlers, &hndl->hash, hndl->key);
+
+	return hndl;
+}
+
+/**
+ * scmi_free_event_handler()  - Free the provided Event handler
+ * @hndl: The event handler structure to free
+ *
+ * Context: Assumes to be called with proper locking acquired depending
+ *	    on the situation.
+ */
+static void scmi_free_event_handler(struct scmi_event_handler *hndl)
+{
+	hash_del(&hndl->hash);
+	kfree(hndl);
+}
+
+/**
+ * scmi_bind_event_handler()  - Helper to attempt binding an handler to an event
+ * @ni: A reference to the notification instance to use
+ * @hndl: The event handler to bind
+ *
+ * If an associated registered event is found, move the handler from the pending
+ * into the registered table.
+ *
+ * Context: Assumes to be called with @pending_mtx already acquired.
+ *
+ * Return: 0 on Success
+ */
+static inline int scmi_bind_event_handler(struct scmi_notify_instance *ni,
+					  struct scmi_event_handler *hndl)
+{
+	struct scmi_registered_event *r_evt;
+
+	r_evt = SCMI_GET_REVT(ni, KEY_XTRACT_PROTO_ID(hndl->key),
+			      KEY_XTRACT_EVT_ID(hndl->key));
+	if (!r_evt)
+		return -EINVAL;
+
+	/* Remove from pending and insert into registered */
+	hash_del(&hndl->hash);
+	hndl->r_evt = r_evt;
+	mutex_lock(&r_evt->proto->registered_mtx);
+	hash_add(r_evt->proto->registered_events_handlers,
+		 &hndl->hash, hndl->key);
+	mutex_unlock(&r_evt->proto->registered_mtx);
+
+	return 0;
+}
+
+/**
+ * scmi_valid_pending_handler()  - Helper to check pending status of handlers
+ * @ni: A reference to the notification instance to use
+ * @hndl: The event handler to check
+ *
+ * An handler is considered pending when its r_evt == NULL, because the related
+ * event was still unknown at handler's registration time; anyway, since all
+ * protocols register their supported events once for all at protocols'
+ * initialization time, a pending handler cannot be considered valid anymore if
+ * the underlying event (which it is waiting for), belongs to an already
+ * initialized and registered protocol.
+ *
+ * Return: 0 on Success
+ */
+static inline int scmi_valid_pending_handler(struct scmi_notify_instance *ni,
+					     struct scmi_event_handler *hndl)
+{
+	struct scmi_registered_events_desc *pd;
+
+	if (!IS_HNDL_PENDING(hndl))
+		return -EINVAL;
+
+	pd = SCMI_GET_PROTO(ni, KEY_XTRACT_PROTO_ID(hndl->key));
+	if (pd)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * scmi_register_event_handler()  - Register whenever possible an Event handler
+ * @ni: A reference to the notification instance to use
+ * @hndl: The event handler to register
+ *
+ * At first try to bind an event handler to its associated event, then check if
+ * it was at least a valid pending handler: if it was not bound nor valid return
+ * false.
+ *
+ * Valid pending incomplete bindings will be periodically retried by a dedicated
+ * worker which is kicked each time a new protocol completes its own
+ * registration phase.
+ *
+ * Context: Assumes to be called with @pending_mtx acquired.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_register_event_handler(struct scmi_notify_instance *ni,
+				       struct scmi_event_handler *hndl)
+{
+	int ret;
+
+	ret = scmi_bind_event_handler(ni, hndl);
+	if (!ret) {
+		dev_dbg(ni->handle->dev, "registered NEW handler - key:%X\n",
+			hndl->key);
+	} else {
+		ret = scmi_valid_pending_handler(ni, hndl);
+		if (!ret)
+			dev_dbg(ni->handle->dev,
+				"registered PENDING handler - key:%X\n",
+				hndl->key);
+	}
+
+	return ret;
+}
+
+/**
+ * __scmi_event_handler_get_ops()  - Utility to get or create an event handler
+ * @ni: A reference to the notification instance to use
+ * @evt_key: The event key to use
+ * @create: A boolean flag to specify if a handler must be created when
+ *	    not already existent
+ *
+ * Search for the desired handler matching the key in both the per-protocol
+ * registered table and the common pending table:
+ * * if found adjust users refcount
+ * * if not found and @create is true, create and register the new handler:
+ *   handler could end up being registered as pending if no matching event
+ *   could be found.
+ *
+ * An handler is guaranteed to reside in one and only one of the tables at
+ * any one time; to ensure this the whole search and create is performed
+ * holding the @pending_mtx lock, with @registered_mtx additionally acquired
+ * if needed.
+ *
+ * Note that when a nested acquisition of these mutexes is needed the locking
+ * order is always (same as in @init_work):
+ * 1. pending_mtx
+ * 2. registered_mtx
+ *
+ * Events generation is NOT enabled right after creation within this routine
+ * since at creation time we usually want to have all setup and ready before
+ * events really start flowing.
+ *
+ * Return: A properly refcounted handler on Success, NULL on Failure
+ */
+static inline struct scmi_event_handler *
+__scmi_event_handler_get_ops(struct scmi_notify_instance *ni,
+			     u32 evt_key, bool create)
+{
+	struct scmi_registered_event *r_evt;
+	struct scmi_event_handler *hndl = NULL;
+
+	r_evt = SCMI_GET_REVT(ni, KEY_XTRACT_PROTO_ID(evt_key),
+			      KEY_XTRACT_EVT_ID(evt_key));
+
+	mutex_lock(&ni->pending_mtx);
+	/* Search registered events at first ... if possible at all */
+	if (r_evt) {
+		mutex_lock(&r_evt->proto->registered_mtx);
+		hndl = KEY_FIND(r_evt->proto->registered_events_handlers,
+				hndl, evt_key);
+		if (hndl)
+			refcount_inc(&hndl->users);
+		mutex_unlock(&r_evt->proto->registered_mtx);
+	}
+
+	/* ...then amongst pending. */
+	if (!hndl) {
+		hndl = KEY_FIND(ni->pending_events_handlers, hndl, evt_key);
+		if (hndl)
+			refcount_inc(&hndl->users);
+	}
+
+	/* Create if still not found and required */
+	if (!hndl && create) {
+		hndl = scmi_allocate_event_handler(ni, evt_key);
+		if (hndl && scmi_register_event_handler(ni, hndl)) {
+			dev_dbg(ni->handle->dev,
+				"purging UNKNOWN handler - key:%X\n",
+				hndl->key);
+			/* this hndl can be only a pending one */
+			scmi_put_handler_unlocked(ni, hndl);
+			hndl = NULL;
+		}
+	}
+	mutex_unlock(&ni->pending_mtx);
+
+	return hndl;
+}
+
+static struct scmi_event_handler *
+scmi_get_handler(struct scmi_notify_instance *ni, u32 evt_key)
+{
+	return __scmi_event_handler_get_ops(ni, evt_key, false);
+}
+
+static struct scmi_event_handler *
+scmi_get_or_create_handler(struct scmi_notify_instance *ni, u32 evt_key)
+{
+	return __scmi_event_handler_get_ops(ni, evt_key, true);
+}
+
+/**
+ * scmi_get_active_handler()  - Helper to get active handlers only
+ * @ni: A reference to the notification instance to use
+ * @evt_key: The event key to use
+ *
+ * Search for the desired handler matching the key only in the per-protocol
+ * table of registered handlers: this is called only from the dispatching path
+ * so want to be as quick as possible and do not care about pending.
+ *
+ * Return: A properly refcounted active handler
+ */
+static struct scmi_event_handler *
+scmi_get_active_handler(struct scmi_notify_instance *ni, u32 evt_key)
+{
+	struct scmi_registered_event *r_evt;
+	struct scmi_event_handler *hndl = NULL;
+
+	r_evt = SCMI_GET_REVT(ni, KEY_XTRACT_PROTO_ID(evt_key),
+			      KEY_XTRACT_EVT_ID(evt_key));
+	if (r_evt) {
+		mutex_lock(&r_evt->proto->registered_mtx);
+		hndl = KEY_FIND(r_evt->proto->registered_events_handlers,
+				hndl, evt_key);
+		if (hndl)
+			refcount_inc(&hndl->users);
+		mutex_unlock(&r_evt->proto->registered_mtx);
+	}
+
+	return hndl;
+}
+
+/**
+ * __scmi_enable_evt()  - Enable/disable events generation
+ * @r_evt: The registered event to act upon
+ * @src_id: The src_id to act upon
+ * @enable: The action to perform: true->Enable, false->Disable
+ *
+ * Takes care of proper refcounting while performing enable/disable: handles
+ * the special case of ALL sources requests by itself.
+ * Returns successfully if at least one of the required src_id has been
+ * successfully enabled/disabled.
+ *
+ * Return: 0 on Success
+ */
+static inline int __scmi_enable_evt(struct scmi_registered_event *r_evt,
+				    u32 src_id, bool enable)
+{
+	int retvals = 0;
+	u32 num_sources;
+	refcount_t *sid;
+
+	if (src_id == SRC_ID_MASK) {
+		src_id = 0;
+		num_sources = r_evt->num_sources;
+	} else if (src_id < r_evt->num_sources) {
+		num_sources = 1;
+	} else {
+		return -EINVAL;
+	}
+
+	mutex_lock(&r_evt->sources_mtx);
+	if (enable) {
+		for (; num_sources; src_id++, num_sources--) {
+			int ret = 0;
+
+			sid = &r_evt->sources[src_id];
+			if (refcount_read(sid) == 0) {
+				ret = REVT_NOTIFY_ENABLE(r_evt, r_evt->evt->id,
+							 src_id);
+				if (!ret)
+					refcount_set(sid, 1);
+			} else {
+				refcount_inc(sid);
+			}
+			retvals += !ret;
+		}
+	} else {
+		for (; num_sources; src_id++, num_sources--) {
+			sid = &r_evt->sources[src_id];
+			if (refcount_dec_and_test(sid))
+				REVT_NOTIFY_DISABLE(r_evt,
+						    r_evt->evt->id, src_id);
+		}
+		retvals = 1;
+	}
+	mutex_unlock(&r_evt->sources_mtx);
+
+	return retvals ? 0 : -EINVAL;
+}
+
+static int scmi_enable_events(struct scmi_event_handler *hndl)
+{
+	int ret = 0;
+
+	if (!hndl->enabled) {
+		ret = __scmi_enable_evt(hndl->r_evt,
+					KEY_XTRACT_SRC_ID(hndl->key), true);
+		if (!ret)
+			hndl->enabled = true;
+	}
+
+	return ret;
+}
+
+static int scmi_disable_events(struct scmi_event_handler *hndl)
+{
+	int ret = 0;
+
+	if (hndl->enabled) {
+		ret = __scmi_enable_evt(hndl->r_evt,
+					KEY_XTRACT_SRC_ID(hndl->key), false);
+		if (!ret)
+			hndl->enabled = false;
+	}
+
+	return ret;
+}
+
+/**
+ * scmi_put_handler_unlocked()  - Put an event handler
+ * @ni: A reference to the notification instance to use
+ * @hndl: The event handler to act upon
+ *
+ * After having got exclusive access to the registered handlers hashtable,
+ * update the refcount and if @hndl is no more in use by anyone:
+ * * ask for events' generation disabling
+ * * unregister and free the handler itself
+ *
+ * Context: Assumes all the proper locking has been managed by the caller.
+ */
+static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
+				      struct scmi_event_handler *hndl)
+{
+	if (refcount_dec_and_test(&hndl->users)) {
+		if (!IS_HNDL_PENDING(hndl))
+			scmi_disable_events(hndl);
+		scmi_free_event_handler(hndl);
+	}
+}
+
+static void scmi_put_handler(struct scmi_notify_instance *ni,
+			     struct scmi_event_handler *hndl)
+{
+	struct scmi_registered_event *r_evt = hndl->r_evt;
+
+	mutex_lock(&ni->pending_mtx);
+	if (r_evt)
+		mutex_lock(&r_evt->proto->registered_mtx);
+
+	scmi_put_handler_unlocked(ni, hndl);
+
+	if (r_evt)
+		mutex_unlock(&r_evt->proto->registered_mtx);
+	mutex_unlock(&ni->pending_mtx);
+}
+
+static void scmi_put_active_handler(struct scmi_notify_instance *ni,
+				    struct scmi_event_handler *hndl)
+{
+	struct scmi_registered_event *r_evt = hndl->r_evt;
+
+	mutex_lock(&r_evt->proto->registered_mtx);
+	scmi_put_handler_unlocked(ni, hndl);
+	mutex_unlock(&r_evt->proto->registered_mtx);
+}
+
+/**
+ * scmi_event_handler_enable_events()  - Enable events associated to an handler
+ * @hndl: The Event handler to act upon
+ *
+ * Return: 0 on Success
+ */
+static int scmi_event_handler_enable_events(struct scmi_event_handler *hndl)
+{
+	if (scmi_enable_events(hndl)) {
+		pr_err("Failed to ENABLE events for key:%X !\n", hndl->key);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * scmi_register_notifier()  - Register a notifier_block for an event
+ * @handle: The handle identifying the platform instance against which the
