arm/arm64: Unify PSCI client support

We make use of the PSCI function IDs, but don't explicitly include the header which defines them. Relying on transitive header includes is fragile and will be broken as headers are refactored.

This patch includes the relevant header file directly so as to avoid future breakage.

Signed-off-by Mark Rutland <[email protected]>

Cc Christoffer Dall <[email protected]>

Cc Marc Zyngier <[email protected]>

arch/arm64/kernel/psci.c +2 -5

-static int psci_get_version(void)
+static u32 psci_get_version(void)
 {
-	int err;
-
-	err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
-	return err;
+	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 }
 
 static int psci_cpu_suspend(struct psci_power_state state,

On Fri, May 08, 2015 at 12:36:37PM +0100, Mark Rutland wrote:

[...]

Quoted 10 lines

arch/arm64/kernel/psci.c +2 -5

-static int psci_get_version(void)
+static u32 psci_get_version(void)
 {
-	int err;
-
-	err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
-	return err;
+	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 }

arch/arm64/kernel/psci.c static int __init psci_probe(void) · line 293

Quoted 4 lines

static int psci_cpu_suspend(struct psci_power_state state,

arch/arm64/kernel/psci.c +0 -0

@@ -295,23 +292,13 @@ static int __init psci_probe(void)
 {
 	int ver = psci_get_version();

Is there a reason to keep ver as an int ?

Other than that the patch looks fine.

Software resident in the secure world (a "Trusted OS") may cause CPU_OFF calls for the CPU it is resident on to be denied. Such a denial would be fatal for the kernel, and so we must detect when this can happen before the point of no return.

This patch implements Trusted OS detection for PSCI 0.2+ systems, using MIGRATE_INFO_TYPE and MIGRATE_INFO_UP_CPU. When a trusted OS is detected as resident on a particular CPU, attempts to hot unplug that CPU will be denied early, before they can prove fatal.

Trusted OS migration is not implemented by this patch. Implementation of migratable UP trusted OSs seems unlikely, and the right policy for migration is unclear (and will likely differ across implementations). As such, it is likely that migration will require cooperation with Trusted OS drivers.

PSCI implementations prior to 0.1 do not provide the facility to detect the presence of a Trusted OS, nor the CPU any such OS is resident on, so without additional information it is not possible to handle Trusted OSs with PSCI 0.1.

Signed-off-by Mark Rutland <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

arch/arm64/kernel/psci.c +13 -0

index 7324db9..25e2610 100644
@@ -43,6 +43,19 @@ struct psci_power_state {
 	u8	affinity_level;
 };
 
+/*
+ * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
+ * calls to its resident CPU, so we must avoid issuing those. We never migrate
+ * a Trusted OS even if it claims to be capable of migration -- doing so will
+ * require cooperation with a Trusted OS driver.
+ */
+static int resident_cpu = -1;
+
+static bool psci_tos_resident_on(int cpu)
+{
+	return cpu == resident_cpu;
+}
+
 struct psci_operations {
 	int (*cpu_suspend)(struct psci_power_state state,
 			   unsigned long entry_point);

arch/arm64/kernel/psci.c +0 -0

 static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
 						 unsigned int cpu)
 {

@@ -261,6 +280,40 @@ static void psci_sys_poweroff(void)
 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);

Quoted 54 lines · Mark Rutland

Software resident in the secure world (a "Trusted OS") may cause CPU_OFF calls for the CPU it is resident on to be denied. Such a denial would be fatal for the kernel, and so we must detect when this can happen before the point of no return.

This patch implements Trusted OS detection for PSCI 0.2+ systems, using MIGRATE_INFO_TYPE and MIGRATE_INFO_UP_CPU. When a trusted OS is detected as resident on a particular CPU, attempts to hot unplug that CPU will be denied early, before they can prove fatal.

Trusted OS migration is not implemented by this patch. Implementation of migratable UP trusted OSs seems unlikely, and the right policy for migration is unclear (and will likely differ across implementations). As such, it is likely that migration will require cooperation with Trusted OS drivers.

PSCI implementations prior to 0.1 do not provide the facility to detect the presence of a Trusted OS, nor the CPU any such OS is resident on, so without additional information it is not possible to handle Trusted OSs with PSCI 0.1.

