Merge tag 'riscv-for-linus-5.18-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:
 "This has a handful of new features:

   - Support for CURRENT_STACK_POINTER, which enables some extra stack
     debugging for HARDENED_USERCOPY.

   - Support for the new SBI CPU idle extension, via cpuidle and suspend
     drivers.

   - Profiling has been enabled in the defconfigs.

  but is mostly fixes and cleanups"

* tag 'riscv-for-linus-5.18-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
  RISC-V: K210 defconfigs: Drop redundant MEMBARRIER=n
  RISC-V: defconfig: Drop redundant SBI HVC and earlycon
  Documentation: riscv: remove non-existent directory from table of contents
  riscv: cpu.c: don't use kernel-doc markers for comments
  RISC-V: Enable profiling by default
  RISC-V: module: fix apply_r_riscv_rcv_branch_rela typo
  RISC-V: Declare per cpu boot data as static
  RISC-V: Fix a comment typo in riscv_of_parent_hartid()
  riscv: Increase stack size under KASAN
  riscv: Fix fill_callchain return value
  riscv: dts: canaan: Fix SPI3 bus width
  riscv: Rename "sp_in_global" to "current_stack_pointer"
  riscv module: remove (NOLOAD)
  RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine
  dt-bindings: Add common bindings for ARM and RISC-V idle states
  cpuidle: Add RISC-V SBI CPU idle driver
  cpuidle: Factor-out power domain related code from PSCI domain driver
  RISC-V: Add SBI HSM suspend related defines
  RISC-V: Add arch functions for non-retentive suspend entry/exit
  RISC-V: Rename relocate() and make it global
  ...

9 files changed, 903 insertions, 135 deletions

diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index c0aeedd66f02..ff71dd662880 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -47,6 +47,10 @@ config CPU_IDLE_GOV_HALTPOLL
 config DT_IDLE_STATES
 	bool
 
+config DT_IDLE_GENPD
+	depends on PM_GENERIC_DOMAINS_OF
+	bool
+
 menu "ARM CPU Idle Drivers"
 depends on ARM || ARM64
 source "drivers/cpuidle/Kconfig.arm"
@@ -62,6 +66,11 @@ depends on PPC
 source "drivers/cpuidle/Kconfig.powerpc"
 endmenu
 
+menu "RISC-V CPU Idle Drivers"
+depends on RISCV
+source "drivers/cpuidle/Kconfig.riscv"
+endmenu
+
 config HALTPOLL_CPUIDLE
 	tristate "Halt poll cpuidle driver"
 	depends on X86 && KVM_GUEST
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 15d6c46c0a47..be7f512109f7 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -27,6 +27,7 @@ config ARM_PSCI_CPUIDLE_DOMAIN
 	bool "PSCI CPU idle Domain"
 	depends on ARM_PSCI_CPUIDLE
 	depends on PM_GENERIC_DOMAINS_OF
+	select DT_IDLE_GENPD
 	default y
 	help
 	  Select this to enable the PSCI based CPUidle driver to use PM domains,
diff --git a/drivers/cpuidle/Kconfig.riscv b/drivers/cpuidle/Kconfig.riscv
new file mode 100644
index 000000000000..78518c26af74
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.riscv
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# RISC-V CPU Idle drivers
+#
+
+config RISCV_SBI_CPUIDLE
+	bool "RISC-V SBI CPU idle Driver"
+	depends on RISCV_SBI
+	select DT_IDLE_STATES
+	select CPU_IDLE_MULTIPLE_DRIVERS
+	select DT_IDLE_GENPD if PM_GENERIC_DOMAINS_OF
+	help
+	  Select this option to enable RISC-V SBI firmware based CPU idle
+	  driver for RISC-V systems. This drivers also supports hierarchical
+	  DT based layout of the idle state.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 26bbc5e74123..d103342b7cfc 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -6,6 +6,7 @@
 obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
 obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
 obj-$(CONFIG_DT_IDLE_STATES)		  += dt_idle_states.o
+obj-$(CONFIG_DT_IDLE_GENPD)		  += dt_idle_genpd.o
 obj-$(CONFIG_ARCH_HAS_CPU_RELAX)	  += poll_state.o
 obj-$(CONFIG_HALTPOLL_CPUIDLE)		  += cpuidle-haltpoll.o
 
