[PATCH v4 0/3] PSCI v0.2 support and DT bindings

[PATCH v4 0/3] PSCI v0.2 support and DT bindings

[Ashwin Chaugule]

Changes in v4:
		-		Correct copyright banner format.
		-		Check if PSCI Version ID is supported.
		-		Add all PSCI RET codes in uapi header.
		-		Explicitely ret 1 from psci_cpu_kill()

Changes in v3:
        -       Roll up common functionality for getting conduit method.
        -       Remove #defines for ARM32 and ARM64 in uapi/linux/psci.h
        -       Remove functions not supported by PSCI v0.1
        -       Misc cleanups.
        -       Add PSCI_AFFINITY_INFO return types in uapi header.
        -       Changed function names for PSCI v0.1 and PSCI v0.2
        -       Added copyright info to uapi header.
        -       Fixed args to affinity_info call.
        -       Fix typo in psci_init definition when PSCI is not defined.

Changes in v2:

        -       Add AFFINITY_INFO and MIGRATE_INFO_TYPE functions.
        -       Add binding Documentation.
        -       Add function to get PSCI version.
        -       Add common #defines in uapi/linux/psci.h
        -       Implement cpu_kill and check if CPU is dead via AFFINITY_INFO.
        -       Misc cleanups.

Changes in v1:

        -       Add new binding "arm, psci-0.2"
        -       Separate conduit and PSCI function assignment methods.

Ashwin Chaugule (3):
  PSCI: Add initial support for PSCIv0.2 functions
  Documentation: devicetree: Add new binding for PSCIv0.2
  ARM: Check if a CPU has gone offline

 Documentation/devicetree/bindings/arm/psci.txt |  35 +++++-
 arch/arm/include/asm/psci.h                    |   7 +-
 arch/arm/kernel/psci.c                         | 155 +++++++++++++++++++-----
 arch/arm/kernel/psci_smp.c                     |  21 ++++
 arch/arm64/kernel/psci.c                       | 160 ++++++++++++++++++++-----
 include/uapi/linux/psci.h                      |  66 ++++++++++
 6 files changed, 383 insertions(+), 61 deletions(-)
 create mode 100644 include/uapi/linux/psci.h

-- 
1.8.3.2

[PATCH v4 1/3] PSCI: Add initial support for PSCIv0.2 functions

[Ashwin Chaugule]

The PSCIv0.2 spec defines standard values of function IDs
and introduces a few new functions. Detect version of PSCI
and appropriately select the right PSCI functions.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
---
 arch/arm/include/asm/psci.h |   7 +-
 arch/arm/kernel/psci.c      | 155 ++++++++++++++++++++++++++++++++++--------
 arch/arm64/kernel/psci.c    | 160 +++++++++++++++++++++++++++++++++++---------
 include/uapi/linux/psci.h   |  61 +++++++++++++++++
 4 files changed, 323 insertions(+), 60 deletions(-)
 create mode 100644 include/uapi/linux/psci.h

diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index c4ae171..b93e34a 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -29,16 +29,19 @@ struct psci_operations {
 	int (*cpu_off)(struct psci_power_state state);
 	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
 	int (*migrate)(unsigned long cpuid);
+	int (*affinity_info)(unsigned long target_affinity,
+			unsigned long lowest_affinity_level);
+	int (*migrate_info_type)(void);
 };
 
 extern struct psci_operations psci_ops;
 extern struct smp_operations psci_smp_ops;
 
 #ifdef CONFIG_ARM_PSCI
-void psci_init(void);
+int psci_init(void);
 bool psci_smp_available(void);
 #else
-static inline void psci_init(void) { }
+static inline int psci_init(void) { }
 static inline bool psci_smp_available(void) { return false; }
 #endif
 
diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
index 4693188..46b23b6 100644
--- a/arch/arm/kernel/psci.c
+++ b/arch/arm/kernel/psci.c
@@ -17,6 +17,7 @@
 
 #include <linux/init.h>
 #include <linux/of.h>
+#include <uapi/linux/psci.h>
 
 #include <asm/compiler.h>
 #include <asm/errno.h>
@@ -27,22 +28,20 @@
 struct psci_operations psci_ops;
 
 static int (*invoke_psci_fn)(u32, u32, u32, u32);
+typedef int (*psci_initcall_t)(const struct device_node *);
 
 enum psci_function {
 	PSCI_FN_CPU_SUSPEND,
 	PSCI_FN_CPU_ON,
 	PSCI_FN_CPU_OFF,
 	PSCI_FN_MIGRATE,
+	PSCI_FN_AFFINITY_INFO,
+	PSCI_FN_MIGRATE_INFO_TYPE,
 	PSCI_FN_MAX,
 };
 
 static u32 psci_function_id[PSCI_FN_MAX];
 