+ *	    callback is registered
+ * @proto_id: Protocol ID
+ * @evt_id: Event ID
+ * @src_id: Source ID, when NULL register for events coming form ALL possible
+ *	    sources
+ * @nb: A standard notifier block to register for the specified event
+ *
+ * Generic helper to register a notifier_block against a protocol event.
+ *
+ * A notifier_block @nb will be registered for each distinct event identified
+ * by the tuple (proto_id, evt_id, src_id) on a dedicated notification chain
+ * so that:
+ *
+ *	(proto_X, evt_Y, src_Z) --> chain_X_Y_Z
+ *
+ * @src_id meaning is protocol specific and identifies the origin of the event
+ * (like domain_id, sensor_id and so forth).
+ *
+ * @src_id can be NULL to signify that the caller is interested in receiving
+ * notifications from ALL the available sources for that protocol OR simply that
+ * the protocol does not support distinct sources.
+ *
+ * As soon as one user for the specified tuple appears, an handler is created,
+ * and that specific event's generation is enabled at the platform level, unless
+ * an associated registered event is found missing, meaning that the needed
+ * protocol is still to be initialized and the handler has just been registered
+ * as still pending.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_register_notifier(const struct scmi_handle *handle,
+				  u8 proto_id, u8 evt_id, u32 *src_id,
+				  struct notifier_block *nb)
+{
+	int ret = 0;
+	u32 evt_key;
+	struct scmi_event_handler *hndl;
+	struct scmi_notify_instance *ni;
+
+	/* Ensure notify_priv is updated */
+	smp_rmb();
+	if (!handle->notify_priv)
+		return -ENODEV;
+	ni = handle->notify_priv;
+
+	evt_key = MAKE_HASH_KEY(proto_id, evt_id,
+				src_id ? *src_id : SRC_ID_MASK);
+	hndl = scmi_get_or_create_handler(ni, evt_key);
+	if (!hndl)
+		return -EINVAL;
+
+	blocking_notifier_chain_register(&hndl->chain, nb);
+
+	/* Enable events for not pending handlers */
+	if (!IS_HNDL_PENDING(hndl)) {
+		ret = scmi_event_handler_enable_events(hndl);
+		if (ret)
+			scmi_put_handler(ni, hndl);
+	}
+
+	return ret;
+}
+
+/**
+ * scmi_unregister_notifier()  - Unregister a notifier_block for an event
+ * @handle: The handle identifying the platform instance against which the
+ *	    callback is unregistered
+ * @proto_id: Protocol ID
+ * @evt_id: Event ID
+ * @src_id: Source ID
+ * @nb: The notifier_block to unregister
+ *
+ * Takes care to unregister the provided @nb from the notification chain
+ * associated to the specified event and, if there are no more users for the
+ * event handler, frees also the associated event handler structures.
+ * (this could possibly cause disabling of event's generation at platform level)
+ *
+ * Return: 0 on Success
+ */
+static int scmi_unregister_notifier(const struct scmi_handle *handle,
+				    u8 proto_id, u8 evt_id, u32 *src_id,
+				    struct notifier_block *nb)
+{
+	u32 evt_key;
+	struct scmi_event_handler *hndl;
+	struct scmi_notify_instance *ni;
+
+	/* Ensure notify_priv is updated */
+	smp_rmb();
+	if (!handle->notify_priv)
+		return -ENODEV;
+	ni = handle->notify_priv;
+
+	evt_key = MAKE_HASH_KEY(proto_id, evt_id,
+				src_id ? *src_id : SRC_ID_MASK);
+	hndl = scmi_get_handler(ni, evt_key);
+	if (!hndl)
+		return -EINVAL;
+
+	/*
+	 * Note that this chain unregistration call is safe on its own
+	 * being internally protected by an rwsem.
+	 */
+	blocking_notifier_chain_unregister(&hndl->chain, nb);
+	scmi_put_handler(ni, hndl);
+
+	/*
+	 * This balances the initial get issued in @scmi_register_notifier.
+	 * If this notifier_block happened to be the last known user callback
+	 * for this event, the handler is here freed and the event's generation
+	 * stopped.
+	 *
+	 * Note that, an ongoing concurrent lookup on the delivery workqueue
+	 * path could still hold the refcount to 1 even after this routine
+	 * completes: in such a case it will be the final put on the delivery
+	 * path which will finally free this unused handler.
+	 */
+	scmi_put_handler(ni, hndl);
+
+	return 0;
+}
+
+/**
+ * scmi_protocols_late_init()  - Worker for late initialization
+ * @work: The work item to use associated to the proper SCMI instance
+ *
+ * This kicks in whenever a new protocol has completed its own registration via
+ * scmi_register_protocol_events(): it is in charge of scanning the table of
+ * pending handlers (registered by users while the related protocol was still
+ * not initialized) and finalizing their initialization whenever possible;
+ * invalid pending handlers are purged at this point in time.
+ */
+static void scmi_protocols_late_init(struct work_struct *work)
+{
+	int bkt;
+	struct scmi_event_handler *hndl;
+	struct scmi_notify_instance *ni;
+	struct hlist_node *tmp;
+
+	ni = container_of(work, struct scmi_notify_instance, init_work);
+
+	/* Ensure protocols and events are up to date */
+	smp_rmb();
+
+	mutex_lock(&ni->pending_mtx);
+	hash_for_each_safe(ni->pending_events_handlers, bkt, tmp, hndl, hash) {
+		int ret;
+
+		ret = scmi_bind_event_handler(ni, hndl);
+		if (!ret) {
+			dev_dbg(ni->handle->dev,
+				"finalized PENDING handler - key:%X\n",
+				hndl->key);
+			ret = scmi_event_handler_enable_events(hndl);
+		} else {
+			ret = scmi_valid_pending_handler(ni, hndl);
+		}
+		if (ret) {
+			dev_dbg(ni->handle->dev,
+				"purging PENDING handler - key:%X\n",
+				hndl->key);
+			/* this hndl can be only a pending one */
+			scmi_put_handler_unlocked(ni, hndl);
+		}
+	}
+	mutex_unlock(&ni->pending_mtx);
+}
+
+/*
+ * notify_ops are attached to the handle so that can be accessed
+ * directly from an scmi_driver to register its own notifiers.
+ */
+static struct scmi_notify_ops notify_ops = {
+	.register_event_notifier = scmi_register_notifier,
+	.unregister_event_notifier = scmi_unregister_notifier,
+};
+
+/**
+ * scmi_notification_init()  - Initializes Notification Core Support
+ * @handle: The handle identifying the platform instance to initialize
+ *
+ * This function lays out all the basic resources needed by the notification
+ * core instance identified by the provided handle: once done, all of the
+ * SCMI Protocols can register their events with the core during their own
+ * initializations.
+ *
+ * Note that failing to initialize the core notifications support does not
+ * cause the whole SCMI Protocols stack to fail its initialization.
+ *
+ * SCMI Notification Initialization happens in 2 steps:
+ * * initialization: basic common allocations (this function)
+ * * registration: protocols asynchronously come into life and registers their
+ *		   own supported list of events with the core; this causes
+ *		   further per-protocol allocations
+ *
+ * Any user's callback registration attempt, referring a still not registered
+ * event, will be registered as pending and finalized later (if possible)
+ * by scmi_protocols_late_init() work.
+ * This allows for lazy initialization of SCMI Protocols due to late (or
+ * missing) SCMI drivers' modules loading.
+ *
+ * Return: 0 on Success
+ */
+int scmi_notification_init(struct scmi_handle *handle)
+{
+	void *gid;
+	struct scmi_notify_instance *ni;
+
+	gid = devres_open_group(handle->dev, NULL, GFP_KERNEL);
+	if (!gid)
+		return -ENOMEM;
+
+	ni = devm_kzalloc(handle->dev, sizeof(*ni), GFP_KERNEL);
+	if (!ni)
+		goto err;
+
+	ni->gid = gid;
+	ni->handle = handle;
+
+	ni->notify_wq = alloc_workqueue("scmi_notify",
+					WQ_UNBOUND | WQ_FREEZABLE | WQ_SYSFS,
+					0);
+	if (!ni->notify_wq)
+		goto err;
+
+	ni->registered_protocols = devm_kcalloc(handle->dev, SCMI_MAX_PROTO,
+						sizeof(char *), GFP_KERNEL);
+	if (!ni->registered_protocols)
+		goto err;
+
+	mutex_init(&ni->pending_mtx);
+	hash_init(ni->pending_events_handlers);
+
+	INIT_WORK(&ni->init_work, scmi_protocols_late_init);
+
+	handle->notify_ops = &notify_ops;
+	handle->notify_priv = ni;
+	/* Ensure handle is up to date */
+	smp_wmb();
+
+	dev_info(handle->dev, "Core Enabled.\n");
+
+	devres_close_group(handle->dev, ni->gid);
+
+	return 0;
+
+err:
+	dev_warn(handle->dev, "Initialization Failed.\n");
+	devres_release_group(handle->dev, NULL);
+	return -ENOMEM;
+}
+
+/**
+ * scmi_notification_exit()  - Shutdown and clean Notification core
+ * @handle: The handle identifying the platform instance to shutdown
+ */
+void scmi_notification_exit(struct scmi_handle *handle)
+{
+	struct scmi_notify_instance *ni;
+
+	/* Ensure notify_priv is updated */
+	smp_rmb();
+	if (!handle->notify_priv)
+		return;
+	ni = handle->notify_priv;
+
+	handle->notify_priv = NULL;
+	/* Ensure handle is up to date */
+	smp_wmb();
+
+	/* Destroy while letting pending work complete */
+	destroy_workqueue(ni->notify_wq);
+
+	devres_release_group(ni->handle->dev, ni->gid);
+}
diff --git a/drivers/firmware/arm_scmi/notify.h b/drivers/firmware/arm_scmi/notify.h
new file mode 100644
index 000000000000..3485f20fa70e
--- /dev/null
+++ b/drivers/firmware/arm_scmi/notify.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * notification header file containing some definitions, structures
+ * and function prototypes related to SCMI Notification handling.
+ *
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef _SCMI_NOTIFY_H
+#define _SCMI_NOTIFY_H
+
+#include <linux/device.h>
+#include <linux/ktime.h>
+#include <linux/types.h>
+
+#define SCMI_PROTO_QUEUE_SZ	4096
+
+/**
+ * struct scmi_event  - Describes an event to be supported
+ * @id: Event ID
+ * @max_payld_sz: Max possible size for the payload of a notification message
+ * @max_report_sz: Max possible size for the report of a notification message
+ *
+ * Each SCMI protocol, during its initialization phase, can describe the events
+ * it wishes to support in a few struct scmi_event and pass them to the core
+ * using scmi_register_protocol_events().
+ */
+struct scmi_event {
+	u8	id;
+	size_t	max_payld_sz;
+	size_t	max_report_sz;
+};
+
+/**
+ * struct scmi_event_ops  - Protocol helpers called by the notification core.
+ * @set_notify_enabled: Enable/disable the required evt_id/src_id notifications
+ *			using the proper custom protocol commands.
+ *			Return 0 on Success
+ * @fill_custom_report: fills a custom event report from the provided
+ *			event message payld identifying the event
+ *			specific src_id.
+ *			Return NULL on failure otherwise @report now fully
+ *			populated
+ *
+ * Context: Helpers described in &struct scmi_event_ops are called only in
+ *	    process context.
+ */
+struct scmi_event_ops {
+	int (*set_notify_enabled)(const struct scmi_handle *handle,
+				  u8 evt_id, u32 src_id, bool enabled);
+	void *(*fill_custom_report)(const struct scmi_handle *handle,
+				    u8 evt_id, ktime_t timestamp,
+				    const void *payld, size_t payld_sz,
+				    void *report, u32 *src_id);
+};
+
+int scmi_notification_init(struct scmi_handle *handle);
+void scmi_notification_exit(struct scmi_handle *handle);
+
+int scmi_register_protocol_events(const struct scmi_handle *handle,
+				  u8 proto_id, size_t queue_sz,
+				  const struct scmi_event_ops *ops,
+				  const struct scmi_event *evt, int num_events,
+				  int num_sources);
+int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
+		const void *buf, size_t len, ktime_t ts);
+
+#endif /* _SCMI_NOTIFY_H */
diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index eadc171e254b..3e1e87012c95 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -5,15 +5,19 @@
  * Copyright (C) 2018 ARM Ltd.
  */
 