Signed-off-by Mark Rutland <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

arch/arm64/kernel/psci.c +13 -0

index 7324db9..25e2610 100644
@@ -43,6 +43,19 @@ struct psci_power_state {
 	u8	affinity_level;
 };
 
+/*
+ * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
+ * calls to its resident CPU, so we must avoid issuing those. We never migrate
+ * a Trusted OS even if it claims to be capable of migration -- doing so will
+ * require cooperation with a Trusted OS driver.
+ */
+static int resident_cpu = -1;
+
+static bool psci_tos_resident_on(int cpu)
+{
+	return cpu == resident_cpu;
+}
+
 struct psci_operations {
 	int (*cpu_suspend)(struct psci_power_state state,
 			   unsigned long entry_point);

arch/arm64/kernel/psci.c struct psci_operations { · line 68

Quoted 4 lines

arch/arm64/kernel/psci.c +1 -0

@@ -52,6 +65,7 @@ struct psci_operations {
 	int (*affinity_info)(unsigned long target_affinity,
 			unsigned long lowest_affinity_level);
 	int (*migrate_info_type)(void);
+	unsigned long (*migrate_info_up_cpu)(void);

Do we really need to keep a pointer in the ops for this function ? I think we can just call it once for all at boot and be done with that.

Actually the same comment applies to migrate_info_type.

Quoted 8 lines

arch/arm64/kernel/psci.c +0 -0

 };
 
 static struct psci_operations psci_ops;

@@ -172,6 +186,11 @@ static int psci_migrate_info_type(void)
 	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
 }
 

arch/arm64/kernel/psci.c static int psci_migrate_info_type(void) · line 192

Quoted 4 lines

arch/arm64/kernel/psci.c +4 -0

+static unsigned long psci_migrate_info_up_cpu(void)
+{
+	return invoke_psci_fn(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, 0, 0, 0);
+}

See above, why can't we just invoke the function at probe time (we do not support migration hence I do not see why we want to keep the function after boot, it will never be called IIUC) ?

Quoted 5 lines

arch/arm64/kernel/psci.c +0 -0

 static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
 						 unsigned int cpu)
 {

@@ -261,6 +280,40 @@ static void psci_sys_poweroff(void)
 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);

arch/arm64/kernel/psci.c static void psci_sys_poweroff(void) · line 290

Quoted 10 lines

arch/arm64/kernel/psci.c +8 -0

 }
 
+/*
+ * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
+ * return DENIED (which would be fatal).
+ */
+static void __init psci_init_migrate(void)
+{
+	unsigned long cpuid;
+	int type, cpu = -1;

Nit: cpu variable initialization is useless.

Apart from these minor comments patch is fine.

Software resident in the secure world (a "Trusted OS") may cause CPU_OFF calls for the CPU it is resident on to be denied. Such a denial would be fatal for the kernel, and so we must detect when this can happen before the point of no return.

This patch implements Trusted OS detection for PSCI 0.2+ systems, using MIGRATE_INFO_TYPE and MIGRATE_INFO_UP_CPU. When a trusted OS is detected as resident on a particular CPU, attempts to hot unplug that CPU will be denied early, before they can prove fatal.

Trusted OS migration is not implemented by this patch. Implementation of migratable UP trusted OSs seems unlikely, and the right policy for migration is unclear (and will likely differ across implementations). As such, it is likely that migration will require cooperation with Trusted OS drivers.

PSCI implementations prior to 0.1 do not provide the facility to detect the presence of a Trusted OS, nor the CPU any such OS is resident on, so without additional information it is not possible to handle Trusted OSs with PSCI 0.1.

Signed-off-by Mark Rutland <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

arch/arm64/kernel/psci.c +47 -0

index 7324db9..25e2610 100644
@@ -43,6 +43,19 @@ struct psci_power_state {
        u8      affinity_level;
 };
 
+/*
+ * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
+ * calls to its resident CPU, so we must avoid issuing those. We never migrate
+ * a Trusted OS even if it claims to be capable of migration -- doing so will
+ * require cooperation with a Trusted OS driver.
+ */
+static int resident_cpu = -1;
+
+static bool psci_tos_resident_on(int cpu)
+{
+       return cpu == resident_cpu;
+}
+
 struct psci_operations {
        int (*cpu_suspend)(struct psci_power_state state,
                           unsigned long entry_point);