@@ -34,3 +35,7 @@ obj-$(CONFIG_MIPS_CPS_CPUIDLE)		+= cpuidle-cps.o
 # POWERPC drivers
 obj-$(CONFIG_PSERIES_CPUIDLE)		+= cpuidle-pseries.o
 obj-$(CONFIG_POWERNV_CPUIDLE)		+= cpuidle-powernv.o
+
+###############################################################################
+# RISC-V drivers
+obj-$(CONFIG_RISCV_SBI_CPUIDLE)		+= cpuidle-riscv-sbi.o
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
index ff2c3f8e4668..755bbdfc5b82 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -47,73 +47,14 @@ static int psci_pd_power_off(struct generic_pm_domain *pd)
 	return 0;
 }
 
-static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
-				     int state_count)
-{
-	int i, ret;
-	u32 psci_state, *psci_state_buf;
-
-	for (i = 0; i < state_count; i++) {
-		ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
-					&psci_state);
-		if (ret)
-			goto free_state;
-
-		psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
-		if (!psci_state_buf) {
-			ret = -ENOMEM;
-			goto free_state;
-		}
-		*psci_state_buf = psci_state;
-		states[i].data = psci_state_buf;
-	}
-
-	return 0;
-
-free_state:
-	i--;
-	for (; i >= 0; i--)
-		kfree(states[i].data);
-	return ret;
-}
-
-static int psci_pd_parse_states(struct device_node *np,
-			struct genpd_power_state **states, int *state_count)
-{
-	int ret;
-
-	/* Parse the domain idle states. */
-	ret = of_genpd_parse_idle_states(np, states, state_count);
-	if (ret)
-		return ret;
-
-	/* Fill out the PSCI specifics for each found state. */
-	ret = psci_pd_parse_state_nodes(*states, *state_count);
-	if (ret)
-		kfree(*states);
-
-	return ret;
-}
-
-static void psci_pd_free_states(struct genpd_power_state *states,
-				unsigned int state_count)
-{
-	int i;
-
-	for (i = 0; i < state_count; i++)
-		kfree(states[i].data);
-	kfree(states);
-}
-
 static int psci_pd_init(struct device_node *np, bool use_osi)
 {
 	struct generic_pm_domain *pd;
 	struct psci_pd_provider *pd_provider;
 	struct dev_power_governor *pd_gov;
-	struct genpd_power_state *states = NULL;
 	int ret = -ENOMEM, state_count = 0;
 
-	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+	pd = dt_idle_pd_alloc(np, psci_dt_parse_state_node);
 	if (!pd)
 		goto out;
 
@@ -121,22 +62,6 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 	if (!pd_provider)
 		goto free_pd;
 
-	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
-	if (!pd->name)
-		goto free_pd_prov;
-
-	/*
-	 * Parse the domain idle states and let genpd manage the state selection
-	 * for those being compatible with "domain-idle-state".
-	 */
-	ret = psci_pd_parse_states(np, &states, &state_count);
-	if (ret)
-		goto free_name;
-
-	pd->free_states = psci_pd_free_states;
-	pd->name = kbasename(pd->name);
-	pd->states = states;
-	pd->state_count = state_count;
 	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
 
 	/* Allow power off when OSI has been successfully enabled. */
@@ -149,10 +74,8 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
 
 	ret = pm_genpd_init(pd, pd_gov, false);
-	if (ret) {
-		psci_pd_free_states(states, state_count);
-		goto free_name;
-	}
+	if (ret)
+		goto free_pd_prov;
 
 	ret = of_genpd_add_provider_simple(np, pd);
 	if (ret)
@@ -166,12 +89,10 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 
 remove_pd:
 	pm_genpd_remove(pd);
-free_name:
-	kfree(pd->name);
 free_pd_prov:
 	kfree(pd_provider);
 free_pd:
-	kfree(pd);
+	dt_idle_pd_free(pd);
 out:
 	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
 	return ret;
@@ -195,30 +116,6 @@ static void psci_pd_remove(void)
 	}
 }
 
-static int psci_pd_init_topology(struct device_node *np)
-{
-	struct device_node *node;
-	struct of_phandle_args child, parent;
-	int ret;
-
-	for_each_child_of_node(np, node) {
-		if (of_parse_phandle_with_args(node, "power-domains",
-					"#power-domain-cells", 0, &parent))
-			continue;
-
-		child.np = node;
-		child.args_count = 0;
-		ret = of_genpd_add_subdomain(&parent, &child);
-		of_node_put(parent.np);
-		if (ret) {
-			of_node_put(node);
-			return ret;
-		}
-	}
-
-	return 0;
-}
-
 static bool psci_pd_try_set_osi_mode(void)
 {
 	int ret;
@@ -282,7 +179,7 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 		goto no_pd;
 