-#define PSCI_RET_SUCCESS		0
-#define PSCI_RET_EOPNOTSUPP		-1
-#define PSCI_RET_EINVAL			-2
-#define PSCI_RET_EPERM			-3
-
 static int psci_to_linux_errno(int errno)
 {
 	switch (errno) {
@@ -59,13 +58,6 @@ static int psci_to_linux_errno(int errno)
 	return -EINVAL;
 }
 
-#define PSCI_POWER_STATE_ID_MASK	0xffff
-#define PSCI_POWER_STATE_ID_SHIFT	0
-#define PSCI_POWER_STATE_TYPE_MASK	0x1
-#define PSCI_POWER_STATE_TYPE_SHIFT	16
-#define PSCI_POWER_STATE_AFFL_MASK	0x3
-#define PSCI_POWER_STATE_AFFL_SHIFT	24
-
 static u32 psci_power_state_pack(struct psci_power_state state)
 {
 	return	((state.id & PSCI_POWER_STATE_ID_MASK)
@@ -110,6 +102,14 @@ static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
 	return function_id;
 }
 
+static int psci_get_version(void)
+{
+	int err;
+
+	err = invoke_psci_fn(PSCI_ID_VERSION, 0, 0, 0);
+	return err;
+}
+
 static int psci_cpu_suspend(struct psci_power_state state,
 			    unsigned long entry_point)
 {
@@ -153,26 +153,36 @@ static int psci_migrate(unsigned long cpuid)
 	return psci_to_linux_errno(err);
 }
 
-static const struct of_device_id psci_of_match[] __initconst = {
-	{ .compatible = "arm,psci",	},
-	{},
-};
+static int psci_affinity_info(unsigned long target_affinity,
+		unsigned long lowest_affinity_level)
+{
+	int err;
+	u32 fn;
 
-void __init psci_init(void)
+	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
+	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
+	return err;
+}
+
+static int psci_migrate_info_type(void)
 {
-	struct device_node *np;
-	const char *method;
-	u32 id;
+	int err;
+	u32 fn;
 
-	np = of_find_matching_node(NULL, psci_of_match);
-	if (!np)
-		return;
+	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
+	err = invoke_psci_fn(fn, 0, 0, 0);
+	return err;
+}
 
-	pr_info("probing function IDs from device-tree\n");
+static int get_set_conduit_method(struct device_node *np)
+{
+	const char *method;
+
+	pr_info("probing for conduit method from DT.\n");
 
 	if (of_property_read_string(np, "method", &method)) {
-		pr_warning("missing \"method\" property\n");
-		goto out_put_node;
+		pr_warn("missing \"method\" property\n");
+		return -ENXIO;
 	}
 
 	if (!strcmp("hvc", method)) {
@@ -180,10 +190,79 @@ void __init psci_init(void)
 	} else if (!strcmp("smc", method)) {
 		invoke_psci_fn = __invoke_psci_fn_smc;
 	} else {
-		pr_warning("invalid \"method\" property: %s\n", method);
+		pr_warn("invalid \"method\" property: %s\n", method);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * PSCI Function IDs for v0.2+ are well defined so use
+ * standard values.
+ */
+static int psci_0_2_init(struct device_node *np)
+{
+	int err, ver;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
 		goto out_put_node;
+
+	ver = psci_get_version();
+
+	if (ver == PSCI_RET_EOPNOTSUPP) {
+		pr_info("PSCI_ID_VERSION Function not supported in firmware.\n");
+	} else {
+		pr_info("PSCIv%d.%d detected in firmware.\n",
+				PSCI_VER_MAJOR(ver), PSCI_VER_MINOR(ver));
+
+		if (PSCI_VER_MAJOR(ver) == 0 && PSCI_VER_MINOR(ver) < 2) {
+			err = -EINVAL;
+			pr_err("Conflicting PSCI version detected.\n");
+			goto out_put_node;
+		}
 	}
 
