Merge tag 'tegra-for-4.10-mailbox' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/drivers

mailbox: Add Tegra HSP driver

This contains the device tree bindings and a driver for the Tegra HSP, a
hardware block that provides hardware synchronization primitives and is
the foundation for inter-processor communication between CPU and BPMP.

* tag 'tegra-for-4.10-mailbox' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  mailbox: tegra-hsp: Use after free in tegra_hsp_remove_doorbells()
  mailbox: Add Tegra HSP driver
  dt-bindings: mailbox: Add Tegra HSP binding
  soc/tegra: Add Tegra186 support

Signed-off-by: Olof Johansson <olof@lixom.net>

6 files changed, 580 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mailbox/nvidia,tegra186-hsp.txt b/Documentation/devicetree/bindings/mailbox/nvidia,tegra186-hsp.txt
new file mode 100644
index 000000000000..b99d25fc2f26
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/nvidia,tegra186-hsp.txt
@@ -0,0 +1,52 @@
+NVIDIA Tegra Hardware Synchronization Primitives (HSP)
+
+The HSP modules are used for the processors to share resources and communicate
+together. It provides a set of hardware synchronization primitives for
+interprocessor communication. So the interprocessor communication (IPC)
+protocols can use hardware synchronization primitives, when operating between
+two processors not in an SMP relationship.
+
+The features that HSP supported are shared mailboxes, shared semaphores,
+arbitrated semaphores and doorbells.
+
+Required properties:
+- name : Should be hsp
+- compatible
+    Array of strings.
+    one of:
+    - "nvidia,tegra186-hsp"
+- reg : Offset and length of the register set for the device.
+- interrupt-names
+    Array of strings.
+    Contains a list of names for the interrupts described by the interrupt
+    property. May contain the following entries, in any order:
+    - "doorbell"
+    Users of this binding MUST look up entries in the interrupt property
+    by name, using this interrupt-names property to do so.
+- interrupts
+    Array of interrupt specifiers.
+    Must contain one entry per entry in the interrupt-names property,
+    in a matching order.
+- #mbox-cells : Should be 2.
+
+The mbox specifier of the "mboxes" property in the client node should
+contain two data. The first one should be the HSP type and the second
+one should be the ID that the client is going to use. Those information
+can be found in the following file.
+
+- <dt-bindings/mailbox/tegra186-hsp.h>.
+
+Example:
+
+hsp_top0: hsp@3c00000 {
+	compatible = "nvidia,tegra186-hsp";
+	reg = <0x0 0x03c00000 0x0 0xa0000>;
+	interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
+	interrupt-names = "doorbell";
+	#mbox-cells = <2>;
+};
+
+client {
+	...
+	mboxes = <&hsp_top0 TEGRA_HSP_MBOX_TYPE_DB TEGRA_HSP_DB_MASTER_XXX>;
+};
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 11eebfe8a4cb..ceff415f201c 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -124,6 +124,15 @@ config MAILBOX_TEST
 	  Test client to help with testing new Controller driver
 	  implementations.
 
+config TEGRA_HSP_MBOX
+	bool "Tegra HSP (Hardware Synchronization Primitives) Driver"
+	depends on ARCH_TEGRA_186_SOC
+	help
+	  The Tegra HSP driver is used for the interprocessor communication
+	  between different remote processors and host processors on Tegra186
+	  and later SoCs. Say Y here if you want to have this support.
+	  If unsure say N.