@@ -52,6 +65,7 @@ struct psci_operations {
        int (*affinity_info)(unsigned long target_affinity,
                        unsigned long lowest_affinity_level);
        int (*migrate_info_type)(void);
+       unsigned long (*migrate_info_up_cpu)(void);
 };
 
 static struct psci_operations psci_ops;

@@ -172,6 +186,11 @@ static int psci_migrate_info_type(void)
        return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
 }
 
+static unsigned long psci_migrate_info_up_cpu(void)
+{
+       return invoke_psci_fn(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, 0, 0, 0);
+}
+
 static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
                                                 unsigned int cpu)
 {

@@ -261,6 +280,40 @@ static void psci_sys_poweroff(void)
        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
 }
 
+/*
+ * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
+ * return DENIED (which would be fatal).
+ */
+static void __init psci_init_migrate(void)
+{
+       unsigned long cpuid;
+       int type, cpu = -1;
+
+       type = psci_ops.migrate_info_type();
+
+       if (type == PSCI_0_2_TOS_MP) {
+               pr_info("Trusted OS migration not required\n");
+               return;
+       }
+
+       if (type == PSCI_RET_NOT_SUPPORTED) {
+               pr_info("MIGRATE_INFO_TYPE not supported.\n");
+               return;
+       }
+
+       if (type != PSCI_0_2_TOS_UP_MIGRATE &&
+           type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
+               pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
+               return;
+       }
+
+       cpuid = psci_ops.migrate_info_up_cpu();

arch/arm64/kernel/psci.c +9 -0

+       cpu = get_logical_index(cpuid);
+       resident_cpu = cpu >= 0 ? cpu : -1;
+
+       pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
+}
+
 static void __init psci_0_2_set_functions(void)
 {
        pr_info("Using standard PSCI v0.2 function IDs\n");

@@ -279,6 +332,7 @@ static void __init psci_0_2_set_functions(void)
        psci_ops.affinity_info = psci_affinity_info;
 
        psci_ops.migrate_info_type = psci_migrate_info_type;
+       psci_ops.migrate_info_up_cpu = psci_migrate_info_up_cpu;
 
        arm_pm_restart = psci_sys_reset;
 

@@ -303,6 +357,8 @@ static int __init psci_probe(void)
 
        psci_0_2_set_functions();
 
+       psci_init_migrate();
+
        return 0;
 }
 

Quoted 49 lines · Mark Rutland

Software resident in the secure world (a "Trusted OS") may cause CPU_OFF calls for the CPU it is resident on to be denied. Such a denial would be fatal for the kernel, and so we must detect when this can happen before the point of no return.

This patch implements Trusted OS detection for PSCI 0.2+ systems, using MIGRATE_INFO_TYPE and MIGRATE_INFO_UP_CPU. When a trusted OS is detected as resident on a particular CPU, attempts to hot unplug that CPU will be denied early, before they can prove fatal.

Trusted OS migration is not implemented by this patch. Implementation of migratable UP trusted OSs seems unlikely, and the right policy for migration is unclear (and will likely differ across implementations). As such, it is likely that migration will require cooperation with Trusted OS drivers.

PSCI implementations prior to 0.1 do not provide the facility to detect the presence of a Trusted OS, nor the CPU any such OS is resident on, so without additional information it is not possible to handle Trusted OSs with PSCI 0.1.

Signed-off-by Mark Rutland <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

arch/arm64/kernel/psci.c +12 -0

index 7324db9..25e2610 100644
@@ -43,6 +43,19 @@ struct psci_power_state {
        u8      affinity_level;
 };
 
+/*
+ * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
+ * calls to its resident CPU, so we must avoid issuing those. We never migrate
+ * a Trusted OS even if it claims to be capable of migration -- doing so will
+ * require cooperation with a Trusted OS driver.
+ */
+static int resident_cpu = -1;
+
+static bool psci_tos_resident_on(int cpu)
+{
+       return cpu == resident_cpu;
+}

Quoted 28 lines

arch/arm64/kernel/psci.c +28 -0

+/*
+ * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
+ * return DENIED (which would be fatal).
+ */
+static void __init psci_init_migrate(void)
+{
+       unsigned long cpuid;
+       int type, cpu = -1;
+
+       type = psci_ops.migrate_info_type();
+
+       if (type == PSCI_0_2_TOS_MP) {
+               pr_info("Trusted OS migration not required\n");
+               return;
+       }
+
+       if (type == PSCI_RET_NOT_SUPPORTED) {
+               pr_info("MIGRATE_INFO_TYPE not supported.\n");
+               return;
+       }
+
+       if (type != PSCI_0_2_TOS_UP_MIGRATE &&
+           type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
+               pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
+               return;
+       }
+
+       cpuid = psci_ops.migrate_info_up_cpu();

[..]