+	pr_info("Using standard PSCI v0.2 function IDs\n");
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_ID_CPU_SUSPEND_32;
+	psci_ops.cpu_suspend = psci_cpu_suspend;
+
+	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_ID_CPU_OFF;
+	psci_ops.cpu_off = psci_cpu_off;
+
+	psci_function_id[PSCI_FN_CPU_ON] = PSCI_ID_CPU_ON_32;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_ID_CPU_MIGRATE_32;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_ID_AFFINITY_INFO_32;
+	psci_ops.affinity_info = psci_affinity_info;
+
+	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] = PSCI_ID_MIGRATE_INFO_TYPE;
+	psci_ops.migrate_info_type = psci_migrate_info_type;
+
+out_put_node:
+	of_node_put(np);
+	return err;
+}
+
+/*
+ * PSCI < v0.2 get PSCI Function IDs via DT.
+ */
+static int psci_0_1_init(struct device_node *np)
+{
+	u32 id;
+	int err;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
+		goto out_put_node;
+
+	pr_info("Using PSCI v0.1 Function IDs from DT\n");
+
 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 		psci_ops.cpu_suspend = psci_cpu_suspend;
@@ -206,5 +285,25 @@ void __init psci_init(void)
 
 out_put_node:
 	of_node_put(np);
-	return;
+	return err;
+}
+
+static const struct of_device_id psci_of_match[] __initconst = {
+	{ .compatible = "arm,psci", .data = psci_0_1_init},
+	{ .compatible = "arm,psci-0.2", .data = psci_0_2_init},
+	{},
+};
+
+int __init psci_init(void)
+{
+	struct device_node *np;
+	const struct of_device_id *matched_np;
+	psci_initcall_t init_fn;
+
+	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
+	if (!np)
+		return -ENODEV;
+
+	init_fn = (psci_initcall_t)matched_np->data;
+	return init_fn(np);
 }
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 4f97db3..46b72b6 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/smp.h>
+#include <uapi/linux/psci.h>
 
 #include <asm/compiler.h>
 #include <asm/cpu_ops.h>
@@ -40,27 +41,28 @@ struct psci_operations {
 	int (*cpu_off)(struct psci_power_state state);
 	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
 	int (*migrate)(unsigned long cpuid);
+	int (*affinity_info)(unsigned long target_affinity,
+			unsigned long lowest_affinity_level);
+	int (*migrate_info_type)(void);
 };
 
 static struct psci_operations psci_ops;
 
 static int (*invoke_psci_fn)(u64, u64, u64, u64);
+typedef int (*psci_initcall_t)(const struct device_node *);
 
 enum psci_function {
 	PSCI_FN_CPU_SUSPEND,
 	PSCI_FN_CPU_ON,
 	PSCI_FN_CPU_OFF,
 	PSCI_FN_MIGRATE,
+	PSCI_FN_AFFINITY_INFO,
+	PSCI_FN_MIGRATE_INFO_TYPE,
 	PSCI_FN_MAX,
 };
 
 static u32 psci_function_id[PSCI_FN_MAX];
 
-#define PSCI_RET_SUCCESS		0
-#define PSCI_RET_EOPNOTSUPP		-1
-#define PSCI_RET_EINVAL			-2
-#define PSCI_RET_EPERM			-3
-
 static int psci_to_linux_errno(int errno)
 {
 	switch (errno) {
@@ -77,13 +79,6 @@ static int psci_to_linux_errno(int errno)
 	return -EINVAL;
 }
 
-#define PSCI_POWER_STATE_ID_MASK	0xffff
-#define PSCI_POWER_STATE_ID_SHIFT	0
-#define PSCI_POWER_STATE_TYPE_MASK	0x1
-#define PSCI_POWER_STATE_TYPE_SHIFT	16
-#define PSCI_POWER_STATE_AFFL_MASK	0x3
-#define PSCI_POWER_STATE_AFFL_SHIFT	24
-
 static u32 psci_power_state_pack(struct psci_power_state state)
 {
 	return	((state.id & PSCI_POWER_STATE_ID_MASK)
@@ -128,6 +123,14 @@ static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
 	return function_id;
 }
 
+static int psci_get_version(void)
+{
+	int err;
+
+	err = invoke_psci_fn(PSCI_ID_VERSION, 0, 0, 0);
+	return err;
+}
+
 static int psci_cpu_suspend(struct psci_power_state state,
 			    unsigned long entry_point)
 {
@@ -171,28 +174,36 @@ static int psci_migrate(unsigned long cpuid)
 	return psci_to_linux_errno(err);
 }
 