+#define pr_fmt(fmt) "SCMI Notifications PERF - " fmt
+
 #include <linux/bits.h>
 #include <linux/of.h>
 #include <linux/io.h>
 #include <linux/io-64-nonatomic-hi-lo.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
+#include <linux/scmi_protocol.h>
 #include <linux/sort.h>
 
 #include "common.h"
+#include "notify.h"
 
 enum scmi_performance_protocol_cmd {
 	PERF_DOMAIN_ATTRIBUTES = 0x3,
@@ -27,11 +31,6 @@ enum scmi_performance_protocol_cmd {
 	PERF_DESCRIBE_FASTCHANNEL = 0xb,
 };
 
-enum scmi_performance_protocol_notify {
-	PERFORMANCE_LIMITS_CHANGED = 0x0,
-	PERFORMANCE_LEVEL_CHANGED = 0x1,
-};
-
 struct scmi_opp {
 	u32 perf;
 	u32 power;
@@ -86,6 +85,19 @@ struct scmi_perf_notify_level_or_limits {
 	__le32 notify_enable;
 };
 
+struct scmi_perf_limits_notify_payld {
+	__le32 agent_id;
+	__le32 domain_id;
+	__le32 range_max;
+	__le32 range_min;
+};
+
+struct scmi_perf_level_notify_payld {
+	__le32 agent_id;
+	__le32 domain_id;
+	__le32 performance_level;
+};
+
 struct scmi_msg_resp_perf_describe_levels {
 	__le16 num_returned;
 	__le16 num_remaining;
@@ -158,6 +170,11 @@ struct scmi_perf_info {
 	struct perf_dom_info *dom_info;
 };
 
+static enum scmi_performance_protocol_cmd evt_2_cmd[] = {
+	PERF_NOTIFY_LIMITS,
+	PERF_NOTIFY_LEVEL,
+};
+
 static int scmi_perf_attributes_get(const struct scmi_handle *handle,
 				    struct scmi_perf_info *pi)
 {
@@ -488,6 +505,29 @@ static int scmi_perf_level_get(const struct scmi_handle *handle, u32 domain,
 	return scmi_perf_mb_level_get(handle, domain, level, poll);
 }
 
+static int scmi_perf_level_limits_notify(const struct scmi_handle *handle,
+					 u32 domain, int message_id,
+					 bool enable)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_perf_notify_level_or_limits *notify;
+
+	ret = scmi_xfer_get_init(handle, message_id, SCMI_PROTOCOL_PERF,
+				 sizeof(*notify), 0, &t);
+	if (ret)
+		return ret;
+
+	notify = t->tx.buf;
+	notify->domain = cpu_to_le32(domain);
+	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
 static bool scmi_perf_fc_size_is_valid(u32 msg, u32 size)
 {
 	if ((msg == PERF_LEVEL_GET || msg == PERF_LEVEL_SET) && size == 4)
@@ -697,6 +737,17 @@ static int scmi_dvfs_est_power_get(const struct scmi_handle *handle, u32 domain,
 	return ret;
 }
 
+static bool scmi_fast_switch_possible(const struct scmi_handle *handle,
+				      struct device *dev)
+{
+	struct perf_dom_info *dom;
+	struct scmi_perf_info *pi = handle->perf_priv;
+
+	dom = pi->dom_info + scmi_dev_domain_id(dev);
+
+	return dom->fc_info && dom->fc_info->level_set_addr;
+}
+
 static struct scmi_perf_ops perf_ops = {
 	.limits_set = scmi_perf_limits_set,
 	.limits_get = scmi_perf_limits_get,
@@ -708,6 +759,90 @@ static struct scmi_perf_ops perf_ops = {
 	.freq_set = scmi_dvfs_freq_set,
 	.freq_get = scmi_dvfs_freq_get,
 	.est_power_get = scmi_dvfs_est_power_get,
+	.fast_switch_possible = scmi_fast_switch_possible,
+};
+
+static int scmi_perf_set_notify_enabled(const struct scmi_handle *handle,
+					u8 evt_id, u32 src_id, bool enable)
+{
+	int ret, cmd_id;
+
+	if (evt_id >= ARRAY_SIZE(evt_2_cmd))
+		return -EINVAL;
+
+	cmd_id = evt_2_cmd[evt_id];
+	ret = scmi_perf_level_limits_notify(handle, src_id, cmd_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *scmi_perf_fill_custom_report(const struct scmi_handle *handle,
+					  u8 evt_id, ktime_t timestamp,
+					  const void *payld, size_t payld_sz,
+					  void *report, u32 *src_id)
+{
+	void *rep = NULL;
+
+	switch (evt_id) {
+	case SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED:
+	{
+		const struct scmi_perf_limits_notify_payld *p = payld;
+		struct scmi_perf_limits_report *r = report;
+
+		if (sizeof(*p) != payld_sz)
+			break;
+
+		r->timestamp = timestamp;
+		r->agent_id = le32_to_cpu(p->agent_id);
+		r->domain_id = le32_to_cpu(p->domain_id);
+		r->range_max = le32_to_cpu(p->range_max);
+		r->range_min = le32_to_cpu(p->range_min);
+		*src_id = r->domain_id;
+		rep = r;
+		break;
+	}
+	case SCMI_EVENT_PERFORMANCE_LEVEL_CHANGED:
+	{
+		const struct scmi_perf_level_notify_payld *p = payld;
+		struct scmi_perf_level_report *r = report;
+
+		if (sizeof(*p) != payld_sz)
+			break;
+
+		r->timestamp = timestamp;
+		r->agent_id = le32_to_cpu(p->agent_id);
+		r->domain_id = le32_to_cpu(p->domain_id);
+		r->performance_level = le32_to_cpu(p->performance_level);
+		*src_id = r->domain_id;
+		rep = r;
+		break;
+	}
+	default:
+		break;
+	}
+
+	return rep;
+}
+
+static const struct scmi_event perf_events[] = {
+	{
+		.id = SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED,
+		.max_payld_sz = sizeof(struct scmi_perf_limits_notify_payld),
+		.max_report_sz = sizeof(struct scmi_perf_limits_report),
+	},
+	{
+		.id = SCMI_EVENT_PERFORMANCE_LEVEL_CHANGED,
+		.max_payld_sz = sizeof(struct scmi_perf_level_notify_payld),
+		.max_report_sz = sizeof(struct scmi_perf_level_report),
+	},
+};
+
+static const struct scmi_event_ops perf_event_ops = {
+	.set_notify_enabled = scmi_perf_set_notify_enabled,
+	.fill_custom_report = scmi_perf_fill_custom_report,
 };
 
 static int scmi_perf_protocol_init(struct scmi_handle *handle)
@@ -742,6 +877,12 @@ static int scmi_perf_protocol_init(struct scmi_handle *handle)
 			scmi_perf_domain_init_fc(handle, domain, &dom->fc_info);
 	}
 