 	/* Link genpd masters/subdomains to model the CPU topology. */
-	ret = psci_pd_init_topology(np);
+	ret = dt_idle_pd_init_topology(np);
 	if (ret)
 		goto remove_pd;
 
@@ -314,28 +211,3 @@ static int __init psci_idle_init_domains(void)
 	return platform_driver_register(&psci_cpuidle_domain_driver);
 }
 subsys_initcall(psci_idle_init_domains);
-
-struct device *psci_dt_attach_cpu(int cpu)
-{
-	struct device *dev;
-
-	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
-	if (IS_ERR_OR_NULL(dev))
-		return dev;
-
-	pm_runtime_irq_safe(dev);
-	if (cpu_online(cpu))
-		pm_runtime_get_sync(dev);
-
-	dev_pm_syscore_device(dev, true);
-
-	return dev;
-}
-
-void psci_dt_detach_cpu(struct device *dev)
-{
-	if (IS_ERR_OR_NULL(dev))
-		return;
-
-	dev_pm_domain_detach(dev, false);
-}
diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h
index d8e925e84c27..4e132640ed64 100644
--- a/drivers/cpuidle/cpuidle-psci.h
+++ b/drivers/cpuidle/cpuidle-psci.h
@@ -10,8 +10,19 @@ void psci_set_domain_state(u32 state);
 int psci_dt_parse_state_node(struct device_node *np, u32 *state);
 
