From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Wed, 8 Jul 2015 18:16:50 +0100 Subject: [PATCH v2 4/5] drivers: firmware: psci: add extended stateid power_state support In-Reply-To: <1436375811-10529-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1436375811-10529-1-git-send-email-lorenzo.pieralisi@arm.com> Message-ID: <1436375811-10529-5-git-send-email-lorenzo.pieralisi@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Cc: Mark Rutland --- 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 24ef3a8..bd2ba5b 100644 --- a/drivers/firmware/psci.c +++ b/drivers/firmware/psci.c @@ -75,14 +75,34 @@ static u32 psci_function_id[PSCI_FN_MAX]; PSCI_0_2_POWER_STATE_TYPE_MASK | \ PSCI_0_2_POWER_STATE_AFFL_MASK) +#define PSCI_1_0_EXT_POWER_STATE_MASK \ + (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \ + PSCI_1_0_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_1_0_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_1_0_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_1_0_EXT_POWER_STATE_MASK : + PSCI_0_2_POWER_STATE_MASK; + + return !(state & ~valid_mask); } static int psci_to_linux_errno(int errno) @@ -203,6 +223,14 @@ 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). @@ -287,6 +315,8 @@ 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..0a9485f 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_1_0_EXT_POWER_STATE_ID_MASK 0xfffffff +#define PSCI_1_0_EXT_POWER_STATE_ID_SHIFT 0 +#define PSCI_1_0_EXT_POWER_STATE_TYPE_SHIFT 30 +#define PSCI_1_0_EXT_POWER_STATE_TYPE_MASK \ + (0x1 << PSCI_1_0_EXT_POWER_STATE_TYPE_SHIFT) + /* 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_1_0_FEATURES_CPU_SUSPEND_PF_SHIFT 1 +#define PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK \ + (0x1 << PSCI_1_0_FEATURES_CPU_SUSPEND_PF_SHIFT) + /* PSCI return values (inclusive of all PSCI versions) */ #define PSCI_RET_SUCCESS 0 #define PSCI_RET_NOT_SUPPORTED -1 -- 2.2.1