-static const struct of_device_id psci_of_match[] __initconst = {
-	{ .compatible = "arm,psci",	},
-	{},
-};
+static int psci_affinity_info(unsigned long target_affinity,
+		unsigned long lowest_affinity_level)
+{
+	int err;
+	u32 fn;
 
-int __init psci_init(void)
+	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
+	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
+	return err;
+}
+
+static int psci_migrate_info_type(void)
 {
-	struct device_node *np;
-	const char *method;
-	u32 id;
-	int err = 0;
+	int err;
+	u32 fn;
 
-	np = of_find_matching_node(NULL, psci_of_match);
-	if (!np)
-		return -ENODEV;
+	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
+	err = invoke_psci_fn(fn, 0, 0, 0);
+	return err;
+}
 
-	pr_info("probing function IDs from device-tree\n");
+static int get_set_conduit_method(struct device_node *np)
+{
+	const char *method;
+
+	pr_info("probing for conduit method from DT.\n");
 
 	if (of_property_read_string(np, "method", &method)) {
-		pr_warning("missing \"method\" property\n");
-		err = -ENXIO;
-		goto out_put_node;
+		pr_warn("missing \"method\" property\n");
+		return -ENXIO;
 	}
 
 	if (!strcmp("hvc", method)) {
@@ -200,11 +211,79 @@ int __init psci_init(void)
 	} else if (!strcmp("smc", method)) {
 		invoke_psci_fn = __invoke_psci_fn_smc;
 	} else {
-		pr_warning("invalid \"method\" property: %s\n", method);
-		err = -EINVAL;
+		pr_warn("invalid \"method\" property: %s\n", method);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * PSCI Function IDs for v0.2+ are well defined so use
+ * standard values.
+ */
+static int psci_0_2_init(struct device_node *np)
+{
+	int err, ver;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
 		goto out_put_node;
+
+	ver = psci_get_version();
+
+	if (ver == PSCI_RET_EOPNOTSUPP) {
+		pr_info("PSCI_ID_VERSION Function not supported in firmware.\n");
+	} else {
+		pr_info("PSCIv%d.%d detected in firmware.\n",
+				PSCI_VER_MAJOR(ver), PSCI_VER_MINOR(ver));
+
+		if (PSCI_VER_MAJOR(ver) == 0 && PSCI_VER_MINOR(ver) < 2) {
+			err = -EINVAL;
+			pr_err("Conflicting PSCI version detected.\n");
+			goto out_put_node;
+		}
 	}
 
+	pr_info("Using standard PSCI v0.2 function IDs\n");
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_ID_CPU_SUSPEND_64;
+	psci_ops.cpu_suspend = psci_cpu_suspend;
+
+	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_ID_CPU_OFF;
+	psci_ops.cpu_off = psci_cpu_off;
+
+	psci_function_id[PSCI_FN_CPU_ON] = PSCI_ID_CPU_ON_64;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_ID_CPU_MIGRATE_64;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_ID_AFFINITY_INFO_64;
+	psci_ops.affinity_info = psci_affinity_info;
+
+	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] = PSCI_ID_MIGRATE_INFO_TYPE;
+	psci_ops.migrate_info_type = psci_migrate_info_type;
+
+out_put_node:
+	of_node_put(np);
+	return err;
+}
+
+/*
+ * PSCI < v0.2 get PSCI Function IDs via DT.
+ */
+static int psci_0_1_init(struct device_node *np)
+{
+	u32 id;
+	int err;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
+		goto out_put_node;
+
+	pr_info("Using PSCI v0.1 Function IDs from DT\n");
+
 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 		psci_ops.cpu_suspend = psci_cpu_suspend;
@@ -230,6 +309,27 @@ out_put_node:
 	return err;
 }
 