+	scmi_register_protocol_events(handle,
+				      SCMI_PROTOCOL_PERF, SCMI_PROTO_QUEUE_SZ,
+				      &perf_event_ops, perf_events,
+				      ARRAY_SIZE(perf_events),
+				      pinfo->num_domains);
+
 	pinfo->version = version;
 	handle->perf_ops = &perf_ops;
 	handle->perf_priv = pinfo;
diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
index cf7f0312381b..46f213644c49 100644
--- a/drivers/firmware/arm_scmi/power.c
+++ b/drivers/firmware/arm_scmi/power.c
@@ -5,19 +5,18 @@
  * Copyright (C) 2018 ARM Ltd.
  */
 
+#define pr_fmt(fmt) "SCMI Notifications POWER - " fmt
+
+#include <linux/scmi_protocol.h>
+
 #include "common.h"
+#include "notify.h"
 
 enum scmi_power_protocol_cmd {
 	POWER_DOMAIN_ATTRIBUTES = 0x3,
 	POWER_STATE_SET = 0x4,
 	POWER_STATE_GET = 0x5,
 	POWER_STATE_NOTIFY = 0x6,
-	POWER_STATE_CHANGE_REQUESTED_NOTIFY = 0x7,
-};
-
-enum scmi_power_protocol_notify {
-	POWER_STATE_CHANGED = 0x0,
-	POWER_STATE_CHANGE_REQUESTED = 0x1,
 };
 
 struct scmi_msg_resp_power_attributes {
@@ -48,6 +47,12 @@ struct scmi_power_state_notify {
 	__le32 notify_enable;
 };
 
+struct scmi_power_state_notify_payld {
+	__le32 agent_id;
+	__le32 domain_id;
+	__le32 power_state;
+};
+
 struct power_dom_info {
 	bool state_set_sync;
 	bool state_set_async;
@@ -186,6 +191,75 @@ static struct scmi_power_ops power_ops = {
 	.state_get = scmi_power_state_get,
 };
 
+static int scmi_power_request_notify(const struct scmi_handle *handle,
+				     u32 domain, bool enable)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_power_state_notify *notify;
+
+	ret = scmi_xfer_get_init(handle, POWER_STATE_NOTIFY,
+				 SCMI_PROTOCOL_POWER, sizeof(*notify), 0, &t);
+	if (ret)
+		return ret;
+
+	notify = t->tx.buf;
+	notify->domain = cpu_to_le32(domain);
+	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_power_set_notify_enabled(const struct scmi_handle *handle,
+					 u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_power_request_notify(handle, src_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLE - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *scmi_power_fill_custom_report(const struct scmi_handle *handle,
+					   u8 evt_id, ktime_t timestamp,
+					   const void *payld, size_t payld_sz,
+					   void *report, u32 *src_id)
+{
+	const struct scmi_power_state_notify_payld *p = payld;
+	struct scmi_power_state_changed_report *r = report;
+
+	if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED || sizeof(*p) != payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->domain_id = le32_to_cpu(p->domain_id);
+	r->power_state = le32_to_cpu(p->power_state);
+	*src_id = r->domain_id;
+
+	return r;
+}
+
+static const struct scmi_event power_events[] = {
+	{
+		.id = SCMI_EVENT_POWER_STATE_CHANGED,
+		.max_payld_sz = sizeof(struct scmi_power_state_notify_payld),
+		.max_report_sz =
+			sizeof(struct scmi_power_state_changed_report),
+	},
+};
+
+static const struct scmi_event_ops power_event_ops = {
+	.set_notify_enabled = scmi_power_set_notify_enabled,
+	.fill_custom_report = scmi_power_fill_custom_report,
+};
+
 static int scmi_power_protocol_init(struct scmi_handle *handle)
 {
 	int domain;
@@ -214,6 +288,12 @@ static int scmi_power_protocol_init(struct scmi_handle *handle)
 		scmi_power_domain_attributes_get(handle, domain, dom);
 	}
 
+	scmi_register_protocol_events(handle,
+				      SCMI_PROTOCOL_POWER, SCMI_PROTO_QUEUE_SZ,
+				      &power_event_ops, power_events,
+				      ARRAY_SIZE(power_events),
+				      pinfo->num_domains);
+
 	pinfo->version = version;
 	handle->power_ops = &power_ops;
 	handle->power_priv = pinfo;
diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index de73054554f3..3691bafca057 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -5,7 +5,12 @@
  * Copyright (C) 2019 ARM Ltd.
  */
 
+#define pr_fmt(fmt) "SCMI Notifications RESET - " fmt
+
+#include <linux/scmi_protocol.h>
+
 #include "common.h"
+#include "notify.h"
 
 enum scmi_reset_protocol_cmd {
 	RESET_DOMAIN_ATTRIBUTES = 0x3,
@@ -13,10 +18,6 @@ enum scmi_reset_protocol_cmd {
 	RESET_NOTIFY = 0x5,
 };
 
-enum scmi_reset_protocol_notify {
-	RESET_ISSUED = 0x0,
-};
-
 #define NUM_RESET_DOMAIN_MASK	0xffff
 #define RESET_NOTIFY_ENABLE	BIT(0)
 
@@ -40,6 +41,18 @@ struct scmi_msg_reset_domain_reset {
 #define ARCH_COLD_RESET		(ARCH_RESET_TYPE | COLD_RESET_STATE)
 };
 
+struct scmi_msg_reset_notify {
+	__le32 id;
+	__le32 event_control;
+#define RESET_TP_NOTIFY_ALL	BIT(0)
+};
+
+struct scmi_reset_issued_notify_payld {
+	__le32 agent_id;
+	__le32 domain_id;
+	__le32 reset_state;
+};
+
 struct reset_dom_info {
 	bool async_reset;
 	bool reset_notify;
@@ -190,6 +203,75 @@ static struct scmi_reset_ops reset_ops = {
 	.deassert = scmi_reset_domain_deassert,
 };
 
+static int scmi_reset_notify(const struct scmi_handle *handle, u32 domain_id,
+			     bool enable)
+{
+	int ret;
+	u32 evt_cntl = enable ? RESET_TP_NOTIFY_ALL : 0;
+	struct scmi_xfer *t;
+	struct scmi_msg_reset_notify *cfg;
+
+	ret = scmi_xfer_get_init(handle, RESET_NOTIFY,
+				 SCMI_PROTOCOL_RESET, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(domain_id);
+	cfg->event_control = cpu_to_le32(evt_cntl);
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_reset_set_notify_enabled(const struct scmi_handle *handle,
+					 u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_reset_notify(handle, src_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *scmi_reset_fill_custom_report(const struct scmi_handle *handle,
+					   u8 evt_id, ktime_t timestamp,
+					   const void *payld, size_t payld_sz,
+					   void *report, u32 *src_id)
+{
+	const struct scmi_reset_issued_notify_payld *p = payld;
+	struct scmi_reset_issued_report *r = report;
+
+	if (evt_id != SCMI_EVENT_RESET_ISSUED || sizeof(*p) != payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->domain_id = le32_to_cpu(p->domain_id);
+	r->reset_state = le32_to_cpu(p->reset_state);
+	*src_id = r->domain_id;
+
+	return r;
+}
+
+static const struct scmi_event reset_events[] = {
+	{
+		.id = SCMI_EVENT_RESET_ISSUED,
+		.max_payld_sz = sizeof(struct scmi_reset_issued_notify_payld),
+		.max_report_sz = sizeof(struct scmi_reset_issued_report),
+	},
+};
+
+static const struct scmi_event_ops reset_event_ops = {
+	.set_notify_enabled = scmi_reset_set_notify_enabled,
+	.fill_custom_report = scmi_reset_fill_custom_report,
+};
+
 static int scmi_reset_protocol_init(struct scmi_handle *handle)
 {
 	int domain;
@@ -218,6 +300,12 @@ static int scmi_reset_protocol_init(struct scmi_handle *handle)
 		scmi_reset_domain_attributes_get(handle, domain, dom);
 	}
 
+	scmi_register_protocol_events(handle,
+				      SCMI_PROTOCOL_RESET, SCMI_PROTO_QUEUE_SZ,
+				      &reset_event_ops, reset_events,
+				      ARRAY_SIZE(reset_events),
+				      pinfo->num_domains);
+
 	pinfo->version = version;
 	handle->reset_ops = &reset_ops;
 	handle->reset_priv = pinfo;
diff --git a/drivers/firmware/arm_scmi/scmi_pm_domain.c b/drivers/firmware/arm_scmi/scmi_pm_domain.c
index bafbfe358f97..9e44479f0284 100644
--- a/drivers/firmware/arm_scmi/scmi_pm_domain.c
+++ b/drivers/firmware/arm_scmi/scmi_pm_domain.c
@@ -85,7 +85,10 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	for (i = 0; i < num_domains; i++, scmi_pd++) {
 		u32 state;
 
-		domains[i] = &scmi_pd->genpd;
+		if (handle->power_ops->state_get(handle, i, &state)) {
+			dev_warn(dev, "failed to get state for domain %d\n", i);
+			continue;
+		}
 
 		scmi_pd->domain = i;
 		scmi_pd->handle = handle;
@@ -94,13 +97,10 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 		scmi_pd->genpd.power_off = scmi_pd_power_off;
 		scmi_pd->genpd.power_on = scmi_pd_power_on;
 
-		if (handle->power_ops->state_get(handle, i, &state)) {
-			dev_warn(dev, "failed to get state for domain %d\n", i);
-			continue;
-		}
-
 		pm_genpd_init(&scmi_pd->genpd, NULL,
 			      state == SCMI_POWER_STATE_GENERIC_OFF);
+
+		domains[i] = &scmi_pd->genpd;
 	}
 
 	scmi_pd_data->domains = domains;
diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index db1b1ab303da..1af0ad362e82 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -5,7 +5,12 @@
  * Copyright (C) 2018 ARM Ltd.
  */
 