Quoted 5 lines

arch/arm64/kernel/psci.c +5 -0

+       cpu = get_logical_index(cpuid);
+       resident_cpu = cpu >= 0 ? cpu : -1;
+
+       pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
+}

arch/arm64/kernel/psci.c static int cpu_psci_cpu_disable(unsigned int cpu) · line 510

Quoted 7 lines

arch/arm64/kernel/psci.c +3 -0

@@ -449,6 +505,11 @@ static int cpu_psci_cpu_disable(unsigned int cpu)
        /* Fail early if we don't have CPU_OFF support */
        if (!psci_ops.cpu_off)
                return -EOPNOTSUPP;
+
+       /* Trusted OS will deny CPU_OFF */
+       if (psci_tos_resident_on(cpu))

IIUC, you're denying CPU_OFF even if MIGRATE_INFO_TYPE = 2. Is that correct?

A PSCI 1.0 implementation may choose to use the new extended StateID format, the presence of which may be queried via the PSCI_FEATURES call. The layout of this new StateID format is incompatible with the existing format, and so to handle both we must abstract attempts to parse the fields.

In preparation for PSCI 1.0 support, this patch introduces psci_power_state_loses_context and psci_power_state_is_valid functions to query information from a PSCI power state, which is no longer decomposed (and hence the pack/unpack functions are removed). As it is no longer decomposed, it is now passed round as an opaque u32 token.

Signed-off-by Mark Rutland <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++----------------------------
 1 file changed, 37 insertions(+), 52 deletions(-)

arch/arm64/kernel/psci.c +37 -52

index 25e2610..185174e 100644
@@ -37,11 +37,19 @@
 #define PSCI_POWER_STATE_TYPE_STANDBY		0
 #define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
 
-struct psci_power_state {
-	u16	id;
-	u8	type;
-	u8	affinity_level;
-};
+static bool psci_power_state_loses_context(u32 state)
+{
+	return !!(state & PSCI_0_2_POWER_STATE_TYPE_MASK);
+}
+
+static bool psci_power_state_is_valid(u32 state)
+{
+	const u32 valid_mask = PSCI_0_2_POWER_STATE_ID_MASK |
+			       PSCI_0_2_POWER_STATE_TYPE_MASK |
+			       PSCI_0_2_POWER_STATE_AFFL_MASK;
+
+	return !(state & ~valid_mask);
+}
 
 /*
  * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF

@@ -57,9 +65,8 @@ static bool psci_tos_resident_on(int cpu)
 }
 
 struct psci_operations {
-	int (*cpu_suspend)(struct psci_power_state state,
-			   unsigned long entry_point);
-	int (*cpu_off)(struct psci_power_state state);
+	int (*cpu_suspend)(u32 state, unsigned long entry_point);
+	int (*cpu_off)(u32 state);
 	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
 	int (*migrate)(unsigned long cpuid);
 	int (*affinity_info)(unsigned long target_affinity,

@@ -84,7 +91,7 @@ enum psci_function {
 	PSCI_FN_MAX,
 };
 
-static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
+static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
 
 static u32 psci_function_id[PSCI_FN_MAX];
 

@@ -104,53 +111,28 @@ static int psci_to_linux_errno(int errno)
 	return -EINVAL;
 }
 
-static u32 psci_power_state_pack(struct psci_power_state state)
-{
-	return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
-			& PSCI_0_2_POWER_STATE_ID_MASK) |
-		((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
-		 & PSCI_0_2_POWER_STATE_TYPE_MASK) |
-		((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
-		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
-}
-
-static void psci_power_state_unpack(u32 power_state,
-				    struct psci_power_state *state)
-{
-	state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
-			PSCI_0_2_POWER_STATE_ID_SHIFT;
-	state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
-			PSCI_0_2_POWER_STATE_TYPE_SHIFT;
-	state->affinity_level =
-			(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
-			PSCI_0_2_POWER_STATE_AFFL_SHIFT;
-}
-
 static u32 psci_get_version(void)
 {
 	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 }
 