+static const struct of_device_id psci_of_match[] __initconst = {
+	{ .compatible = "arm,psci",	.data = psci_0_1_init},
+	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
+	{},
+};
+
+int __init psci_init(void)
+{
+	struct device_node *np;
+	const struct of_device_id *matched_np;
+	psci_initcall_t init_fn;
+
+	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
+
+	if (!np)
+		return -ENODEV;
+
+	init_fn = (psci_initcall_t)matched_np->data;
+	return init_fn(np);
+}
+
 #ifdef CONFIG_SMP
 
 static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
new file mode 100644
index 0000000..0354bb1
--- /dev/null
+++ b/include/uapi/linux/psci.h
@@ -0,0 +1,61 @@
+/*
+ *	Copyright (C) 2014 Linaro Ltd.
+ *	Author:	Ashwin Chaugule <ashwin.chaugule@linaro.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that 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.
+ *
+ */
+
+#ifndef _UAPI_LINUX_PSCI_H
+#define _UAPI_LINUX_PSCI_H
+
+/* PSCI Function IDs as per PSCI spec v0.2 */
+#define PSCI_ID_VERSION					0x84000000
+#define PSCI_ID_CPU_SUSPEND_32			0x84000001
+#define PSCI_ID_CPU_SUSPEND_64			0xc4000001
+#define PSCI_ID_CPU_OFF					0x84000002
+#define PSCI_ID_CPU_ON_32				0x84000003
+#define PSCI_ID_CPU_ON_64				0xC4000003
+#define PSCI_ID_AFFINITY_INFO_32		0x84000004
+#define PSCI_ID_AFFINITY_INFO_64		0xC4000004
+#define PSCI_ID_CPU_MIGRATE_32			0x84000005
+#define PSCI_ID_CPU_MIGRATE_64			0xc4000005
+#define PSCI_ID_MIGRATE_INFO_TYPE		0x84000006
+#define PSCI_ID_MIGRATE_INFO_UP_CPU_32	0x84000007
+#define PSCI_ID_MIGRATE_INFO_UP_CPU_64	0xc4000007
+#define PSCI_ID_SYSTEM_OFF				0x84000008
+#define PSCI_ID_SYSTEM_RESET			0x84000009
+
+#define PSCI_RET_SUCCESS			0
+#define PSCI_RET_EOPNOTSUPP			-1
+#define PSCI_RET_EINVAL				-2
+#define PSCI_RET_EPERM				-3
+#define PSCI_RET_ALREADY_ON			-4
+#define PSCI_RET_ON_PENDING			-5
+#define PSCI_RET_INTERNAL_FAILURE	-6
+#define PSCI_RET_NOT_PRESENT		-7
+#define PSCI_RET_DISABLED			-8
+
+#define PSCI_POWER_STATE_ID_MASK	0xffff
+#define PSCI_POWER_STATE_ID_SHIFT	0
+#define PSCI_POWER_STATE_TYPE_MASK	0x1
+#define PSCI_POWER_STATE_TYPE_SHIFT	16
+#define PSCI_POWER_STATE_AFFL_MASK	0x3
+#define PSCI_POWER_STATE_AFFL_SHIFT	24
+
+#define PSCI_VER_MAJOR_MASK		0xffff0000
+#define PSCI_VER_MINOR_MASK		0x0000ffff
+#define PSCI_VER_MAJOR_SHIFT	16
+#define PSCI_VER_MAJOR(ver)		\
+	((ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT)
+#define PSCI_VER_MINOR(ver)		(ver & PSCI_VER_MINOR_MASK)
+
+#endif /* _UAPI_LINUX_PSCI_H */
-- 
1.8.3.2

[PATCH v4 2/3] Documentation: devicetree: Add new binding for PSCIv0.2

[Ashwin Chaugule]

The PSCI v0.2+ spec defines standard values for PSCI function IDs.
Add a new binding entry so that pre v0.2 implementations can
use DT entries for function IDs and v0.2+ implementations use
standard entries as defined by the PSCIv0.2 specification.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/arm/psci.txt | 35 +++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt
index 433afe9..d01a90b 100644
--- a/Documentation/devicetree/bindings/arm/psci.txt
+++ b/Documentation/devicetree/bindings/arm/psci.txt
@@ -21,7 +21,15 @@ to #0.
 
 Main node required properties:
 
- - compatible    : Must be "arm,psci"
+ - compatible    : should contain at least one of:
+
+				 * "arm,psci" : for implementations complying to PSCI versions prior to
+					0.2. For these cases function IDs must be provided.
+
+				 * "arm,psci-0.2" : for implementations complying to PSCI 0.2. Function
+					IDs are not required and should be ignored by an OS with PSCI 0.2
+					support, but are permitted to be present for compatibility with
+					existing software when "arm,psci" is later in the compatible list.
 