 #ifdef CONFIG_ARM_PSCI_CPUIDLE_DOMAIN
-struct device *psci_dt_attach_cpu(int cpu);
-void psci_dt_detach_cpu(struct device *dev);
+
+#include "dt_idle_genpd.h"
+
+static inline struct device *psci_dt_attach_cpu(int cpu)
+{
+	return dt_idle_attach_cpu(cpu, "psci");
+}
+
+static inline void psci_dt_detach_cpu(struct device *dev)
+{
+	dt_idle_detach_cpu(dev);
+}
+
 #else
 static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; }
 static inline void psci_dt_detach_cpu(struct device *dev) { }
diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c
new file mode 100644
index 000000000000..b459eda2cd37
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -0,0 +1,627 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RISC-V SBI CPU idle driver.
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "cpuidle-riscv-sbi: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/cpu_cooling.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <asm/cpuidle.h>
+#include <asm/sbi.h>
+#include <asm/suspend.h>
+
+#include "dt_idle_states.h"
+#include "dt_idle_genpd.h"
+
+struct sbi_cpuidle_data {
+	u32 *states;
+	struct device *dev;
+};
+
+struct sbi_domain_state {
+	bool available;
+	u32 state;
+};
+
+static DEFINE_PER_CPU_READ_MOSTLY(struct sbi_cpuidle_data, sbi_cpuidle_data);
+static DEFINE_PER_CPU(struct sbi_domain_state, domain_state);
+static bool sbi_cpuidle_use_osi;
+static bool sbi_cpuidle_use_cpuhp;
+static bool sbi_cpuidle_pd_allow_domain_state;
+
+static inline void sbi_set_domain_state(u32 state)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	data->available = true;
+	data->state = state;
+}
+
+static inline u32 sbi_get_domain_state(void)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	return data->state;
+}
+
+static inline void sbi_clear_domain_state(void)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	data->available = false;
+}
+
+static inline bool sbi_is_domain_state_available(void)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	return data->available;
+}
+
+static int sbi_suspend_finisher(unsigned long suspend_type,
+				unsigned long resume_addr,
+				unsigned long opaque)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND,
+			suspend_type, resume_addr, opaque, 0, 0, 0);
+
+	return (ret.error) ? sbi_err_map_linux_errno(ret.error) : 0;
+}
+
+static int sbi_suspend(u32 state)
+{
+	if (state & SBI_HSM_SUSP_NON_RET_BIT)
+		return cpu_suspend(state, sbi_suspend_finisher);
+	else
+		return sbi_suspend_finisher(state, 0, 0);
+}
+
+static int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
+				   struct cpuidle_driver *drv, int idx)
+{
+	u32 *states = __this_cpu_read(sbi_cpuidle_data.states);
+
+	return CPU_PM_CPU_IDLE_ENTER_PARAM(sbi_suspend, idx, states[idx]);
+}
+
+static int __sbi_enter_domain_idle_state(struct cpuidle_device *dev,
+					  struct cpuidle_driver *drv, int idx,
+					  bool s2idle)
+{
+	struct sbi_cpuidle_data *data = this_cpu_ptr(&sbi_cpuidle_data);
+	u32 *states = data->states;
+	struct device *pd_dev = data->dev;
+	u32 state;
+	int ret;
+
+	ret = cpu_pm_enter();
+	if (ret)
+		return -1;
+
+	/* Do runtime PM to manage a hierarchical CPU toplogy. */
+	rcu_irq_enter_irqson();
+	if (s2idle)
+		dev_pm_genpd_suspend(pd_dev);
+	else
+		pm_runtime_put_sync_suspend(pd_dev);
+	rcu_irq_exit_irqson();
+
+	if (sbi_is_domain_state_available())
+		state = sbi_get_domain_state();
+	else
+		state = states[idx];
+
+	ret = sbi_suspend(state) ? -1 : idx;
+
+	rcu_irq_enter_irqson();
+	if (s2idle)
+		dev_pm_genpd_resume(pd_dev);
+	else
+		pm_runtime_get_sync(pd_dev);
+	rcu_irq_exit_irqson();
+
+	cpu_pm_exit();
+
+	/* Clear the domain state to start fresh when back from idle. */
+	sbi_clear_domain_state();
+	return ret;
+}
+
+static int sbi_enter_domain_idle_state(struct cpuidle_device *dev,
+				       struct cpuidle_driver *drv, int idx)
+{
+	return __sbi_enter_domain_idle_state(dev, drv, idx, false);
+}
+
+static int sbi_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
+					      struct cpuidle_driver *drv,
+					      int idx)
+{