-static int psci_cpu_suspend(struct psci_power_state state,
-			    unsigned long entry_point)
+static int psci_cpu_suspend(u32 state, unsigned long entry_point)
 {
 	int err;
-	u32 fn, power_state;
+	u32 fn;
 
 	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
-	power_state = psci_power_state_pack(state);
-	err = invoke_psci_fn(fn, power_state, entry_point, 0);
+	err = invoke_psci_fn(fn, state, entry_point, 0);
 	return psci_to_linux_errno(err);
 }
 
-static int psci_cpu_off(struct psci_power_state state)
+static int psci_cpu_off(u32 state)
 {
 	int err;
-	u32 fn, power_state;
+	u32 fn;
 
 	fn = psci_function_id[PSCI_FN_CPU_OFF];
-	power_state = psci_power_state_pack(state);
-	err = invoke_psci_fn(fn, power_state, 0, 0);
+	err = invoke_psci_fn(fn, state, 0, 0);
 	return psci_to_linux_errno(err);
 }
 

@@ -195,7 +177,7 @@ static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
 						 unsigned int cpu)
 {
 	int i, ret, count = 0;
-	struct psci_power_state *psci_states;
+	u32 *psci_states;
 	struct device_node *state_node;
 
 	/*

@@ -220,13 +202,13 @@ static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
 		return -ENOMEM;
 
 	for (i = 0; i < count; i++) {
-		u32 psci_power_state;
+		u32 state;
 
 		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
 
 		ret = of_property_read_u32(state_node,
 					   "arm,psci-suspend-param",
-					   &psci_power_state);
+					   &state);
 		if (ret) {
 			pr_warn(" * %s missing arm,psci-suspend-param property\n",
 				state_node->full_name);

@@ -235,9 +217,13 @@ static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
 		}
 
 		of_node_put(state_node);
-		pr_debug("psci-power-state %#x index %d\n", psci_power_state,
-							    i);
-		psci_power_state_unpack(psci_power_state, &psci_states[i]);
+		pr_debug("psci-power-state %#x index %d\n", state, i);
+		if (!psci_power_state_is_valid(state)) {
+			pr_warn("Invalid PSCI power state %#x\n", state);
+			ret = -EINVAL;
+			goto free_mem;
+		}
+		psci_states[i] = state;
 	}
 	/* Idle states parsed correctly, initialize per-cpu pointer */
 	per_cpu(psci_power_state, cpu) = psci_states;

@@ -520,9 +506,8 @@ static void cpu_psci_cpu_die(unsigned int cpu)
 	 * There are no known implementations of PSCI actually using the
 	 * power state field, pass a sensible default for now.
 	 */
-	struct psci_power_state state = {
-		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
-	};
+	u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
+		    PSCI_0_2_POWER_STATE_TYPE_SHIFT;
 
 	ret = psci_ops.cpu_off(state);
 

@@ -561,7 +546,7 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
 
 static int psci_suspend_finisher(unsigned long index)
 {
-	struct psci_power_state *state = __this_cpu_read(psci_power_state);
+	u32 *state = __this_cpu_read(psci_power_state);
 
 	return psci_ops.cpu_suspend(state[index - 1],
 				    virt_to_phys(cpu_resume));

@@ -570,7 +555,7 @@ static int psci_suspend_finisher(unsigned long index)
 static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
 {
 	int ret;
-	struct psci_power_state *state = __this_cpu_read(psci_power_state);
+	u32 *state = __this_cpu_read(psci_power_state);
 	/*
 	 * idle state index 0 corresponds to wfi, should never be called
 	 * from the cpu_suspend operations

@@ -578,7 +563,7 @@ static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
 	if (WARN_ON_ONCE(!index))
 		return -EINVAL;
 
-	if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
+	if (!psci_power_state_loses_context(state[index - 1]))
 		ret = psci_ops.cpu_suspend(state[index - 1], 0);
 	else
 		ret = __cpu_suspend(index, psci_suspend_finisher);

Signature · 1 line

1.9.1

The 32-bit ARM port doesn't have ACPI headers, and conditionally including them is going to look horrendous. In preparation for sharing the PSCI invocation code with 32-bit, move the acpi_psci_* function declarations and definitions such that the PSCI client code need not include ACPI headers.

