On 29 May 2015 at 08:16, Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote:
> PSCI v1.0 augmented the power_state parameter format specification
> (extended stateid) and introduced a way to probe it through the
> PSCI_FEATURES interface.
>
> This patch implements code that detects the power_state format at
> run-time through the PSCI_FEATURES interface, so that the power_state
> argument can be properly detected and validated in the kernel according
> to the information provided through firmware.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> ---
> drivers/firmware/psci.c | 34 ++++++++++++++++++++++++++++++++--
> include/uapi/linux/psci.h | 12 ++++++++++++
> 2 files changed, 44 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 2330099..4063784 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -74,14 +74,34 @@ static u32 psci_function_id[PSCI_FN_MAX];
> PSCI_0_2_POWER_STATE_TYPE_MASK | \
> PSCI_0_2_POWER_STATE_AFFL_MASK)
>
> +#define PSCI_EXT_POWER_STATE_MASK \
> + (PSCI_EXT_POWER_STATE_ID_MASK | \
> + PSCI_EXT_POWER_STATE_TYPE_MASK)
> +
> +static u32 psci_cpu_suspend_feature;
> +
> +static inline bool psci_has_ext_power_state(void)
> +{
> + return psci_cpu_suspend_feature &
> + PSCI_FEATURES_CPU_SUSPEND_PF_MASK;
> +}
> +
> bool psci_power_state_loses_context(u32 state)
> {
> - return state & PSCI_0_2_POWER_STATE_TYPE_MASK;
> + const u32 mask = psci_has_ext_power_state() ?
> + PSCI_EXT_POWER_STATE_TYPE_MASK :
> + PSCI_0_2_POWER_STATE_TYPE_MASK;
> +
> + return state & mask;
> }
>
> bool psci_power_state_is_valid(u32 state)
> {
> - return !(state & ~PSCI_0_2_POWER_STATE_MASK);
> + const u32 valid_mask = psci_has_ext_power_state() ?
> + PSCI_EXT_POWER_STATE_MASK :
> + PSCI_0_2_POWER_STATE_MASK;
> +
> + return !(state & ~valid_mask);
> }
>
> static int psci_to_linux_errno(int errno)
> @@ -202,6 +222,14 @@ static int __init psci_features(u32 psci_func_id)
> psci_func_id, 0, 0);
> }
>
> +static void __init psci_init_cpu_suspend(void)
> +{
> + int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
> +
> + if (feature != PSCI_RET_NOT_SUPPORTED)
> + psci_cpu_suspend_feature = feature;
> +}
> +
> /*
> * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
> * return DENIED (which would be fatal).
> @@ -280,6 +308,8 @@ static int __init psci_probe(void)
>
> psci_init_migrate();
>
> + psci_init_cpu_suspend();
> +
> return 0;
> }
>
> diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
> index 187b828d..2598d7c 100644
> --- a/include/uapi/linux/psci.h
> +++ b/include/uapi/linux/psci.h
> @@ -58,6 +58,13 @@
> #define PSCI_0_2_POWER_STATE_AFFL_MASK \
> (0x3 << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
>
> +/* PSCI extended power state encoding for CPU_SUSPEND function */
> +#define PSCI_EXT_POWER_STATE_ID_MASK 0xfffffff
> +#define PSCI_EXT_POWER_STATE_ID_SHIFT 0
> +#define PSCI_EXT_POWER_STATE_TYPE_SHIFT 30
> +#define PSCI_EXT_POWER_STATE_TYPE_MASK \
> + (0x1 << PSCI_EXT_POWER_STATE_TYPE_SHIFT)
> +
For consistency, dont you need version numbers here, like we have for v0.2?
> /* PSCI v0.2 affinity level state returned by AFFINITY_INFO */
> #define PSCI_0_2_AFFINITY_LEVEL_ON 0
> #define PSCI_0_2_AFFINITY_LEVEL_OFF 1
> @@ -78,6 +85,11 @@
> #define PSCI_VERSION_MINOR(ver) \
> ((ver) & PSCI_VERSION_MINOR_MASK)
>
> +/* PSCI features decoding (>=1.0) */
> +#define PSCI_FEATURES_CPU_SUSPEND_PF_SHIFT 1
> +#define PSCI_FEATURES_CPU_SUSPEND_PF_MASK \
> + (0x1 << PSCI_FEATURES_CPU_SUSPEND_PF_SHIFT)
> +
Likewise.
> /* PSCI return values (inclusive of all PSCI versions) */
> #define PSCI_RET_SUCCESS 0
> #define PSCI_RET_NOT_SUPPORTED -1
> --
> 2.2.1
>
>
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