+	return __sbi_enter_domain_idle_state(dev, drv, idx, true);
+}
+
+static int sbi_cpuidle_cpuhp_up(unsigned int cpu)
+{
+	struct device *pd_dev = __this_cpu_read(sbi_cpuidle_data.dev);
+
+	if (pd_dev)
+		pm_runtime_get_sync(pd_dev);
+
+	return 0;
+}
+
+static int sbi_cpuidle_cpuhp_down(unsigned int cpu)
+{
+	struct device *pd_dev = __this_cpu_read(sbi_cpuidle_data.dev);
+
+	if (pd_dev) {
+		pm_runtime_put_sync(pd_dev);
+		/* Clear domain state to start fresh at next online. */
+		sbi_clear_domain_state();
+	}
+
+	return 0;
+}
+
+static void sbi_idle_init_cpuhp(void)
+{
+	int err;
+
+	if (!sbi_cpuidle_use_cpuhp)
+		return;
+
+	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
+					"cpuidle/sbi:online",
+					sbi_cpuidle_cpuhp_up,
+					sbi_cpuidle_cpuhp_down);
+	if (err)
+		pr_warn("Failed %d while setup cpuhp state\n", err);
+}
+
+static const struct of_device_id sbi_cpuidle_state_match[] = {
+	{ .compatible = "riscv,idle-state",
+	  .data = sbi_cpuidle_enter_state },
+	{ },
+};
+
+static bool sbi_suspend_state_is_valid(u32 state)
+{
+	if (state > SBI_HSM_SUSPEND_RET_DEFAULT &&
+	    state < SBI_HSM_SUSPEND_RET_PLATFORM)
+		return false;
+	if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT &&
+	    state < SBI_HSM_SUSPEND_NON_RET_PLATFORM)
+		return false;
+	return true;
+}
+
+static int sbi_dt_parse_state_node(struct device_node *np, u32 *state)
+{
+	int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state);
+
+	if (err) {
+		pr_warn("%pOF missing riscv,sbi-suspend-param property\n", np);
+		return err;
+	}
+
+	if (!sbi_suspend_state_is_valid(*state)) {
+		pr_warn("Invalid SBI suspend state %#x\n", *state);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sbi_dt_cpu_init_topology(struct cpuidle_driver *drv,
+				     struct sbi_cpuidle_data *data,
+				     unsigned int state_count, int cpu)
+{
+	/* Currently limit the hierarchical topology to be used in OSI mode. */
+	if (!sbi_cpuidle_use_osi)
+		return 0;
+
+	data->dev = dt_idle_attach_cpu(cpu, "sbi");
+	if (IS_ERR_OR_NULL(data->dev))
+		return PTR_ERR_OR_ZERO(data->dev);
+
+	/*
+	 * Using the deepest state for the CPU to trigger a potential selection
+	 * of a shared state for the domain, assumes the domain states are all
+	 * deeper states.
+	 */
+	drv->states[state_count - 1].enter = sbi_enter_domain_idle_state;
+	drv->states[state_count - 1].enter_s2idle =
+					sbi_enter_s2idle_domain_idle_state;
+	sbi_cpuidle_use_cpuhp = true;
+
+	return 0;
+}
+
+static int sbi_cpuidle_dt_init_states(struct device *dev,
+					struct cpuidle_driver *drv,
+					unsigned int cpu,
+					unsigned int state_count)
+{
+	struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu);
+	struct device_node *state_node;
+	struct device_node *cpu_node;
+	u32 *states;
+	int i, ret;
+
+	cpu_node = of_cpu_device_node_get(cpu);
+	if (!cpu_node)
+		return -ENODEV;
+
+	states = devm_kcalloc(dev, state_count, sizeof(*states), GFP_KERNEL);
+	if (!states) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	/* Parse SBI specific details from state DT nodes */
+	for (i = 1; i < state_count; i++) {
+		state_node = of_get_cpu_state_node(cpu_node, i - 1);
+		if (!state_node)
+			break;
+
+		ret = sbi_dt_parse_state_node(state_node, &states[i]);
+		of_node_put(state_node);
+
+		if (ret)
+			return ret;
+
+		pr_debug("sbi-state %#x index %d\n", states[i], i);
+	}
+	if (i != state_count) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	/* Initialize optional data, used for the hierarchical topology. */
+	ret = sbi_dt_cpu_init_topology(drv, data, state_count, cpu);
+	if (ret < 0)
+		return ret;
+
+	/* Store states in the per-cpu struct. */
+	data->states = states;
+
+fail:
+	of_node_put(cpu_node);
+
+	return ret;
+}
+
+static void sbi_cpuidle_deinit_cpu(int cpu)
+{
+	struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu);
+
+	dt_idle_detach_cpu(data->dev);
+	sbi_cpuidle_use_cpuhp = false;
+}
+
+static int sbi_cpuidle_init_cpu(struct device *dev, int cpu)
+{
+	struct cpuidle_driver *drv;
+	unsigned int state_count = 0;
+	int ret = 0;