While it would seem like we could simply hide the ACPI includes in psci.h, the ACPI headers have hilarious circular dependencies which make this infeasible without reorganising most of ACPICA. So rather than doing that, move the acpi_psci_* prototypes into psci.h.

The psci_acpi_init function is made dependent on CONFIG_ACPI (with a stub implementation in asm/psci.h) such that it need not be built for 32-bit ARM or kernels without ACPI support. The currently missing __init annotations are added to the prototypes in the header.

Signed-off-by Mark Rutland <[email protected]>

Cc Al Stone <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Hanjun Guo <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm64/include/asm/acpi.h | 14 --------------
 arch/arm64/include/asm/psci.h | 11 +++++++++--
 arch/arm64/kernel/acpi.c      | 11 +++++++++++
 arch/arm64/kernel/psci.c      |  4 ++--
 4 files changed, 22 insertions(+), 18 deletions(-)

arch/arm64/include/asm/acpi.h +0 -14

index 59c05d8..b0fecad 100644
@@ -39,18 +39,6 @@ extern int acpi_disabled;
 extern int acpi_noirq;
 extern int acpi_pci_disabled;
 
-/* 1 to indicate PSCI 0.2+ is implemented */
-static inline bool acpi_psci_present(void)
-{
-       return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
-}
-
-/* 1 to indicate HVC must be used instead of SMC as the PSCI conduit */
-static inline bool acpi_psci_use_hvc(void)
-{
-       return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
-}
-
 static inline void disable_acpi(void)
 {
        acpi_disabled = 1;

@@ -88,8 +76,6 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 void __init acpi_init_cpus(void);
 
 #else
-static inline bool acpi_psci_present(void) { return false; }
-static inline bool acpi_psci_use_hvc(void) { return false; }
 static inline void acpi_init_cpus(void) { }
 #endif /* CONFIG_ACPI */
 

arch/arm64/include/asm/psci.h +9 -2

index 2454bc5..b5d4c1d 100644
@@ -14,7 +14,14 @@
 #ifndef __ASM_PSCI_H
 #define __ASM_PSCI_H
 
-int psci_dt_init(void);
-int psci_acpi_init(void);
+int __init psci_dt_init(void);
+
+#ifdef CONFIG_ACPI
+int __init psci_acpi_init(void);
+bool __init acpi_psci_present(void);
+bool __init acpi_psci_use_hvc(void);
+#else
+static inline int psci_acpi_init(void) { return 0; }
+#endif
 
 #endif /* __ASM_PSCI_H */

arch/arm64/kernel/acpi.c +11 -0

index 8b83955..fe56771b 100644
@@ -95,6 +95,17 @@ void __init __acpi_unmap_table(char *map, unsigned long size)
        early_memunmap(map, size);
 }
 
+bool __init acpi_psci_present(void)
+{
+       return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
+}
+
+/* Whether HVC must be used instead of SMC as the PSCI conduit */
+bool __init acpi_psci_use_hvc(void)
+{
+       return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
+}
+
 /**
  * acpi_map_gic_cpu_interface - generates a logical cpu number
  * and map to MPIDR represented by GICC structure

arch/arm64/kernel/psci.c +2 -3

index 185174e..ea89429 100644
@@ -15,7 +15,6 @@
 
 #define pr_fmt(fmt) "psci: " fmt
 
-#include <linux/acpi.h>
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/smp.h>

@@ -25,7 +24,6 @@
 #include <linux/slab.h>
 #include <uapi/linux/psci.h>
 
-#include <asm/acpi.h>
 #include <asm/compiler.h>
 #include <asm/cpu_ops.h>
 #include <asm/errno.h>

@@ -438,6 +436,7 @@ int __init psci_dt_init(void)
        return init_fn(np);
 }
 
+#ifdef CONFIG_ACPI
 /*
  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
  * explicitly clarified in SBBR

@@ -458,6 +457,7 @@ int __init psci_acpi_init(void)
 
        return psci_probe();
 }
+#endif
 
 #ifdef CONFIG_SMP
 
--

1.9.1

Now that the common PSCI client code has been factored out to drivers/firmware, and made safe for 32-bit use, move the 32-bit ARM code over to it. This results in a moderate reduction of duplicated lines, and will prevent further duplication as the PSCI client code is updated for PSCI 1.0 and beyond.

The two legacy platform users of the PSCI invocation code are updated to account for interface changes. In both cases the power state parameter is changed to an opaque u32 token in preparation for PSCI 1.0 power state changes.