+
 config XGENE_SLIMPRO_MBOX
 	tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
 	depends on ARCH_XGENE
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index ace6fed8fea9..7dde4f609ae8 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -29,3 +29,5 @@ obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
 obj-$(CONFIG_HI6220_MBOX)	+= hi6220-mailbox.o
 
 obj-$(CONFIG_BCM_PDC_MBOX)	+= bcm-pdc-mailbox.o
+
+obj-$(CONFIG_TEGRA_HSP_MBOX)	+= tegra-hsp.o
diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
new file mode 100644
index 000000000000..0cde356c11ab
--- /dev/null
+++ b/drivers/mailbox/tegra-hsp.c
@@ -0,0 +1,479 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/mailbox/tegra186-hsp.h>
+
+#define HSP_INT_DIMENSIONING	0x380
+#define HSP_nSM_SHIFT		0
+#define HSP_nSS_SHIFT		4
+#define HSP_nAS_SHIFT		8
+#define HSP_nDB_SHIFT		12
+#define HSP_nSI_SHIFT		16
+#define HSP_nINT_MASK		0xf
+
+#define HSP_DB_TRIGGER	0x0
+#define HSP_DB_ENABLE	0x4
+#define HSP_DB_RAW	0x8
+#define HSP_DB_PENDING	0xc
+
+#define HSP_DB_CCPLEX		1
+#define HSP_DB_BPMP		3
+#define HSP_DB_MAX		7
+
+struct tegra_hsp_channel;
+struct tegra_hsp;
+
+struct tegra_hsp_channel {
+	struct tegra_hsp *hsp;
+	struct mbox_chan *chan;
+	void __iomem *regs;
+};
+
+struct tegra_hsp_doorbell {
+	struct tegra_hsp_channel channel;
+	struct list_head list;
+	const char *name;
+	unsigned int master;
+	unsigned int index;
+};
+
+struct tegra_hsp_db_map {
+	const char *name;
+	unsigned int master;
+	unsigned int index;
+};
+
+struct tegra_hsp_soc {
+	const struct tegra_hsp_db_map *map;
+};
+
+struct tegra_hsp {
+	const struct tegra_hsp_soc *soc;
+	struct mbox_controller mbox;
+	void __iomem *regs;
+	unsigned int irq;
+	unsigned int num_sm;
+	unsigned int num_as;
+	unsigned int num_ss;
+	unsigned int num_db;
+	unsigned int num_si;
+	spinlock_t lock;
+
+	struct list_head doorbells;
+};
+
+static inline struct tegra_hsp *
+to_tegra_hsp(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct tegra_hsp, mbox);
+}
+
+static inline u32 tegra_hsp_readl(struct tegra_hsp *hsp, unsigned int offset)
+{
+	return readl(hsp->regs + offset);
+}
+
+static inline void tegra_hsp_writel(struct tegra_hsp *hsp, u32 value,
+				    unsigned int offset)
+{
+	writel(value, hsp->regs + offset);
+}
+
+static inline u32 tegra_hsp_channel_readl(struct tegra_hsp_channel *channel,
+					  unsigned int offset)
+{
+	return readl(channel->regs + offset);
+}
+
+static inline void tegra_hsp_channel_writel(struct tegra_hsp_channel *channel,
+					    u32 value, unsigned int offset)
+{
+	writel(value, channel->regs + offset);
+}
+
+static bool tegra_hsp_doorbell_can_ring(struct tegra_hsp_doorbell *db)
+{
+	u32 value;
+
+	value = tegra_hsp_channel_readl(&db->channel, HSP_DB_ENABLE);
+
+	return (value & BIT(TEGRA_HSP_DB_MASTER_CCPLEX)) != 0;
+}
+
+static struct tegra_hsp_doorbell *
+__tegra_hsp_doorbell_get(struct tegra_hsp *hsp, unsigned int master)
+{
+	struct tegra_hsp_doorbell *entry;
+
+	list_for_each_entry(entry, &hsp->doorbells, list)
+		if (entry->master == master)
+			return entry;
+
+	return NULL;
+}
+
+static struct tegra_hsp_doorbell *
+tegra_hsp_doorbell_get(struct tegra_hsp *hsp, unsigned int master)
+{
+	struct tegra_hsp_doorbell *db;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+	db = __tegra_hsp_doorbell_get(hsp, master);
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return db;
+}
+
+static irqreturn_t tegra_hsp_doorbell_irq(int irq, void *data)
+{
+	struct tegra_hsp *hsp = data;
+	struct tegra_hsp_doorbell *db;
+	unsigned long master, value;
+
+	db = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+	if (!db)
+		return IRQ_NONE;
+
+	value = tegra_hsp_channel_readl(&db->channel, HSP_DB_PENDING);
+	tegra_hsp_channel_writel(&db->channel, value, HSP_DB_PENDING);
+
+	spin_lock(&hsp->lock);
+
+	for_each_set_bit(master, &value, hsp->mbox.num_chans) {
+		struct tegra_hsp_doorbell *db;
+
+		db = __tegra_hsp_doorbell_get(hsp, master);
+		/*
+		 * Depending on the bootloader chain, the CCPLEX doorbell will
+		 * have some doorbells enabled, which means that requesting an
+		 * interrupt will immediately fire.