+#define pr_fmt(fmt) "SCMI Notifications SENSOR - " fmt
+
+#include <linux/scmi_protocol.h>
+
 #include "common.h"
+#include "notify.h"
 
 enum scmi_sensor_protocol_cmd {
 	SENSOR_DESCRIPTION_GET = 0x3,
@@ -14,10 +19,6 @@ enum scmi_sensor_protocol_cmd {
 	SENSOR_READING_GET = 0x6,
 };
 
-enum scmi_sensor_protocol_notify {
-	SENSOR_TRIP_POINT_EVENT = 0x0,
-};
-
 struct scmi_msg_resp_sensor_attributes {
 	__le16 num_sensors;
 	u8 max_requests;
@@ -71,6 +72,12 @@ struct scmi_msg_sensor_reading_get {
 #define SENSOR_READ_ASYNC	BIT(0)
 };
 
+struct scmi_sensor_trip_notify_payld {
+	__le32 agent_id;
+	__le32 sensor_id;
+	__le32 trip_point_desc;
+};
+
 struct sensors_info {
 	u32 version;
 	int num_sensors;
@@ -271,11 +278,57 @@ static int scmi_sensor_count_get(const struct scmi_handle *handle)
 static struct scmi_sensor_ops sensor_ops = {
 	.count_get = scmi_sensor_count_get,
 	.info_get = scmi_sensor_info_get,
-	.trip_point_notify = scmi_sensor_trip_point_notify,
 	.trip_point_config = scmi_sensor_trip_point_config,
 	.reading_get = scmi_sensor_reading_get,
 };
 
+static int scmi_sensor_set_notify_enabled(const struct scmi_handle *handle,
+					  u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_sensor_trip_point_notify(handle, src_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *scmi_sensor_fill_custom_report(const struct scmi_handle *handle,
+					    u8 evt_id, ktime_t timestamp,
+					    const void *payld, size_t payld_sz,
+					    void *report, u32 *src_id)
+{
+	const struct scmi_sensor_trip_notify_payld *p = payld;
+	struct scmi_sensor_trip_point_report *r = report;
+
+	if (evt_id != SCMI_EVENT_SENSOR_TRIP_POINT_EVENT ||
+	    sizeof(*p) != payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->sensor_id = le32_to_cpu(p->sensor_id);
+	r->trip_point_desc = le32_to_cpu(p->trip_point_desc);
+	*src_id = r->sensor_id;
+
+	return r;
+}
+
+static const struct scmi_event sensor_events[] = {
+	{
+		.id = SCMI_EVENT_SENSOR_TRIP_POINT_EVENT,
+		.max_payld_sz = sizeof(struct scmi_sensor_trip_notify_payld),
+		.max_report_sz = sizeof(struct scmi_sensor_trip_point_report),
+	},
+};
+
+static const struct scmi_event_ops sensor_event_ops = {
+	.set_notify_enabled = scmi_sensor_set_notify_enabled,
+	.fill_custom_report = scmi_sensor_fill_custom_report,
+};
+
 static int scmi_sensors_protocol_init(struct scmi_handle *handle)
 {
 	u32 version;
@@ -299,6 +352,12 @@ static int scmi_sensors_protocol_init(struct scmi_handle *handle)
 
 	scmi_sensor_description_get(handle, sinfo);
 
+	scmi_register_protocol_events(handle,
+				      SCMI_PROTOCOL_SENSOR, SCMI_PROTO_QUEUE_SZ,
+				      &sensor_event_ops, sensor_events,
+				      ARRAY_SIZE(sensor_events),
+				      sinfo->num_sensors);
+
 	sinfo->version = version;
 	handle->sensor_ops = &sensor_ops;
 	handle->sensor_priv = sinfo;
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 49bc4b0e8428..a1537d123e38 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -21,6 +21,7 @@
  *
  * @cinfo: SCMI channel info
  * @shmem: Transmit/Receive shared memory area
+ * @shmem_lock: Lock to protect access to Tx/Rx shared memory area
  * @func_id: smc/hvc call function id
  */
 
diff --git a/drivers/firmware/imx/Makefile b/drivers/firmware/imx/Makefile
index 08bc9ddfbdfb..b76acbade2a0 100644
--- a/drivers/firmware/imx/Makefile
+++ b/drivers/firmware/imx/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_IMX_DSP)		+= imx-dsp.o
-obj-$(CONFIG_IMX_SCU)		+= imx-scu.o misc.o imx-scu-irq.o
+obj-$(CONFIG_IMX_SCU)		+= imx-scu.o misc.o imx-scu-irq.o rm.o imx-scu-soc.o
 obj-$(CONFIG_IMX_SCU_PD)	+= scu-pd.o
diff --git a/drivers/firmware/imx/imx-scu-irq.c b/drivers/firmware/imx/imx-scu-irq.c
index db655e87cdc8..d9dcc20945c6 100644
--- a/drivers/firmware/imx/imx-scu-irq.c
+++ b/drivers/firmware/imx/imx-scu-irq.c
@@ -10,6 +10,7 @@
 #include <linux/firmware/imx/ipc.h>
 #include <linux/firmware/imx/sci.h>
 #include <linux/mailbox_client.h>
+#include <linux/suspend.h>
 
 #define IMX_SC_IRQ_FUNC_ENABLE	1
 #define IMX_SC_IRQ_FUNC_STATUS	2
@@ -91,6 +92,7 @@ static void imx_scu_irq_work_handler(struct work_struct *work)
 		if (!irq_status)
 			continue;
 
+		pm_system_wakeup();
 		imx_scu_irq_notifier_call_chain(irq_status, &i);
 	}
 }
diff --git a/drivers/firmware/imx/imx-scu-soc.c b/drivers/firmware/imx/imx-scu-soc.c
new file mode 100644
index 000000000000..2f32353de2c9
--- /dev/null
+++ b/drivers/firmware/imx/imx-scu-soc.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <dt-bindings/firmware/imx/rsrc.h>
+#include <linux/firmware/imx/sci.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+static struct imx_sc_ipc *imx_sc_soc_ipc_handle;
+
+struct imx_sc_msg_misc_get_soc_id {
+	struct imx_sc_rpc_msg hdr;
+	union {
+		struct {
+			u32 control;
+			u16 resource;
+		} __packed req;
+		struct {
+			u32 id;
+		} resp;
+	} data;
+} __packed __aligned(4);
+
+struct imx_sc_msg_misc_get_soc_uid {
+	struct imx_sc_rpc_msg hdr;
+	u32 uid_low;
+	u32 uid_high;
+} __packed;
+
+static int imx_scu_soc_uid(u64 *soc_uid)
+{
+	struct imx_sc_msg_misc_get_soc_uid msg;
+	struct imx_sc_rpc_msg *hdr = &msg.hdr;
+	int ret;
+
+	hdr->ver = IMX_SC_RPC_VERSION;
+	hdr->svc = IMX_SC_RPC_SVC_MISC;
+	hdr->func = IMX_SC_MISC_FUNC_UNIQUE_ID;
+	hdr->size = 1;
+
+	ret = imx_scu_call_rpc(imx_sc_soc_ipc_handle, &msg, true);
+	if (ret) {
+		pr_err("%s: get soc uid failed, ret %d\n", __func__, ret);
+		return ret;
+	}
+
+	*soc_uid = msg.uid_high;
+	*soc_uid <<= 32;
+	*soc_uid |= msg.uid_low;
+
+	return 0;
+}
+
+static int imx_scu_soc_id(void)
+{
+	struct imx_sc_msg_misc_get_soc_id msg;
+	struct imx_sc_rpc_msg *hdr = &msg.hdr;
+	int ret;
+
+	hdr->ver = IMX_SC_RPC_VERSION;
+	hdr->svc = IMX_SC_RPC_SVC_MISC;
+	hdr->func = IMX_SC_MISC_FUNC_GET_CONTROL;
+	hdr->size = 3;
+
+	msg.data.req.control = IMX_SC_C_ID;
+	msg.data.req.resource = IMX_SC_R_SYSTEM;
+
+	ret = imx_scu_call_rpc(imx_sc_soc_ipc_handle, &msg, true);
+	if (ret) {
+		pr_err("%s: get soc info failed, ret %d\n", __func__, ret);
+		return ret;
+	}
+
+	return msg.data.resp.id;
+}
+
+int imx_scu_soc_init(struct device *dev)
+{
+	struct soc_device_attribute *soc_dev_attr;
+	struct soc_device *soc_dev;
+	int id, ret;
+	u64 uid = 0;
+	u32 val;
+
+	ret = imx_scu_get_handle(&imx_sc_soc_ipc_handle);
+	if (ret)
+		return ret;
+
+	soc_dev_attr = devm_kzalloc(dev, sizeof(*soc_dev_attr),
+				    GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	soc_dev_attr->family = "Freescale i.MX";
+
+	ret = of_property_read_string(of_root,
+				      "model",
+				      &soc_dev_attr->machine);
+	if (ret)
+		return ret;
+
+	id = imx_scu_soc_id();
+	if (id < 0)
+		return -EINVAL;
+
+	ret = imx_scu_soc_uid(&uid);
+	if (ret < 0)
+		return -EINVAL;
+
+	/* format soc_id value passed from SCU firmware */
+	val = id & 0x1f;
+	soc_dev_attr->soc_id = devm_kasprintf(dev, GFP_KERNEL, "0x%x", val);
+	if (!soc_dev_attr->soc_id)
+		return -ENOMEM;
+
+	/* format revision value passed from SCU firmware */
+	val = (id >> 5) & 0xf;
+	val = (((val >> 2) + 1) << 4) | (val & 0x3);
+	soc_dev_attr->revision = devm_kasprintf(dev, GFP_KERNEL, "%d.%d",
+						(val >> 4) & 0xf, val & 0xf);
+	if (!soc_dev_attr->revision)
+		return -ENOMEM;
+
+	soc_dev_attr->serial_number = devm_kasprintf(dev, GFP_KERNEL,
+						     "%016llX", uid);
+	if (!soc_dev_attr->serial_number)
+		return -ENOMEM;
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev))
+		return PTR_ERR(soc_dev);
+
+	return 0;
+}
diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
index 2ab048222fe9..dca79caccd01 100644
--- a/drivers/firmware/imx/imx-scu.c
+++ b/drivers/firmware/imx/imx-scu.c
@@ -328,6 +328,10 @@ static int imx_scu_probe(struct platform_device *pdev)
 
 	imx_sc_ipc_handle = sc_ipc;
 
