[PATCH v2 1/3] PSCI: Use DT Function ID values only for old versions of spec

Ashwin Chaugule ashwin.chaugule at linaro.org
Thu Mar 27 11:38:33 EDT 2014


PSCI v0.2+ spec mandates specific values of Function IDs
for ARM32 and ARM64. Use DT bindings of Function IDs only
when using older versions. Use standard values otherwise.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule at linaro.org>
---
 arch/arm/include/asm/psci.h |   7 +-
 arch/arm/kernel/psci.c      | 155 ++++++++++++++++++++++++++++++++++++++++----
 arch/arm64/kernel/psci.c    | 154 +++++++++++++++++++++++++++++++++++++++----
 include/uapi/linux/psci.h   |  45 +++++++++++++
 4 files changed, 334 insertions(+), 27 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..f867633 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 init 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..77e6968 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>
@@ -27,12 +28,15 @@
 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,
 };
 
@@ -110,6 +114,18 @@ static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
 	return function_id;
 }
 
+#define PSCI_VER_MAJOR_MASK		0xffff0000
+#define PSCI_VER_MINOR_MASK		0x0000ffff
+#define PSCI_VER_MAJOR_SHIFT	16
+
+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)
 {
@@ -153,25 +169,100 @@ 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)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
+	err = invoke_psci_fn(fn, 0, 0, 0);
+	return err;
+}
+
+/*
+ * PSCI Function IDs for v0.2+ are well defined so use
+ * standard values.
+ */
+static int psci_static_init(struct device_node *np)
 {
-	struct device_node *np;
 	const char *method;
-	u32 id;
+	int err = 0;
+	int ver = 0;
 
-	np = of_find_matching_node(NULL, psci_of_match);
-	if (!np)
-		return;
+	pr_info("probing for conduit method from DT.\n");
+
+	if (of_property_read_string(np, "method", &method)) {
+		pr_warn("missing \"method\" property\n");
+		err = -ENXIO;
+		goto out_put_node;
+	}
+
+	if (!strcmp("hvc", method)) {
+		invoke_psci_fn = __invoke_psci_fn_hvc;
+	} else if (!strcmp("smc", method)) {
+		invoke_psci_fn = __invoke_psci_fn_smc;
+	} else {
+		pr_warn("invalid \"method\" property: %s\n", method);
+		err = -EINVAL;
+		goto out_put_node;
+	}
+
+	ver = psci_get_version();
+
+	pr_info("PSCIv%d.%d detected in firmware.\n",
+			(ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT,
+			(ver & PSCI_VER_MINOR_MASK));
+
+	pr_info("Using standard PSCI v0.2 function IDs\n");
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_ID_CPU_SUSPEND;
+	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;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_ID_CPU_MIGRATE;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_ID_AFFINITY_INFO;
+	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 can override PSCI function IDs via DT.
+ */
+static int psci_of_init(struct device_node *np)
+{
+	const char *method;
+	u32 id;
+	int err = 0;
+	int ver = 0;
 
 	pr_info("probing function IDs from device-tree\n");
 
 	if (of_property_read_string(np, "method", &method)) {
-		pr_warning("missing \"method\" property\n");
+		pr_warn("missing \"method\" property\n");
+		err = -EINVAL;
 		goto out_put_node;
 	}
 
@@ -180,10 +271,17 @@ 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);
+		err = -ENXIO;
 		goto out_put_node;
 	}
 
+	ver = psci_get_version();
+
+	pr_info("PSCIv%d.%d detected in firmware.\n",
+			(ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT,
+			(ver & PSCI_VER_MINOR_MASK));
+
 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 		psci_ops.cpu_suspend = psci_cpu_suspend;
@@ -204,7 +302,38 @@ void __init psci_init(void)
 		psci_ops.migrate = psci_migrate;
 	}
 
+	if (!of_property_read_u32(np, "affinity_info", &id)) {
+		psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_ID_AFFINITY_INFO;
+		psci_ops.affinity_info = psci_affinity_info;
+	}
+
+	if (!of_property_read_u32(np, "migrate_info_type", &id)) {
+		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;
+	return err;
+}
+
+static const struct of_device_id psci_of_match[] __initconst = {
+	{ .compatible = "arm,psci", .data = psci_of_init},
+	{ .compatible = "arm,psci-0.2", .data = psci_static_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..61b7871 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>
@@ -40,17 +41,23 @@ 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,
 };
 
@@ -128,6 +135,18 @@ static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
 	return function_id;
 }
 
+#define PSCI_VER_MAJOR_MASK		0xffff0000
+#define PSCI_VER_MINOR_MASK		0x0000ffff
+#define PSCI_VER_MAJOR_SHIFT	16
+
+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)
 {
@@ -171,26 +190,99 @@ 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)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
+	err = invoke_psci_fn(fn, 0, 0, 0);
+	return err;
+}
+
+/*
+ * PSCI Function IDs for v0.2+ are well defined so use
+ * standard values.
+ */
+static int psci_static_init(struct device_node *np)
 {
-	struct device_node *np;
 	const char *method;
-	u32 id;
 	int err = 0;
+	int ver = 0;
 
