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Commit a5c00bb2 authored by Lorenzo Pieralisi's avatar Lorenzo Pieralisi
Browse files

drivers: firmware: psci: add extended stateid power_state support 



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: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: default avatarJisheng Zhang <jszhang@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
parent 5f004e0c

drivers/firmware/psci.c

+32 −2
Original line number Diff line number Diff line
@@ -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;

}

include/uapi/linux/psci.h

+12 −0
Original line number Diff line number Diff line
@@ -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