+	ret = imx_scu_soc_init(dev);
+	if (ret)
+		dev_warn(dev, "failed to initialize SoC info: %d\n", ret);
+
 	ret = imx_scu_enable_general_irq_channel(dev);
 	if (ret)
 		dev_warn(dev,
diff --git a/drivers/firmware/imx/rm.c b/drivers/firmware/imx/rm.c
new file mode 100644
index 000000000000..a12db6ff323b
--- /dev/null
+++ b/drivers/firmware/imx/rm.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2020 NXP
+ *
+ * File containing client-side RPC functions for the RM service. These
+ * function are ported to clients that communicate to the SC.
+ */
+
+#include <linux/firmware/imx/svc/rm.h>
+
+struct imx_sc_msg_rm_rsrc_owned {
+	struct imx_sc_rpc_msg hdr;
+	u16 resource;
+} __packed __aligned(4);
+
+/*
+ * This function check @resource is owned by current partition or not
+ *
+ * @param[in]     ipc         IPC handle
+ * @param[in]     resource    resource the control is associated with
+ *
+ * @return Returns 0 for not owned and 1 for owned.
+ */
+bool imx_sc_rm_is_resource_owned(struct imx_sc_ipc *ipc, u16 resource)
+{
+	struct imx_sc_msg_rm_rsrc_owned msg;
+	struct imx_sc_rpc_msg *hdr = &msg.hdr;
+
+	hdr->ver = IMX_SC_RPC_VERSION;
+	hdr->svc = IMX_SC_RPC_SVC_RM;
+	hdr->func = IMX_SC_RM_FUNC_IS_RESOURCE_OWNED;
+	hdr->size = 2;
+
+	msg.resource = resource;
+
+	/*
+	 * SCU firmware only returns value 0 or 1
+	 * for resource owned check which means not owned or owned.
+	 * So it is always successful.
+	 */
+	imx_scu_call_rpc(ipc, &msg, true);
+
+	return hdr->func;
+}
+EXPORT_SYMBOL(imx_sc_rm_is_resource_owned);
diff --git a/drivers/firmware/imx/scu-pd.c b/drivers/firmware/imx/scu-pd.c
index fb5523aa16ee..af3d6d9ead28 100644
--- a/drivers/firmware/imx/scu-pd.c
+++ b/drivers/firmware/imx/scu-pd.c
@@ -167,8 +167,18 @@ static const struct imx_sc_pd_range imx8qxp_scu_pd_ranges[] = {
 	{ "dc0-pll", IMX_SC_R_DC_0_PLL_0, 2, true, 0 },
 
 	/* CM40 SS */
-	{ "cm40_i2c", IMX_SC_R_M4_0_I2C, 1, 0 },
-	{ "cm40_intmux", IMX_SC_R_M4_0_INTMUX, 1, 0 },
+	{ "cm40-i2c", IMX_SC_R_M4_0_I2C, 1, false, 0 },
+	{ "cm40-intmux", IMX_SC_R_M4_0_INTMUX, 1, false, 0 },
+	{ "cm40-pid", IMX_SC_R_M4_0_PID0, 5, true, 0},
+	{ "cm40-mu-a1", IMX_SC_R_M4_0_MU_1A, 1, false, 0},
+	{ "cm40-lpuart", IMX_SC_R_M4_0_UART, 1, false, 0},
+
+	/* CM41 SS */
+	{ "cm41-i2c", IMX_SC_R_M4_1_I2C, 1, false, 0 },
+	{ "cm41-intmux", IMX_SC_R_M4_1_INTMUX, 1, false, 0 },
+	{ "cm41-pid", IMX_SC_R_M4_1_PID0, 5, true, 0},
+	{ "cm41-mu-a1", IMX_SC_R_M4_1_MU_1A, 1, false, 0},
+	{ "cm41-lpuart", IMX_SC_R_M4_1_UART, 1, false, 0},
 };
 
 static const struct imx_sc_pd_soc imx8qxp_scu_pd = {
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 0e7233a20f34..8393bb3265cc 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -391,7 +391,7 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
 
 	desc.args[1] = enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
 
-	return qcom_scm_call(__scm->dev, &desc, NULL);
+	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
 }
 
 static void qcom_scm_set_download_mode(bool enable)
@@ -650,7 +650,7 @@ int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val)
 	int ret;
 
 
-	ret = qcom_scm_call(__scm->dev, &desc, &res);
+	ret = qcom_scm_call_atomic(__scm->dev, &desc, &res);
 	if (ret >= 0)
 		*val = res.result[0];
 
@@ -669,8 +669,7 @@ int qcom_scm_io_writel(phys_addr_t addr, unsigned int val)
 		.owner = ARM_SMCCC_OWNER_SIP,
 	};
 
-
-	return qcom_scm_call(__scm->dev, &desc, NULL);
+	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
 }
 EXPORT_SYMBOL(qcom_scm_io_writel);
 
@@ -1151,6 +1150,7 @@ static const struct of_device_id qcom_scm_dt_match[] = {
 							     SCM_HAS_IFACE_CLK |
 							     SCM_HAS_BUS_CLK)
 	},
+	{ .compatible = "qcom,scm-msm8994" },
 	{ .compatible = "qcom,scm-msm8996" },
 	{ .compatible = "qcom,scm" },
 	{}
diff --git a/drivers/firmware/smccc/Kconfig b/drivers/firmware/smccc/Kconfig
index 27b675d76235..15e7466179a6 100644
--- a/drivers/firmware/smccc/Kconfig
+++ b/drivers/firmware/smccc/Kconfig
@@ -14,3 +14,12 @@ config HAVE_ARM_SMCCC_DISCOVERY
 	 to add SMCCC discovery mechanism though the PSCI firmware
 	 implementation of PSCI_FEATURES(SMCCC_VERSION) which returns
 	 success on firmware compliant to SMCCC v1.1 and above.
+
+config ARM_SMCCC_SOC_ID
+	bool "SoC bus device for the ARM SMCCC SOC_ID"
+	depends on HAVE_ARM_SMCCC_DISCOVERY
+	default y
+	select SOC_BUS
+	help
+	  Include support for the SoC bus on the ARM SMCCC firmware based
+	  platforms providing some sysfs information about the SoC variant.
diff --git a/drivers/firmware/smccc/Makefile b/drivers/firmware/smccc/Makefile
index 6f369fe3f0b9..72ab84042832 100644
--- a/drivers/firmware/smccc/Makefile
+++ b/drivers/firmware/smccc/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 #
 obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY)	+= smccc.o
+obj-$(CONFIG_ARM_SMCCC_SOC_ID)	+= soc_id.o
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
new file mode 100644
index 000000000000..581aa5e9b077
--- /dev/null
+++ b/drivers/firmware/smccc/soc_id.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK	GENMASK(30, 24)
+/*
+ * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C)
+ * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification
+ * code with parity bit for the SiP. We can drop the parity bit.
+ */
+#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK	GENMASK(22, 16)
+#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK	GENMASK(15, 0)
+
+#define JEP106_BANK_CONT_CODE(x)	\
+	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x)))
+#define JEP106_ID_CODE(x)	\
+	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x)))
+#define IMP_DEF_SOC_ID(x)	\
+	(u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x)))
+
+static struct soc_device *soc_dev;
+static struct soc_device_attribute *soc_dev_attr;
+
+static int __init smccc_soc_init(void)
+{
+	struct arm_smccc_res res;
+	int soc_id_rev, soc_id_version;
+	static char soc_id_str[20], soc_id_rev_str[12];
+	static char soc_id_jep106_id_str[12];
+
+	if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+		return 0;
+
+	if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE) {
+		pr_err("%s: invalid SMCCC conduit\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+			     ARM_SMCCC_ARCH_SOC_ID, &res);
+
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED) {
+		pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
+		return 0;
+	}
+
+	if ((int)res.a0 < 0) {
+		pr_info("ARCH_FEATURES(ARCH_SOC_ID) returned error: %lx\n",
+			res.a0);
+		return -EINVAL;
+	}
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
+	if ((int)res.a0 < 0) {
+		pr_err("ARCH_SOC_ID(0) returned error: %lx\n", res.a0);
+		return -EINVAL;
+	}
+
+	soc_id_version = res.a0;
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
+	if ((int)res.a0 < 0) {
+		pr_err("ARCH_SOC_ID(1) returned error: %lx\n", res.a0);
+		return -EINVAL;
+	}
+
+	soc_id_rev = res.a0;
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
+	sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
+		JEP106_BANK_CONT_CODE(soc_id_version),
+		JEP106_ID_CODE(soc_id_version));
+	sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
+		IMP_DEF_SOC_ID(soc_id_version));
+
+	soc_dev_attr->soc_id = soc_id_str;
+	soc_dev_attr->revision = soc_id_rev_str;
+	soc_dev_attr->family = soc_id_jep106_id_str;
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr);
+		return PTR_ERR(soc_dev);
+	}
+
+	pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
+		soc_dev_attr->revision);
+
+	return 0;
+}
+module_init(smccc_soc_init);
+
+static void __exit smccc_soc_exit(void)
+{
+	if (soc_dev)
+		soc_device_unregister(soc_dev);
+	kfree(soc_dev_attr);
+}
+module_exit(smccc_soc_exit);
diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
index 636b40d4364d..c1bbba9ee93a 100644
--- a/drivers/firmware/tegra/bpmp-debugfs.c
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -4,11 +4,14 @@
  */
 #include <linux/debugfs.h>
 #include <linux/dma-mapping.h>
+#include <linux/slab.h>
 #include <linux/uaccess.h>
 
 #include <soc/tegra/bpmp.h>
 #include <soc/tegra/bpmp-abi.h>
 
+static DEFINE_MUTEX(bpmp_debug_lock);
+
 struct seqbuf {
 	char *buf;
 	size_t pos;
@@ -96,6 +99,354 @@ static const char *get_filename(struct tegra_bpmp *bpmp,
 	return filename;
 }
 