  - method        : The method of calling the PSCI firmware. Permitted
                    values are:
@@ -45,6 +53,8 @@ Main node optional properties:
 
 Example:
 
+Case 1: PSCI v0.1 only.
+
 	psci {
 		compatible	= "arm,psci";
 		method		= "smc";
@@ -53,3 +63,26 @@ Example:
 		cpu_on		= <0x95c10002>;
 		migrate		= <0x95c10003>;
 	};
+
+
+Case 2: PSCI v0.2 only
+
+	psci {
+		compatible	= "arm,psci-0.2";
+		method		= "smc";
+	};
+
+Case 3: PSCI v0.2 and PSCI v0.1.
+
+	As described above, for compatibility with existing kernels, the
+	hypervisor will likely want to provide IDs, e.g.
+
+	psci {
+		compatible = "arm,psci-0.2", "arm,psci";
+		method = "hvc";
+
+		cpu_on = < arbitrary value >;
+		cpu_off = < arbitrary value >;
+
+		...
+	};
-- 
1.8.3.2

[PATCH v4 3/3] ARM: Check if a CPU has gone offline

[Ashwin Chaugule]

PSCIv0.2 adds a new function called AFFINITY_INFO, which
can be used to query if a specified CPU has actually gone
offline. Calling this function via cpu_kill ensures that
a CPU has quiesced after a call to cpu_die.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 arch/arm/kernel/psci_smp.c | 21 +++++++++++++++++++++
 include/uapi/linux/psci.h  |  5 +++++
 2 files changed, 26 insertions(+)

diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
index 570a48c..c6f1420 100644
--- a/arch/arm/kernel/psci_smp.c
+++ b/arch/arm/kernel/psci_smp.c
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/of.h>
+#include <uapi/linux/psci.h>
 
 #include <asm/psci.h>
 #include <asm/smp_plat.h>
@@ -66,6 +67,25 @@ void __ref psci_cpu_die(unsigned int cpu)
        /* We should never return */
        panic("psci: cpu %d failed to shutdown\n", cpu);
 }
+
+int __ref psci_cpu_kill(unsigned int cpu)
+{
+	int err;
+
+	if (!psci_ops.affinity_info)
+		return 1;
+
+	err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
+
+	if (err != PSCI_AFFINITY_INFO_RET_OFF) {
+		pr_err("psci: Cannot kill CPU:%d, psci ret val: %d\n",
+				cpu, err);
+		/* Make platform_cpu_kill() fail. */
+		return 0;
+	}
+	return 1;
+}
+
 #endif
 
 bool __init psci_smp_available(void)
@@ -78,5 +98,6 @@ struct smp_operations __initdata psci_smp_ops = {
 	.smp_boot_secondary	= psci_boot_secondary,
 #ifdef CONFIG_HOTPLUG_CPU
 	.cpu_die		= psci_cpu_die,
+	.cpu_kill		= psci_cpu_kill,
 #endif
 };
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index 0354bb1..65b4878 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -58,4 +58,9 @@
 	((ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT)
 #define PSCI_VER_MINOR(ver)		(ver & PSCI_VER_MINOR_MASK)
 
+/* Return values from the PSCI_ID_AFFINITY_INFO Function. */
+#define PSCI_AFFINITY_INFO_RET_ON			0
+#define PSCI_AFFINITY_INFO_RET_OFF			1
+#define PSCI_AFFINITY_INFO_RET_ON_PENDING	2
+
 #endif /* _UAPI_LINUX_PSCI_H */
-- 
1.8.3.2

[Linaro-acpi] [PATCH v4 1/3] PSCI: Add initial support for PSCIv0.2 functions

[Sudeep Holla]