+
+	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
+	if (!drv)
+		return -ENOMEM;
+
+	drv->name = "sbi_cpuidle";
+	drv->owner = THIS_MODULE;
+	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+
+	/* RISC-V architectural WFI to be represented as state index 0. */
+	drv->states[0].enter = sbi_cpuidle_enter_state;
+	drv->states[0].exit_latency = 1;
+	drv->states[0].target_residency = 1;
+	drv->states[0].power_usage = UINT_MAX;
+	strcpy(drv->states[0].name, "WFI");
+	strcpy(drv->states[0].desc, "RISC-V WFI");
+
+	/*
+	 * If no DT idle states are detected (ret == 0) let the driver
+	 * initialization fail accordingly since there is no reason to
+	 * initialize the idle driver if only wfi is supported, the
+	 * default archictectural back-end already executes wfi
+	 * on idle entry.
+	 */
+	ret = dt_init_idle_driver(drv, sbi_cpuidle_state_match, 1);
+	if (ret <= 0) {
+		pr_debug("HART%ld: failed to parse DT idle states\n",
+			 cpuid_to_hartid_map(cpu));
+		return ret ? : -ENODEV;
+	}
+	state_count = ret + 1; /* Include WFI state as well */
+
+	/* Initialize idle states from DT. */
+	ret = sbi_cpuidle_dt_init_states(dev, drv, cpu, state_count);
+	if (ret) {
+		pr_err("HART%ld: failed to init idle states\n",
+		       cpuid_to_hartid_map(cpu));
+		return ret;
+	}
+
+	ret = cpuidle_register(drv, NULL);
+	if (ret)
+		goto deinit;
+
+	cpuidle_cooling_register(drv);
+
+	return 0;
+deinit:
+	sbi_cpuidle_deinit_cpu(cpu);
+	return ret;
+}
+
+static void sbi_cpuidle_domain_sync_state(struct device *dev)
+{
+	/*
+	 * All devices have now been attached/probed to the PM domain
+	 * topology, hence it's fine to allow domain states to be picked.
+	 */
+	sbi_cpuidle_pd_allow_domain_state = true;
+}
+
+#ifdef CONFIG_DT_IDLE_GENPD
+
+static int sbi_cpuidle_pd_power_off(struct generic_pm_domain *pd)
+{
+	struct genpd_power_state *state = &pd->states[pd->state_idx];
+	u32 *pd_state;
+
+	if (!state->data)
+		return 0;
+
+	if (!sbi_cpuidle_pd_allow_domain_state)
+		return -EBUSY;
+
+	/* OSI mode is enabled, set the corresponding domain state. */
+	pd_state = state->data;
+	sbi_set_domain_state(*pd_state);
+
+	return 0;
+}
+
+struct sbi_pd_provider {
+	struct list_head link;
+	struct device_node *node;
+};
+
+static LIST_HEAD(sbi_pd_providers);
+
+static int sbi_pd_init(struct device_node *np)
+{
+	struct generic_pm_domain *pd;
+	struct sbi_pd_provider *pd_provider;
+	struct dev_power_governor *pd_gov;
+	int ret = -ENOMEM, state_count = 0;
+
+	pd = dt_idle_pd_alloc(np, sbi_dt_parse_state_node);
+	if (!pd)
+		goto out;
+
+	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
+	if (!pd_provider)
+		goto free_pd;
+
+	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
+
+	/* Allow power off when OSI is available. */
+	if (sbi_cpuidle_use_osi)
+		pd->power_off = sbi_cpuidle_pd_power_off;
+	else
+		pd->flags |= GENPD_FLAG_ALWAYS_ON;
+
+	/* Use governor for CPU PM domains if it has some states to manage. */
+	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
+
+	ret = pm_genpd_init(pd, pd_gov, false);
+	if (ret)
+		goto free_pd_prov;
+
+	ret = of_genpd_add_provider_simple(np, pd);
+	if (ret)
+		goto remove_pd;
+
+	pd_provider->node = of_node_get(np);
+	list_add(&pd_provider->link, &sbi_pd_providers);
+
+	pr_debug("init PM domain %s\n", pd->name);
+	return 0;
+
+remove_pd:
+	pm_genpd_remove(pd);
+free_pd_prov:
+	kfree(pd_provider);
+free_pd:
+	dt_idle_pd_free(pd);
+out:
+	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
+	return ret;
+}
+
+static void sbi_pd_remove(void)
+{
+	struct sbi_pd_provider *pd_provider, *it;
+	struct generic_pm_domain *genpd;
+
+	list_for_each_entry_safe(pd_provider, it, &sbi_pd_providers, link) {
+		of_genpd_del_provider(pd_provider->node);
+
+		genpd = of_genpd_remove_last(pd_provider->node);
+		if (!IS_ERR(genpd))
+			kfree(genpd);
+
+		of_node_put(pd_provider->node);
+		list_del(&pd_provider->link);
+		kfree(pd_provider);
+	}
+}
+
+static int sbi_genpd_probe(struct device_node *np)
+{
+	struct device_node *node;
+	int ret = 0, pd_count = 0;
+