Signed-off-by Mark Rutland <[email protected]>

Cc Ashwin Chaugule <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Rob Herring <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm/Kconfig                  |   1 +
 arch/arm/include/asm/psci.h       |  23 ---
 arch/arm/kernel/Makefile          |   2 +-
 arch/arm/kernel/psci.c            | 299 --------------------------------------
 arch/arm/kernel/psci_smp.c        |  29 +++-
 arch/arm/kernel/setup.c           |   3 +-
 arch/arm/mach-highbank/highbank.c |   2 +-
 arch/arm/mach-highbank/pm.c       |   8 +-
 drivers/cpuidle/cpuidle-calxeda.c |   7 +-
 9 files changed, 32 insertions(+), 342 deletions(-)
 delete mode 100644 arch/arm/kernel/psci.c

arch/arm/Kconfig +1 -0

index 45df48b..191291f 100644
@@ -1465,6 +1465,7 @@ config HOTPLUG_CPU
 config ARM_PSCI
        bool "Support for the ARM Power State Coordination Interface (PSCI)"
        depends on CPU_V7
+       select ARM_PSCI_FW
        help
          Say Y here if you want Linux to communicate with system firmware
          implementing the PSCI specification for CPU-centric power

arch/arm/include/asm/psci.h +0 -23

index c25ef3e..68ee3ce 100644
@@ -14,34 +14,11 @@
 #ifndef __ASM_ARM_PSCI_H
 #define __ASM_ARM_PSCI_H
 
-#define PSCI_POWER_STATE_TYPE_STANDBY          0
-#define PSCI_POWER_STATE_TYPE_POWER_DOWN       1
-
-struct psci_power_state {
-       u16     id;
-       u8      type;
-       u8      affinity_level;
-};
-
-struct psci_operations {
-       int (*cpu_suspend)(struct psci_power_state state,
-                          unsigned long entry_point);
-       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
-int psci_init(void);
 bool psci_smp_available(void);
 #else
-static inline int psci_init(void) { return 0; }
 static inline bool psci_smp_available(void) { return false; }
 #endif
 

arch/arm/kernel/Makefile +1 -1

index 752725d..2c06383 100644
@@ -86,7 +86,7 @@ obj-$(CONFIG_EARLY_PRINTK)    += early_printk.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)     += hyp-stub.o
 ifeq ($(CONFIG_ARM_PSCI),y)
-obj-y                          += psci.o psci-call.o
+obj-y                          += psci-call.o
 obj-$(CONFIG_SMP)              += psci_smp.o
 endif
 