-	np = of_find_matching_node(NULL, psci_of_match);
-	if (!np)
-		return -ENODEV;
+	pr_info("probing for conduit method from DT.\n");
+
+	if (of_property_read_string(np, "method", &method)) {
+		pr_warn("missing \"method\" property\n");
+		err = -ENXIO;
+		goto out_put_node;
+	}
+
+	if (!strcmp("hvc", method)) {
+		invoke_psci_fn = __invoke_psci_fn_hvc;
+	} else if (!strcmp("smc", method)) {
+		invoke_psci_fn = __invoke_psci_fn_smc;
+	} else {
+		pr_warn("invalid \"method\" property: %s\n", method);
+		err = -EINVAL;
+		goto out_put_node;
+	}
+
+	ver = psci_get_version();
+
+	pr_info("PSCIv%d.%d detected in firmware.\n",
+			(ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT,
+			(ver & PSCI_VER_MINOR_MASK));
+
+	pr_info("Using standard PSCI v0.2 function IDs\n");
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_ID_CPU_SUSPEND;
+	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;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_ID_CPU_MIGRATE;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_ID_AFFINITY_INFO;
+	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 can override PSCI function IDs via DT.
+ */
+static int psci_of_init(struct device_node *np)
+{
+	const char *method;
+	u32 id;
+	int err = 0;
+	int ver = 0;
 
 	pr_info("probing function IDs from device-tree\n");
 
 	if (of_property_read_string(np, "method", &method)) {
-		pr_warning("missing \"method\" property\n");
+		pr_warn("missing \"method\" property\n");
 		err = -ENXIO;
 		goto out_put_node;
 	}
@@ -200,11 +292,17 @@ 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);
+		pr_warn("invalid \"method\" property: %s\n", method);
 		err = -EINVAL;
 		goto out_put_node;
 	}
 
+	ver = psci_get_version();
+
+	pr_info("PSCIv%d.%d detected in firmware.\n",
+			(ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT,
+			(ver & PSCI_VER_MINOR_MASK));
+
 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 		psci_ops.cpu_suspend = psci_cpu_suspend;
@@ -225,11 +323,43 @@ int __init psci_init(void)
 		psci_ops.migrate = psci_migrate;
 	}
 
+	if (!of_property_read_u32(np, "affinity_info", &id)) {
+		psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_ID_AFFINITY_INFO;
+		psci_ops.affinity_info = psci_affinity_info;
+	}
+
+	if (!of_property_read_u32(np, "migrate_info_type", &id)) {
+		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;
 }
 
+static const struct of_device_id psci_of_match[] __initconst = {
+	{ .compatible = "arm,psci",	.data = psci_of_init},
+	{ .compatible = "arm,psci-0.2",	.data = psci_static_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..b271e9a
--- /dev/null
+++ b/include/uapi/linux/psci.h
@@ -0,0 +1,45 @@
+/*
+ *  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 for ARM32 as per PSCI spec v0.2 */
+#ifdef CONFIG_ARM_PSCI
+#define PSCI_ID_VERSION				0x84000000
+#define PSCI_ID_CPU_SUSPEND			0x84000001
+#define PSCI_ID_CPU_OFF				0x84000002
+#define PSCI_ID_CPU_ON				0x84000003
+#define PSCI_ID_AFFINITY_INFO		0x84000004
+#define PSCI_ID_CPU_MIGRATE			0x84000005
+#define PSCI_ID_MIGRATE_INFO_TYPE	0x84000006
+#define PSCI_ID_MIGRATE_INFO_UP_CPU	0x84000007
+#define PSCI_ID_SYSTEM_OFF			0x84000008
+#define PSCI_ID_SYSTEM_RESET		0x84000009
+#endif
+
+/* PSCI Function IDs for ARM64 as per PSCI spec v0.2 */
+#ifdef CONFIG_ARM64
+#define PSCI_ID_VERSION				0x84000000
+#define PSCI_ID_CPU_SUSPEND			0xc4000001
+#define PSCI_ID_CPU_OFF				0x84000002
+#define PSCI_ID_CPU_ON				0xc4000003
+#define PSCI_ID_AFFINITY_INFO		0xc4000004
+#define PSCI_ID_CPU_MIGRATE			0xc4000005
+#define PSCI_ID_MIGRATE_INFO_TYPE	0x84000006
+#define PSCI_ID_MIGRATE_INFO_UP_CPU	0xc4000007
+#define PSCI_ID_SYSTEM_OFF			0x84000008
+#define PSCI_ID_SYSTEM_RESET		0x84000009
+#endif
+
+#endif /* _UAPI_LINUX_PSCI_H */
-- 
1.8.3.2




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