+	if (!np)
+		return -ENODEV;
+
+	/*
+	 * Parse child nodes for the "#power-domain-cells" property and
+	 * initialize a genpd/genpd-of-provider pair when it's found.
+	 */
+	for_each_child_of_node(np, node) {
+		if (!of_find_property(node, "#power-domain-cells", NULL))
+			continue;
+
+		ret = sbi_pd_init(node);
+		if (ret)
+			goto put_node;
+
+		pd_count++;
+	}
+
+	/* Bail out if not using the hierarchical CPU topology. */
+	if (!pd_count)
+		goto no_pd;
+
+	/* Link genpd masters/subdomains to model the CPU topology. */
+	ret = dt_idle_pd_init_topology(np);
+	if (ret)
+		goto remove_pd;
+
+	return 0;
+
+put_node:
+	of_node_put(node);
+remove_pd:
+	sbi_pd_remove();
+	pr_err("failed to create CPU PM domains ret=%d\n", ret);
+no_pd:
+	return ret;
+}
+
+#else
+
+static inline int sbi_genpd_probe(struct device_node *np)
+{
+	return 0;
+}
+
+#endif
+
+static int sbi_cpuidle_probe(struct platform_device *pdev)
+{
+	int cpu, ret;
+	struct cpuidle_driver *drv;
+	struct cpuidle_device *dev;
+	struct device_node *np, *pds_node;
+
+	/* Detect OSI support based on CPU DT nodes */
+	sbi_cpuidle_use_osi = true;
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		if (np &&
+		    of_find_property(np, "power-domains", NULL) &&
+		    of_find_property(np, "power-domain-names", NULL)) {
+			continue;
+		} else {
+			sbi_cpuidle_use_osi = false;
+			break;
+		}
+	}
+
+	/* Populate generic power domains from DT nodes */
+	pds_node = of_find_node_by_path("/cpus/power-domains");
+	if (pds_node) {
+		ret = sbi_genpd_probe(pds_node);
+		of_node_put(pds_node);
+		if (ret)
+			return ret;
+	}
+
+	/* Initialize CPU idle driver for each CPU */
+	for_each_possible_cpu(cpu) {
+		ret = sbi_cpuidle_init_cpu(&pdev->dev, cpu);
+		if (ret) {
+			pr_debug("HART%ld: idle driver init failed\n",
+				 cpuid_to_hartid_map(cpu));
+			goto out_fail;
+		}
+	}
+
+	/* Setup CPU hotplut notifiers */
+	sbi_idle_init_cpuhp();
+
+	pr_info("idle driver registered for all CPUs\n");
+
+	return 0;
+
+out_fail:
+	while (--cpu >= 0) {
+		dev = per_cpu(cpuidle_devices, cpu);
+		drv = cpuidle_get_cpu_driver(dev);
+		cpuidle_unregister(drv);
+		sbi_cpuidle_deinit_cpu(cpu);
+	}
+
+	return ret;
+}
+
+static struct platform_driver sbi_cpuidle_driver = {
+	.probe = sbi_cpuidle_probe,
+	.driver = {
+		.name = "sbi-cpuidle",
+		.sync_state = sbi_cpuidle_domain_sync_state,
+	},
+};
+
+static int __init sbi_cpuidle_init(void)
+{
+	int ret;
+	struct platform_device *pdev;
+
+	/*
+	 * The SBI HSM suspend function is only available when:
+	 * 1) SBI version is 0.3 or higher
+	 * 2) SBI HSM extension is available
+	 */
+	if ((sbi_spec_version < sbi_mk_version(0, 3)) ||
+	    sbi_probe_extension(SBI_EXT_HSM) <= 0) {
+		pr_info("HSM suspend not available\n");
+		return 0;
+	}
+
+	ret = platform_driver_register(&sbi_cpuidle_driver);
+	if (ret)
+		return ret;
+
+	pdev = platform_device_register_simple("sbi-cpuidle",
+						-1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		platform_driver_unregister(&sbi_cpuidle_driver);
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
+device_initcall(sbi_cpuidle_init);
diff --git a/drivers/cpuidle/dt_idle_genpd.c b/drivers/cpuidle/dt_idle_genpd.c
new file mode 100644
index 000000000000..b37165514d4e
--- /dev/null
+++ b/drivers/cpuidle/dt_idle_genpd.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PM domains for CPUs via genpd.
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "dt-idle-genpd: " fmt
+
+#include <linux/cpu.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "dt_idle_genpd.h"
+
+static int pd_parse_state_nodes(
+			int (*parse_state)(struct device_node *, u32 *),
+			struct genpd_power_state *states, int state_count)
+{
+	int i, ret;
+	u32 state, *state_buf;
+
+	for (i = 0; i < state_count; i++) {
+		ret = parse_state(to_of_node(states[i].fwnode), &state);
+		if (ret)
+			goto free_state;
+
+		state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
+		if (!state_buf) {
+			ret = -ENOMEM;
+			goto free_state;
+		}
+		*state_buf = state;
+		states[i].data = state_buf;
+	}
+