+static int mrq_debug_open(struct tegra_bpmp *bpmp, const char *name,
+			  uint32_t *fd, uint32_t *len, bool write)
+{
+	struct mrq_debug_request req = {
+		.cmd = cpu_to_le32(write ? CMD_DEBUG_OPEN_WO : CMD_DEBUG_OPEN_RO),
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	ssize_t sz_name;
+	int err = 0;
+
+	sz_name = strscpy(req.fop.name, name, sizeof(req.fop.name));
+	if (sz_name < 0) {
+		pr_err("File name too large: %s\n", name);
+		return -EINVAL;
+	}
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err < 0)
+		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
+
+	*len = resp.fop.datalen;
+	*fd = resp.fop.fd;
+
+	return 0;
+}
+
+static int mrq_debug_close(struct tegra_bpmp *bpmp, uint32_t fd)
+{
+	struct mrq_debug_request req = {
+		.cmd = cpu_to_le32(CMD_DEBUG_CLOSE),
+		.frd = {
+			.fd = fd,
+		},
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	int err = 0;
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err < 0)
+		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int mrq_debug_read(struct tegra_bpmp *bpmp, const char *name,
+			  char *data, size_t sz_data, uint32_t *nbytes)
+{
+	struct mrq_debug_request req = {
+		.cmd = cpu_to_le32(CMD_DEBUG_READ),
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	uint32_t fd = 0, len = 0;
+	int remaining, err;
+
+	mutex_lock(&bpmp_debug_lock);
+	err = mrq_debug_open(bpmp, name, &fd, &len, 0);
+	if (err)
+		goto out;
+
+	if (len > sz_data) {
+		err = -EFBIG;
+		goto close;
+	}
+
+	req.frd.fd = fd;
+	remaining = len;
+
+	while (remaining > 0) {
+		err = tegra_bpmp_transfer(bpmp, &msg);
+		if (err < 0) {
+			goto close;
+		} else if (msg.rx.ret < 0) {
+			err = -EINVAL;
+			goto close;
+		}
+
+		if (resp.frd.readlen > remaining) {
+			pr_err("%s: read data length invalid\n", __func__);
+			err = -EINVAL;
+			goto close;
+		}
+
+		memcpy(data, resp.frd.data, resp.frd.readlen);
+		data += resp.frd.readlen;
+		remaining -= resp.frd.readlen;
+	}
+
+	*nbytes = len;
+
+close:
+	err = mrq_debug_close(bpmp, fd);
+out:
+	mutex_unlock(&bpmp_debug_lock);
+	return err;
+}
+
+static int mrq_debug_write(struct tegra_bpmp *bpmp, const char *name,
+			   uint8_t *data, size_t sz_data)
+{
+	struct mrq_debug_request req = {
+		.cmd = cpu_to_le32(CMD_DEBUG_WRITE)
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	uint32_t fd = 0, len = 0;
+	size_t remaining;
+	int err;
+
+	mutex_lock(&bpmp_debug_lock);
+	err = mrq_debug_open(bpmp, name, &fd, &len, 1);
+	if (err)
+		goto out;
+
+	if (sz_data > len) {
+		err = -EINVAL;
+		goto close;
+	}
+
+	req.fwr.fd = fd;
+	remaining = sz_data;
+
+	while (remaining > 0) {
+		len = min(remaining, sizeof(req.fwr.data));
+		memcpy(req.fwr.data, data, len);
+		req.fwr.datalen = len;
+
+		err = tegra_bpmp_transfer(bpmp, &msg);
+		if (err < 0) {
+			goto close;
+		} else if (msg.rx.ret < 0) {
+			err = -EINVAL;
+			goto close;
+		}
+
+		data += req.fwr.datalen;
+		remaining -= req.fwr.datalen;
+	}
+
+close:
+	err = mrq_debug_close(bpmp, fd);
+out:
+	mutex_unlock(&bpmp_debug_lock);
+	return err;
+}
+
+static int bpmp_debug_show(struct seq_file *m, void *p)
+{
+	struct file *file = m->private;
+	struct inode *inode = file_inode(file);
+	struct tegra_bpmp *bpmp = inode->i_private;
+	char *databuf = NULL;
+	char fnamebuf[256];
+	const char *filename;
+	uint32_t nbytes = 0;
+	size_t len;
+	int err;
+
+	len = seq_get_buf(m, &databuf);
+	if (!databuf)
+		return -ENOMEM;
+
+	filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+	if (!filename)
+		return -ENOENT;
+
+	err = mrq_debug_read(bpmp, filename, databuf, len, &nbytes);
+	if (!err)
+		seq_commit(m, nbytes);
+
+	return err;
+}
+
+static ssize_t bpmp_debug_store(struct file *file, const char __user *buf,
+		size_t count, loff_t *f_pos)
+{
+	struct inode *inode = file_inode(file);
+	struct tegra_bpmp *bpmp = inode->i_private;
+	char *databuf = NULL;
+	char fnamebuf[256];
+	const char *filename;
+	ssize_t err;
+
+	filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+	if (!filename)
+		return -ENOENT;
+
+	databuf = kmalloc(count, GFP_KERNEL);
+	if (!databuf)
+		return -ENOMEM;
+
+	if (copy_from_user(databuf, buf, count)) {
+		err = -EFAULT;
+		goto free_ret;
+	}
+
+	err = mrq_debug_write(bpmp, filename, databuf, count);
+
+free_ret:
+	kfree(databuf);
+
+	return err ?: count;
+}
+
+static int bpmp_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open_size(file, bpmp_debug_show, file, SZ_256K);
+}
+
+static const struct file_operations bpmp_debug_fops = {
+	.open		= bpmp_debug_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.write		= bpmp_debug_store,
+	.release	= single_release,
+};
+
+static int bpmp_populate_debugfs_inband(struct tegra_bpmp *bpmp,
+					struct dentry *parent,
+					char *ppath)
+{
+	const size_t pathlen = SZ_256;
+	const size_t bufsize = SZ_16K;
+	uint32_t dsize, attrs = 0;
+	struct dentry *dentry;
+	struct seqbuf seqbuf;
+	char *buf, *pathbuf;
+	const char *name;
+	int err = 0;
+
+	if (!bpmp || !parent || !ppath)
+		return -EINVAL;
+
+	buf = kmalloc(bufsize, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	pathbuf = kzalloc(pathlen, GFP_KERNEL);
+	if (!pathbuf) {
+		kfree(buf);
+		return -ENOMEM;
+	}
+
+	err = mrq_debug_read(bpmp, ppath, buf, bufsize, &dsize);
+	if (err)
+		goto out;
+
+	seqbuf_init(&seqbuf, buf, dsize);
+
+	while (!seqbuf_eof(&seqbuf)) {
+		err = seqbuf_read_u32(&seqbuf, &attrs);
+		if (err)
+			goto out;
+
+		err = seqbuf_read_str(&seqbuf, &name);
+		if (err < 0)
+			goto out;
+
+		if (attrs & DEBUGFS_S_ISDIR) {
+			size_t len;
+
+			dentry = debugfs_create_dir(name, parent);
+			if (IS_ERR(dentry)) {
+				err = PTR_ERR(dentry);
+				goto out;
+			}
+
+			len = strlen(ppath) + strlen(name) + 1;
+			if (len >= pathlen) {
+				err = -EINVAL;
+				goto out;
+			}
+
+			strncpy(pathbuf, ppath, pathlen);
+			strncat(pathbuf, name, strlen(name));
+			strcat(pathbuf, "/");
+
+			err = bpmp_populate_debugfs_inband(bpmp, dentry,
+							   pathbuf);
+			if (err < 0)
+				goto out;
+		} else {
+			umode_t mode;
+
+			mode = attrs & DEBUGFS_S_IRUSR ? 0400 : 0;
+			mode |= attrs & DEBUGFS_S_IWUSR ? 0200 : 0;
+			dentry = debugfs_create_file(name, mode, parent, bpmp,
+						     &bpmp_debug_fops);
+			if (!dentry) {
+				err = -ENOMEM;
+				goto out;
+			}
+		}
+	}
+
+out:
+	kfree(pathbuf);
+	kfree(buf);
+
+	return err;
+}
+
 static int mrq_debugfs_read(struct tegra_bpmp *bpmp,
 			    dma_addr_t name, size_t sz_name,
 			    dma_addr_t data, size_t sz_data,
@@ -127,6 +478,8 @@ static int mrq_debugfs_read(struct tegra_bpmp *bpmp,
 	err = tegra_bpmp_transfer(bpmp, &msg);
 	if (err < 0)
 		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
 
 	*nbytes = (size_t)resp.fop.nbytes;
 
@@ -184,6 +537,8 @@ static int mrq_debugfs_dumpdir(struct tegra_bpmp *bpmp, dma_addr_t addr,
 	err = tegra_bpmp_transfer(bpmp, &msg);
 	if (err < 0)
 		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
 
 	*nbytes = (size_t)resp.dumpdir.nbytes;
 
@@ -202,7 +557,7 @@ static int debugfs_show(struct seq_file *m, void *p)
 	char buf[256];
 	const char *filename;
 	size_t len, nbytes;
-	int ret;
+	int err;
 
 	filename = get_filename(bpmp, file, buf, sizeof(buf));
 	if (!filename)
@@ -216,24 +571,24 @@ static int debugfs_show(struct seq_file *m, void *p)
 	datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
 				      GFP_KERNEL | GFP_DMA32);
 	if (!datavirt) {
-		ret = -ENOMEM;
+		err = -ENOMEM;
 		goto free_namebuf;
 	}
 
 	len = strlen(filename);
 	strncpy(namevirt, filename, namesize);
 
-	ret = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize,
+	err = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize,
 			       &nbytes);
 
-	if (!ret)
+	if (!err)
 		seq_write(m, datavirt, nbytes);
 
 	dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
 free_namebuf:
 	dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
 
-	return ret;
+	return err;
 }
 
 static int debugfs_open(struct inode *inode, struct file *file)
@@ -253,7 +608,7 @@ static ssize_t debugfs_store(struct file *file, const char __user *buf,
 	char fnamebuf[256];
 	const char *filename;
 	size_t len;
-	int ret;
+	int err;
 
 	filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
 	if (!filename)
@@ -267,7 +622,7 @@ static ssize_t debugfs_store(struct file *file, const char __user *buf,
 	datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
 				      GFP_KERNEL | GFP_DMA32);
 	if (!datavirt) {
-		ret = -ENOMEM;
+		err = -ENOMEM;
 		goto free_namebuf;
 	}
 
@@ -275,11 +630,11 @@ static ssize_t debugfs_store(struct file *file, const char __user *buf,
 	strncpy(namevirt, filename, namesize);
 
 	if (copy_from_user(datavirt, buf, count)) {
-		ret = -EFAULT;
+		err = -EFAULT;
 		goto free_databuf;
 	}
 
-	ret = mrq_debugfs_write(bpmp, namephys, len, dataphys,
+	err = mrq_debugfs_write(bpmp, namephys, len, dataphys,
 				count);
 
 free_databuf:
@@ -287,7 +642,7 @@ free_databuf:
 free_namebuf:
 	dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
 
-	return ret ?: count;
+	return err ?: count;
 }
 
 static const struct file_operations debugfs_fops = {
@@ -350,59 +705,66 @@ static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
 	return 0;
 }
 
