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

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@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

On Thu, Mar 27, 2014 at 10:38 AM, Ashwin Chaugule
<ashwin.chaugule@linaro.org> wrote:
> 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.

The subject line is a bit out of date.

> 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    | 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;

Initialization not needed.

>
> -       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;
> +       }

This should all be common setup.

> +
> +       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 it doesn't report 0.2, then we should probably bail (possibly
falling back to 0.1).

> +
> +       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();

This may not be safe to do on 0.1 as the call didn't exist.

> +
> +       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;
> +       }

These 2 functions don't exist for 0.1.

> +
>  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},

"of" and "static" don't really describe the difference here. Use
something like psci_init_0_1 and psci_init_0_2.

> +       {},
> +};
> +
> +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

Same comments apply to this file.

> @@ -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 @@
> +/*

Linaro copyright?

> + *  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

You don't need ifdefs here. The 32-bit calls are valid on arm64 as
that is what 32-bit guests will use. Just do something like this:

#define PSCI_ID_VERSION                                0x84000000
#define PSCI_ID_CPU_SUSPEND_32                    0x84000001
#define PSCI_ID_CPU_SUSPEND_64                    0xc4000001


> +#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
>

Hi Rob,

On 27 March 2014 12:41, Rob Herring <rob.herring@linaro.org> wrote:
> On Thu, Mar 27, 2014 at 10:38 AM, Ashwin Chaugule
> <ashwin.chaugule@linaro.org> wrote:
>> 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.
>
> The subject line is a bit out of date.

Yea. This patch has now become more of a PSCIv0.2 implementation.

>> +       int err = 0;
>> +       int ver = 0;
>
> Initialization not needed.

Ok.

>>
>> -       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;
>> +       }
>
> This should all be common setup.

I'll roll this up into a helper.

>> +
>> +       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 it doesn't report 0.2, then we should probably bail (possibly
> falling back to 0.1).

Hm. I'd prefer bailing out here. That would hopefully force the user
to check the PSCI implementation.
Theres always the option of trying out "arm, psci" later.


>> +       ver = psci_get_version();
>
> This may not be safe to do on 0.1 as the call didn't exist.

Ok, I will take it out from this function.

>
>> +
>> +       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;
>> +       }
>
> These 2 functions don't exist for 0.1.

Will remove.

>> +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},
>
> "of" and "static" don't really describe the difference here. Use
> something like psci_init_0_1 and psci_init_0_2.

Ok.

> Same comments apply to this file.
>> index 0000000..b271e9a
>> --- /dev/null
>> +++ b/include/uapi/linux/psci.h
>> @@ -0,0 +1,45 @@
>> +/*
>
> Linaro copyright?
>

Will add.

>> +#ifdef CONFIG_ARM64
>
> You don't need ifdefs here. The 32-bit calls are valid on arm64 as
> that is what 32-bit guests will use. Just do something like this:
>
> #define PSCI_ID_VERSION                                0x84000000
> #define PSCI_ID_CPU_SUSPEND_32                    0x84000001
> #define PSCI_ID_CPU_SUSPEND_64                    0xc4000001
>

Ok, thats better.

Cheers,
Ashwin