Hi Ashwin,

On 31/03/14 16:02, Ashwin Chaugule wrote:
> The PSCIv0.2 spec defines standard values of function IDs
> and introduces a few new functions. Detect version of PSCI
> and appropriately select the right PSCI functions.
> 
> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> ---
>  arch/arm/include/asm/psci.h |   7 +-
>  arch/arm/kernel/psci.c      | 155 ++++++++++++++++++++++++++++++++++--------
>  arch/arm64/kernel/psci.c    | 160 +++++++++++++++++++++++++++++++++++---------
>  include/uapi/linux/psci.h   |  61 +++++++++++++++++
>  4 files changed, 323 insertions(+), 60 deletions(-)
>  create mode 100644 include/uapi/linux/psci.h
> 
> diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
> index c4ae171..b93e34a 100644
> --- a/arch/arm/include/asm/psci.h
> +++ b/arch/arm/include/asm/psci.h
> @@ -29,16 +29,19 @@ struct psci_operations {
>         int (*cpu_off)(struct psci_power_state state);
>         int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
>         int (*migrate)(unsigned long cpuid);
> +       int (*affinity_info)(unsigned long target_affinity,
> +                       unsigned long lowest_affinity_level);
> +       int (*migrate_info_type)(void);
>  };
> 
>  extern struct psci_operations psci_ops;
>  extern struct smp_operations psci_smp_ops;
> 
>  #ifdef CONFIG_ARM_PSCI
> -void psci_init(void);
> +int psci_init(void);
>  bool psci_smp_available(void);
>  #else
> -static inline void psci_init(void) { }
> +static inline int psci_init(void) { }
>  static inline bool psci_smp_available(void) { return false; }
>  #endif
> 
> diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
> index 4693188..46b23b6 100644
> --- a/arch/arm/kernel/psci.c
> +++ b/arch/arm/kernel/psci.c
> @@ -17,6 +17,7 @@
> 
>  #include <linux/init.h>
>  #include <linux/of.h>
> +#include <uapi/linux/psci.h>
> 
>  #include <asm/compiler.h>
>  #include <asm/errno.h>
> @@ -27,22 +28,20 @@
>  struct psci_operations psci_ops;
> 
>  static int (*invoke_psci_fn)(u32, u32, u32, u32);
> +typedef int (*psci_initcall_t)(const struct device_node *);
> 
>  enum psci_function {
>         PSCI_FN_CPU_SUSPEND,
>         PSCI_FN_CPU_ON,
>         PSCI_FN_CPU_OFF,
>         PSCI_FN_MIGRATE,
> +       PSCI_FN_AFFINITY_INFO,
> +       PSCI_FN_MIGRATE_INFO_TYPE,
>         PSCI_FN_MAX,
>  };
> 
>  static u32 psci_function_id[PSCI_FN_MAX];
> 
> -#define PSCI_RET_SUCCESS               0
> -#define PSCI_RET_EOPNOTSUPP            -1
> -#define PSCI_RET_EINVAL                        -2
> -#define PSCI_RET_EPERM                 -3
> -
>  static int psci_to_linux_errno(int errno)
>  {
>         switch (errno) {
> @@ -59,13 +58,6 @@ static int psci_to_linux_errno(int errno)
>         return -EINVAL;
>  }
> 
> -#define PSCI_POWER_STATE_ID_MASK       0xffff
> -#define PSCI_POWER_STATE_ID_SHIFT      0
> -#define PSCI_POWER_STATE_TYPE_MASK     0x1
> -#define PSCI_POWER_STATE_TYPE_SHIFT    16
> -#define PSCI_POWER_STATE_AFFL_MASK     0x3
> -#define PSCI_POWER_STATE_AFFL_SHIFT    24
> -
>  static u32 psci_power_state_pack(struct psci_power_state state)
>  {
>         return  ((state.id & PSCI_POWER_STATE_ID_MASK)
> @@ -110,6 +102,14 @@ static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
>         return function_id;
>  }
> 
> +static int psci_get_version(void)
> +{
> +       int err;
> +
> +       err = invoke_psci_fn(PSCI_ID_VERSION, 0, 0, 0);
> +       return err;
> +}
> +
>  static int psci_cpu_suspend(struct psci_power_state state,
>                             unsigned long entry_point)
>  {
> @@ -153,26 +153,36 @@ static int psci_migrate(unsigned long cpuid)
>         return psci_to_linux_errno(err);
>  }
> 
> -static const struct of_device_id psci_of_match[] __initconst = {
> -       { .compatible = "arm,psci",     },
> -       {},
> -};
> +static int psci_affinity_info(unsigned long target_affinity,
> +               unsigned long lowest_affinity_level)
> +{
> +       int err;
> +       u32 fn;
> 
> -void __init psci_init(void)
> +       fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
> +       err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
> +       return err;
> +}
> +
> +static int psci_migrate_info_type(void)
>  {
> -       struct device_node *np;
> -       const char *method;
> -       u32 id;
> +       int err;
> +       u32 fn;
> 
> -       np = of_find_matching_node(NULL, psci_of_match);
> -       if (!np)
> -               return;
> +       fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
> +       err = invoke_psci_fn(fn, 0, 0, 0);
> +       return err;
> +}
> 
> -       pr_info("probing function IDs from device-tree\n");
> +static int get_set_conduit_method(struct device_node *np)
> +{
> +       const char *method;
> +
> +       pr_info("probing for conduit method from DT.\n");
> 
>         if (of_property_read_string(np, "method", &method)) {
> -               pr_warning("missing \"method\" property\n");
> -               goto out_put_node;
> +               pr_warn("missing \"method\" property\n");
> +               return -ENXIO;
>         }
> 
>         if (!strcmp("hvc", method)) {
> @@ -180,10 +190,79 @@ void __init psci_init(void)
>         } else if (!strcmp("smc", method)) {
>                 invoke_psci_fn = __invoke_psci_fn_smc;
>         } else {
> -               pr_warning("invalid \"method\" property: %s\n", method);
> +               pr_warn("invalid \"method\" property: %s\n", method);
> +               return -EINVAL;
> +       }
> +       return 0;
> +}
> +
> +/*
> + * PSCI Function IDs for v0.2+ are well defined so use
> + * standard values.
> + */
> +static int psci_0_2_init(struct device_node *np)
> +{
> +       int err, ver;
> +
> +       err = get_set_conduit_method(np);
> +
> +       if (err)
>                 goto out_put_node;
> +
> +       ver = psci_get_version();
> +
> +       if (ver == PSCI_RET_EOPNOTSUPP) {
> +               pr_info("PSCI_ID_VERSION Function not supported in firmware.\n");