+		 *
+		 * In that case, db->channel.chan will still be NULL here and
+		 * cause a crash if not properly guarded.
+		 *
+		 * It remains to be seen if ignoring the doorbell in that case
+		 * is the correct solution.
+		 */
+		if (db && db->channel.chan)
+			mbox_chan_received_data(db->channel.chan, NULL);
+	}
+
+	spin_unlock(&hsp->lock);
+
+	return IRQ_HANDLED;
+}
+
+static struct tegra_hsp_channel *
+tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name,
+			  unsigned int master, unsigned int index)
+{
+	struct tegra_hsp_doorbell *db;
+	unsigned int offset;
+	unsigned long flags;
+
+	db = kzalloc(sizeof(*db), GFP_KERNEL);
+	if (!db)
+		return ERR_PTR(-ENOMEM);
+
+	offset = (1 + (hsp->num_sm / 2) + hsp->num_ss + hsp->num_as) << 16;
+	offset += index * 0x100;
+
+	db->channel.regs = hsp->regs + offset;
+	db->channel.hsp = hsp;
+
+	db->name = kstrdup_const(name, GFP_KERNEL);
+	db->master = master;
+	db->index = index;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+	list_add_tail(&db->list, &hsp->doorbells);
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return &db->channel;
+}
+
+static void __tegra_hsp_doorbell_destroy(struct tegra_hsp_doorbell *db)
+{
+	list_del(&db->list);
+	kfree_const(db->name);
+	kfree(db);
+}
+
+static int tegra_hsp_doorbell_send_data(struct mbox_chan *chan, void *data)
+{
+	struct tegra_hsp_doorbell *db = chan->con_priv;
+
+	tegra_hsp_channel_writel(&db->channel, 1, HSP_DB_TRIGGER);
+
+	return 0;
+}
+
+static int tegra_hsp_doorbell_startup(struct mbox_chan *chan)
+{
+	struct tegra_hsp_doorbell *db = chan->con_priv;
+	struct tegra_hsp *hsp = db->channel.hsp;
+	struct tegra_hsp_doorbell *ccplex;
+	unsigned long flags;
+	u32 value;
+
+	if (db->master >= hsp->mbox.num_chans) {
+		dev_err(hsp->mbox.dev,
+			"invalid master ID %u for HSP channel\n",
+			db->master);
+		return -EINVAL;
+	}
+
+	ccplex = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+	if (!ccplex)
+		return -ENODEV;
+
+	if (!tegra_hsp_doorbell_can_ring(db))
+		return -ENODEV;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	value = tegra_hsp_channel_readl(&ccplex->channel, HSP_DB_ENABLE);
+	value |= BIT(db->master);
+	tegra_hsp_channel_writel(&ccplex->channel, value, HSP_DB_ENABLE);
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return 0;
+}
+
+static void tegra_hsp_doorbell_shutdown(struct mbox_chan *chan)
+{
+	struct tegra_hsp_doorbell *db = chan->con_priv;
+	struct tegra_hsp *hsp = db->channel.hsp;
+	struct tegra_hsp_doorbell *ccplex;
+	unsigned long flags;
+	u32 value;
+
+	ccplex = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+	if (!ccplex)
+		return;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	value = tegra_hsp_channel_readl(&ccplex->channel, HSP_DB_ENABLE);
+	value &= ~BIT(db->master);
+	tegra_hsp_channel_writel(&ccplex->channel, value, HSP_DB_ENABLE);
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+}
+
+static const struct mbox_chan_ops tegra_hsp_doorbell_ops = {
+	.send_data = tegra_hsp_doorbell_send_data,
+	.startup = tegra_hsp_doorbell_startup,
+	.shutdown = tegra_hsp_doorbell_shutdown,
+};
+
+static struct mbox_chan *of_tegra_hsp_xlate(struct mbox_controller *mbox,