-static int create_debugfs_mirror(struct tegra_bpmp *bpmp, void *buf,
-				 size_t bufsize, struct dentry *root)
+static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp)
 {
 	struct seqbuf seqbuf;
+	const size_t sz = SZ_512K;
+	dma_addr_t phys;
+	size_t nbytes;
+	void *virt;
 	int err;
 
-	bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
-	if (!bpmp->debugfs_mirror)
+	virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
+				  GFP_KERNEL | GFP_DMA32);
+	if (!virt)
 		return -ENOMEM;
 
-	seqbuf_init(&seqbuf, buf, bufsize);
-	err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
+	err = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
 	if (err < 0) {
-		debugfs_remove_recursive(bpmp->debugfs_mirror);
-		bpmp->debugfs_mirror = NULL;
+		goto free;
+	} else if (nbytes > sz) {
+		err = -EINVAL;
+		goto free;
 	}
 
+	seqbuf_init(&seqbuf, virt, nbytes);
+	err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
+free:
+	dma_free_coherent(bpmp->dev, sz, virt, phys);
+
 	return err;
 }
 
 int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
 {
-	dma_addr_t phys;
-	void *virt;
-	const size_t sz = SZ_256K;
-	size_t nbytes;
-	int ret;
 	struct dentry *root;
+	bool inband;
+	int err;
 
-	if (!tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUGFS))
+	inband = tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUG);
+
+	if (!inband && !tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUGFS))
 		return 0;
 
 	root = debugfs_create_dir("bpmp", NULL);
 	if (!root)
 		return -ENOMEM;
 
-	virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
-				  GFP_KERNEL | GFP_DMA32);
-	if (!virt) {
-		ret = -ENOMEM;
+	bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
+	if (!bpmp->debugfs_mirror) {
+		err = -ENOMEM;
 		goto out;
 	}
 
-	ret = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
-	if (ret < 0)
-		goto free;
+	if (inband)
+		err = bpmp_populate_debugfs_inband(bpmp, bpmp->debugfs_mirror,
+						   "/");
+	else
+		err = bpmp_populate_debugfs_shmem(bpmp);
 
-	ret = create_debugfs_mirror(bpmp, virt, nbytes, root);
-free:
-	dma_free_coherent(bpmp->dev, sz, virt, phys);
 out:
-	if (ret < 0)
-		debugfs_remove(root);
+	if (err < 0)
+		debugfs_remove_recursive(root);
 
-	return ret;
+	return err;
 }
diff --git a/drivers/firmware/tegra/bpmp.c b/drivers/firmware/tegra/bpmp.c
index fe6702df24bf..4d93d8925e14 100644
--- a/drivers/firmware/tegra/bpmp.c
+++ b/drivers/firmware/tegra/bpmp.c
@@ -515,10 +515,10 @@ bool tegra_bpmp_mrq_is_supported(struct tegra_bpmp *bpmp, unsigned int mrq)
 			.size = sizeof(resp),
 		},
 	};
-	int ret;
+	int err;
 
-	ret = tegra_bpmp_transfer(bpmp, &msg);
-	if (ret || msg.rx.ret)
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err || msg.rx.ret)
 		return false;
 
 	return resp.status == 0;
diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 4126be9e3216..53cee17d0115 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -2,7 +2,7 @@
 /*
  * Texas Instruments System Control Interface Protocol Driver
  *
- * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
  *	Nishanth Menon
  */
 
diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
index f0d068c03944..57cd04062994 100644
--- a/drivers/firmware/ti_sci.h
+++ b/drivers/firmware/ti_sci.h
@@ -6,7 +6,7 @@
  * The system works in a message response protocol
  * See: http://processors.wiki.ti.com/index.php/TISCI for details
  *
- * Copyright (C)  2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ * Copyright (C)  2015-2016 Texas Instruments Incorporated - https://www.ti.com/
  */
 
 #ifndef __TI_SCI_H
diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c
index e27f68437b56..50bb2a6d6ccf 100644
--- a/drivers/firmware/turris-mox-rwtm.c
+++ b/drivers/firmware/turris-mox-rwtm.c
@@ -7,6 +7,7 @@
 
 #include <linux/armada-37xx-rwtm-mailbox.h>
 #include <linux/completion.h>
+#include <linux/debugfs.h>
 #include <linux/dma-mapping.h>
 #include <linux/hw_random.h>
 #include <linux/mailbox_client.h>
@@ -69,6 +70,18 @@ struct mox_rwtm {
 	/* public key burned in eFuse */
 	int has_pubkey;
 	u8 pubkey[135];
+
+#ifdef CONFIG_DEBUG_FS
+	/*
+	 * Signature process. This is currently done via debugfs, because it
+	 * does not conform to the sysfs standard "one file per attribute".
+	 * It should be rewritten via crypto API once akcipher API is available
+	 * from userspace.
+	 */
+	struct dentry *debugfs_root;
+	u32 last_sig[34];
+	int last_sig_done;
+#endif
 };
 
 struct mox_kobject {
@@ -279,6 +292,152 @@ unlock_mutex:
 	return ret;
 }
 
+#ifdef CONFIG_DEBUG_FS
+static int rwtm_debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t do_sign_read(struct file *file, char __user *buf, size_t len,
+			    loff_t *ppos)
+{
+	struct mox_rwtm *rwtm = file->private_data;
+	ssize_t ret;
+
+	/* only allow one read, of 136 bytes, from position 0 */
+	if (*ppos != 0)
+		return 0;
+
+	if (len < 136)
+		return -EINVAL;
+
+	if (!rwtm->last_sig_done)
+		return -ENODATA;
+
+	/* 2 arrays of 17 32-bit words are 136 bytes */
+	ret = simple_read_from_buffer(buf, len, ppos, rwtm->last_sig, 136);
+	rwtm->last_sig_done = 0;
+
+	return ret;
+}
+
+static ssize_t do_sign_write(struct file *file, const char __user *buf,
+			     size_t len, loff_t *ppos)
+{
+	struct mox_rwtm *rwtm = file->private_data;
+	struct armada_37xx_rwtm_rx_msg *reply = &rwtm->reply;
+	struct armada_37xx_rwtm_tx_msg msg;
+	loff_t dummy = 0;
+	ssize_t ret;
+
+	/* the input is a SHA-512 hash, so exactly 64 bytes have to be read */
+	if (len != 64)
+		return -EINVAL;
+
+	/* if last result is not zero user has not read that information yet */
+	if (rwtm->last_sig_done)
+		return -EBUSY;
+
+	if (!mutex_trylock(&rwtm->busy))
+		return -EBUSY;
+
+	/*
+	 * Here we have to send:
+	 *   1. Address of the input to sign.
+	 *      The input is an array of 17 32-bit words, the first (most
+	 *      significat) is 0, the rest 16 words are copied from the SHA-512
+	 *      hash given by the user and converted from BE to LE.
+	 *   2. Address of the buffer where ECDSA signature value R shall be
+	 *      stored by the rWTM firmware.
+	 *   3. Address of the buffer where ECDSA signature value S shall be
+	 *      stored by the rWTM firmware.
+	 */
+	memset(rwtm->buf, 0, 4);
+	ret = simple_write_to_buffer(rwtm->buf + 4, 64, &dummy, buf, len);
+	if (ret < 0)
+		goto unlock_mutex;
+	be32_to_cpu_array(rwtm->buf, rwtm->buf, 17);
+
+	msg.command = MBOX_CMD_SIGN;
+	msg.args[0] = 1;
+	msg.args[1] = rwtm->buf_phys;
+	msg.args[2] = rwtm->buf_phys + 68;
+	msg.args[3] = rwtm->buf_phys + 2 * 68;
+	ret = mbox_send_message(rwtm->mbox, &msg);
+	if (ret < 0)
+		goto unlock_mutex;
+
+	ret = wait_for_completion_interruptible(&rwtm->cmd_done);
+	if (ret < 0)
+		goto unlock_mutex;
+
+	ret = MBOX_STS_VALUE(reply->retval);
+	if (MBOX_STS_ERROR(reply->retval) != MBOX_STS_SUCCESS)
+		goto unlock_mutex;
+
+	/*
+	 * Here we read the R and S values of the ECDSA signature
+	 * computed by the rWTM firmware and convert their words from
+	 * LE to BE.
+	 */
+	memcpy(rwtm->last_sig, rwtm->buf + 68, 136);
+	cpu_to_be32_array(rwtm->last_sig, rwtm->last_sig, 34);
+	rwtm->last_sig_done = 1;
+
+	mutex_unlock(&rwtm->busy);
+	return len;
+unlock_mutex:
+	mutex_unlock(&rwtm->busy);
+	return ret;
+}
+
+static const struct file_operations do_sign_fops = {
+	.owner	= THIS_MODULE,
+	.open	= rwtm_debug_open,
+	.read	= do_sign_read,
+	.write	= do_sign_write,
+	.llseek	= no_llseek,
+};
+
+static int rwtm_register_debugfs(struct mox_rwtm *rwtm)
+{
+	struct dentry *root, *entry;
+
+	root = debugfs_create_dir("turris-mox-rwtm", NULL);
+
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	entry = debugfs_create_file_unsafe("do_sign", 0600, root, rwtm,
+					   &do_sign_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	rwtm->debugfs_root = root;
+
+	return 0;
+err_remove:
+	debugfs_remove_recursive(root);
+	return PTR_ERR(entry);
+}
+
+static void rwtm_unregister_debugfs(struct mox_rwtm *rwtm)
+{
+	debugfs_remove_recursive(rwtm->debugfs_root);
+}
+#else
+static inline int rwtm_register_debugfs(struct mox_rwtm *rwtm)
+{
+	return 0;
+}
+
+static inline void rwtm_unregister_debugfs(struct mox_rwtm *rwtm)
+{
+}
+#endif
+
 static int turris_mox_rwtm_probe(struct platform_device *pdev)
 {
 	struct mox_rwtm *rwtm;
@@ -340,6 +499,12 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev)
 		goto free_channel;
 	}
 
+	ret = rwtm_register_debugfs(rwtm);
+	if (ret < 0) {
+		dev_err(dev, "Failed creating debugfs entries: %i\n", ret);
+		goto free_channel;
+	}
+
 	return 0;
 
 free_channel:
@@ -355,6 +520,7 @@ static int turris_mox_rwtm_remove(struct platform_device *pdev)
 {
 	struct mox_rwtm *rwtm = platform_get_drvdata(pdev);
 
+	rwtm_unregister_debugfs(rwtm);
 	sysfs_remove_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs);
 	kobject_put(rwtm_to_kobj(rwtm));
 	mbox_free_channel(rwtm->mbox);