IMO you should stop here as the implementation conforming to the specification
must return a minor version number of 2 and major version number of 0. You
can't proceed, assume ids and use them.

Regards,
Sudeep

[Linaro-acpi] [PATCH v4 1/3] PSCI: Add initial support for PSCIv0.2 functions

[Ashwin Chaugule]

Hi Sudeep,

On 31 March 2014 12:52, Sudeep Holla <sudeep.holla@arm.com> wrote:

>> +       if (ver == PSCI_RET_EOPNOTSUPP) {
>> +               pr_info("PSCI_ID_VERSION Function not supported in firmware.\n");
>
> IMO you should stop here as the implementation conforming to the specification
> must return a minor version number of 2 and major version number of 0. You
> can't proceed, assume ids and use them.
>

hm, you're right, I missed that.

Cheers,
Ashwin

[Linaro-acpi] [PATCH v4 1/3] PSCI: Add initial support for PSCIv0.2 functions

[Ashwin Chaugule]

On 31 March 2014 13:09, Ashwin Chaugule <ashwin.chaugule@linaro.org> wrote:
> Hi Sudeep,
>
> On 31 March 2014 12:52, Sudeep Holla <sudeep.holla@arm.com> wrote:
>
>>> +       if (ver == PSCI_RET_EOPNOTSUPP) {
>>> +               pr_info("PSCI_ID_VERSION Function not supported in firmware.\n");
>>
>> IMO you should stop here as the implementation conforming to the specification
>> must return a minor version number of 2 and major version number of 0. You
>> can't proceed, assume ids and use them.
>>
>
> hm, you're right, I missed that.

Something like this?

if (ver == PSCI_RET_EOPNOTSUPP) {
         /* PSCI v0.2+ mandates implementation of PSCI_ID_VERSION. */
         pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
         err = -EOPNOTSUPP;
         goto out_put_node;


>
> Cheers,
> Ashwin

[Linaro-acpi] [PATCH v4 1/3] PSCI: Add initial support for PSCIv0.2 functions

[Sudeep Holla]

Hi Ashwin,

On 31/03/14 18:25, Ashwin Chaugule wrote:
> On 31 March 2014 13:09, Ashwin Chaugule <ashwin.chaugule@linaro.org> wrote:
>> Hi Sudeep,
>>
>> On 31 March 2014 12:52, Sudeep Holla <sudeep.holla@arm.com> wrote:
>>
>>>> +       if (ver == PSCI_RET_EOPNOTSUPP) {
>>>> +               pr_info("PSCI_ID_VERSION Function not supported in firmware.\n");
>>>
>>> IMO you should stop here as the implementation conforming to the specification
>>> must return a minor version number of 2 and major version number of 0. You
>>> can't proceed, assume ids and use them.
>>>
>>
>> hm, you're right, I missed that.
> 
> Something like this?
> 
> if (ver == PSCI_RET_EOPNOTSUPP) {
>          /* PSCI v0.2+ mandates implementation of PSCI_ID_VERSION. */
>          pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
>          err = -EOPNOTSUPP;
>          goto out_put_node;
> 

Yes that looks fine to me.

Regards,
Sudeep