[PATCH v6 1/3] PSCI: Add initial support for PSCIv0.2 functions

[ashwin.chaugule@linaro.org (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        | 179 ++++++++++++++++++++++++++++++++---------
 arch/arm64/include/asm/psci.h |   2 +-
 arch/arm64/kernel/psci.c      | 183 +++++++++++++++++++++++++++++++++---------
 4 files changed, 294 insertions(+), 77 deletions(-)

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..ead8cdb 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>
@@ -27,53 +28,44 @@
 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) {
 	case PSCI_RET_SUCCESS:
 		return 0;
-	case PSCI_RET_EOPNOTSUPP:
+	case PSCI_RET_NOT_SUPPORTED:
 		return -EOPNOTSUPP;
-	case PSCI_RET_EINVAL:
+	case PSCI_RET_INVALID_PARAMS:
 		return -EINVAL;
-	case PSCI_RET_EPERM:
+	case PSCI_RET_DENIED:
 		return -EPERM;
 	};
 
 	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)
-			<< PSCI_POWER_STATE_ID_SHIFT)	|
-		((state.type & PSCI_POWER_STATE_TYPE_MASK)
-			<< PSCI_POWER_STATE_TYPE_SHIFT)	|
-		((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
-			<< PSCI_POWER_STATE_AFFL_SHIFT);
+	return	((state.id & PSCI_0_2_POWER_STATE_ID_MASK)
+			<< PSCI_0_2_POWER_STATE_ID_SHIFT)	|
+		((state.type & PSCI_0_2_POWER_STATE_TYPE_MASK)
+			<< PSCI_0_2_POWER_STATE_TYPE_SHIFT)	|
+		((state.affinity_level & PSCI_0_2_POWER_STATE_AFFL_MASK)
+			<< PSCI_0_2_POWER_STATE_AFFL_SHIFT);
 }
 
 /*
@@ -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_0_2_FN_PSCI_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 +190,85 @@ 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_NOT_SUPPORTED) {
+		/* 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;
+	} else {
+		pr_info("PSCIv%d.%d detected in firmware.\n",
+				PSCI_VERSION_MAJOR(ver),
+				PSCI_VERSION_MINOR(ver));
+
+		if (PSCI_VERSION_MAJOR(ver) == 0 &&
+				PSCI_VERSION_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_0_2_FN_CPU_SUSPEND;
+	psci_ops.cpu_suspend = psci_cpu_suspend;
+
+	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
+	psci_ops.cpu_off = psci_cpu_off;
+
+	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_CPU_ON;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_MIGRATE;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN_AFFINITY_INFO;
+	psci_ops.affinity_info = psci_affinity_info;
+
+	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
+		PSCI_0_2_FN_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 +291,25 @@ 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/include/asm/psci.h b/arch/arm64/include/asm/psci.h
index d15ab8b4..e5312ea 100644
--- a/arch/arm64/include/asm/psci.h
+++ b/arch/arm64/include/asm/psci.h
@@ -14,6 +14,6 @@
 #ifndef __ASM_PSCI_H
 #define __ASM_PSCI_H
 
-void psci_init(void);
+int psci_init(void);
 
 #endif /* __ASM_PSCI_H */
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index ea4828a..63a7685 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>
@@ -40,58 +41,52 @@ 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) {
 	case PSCI_RET_SUCCESS:
 		return 0;
-	case PSCI_RET_EOPNOTSUPP:
+	case PSCI_RET_NOT_SUPPORTED:
 		return -EOPNOTSUPP;
-	case PSCI_RET_EINVAL:
+	case PSCI_RET_INVALID_PARAMS:
 		return -EINVAL;
-	case PSCI_RET_EPERM:
+	case PSCI_RET_DENIED:
 		return -EPERM;
 	};
 
 	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)
-			<< PSCI_POWER_STATE_ID_SHIFT)	|
-		((state.type & PSCI_POWER_STATE_TYPE_MASK)
-			<< PSCI_POWER_STATE_TYPE_SHIFT)	|
-		((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
-			<< PSCI_POWER_STATE_AFFL_SHIFT);
+	return	((state.id & PSCI_0_2_POWER_STATE_ID_MASK)
+			<< PSCI_0_2_POWER_STATE_ID_SHIFT)	|
+		((state.type & PSCI_0_2_POWER_STATE_TYPE_MASK)
+			<< PSCI_0_2_POWER_STATE_TYPE_SHIFT)	|
+		((state.affinity_level & PSCI_0_2_POWER_STATE_AFFL_MASK)
+			<< PSCI_0_2_POWER_STATE_AFFL_SHIFT);
 }
 
 /*
@@ -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_0_2_FN_PSCI_VERSION, 0, 0, 0);
+	return err;
+}
+
 static int psci_cpu_suspend(struct psci_power_state state,
 			    unsigned long entry_point)
 {
@@ -171,26 +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;
+
+	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
+	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
+	return err;
+}
 
-void __init psci_init(void)
+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)) {
@@ -198,10 +211,85 @@ 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_NOT_SUPPORTED) {
+		/* 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;
+	} else {
+		pr_info("PSCIv%d.%d detected in firmware.\n",
+				PSCI_VERSION_MAJOR(ver),
+				PSCI_VERSION_MINOR(ver));
+
+		if (PSCI_VERSION_MAJOR(ver) == 0 &&
+				PSCI_VERSION_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_0_2_FN64_CPU_SUSPEND;
+	psci_ops.cpu_suspend = psci_cpu_suspend;
+
+	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
+	psci_ops.cpu_off = psci_cpu_off;
+
+	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO;
+	psci_ops.affinity_info = psci_affinity_info;
+
+	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
+		PSCI_0_2_FN_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;
@@ -224,7 +312,28 @@ 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);
 }
 
 #ifdef CONFIG_SMP
-- 
1.8.3.2