+					    const struct of_phandle_args *args)
+{
+	struct tegra_hsp_channel *channel = ERR_PTR(-ENODEV);
+	struct tegra_hsp *hsp = to_tegra_hsp(mbox);
+	unsigned int type = args->args[0];
+	unsigned int master = args->args[1];
+	struct tegra_hsp_doorbell *db;
+	struct mbox_chan *chan;
+	unsigned long flags;
+	unsigned int i;
+
+	switch (type) {
+	case TEGRA_HSP_MBOX_TYPE_DB:
+		db = tegra_hsp_doorbell_get(hsp, master);
+		if (db)
+			channel = &db->channel;
+
+		break;
+
+	default:
+		break;
+	}
+
+	if (IS_ERR(channel))
+		return ERR_CAST(channel);
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	for (i = 0; i < hsp->mbox.num_chans; i++) {
+		chan = &hsp->mbox.chans[i];
+		if (!chan->con_priv) {
+			chan->con_priv = channel;
+			channel->chan = chan;
+			break;
+		}
+
+		chan = NULL;
+	}
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return chan ?: ERR_PTR(-EBUSY);
+}
+
+static void tegra_hsp_remove_doorbells(struct tegra_hsp *hsp)
+{
+	struct tegra_hsp_doorbell *db, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	list_for_each_entry_safe(db, tmp, &hsp->doorbells, list)
+		__tegra_hsp_doorbell_destroy(db);
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+}
+
+static int tegra_hsp_add_doorbells(struct tegra_hsp *hsp)
+{
+	const struct tegra_hsp_db_map *map = hsp->soc->map;
+	struct tegra_hsp_channel *channel;
+
+	while (map->name) {
+		channel = tegra_hsp_doorbell_create(hsp, map->name,
+						    map->master, map->index);
+		if (IS_ERR(channel)) {
+			tegra_hsp_remove_doorbells(hsp);
+			return PTR_ERR(channel);
+		}
+
+		map++;
+	}
+
+	return 0;
+}
+
+static int tegra_hsp_probe(struct platform_device *pdev)
+{
+	struct tegra_hsp *hsp;
+	struct resource *res;
+	u32 value;
+	int err;
+
+	hsp = devm_kzalloc(&pdev->dev, sizeof(*hsp), GFP_KERNEL);
+	if (!hsp)
+		return -ENOMEM;
+
+	hsp->soc = of_device_get_match_data(&pdev->dev);
+	INIT_LIST_HEAD(&hsp->doorbells);
+	spin_lock_init(&hsp->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	hsp->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(hsp->regs))
+		return PTR_ERR(hsp->regs);
+
+	value = tegra_hsp_readl(hsp, HSP_INT_DIMENSIONING);
+	hsp->num_sm = (value >> HSP_nSM_SHIFT) & HSP_nINT_MASK;
+	hsp->num_ss = (value >> HSP_nSS_SHIFT) & HSP_nINT_MASK;
+	hsp->num_as = (value >> HSP_nAS_SHIFT) & HSP_nINT_MASK;
+	hsp->num_db = (value >> HSP_nDB_SHIFT) & HSP_nINT_MASK;
+	hsp->num_si = (value >> HSP_nSI_SHIFT) & HSP_nINT_MASK;
+
+	err = platform_get_irq_byname(pdev, "doorbell");
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to get doorbell IRQ: %d\n", err);
+		return err;
+	}
+
+	hsp->irq = err;
+
+	hsp->mbox.of_xlate = of_tegra_hsp_xlate;
+	hsp->mbox.num_chans = 32;
+	hsp->mbox.dev = &pdev->dev;
+	hsp->mbox.txdone_irq = false;
+	hsp->mbox.txdone_poll = false;
+	hsp->mbox.ops = &tegra_hsp_doorbell_ops;
+
+	hsp->mbox.chans = devm_kcalloc(&pdev->dev, hsp->mbox.num_chans,
+					sizeof(*hsp->mbox.chans),
+					GFP_KERNEL);
+	if (!hsp->mbox.chans)
+		return -ENOMEM;
+
+	err = tegra_hsp_add_doorbells(hsp);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to add doorbells: %d\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, hsp);