+	return 0;
+
+free_state:
+	i--;
+	for (; i >= 0; i--)
+		kfree(states[i].data);
+	return ret;
+}
+
+static int pd_parse_states(struct device_node *np,
+			   int (*parse_state)(struct device_node *, u32 *),
+			   struct genpd_power_state **states,
+			   int *state_count)
+{
+	int ret;
+
+	/* Parse the domain idle states. */
+	ret = of_genpd_parse_idle_states(np, states, state_count);
+	if (ret)
+		return ret;
+
+	/* Fill out the dt specifics for each found state. */
+	ret = pd_parse_state_nodes(parse_state, *states, *state_count);
+	if (ret)
+		kfree(*states);
+
+	return ret;
+}
+
+static void pd_free_states(struct genpd_power_state *states,
+			    unsigned int state_count)
+{
+	int i;
+
+	for (i = 0; i < state_count; i++)
+		kfree(states[i].data);
+	kfree(states);
+}
+
+void dt_idle_pd_free(struct generic_pm_domain *pd)
+{
+	pd_free_states(pd->states, pd->state_count);
+	kfree(pd->name);
+	kfree(pd);
+}
+
+struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np,
+			int (*parse_state)(struct device_node *, u32 *))
+{
+	struct generic_pm_domain *pd;
+	struct genpd_power_state *states = NULL;
+	int ret, state_count = 0;
+
+	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		goto out;
+
+	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
+	if (!pd->name)
+		goto free_pd;
+
+	/*
+	 * Parse the domain idle states and let genpd manage the state selection
+	 * for those being compatible with "domain-idle-state".
+	 */
+	ret = pd_parse_states(np, parse_state, &states, &state_count);
+	if (ret)
+		goto free_name;
+
+	pd->free_states = pd_free_states;
+	pd->name = kbasename(pd->name);
+	pd->states = states;
+	pd->state_count = state_count;
+
+	pr_debug("alloc PM domain %s\n", pd->name);
+	return pd;
+
+free_name:
+	kfree(pd->name);
+free_pd:
+	kfree(pd);
+out:
+	pr_err("failed to alloc PM domain %pOF\n", np);
+	return NULL;
+}
+
+int dt_idle_pd_init_topology(struct device_node *np)
+{
+	struct device_node *node;
+	struct of_phandle_args child, parent;
+	int ret;
+
+	for_each_child_of_node(np, node) {
+		if (of_parse_phandle_with_args(node, "power-domains",
+					"#power-domain-cells", 0, &parent))
+			continue;
+
+		child.np = node;
+		child.args_count = 0;
+		ret = of_genpd_add_subdomain(&parent, &child);
+		of_node_put(parent.np);
+		if (ret) {
+			of_node_put(node);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+struct device *dt_idle_attach_cpu(int cpu, const char *name)
+{
+	struct device *dev;
+
+	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
+	if (IS_ERR_OR_NULL(dev))
+		return dev;
+
+	pm_runtime_irq_safe(dev);
+	if (cpu_online(cpu))
+		pm_runtime_get_sync(dev);
+
+	dev_pm_syscore_device(dev, true);
+
+	return dev;
+}
+
+void dt_idle_detach_cpu(struct device *dev)
+{
+	if (IS_ERR_OR_NULL(dev))
+		return;
+
+	dev_pm_domain_detach(dev, false);
+}
diff --git a/drivers/cpuidle/dt_idle_genpd.h b/drivers/cpuidle/dt_idle_genpd.h
new file mode 100644
index 000000000000..a95483d08a02
--- /dev/null
+++ b/drivers/cpuidle/dt_idle_genpd.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DT_IDLE_GENPD
+#define __DT_IDLE_GENPD
+
+struct device_node;
+struct generic_pm_domain;
+
+#ifdef CONFIG_DT_IDLE_GENPD
+
+void dt_idle_pd_free(struct generic_pm_domain *pd);
+
+struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np,
+			int (*parse_state)(struct device_node *, u32 *));
+
+int dt_idle_pd_init_topology(struct device_node *np);
+
+struct device *dt_idle_attach_cpu(int cpu, const char *name);
+
+void dt_idle_detach_cpu(struct device *dev);
+
+#else
+
+static inline void dt_idle_pd_free(struct generic_pm_domain *pd)
+{
+}
+
+static inline struct generic_pm_domain *dt_idle_pd_alloc(
+			struct device_node *np,
+			int (*parse_state)(struct device_node *, u32 *))
+{
+	return NULL;
+}
+
+static inline int dt_idle_pd_init_topology(struct device_node *np)
+{
+	return 0;
+}
+
+static inline struct device *dt_idle_attach_cpu(int cpu, const char *name)
+{
+	return NULL;
+}
+
+static inline void dt_idle_detach_cpu(struct device *dev)
+{
+}
+
+#endif
+
+#endif