Re: [Linaro-acpi] [PATCH v1 1/2] PSCI: Use DT Function ID values only for old versions of spec

On Wed, Mar 19, 2014 at 08:54:24PM -0400, Ashwin Chaugule wrote:

The 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 static values otherwise. This patch also prepares the code to easily use the ACPI API which is based off of PSCI v0.2+.

Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org

arch/arm/include/asm/psci.h | 15 ++++++ arch/arm/kernel/psci.c | 110 +++++++++++++++++++++++++++++++++++++----- arch/arm64/include/asm/psci.h | 12 +++++ arch/arm64/kernel/psci.c | 106 +++++++++++++++++++++++++++++++++++----- 4 files changed, 218 insertions(+), 25 deletions(-)

diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h index c4ae171..3f8ebf9 100644 --- a/arch/arm/include/asm/psci.h +++ b/arch/arm/include/asm/psci.h @@ -17,6 +17,19 @@ #define PSCI_POWER_STATE_TYPE_STANDBY 0 #define PSCI_POWER_STATE_TYPE_POWER_DOWN 1 +/* PSCI Function ID's for ARM32 as per PSCI spec v0.2 */

+#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

struct psci_power_state { u16 id; u8 type; @@ -36,9 +49,11 @@ extern struct smp_operations psci_smp_ops; #ifdef CONFIG_ARM_PSCI void psci_init(void); +int psci_get_version(void); bool psci_smp_available(void); #else static inline void psci_init(void) { } +static inline int psci_get_version(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..48e0b0a 100644 --- a/arch/arm/kernel/psci.c +++ b/arch/arm/kernel/psci.c @@ -27,6 +27,7 @@ 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, @@ -110,6 +111,20 @@ 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;
• u32 fn;
• fn = PSCI_ID_VERSION;
• err = invoke_psci_fn(fn, 0, 0, 0);
• return err;

+}

static int psci_cpu_suspend(struct psci_power_state state, unsigned long entry_point) { @@ -153,25 +168,65 @@ 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", },
• {},

-}; +/*

• • PSCI Function ID's for v0.2+ are well defined so use
• • static values.
• */

+static int psci_static_init(struct device_node *np) +{

• const char *method;
• int err = 0;
• 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;
  

• }

-void __init psci_init(void)

• pr_info("Using static PSCIv0.2+ 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;

+out_put_node:

• of_node_put(np);
• return err;

+}

+/*

• • PSCI < v0.2 can override PSCI function ID's via DT.
• */

+static int psci_of_init(struct device_node *np) {

• struct device_node *np; const char *method; u32 id;
• np = of_find_matching_node(NULL, psci_of_match);
• if (!np)

• return;
  

• int err = 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; }

@@ -180,7 +235,8 @@ 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; }

@@ -206,5 +262,33 @@ 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_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;
• int ver = 0;
• np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
• if (!np)

• return -ENODEV;
  

• ver = psci_get_version();
• pr_info("using static PSCIv%d.%d Function IDs\n",

• 	(ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT,
  

• 	(ver & PSCI_VER_MINOR_MASK));
  

• 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 e5312ea..b72678f 100644 --- a/arch/arm64/include/asm/psci.h +++ b/arch/arm64/include/asm/psci.h @@ -16,4 +16,16 @@ int psci_init(void); +/* PSCI Function ID's for ARM64 as per PSCI spec v0.2 */ +#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 /* __ASM_PSCI_H */ diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 4f97db3..d4cff4e 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -45,12 +45,14 @@ struct psci_operations { 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_MAX,

}; @@ -128,6 +130,20 @@ 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;
• u32 fn;
• fn = PSCI_ID_VERSION;
• err = invoke_psci_fn(fn, 0, 0, 0);
• return err;

+}

static int psci_cpu_suspend(struct psci_power_state state, unsigned long entry_point) { @@ -171,26 +187,64 @@ 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", },
• {},

-}; +/*

• • PSCI Function ID's for v0.2+ are well defined so use
• • static values.
• */

+static int psci_static_init(struct device_node *np) +{

• const char *method;
• int err = 0;

-int __init psci_init(void)

• 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;
  

• }
• pr_info("Using static PSCIv0.2+ 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;

+out_put_node:

• of_node_put(np);
• return err;

Can any of this code not be shared between arm and arm64?

Looks almost identical.

-Christoffer