+
+	err = mbox_controller_register(&hsp->mbox);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register mailbox: %d\n", err);
+		tegra_hsp_remove_doorbells(hsp);
+		return err;
+	}
+
+	err = devm_request_irq(&pdev->dev, hsp->irq, tegra_hsp_doorbell_irq,
+			       IRQF_NO_SUSPEND, dev_name(&pdev->dev), hsp);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to request IRQ#%u: %d\n",
+			hsp->irq, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int tegra_hsp_remove(struct platform_device *pdev)
+{
+	struct tegra_hsp *hsp = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&hsp->mbox);
+	tegra_hsp_remove_doorbells(hsp);
+
+	return 0;
+}
+
+static const struct tegra_hsp_db_map tegra186_hsp_db_map[] = {
+	{ "ccplex", TEGRA_HSP_DB_MASTER_CCPLEX, HSP_DB_CCPLEX, },
+	{ "bpmp",   TEGRA_HSP_DB_MASTER_BPMP,   HSP_DB_BPMP,   },
+	{ /* sentinel */ }
+};
+
+static const struct tegra_hsp_soc tegra186_hsp_soc = {
+	.map = tegra186_hsp_db_map,
+};
+
+static const struct of_device_id tegra_hsp_match[] = {
+	{ .compatible = "nvidia,tegra186-hsp", .data = &tegra186_hsp_soc },
+	{ }
+};
+
+static struct platform_driver tegra_hsp_driver = {
+	.driver = {
+		.name = "tegra-hsp",
+		.of_match_table = tegra_hsp_match,
+	},
+	.probe = tegra_hsp_probe,
+	.remove = tegra_hsp_remove,
+};
+
+static int __init tegra_hsp_init(void)
+{
+	return platform_driver_register(&tegra_hsp_driver);
+}
+core_initcall(tegra_hsp_init);
diff --git a/drivers/soc/tegra/Kconfig b/drivers/soc/tegra/Kconfig
index 03089ad2fc65..e5e124c07066 100644
--- a/drivers/soc/tegra/Kconfig
+++ b/drivers/soc/tegra/Kconfig
@@ -77,5 +77,19 @@ config ARCH_TEGRA_210_SOC
 	  controllers, such as GPIO, I2C, SPI, SDHCI, PCIe, SATA and XHCI, to
 	  name only a few.
 
+config ARCH_TEGRA_186_SOC
+	bool "NVIDIA Tegra186 SoC"
+	select MAILBOX
+	select TEGRA_BPMP
+	select TEGRA_HSP_MBOX
+	select TEGRA_IVC
+	help
+	  Enable support for the NVIDIA Tegar186 SoC. The Tegra186 features a
+	  combination of Denver and Cortex-A57 CPU cores and a GPU based on
+	  the Pascal architecture. It contains an ADSP with a Cortex-A9 CPU
+	  used for audio processing, hardware video encoders/decoders with
+	  multi-format support, ISP for image capture processing and BPMP for
+	  power management.
+
 endif
 endif
diff --git a/include/dt-bindings/mailbox/tegra186-hsp.h b/include/dt-bindings/mailbox/tegra186-hsp.h
new file mode 100644
index 000000000000..f5d66e5f5f10
--- /dev/null
+++ b/include/dt-bindings/mailbox/tegra186-hsp.h
@@ -0,0 +1,24 @@
+/*
+ * This header provides constants for binding nvidia,tegra186-hsp.
+ */
+
+#ifndef _DT_BINDINGS_MAILBOX_TEGRA186_HSP_H
+#define _DT_BINDINGS_MAILBOX_TEGRA186_HSP_H
+
+/*
+ * These define the type of mailbox that is to be used (doorbell, shared
+ * mailbox, shared semaphore or arbitrated semaphore).
+ */
+#define TEGRA_HSP_MBOX_TYPE_DB 0x0
+#define TEGRA_HSP_MBOX_TYPE_SM 0x1
+#define TEGRA_HSP_MBOX_TYPE_SS 0x2
+#define TEGRA_HSP_MBOX_TYPE_AS 0x3
+
+/*
+ * These defines represent the bit associated with the given master ID in the
+ * doorbell registers.
+ */
+#define TEGRA_HSP_DB_MASTER_CCPLEX 17
+#define TEGRA_HSP_DB_MASTER_BPMP 19
+
+#endif