arch/arm/kernel/psci.c deleted +0 -299

deleted file mode 100644
index f90fdf4..0000000
@@ -1,299 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * 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.
- *
- * Copyright (C) 2012 ARM Limited
- *
- * Author: Will Deacon <[email protected]>
- */
-
-#define pr_fmt(fmt) "psci: " fmt
-
-#include <linux/init.h>
-#include <linux/of.h>
-#include <linux/reboot.h>
-#include <linux/pm.h>
-#include <uapi/linux/psci.h>
-
-#include <asm/compiler.h>
-#include <asm/errno.h>
-#include <asm/psci.h>
-#include <asm/system_misc.h>
-
-struct psci_operations psci_ops;
-
-static int (*invoke_psci_fn)(u32, u32, u32, u32);
-typedef int (*psci_initcall_t)(const struct device_node *);
-
-asmlinkage int __invoke_psci_fn_hvc(u32, u32, u32, u32);
-asmlinkage int __invoke_psci_fn_smc(u32, u32, u32, u32);
-
-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,
-};
-
-static u32 psci_function_id[PSCI_FN_MAX];
-
-static int psci_to_linux_errno(int errno)
-{
-       switch (errno) {
-       case PSCI_RET_SUCCESS:
-               return 0;
-       case PSCI_RET_NOT_SUPPORTED:
-               return -EOPNOTSUPP;
-       case PSCI_RET_INVALID_PARAMS:
-               return -EINVAL;
-       case PSCI_RET_DENIED:
-               return -EPERM;
-       };
-
-       return -EINVAL;
-}
-
-static u32 psci_power_state_pack(struct psci_power_state state)
-{
-       return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
-                       & PSCI_0_2_POWER_STATE_ID_MASK) |
-               ((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
-                & PSCI_0_2_POWER_STATE_TYPE_MASK) |
-               ((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
-                & PSCI_0_2_POWER_STATE_AFFL_MASK);
-}
-
-static int psci_get_version(void)
-{
-       int err;
-
-       err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
-       return err;
-}
-
-static int psci_cpu_suspend(struct psci_power_state state,
-                           unsigned long entry_point)
-{
-       int err;
-       u32 fn, power_state;
-
-       fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
-       power_state = psci_power_state_pack(state);
-       err = invoke_psci_fn(fn, power_state, entry_point, 0);
-       return psci_to_linux_errno(err);
-}
-
-static int psci_cpu_off(struct psci_power_state state)
-{
-       int err;
-       u32 fn, power_state;
-
-       fn = psci_function_id[PSCI_FN_CPU_OFF];
-       power_state = psci_power_state_pack(state);
-       err = invoke_psci_fn(fn, power_state, 0, 0);
-       return psci_to_linux_errno(err);
-}
-
-static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
-{
-       int err;
-       u32 fn;
-
-       fn = psci_function_id[PSCI_FN_CPU_ON];
-       err = invoke_psci_fn(fn, cpuid, entry_point, 0);
-       return psci_to_linux_errno(err);
-}
-
-static int psci_migrate(unsigned long cpuid)
-{
-       int err;
-       u32 fn;
-
-       fn = psci_function_id[PSCI_FN_MIGRATE];
-       err = invoke_psci_fn(fn, cpuid, 0, 0);
-       return psci_to_linux_errno(err);
-}
-
-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;
-}
-
-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;
-}
-
-static int get_set_conduit_method(struct device_node *np)
-{
-       const char *method;
-
-       pr_info("probing for conduit method from DT.\n");
-
-       if (of_property_read_string(np, "method", &method)) {
-               pr_warn("missing \"method\" property\n");
-               return -ENXIO;
-       }
-
-       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);
-               return -EINVAL;
-       }
-       return 0;
-}
-
-static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
-{
-       invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
-}
-
-static void psci_sys_poweroff(void)
-{
-       invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
-}
-
-/*
- * PSCI Function IDs for v0.2+ are well defined so use
- * standard values.
- */
-static int psci_0_2_init(struct device_node *np)
-{
-       int err, ver;
-
-       err = get_set_conduit_method(np);
-
-       if (err)
-               goto out_put_node;
-
-       ver = psci_get_version();
-
-       if (ver == PSCI_RET_NOT_SUPPORTED) {
-               /* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
-               pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
-               err = -EOPNOTSUPP;
-               goto out_put_node;
-       } else {
-               pr_info("PSCIv%d.%d detected in firmware.\n",
-                               PSCI_VERSION_MAJOR(ver),
-                               PSCI_VERSION_MINOR(ver));
-
-               if (PSCI_VERSION_MAJOR(ver) == 0 &&
-                               PSCI_VERSION_MINOR(ver) < 2) {
-                       err = -EINVAL;
-                       pr_err("Conflicting PSCI version detected.\n");
-                       goto out_put_node;
-               }
-       }
-
-       pr_info("Using standard PSCI v0.2 function IDs\n");
-       psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_CPU_SUSPEND;
-       psci_ops.cpu_suspend = psci_cpu_suspend;
-
-       psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
-       psci_ops.cpu_off = psci_cpu_off;
-
-       psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_CPU_ON;
-       psci_ops.cpu_on = psci_cpu_on;
-
-       psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_MIGRATE;
-       psci_ops.migrate = psci_migrate;
-
-       psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN_AFFINITY_INFO;
-       psci_ops.affinity_info = psci_affinity_info;
-
-       psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
-               PSCI_0_2_FN_MIGRATE_INFO_TYPE;
-       psci_ops.migrate_info_type = psci_migrate_info_type;
-
-       arm_pm_restart = psci_sys_reset;
-
-       pm_power_off = psci_sys_poweroff;
-
-out_put_node:
-       of_node_put(np);
-       return err;
-}
-
-/*
- * PSCI < v0.2 get PSCI Function IDs via DT.
- */
-static int psci_0_1_init(struct device_node *np)
-{
-       u32 id;
-       int err;
-
-       err = get_set_conduit_method(np);
-
-       if (err)
-               goto out_put_node;
-
-       pr_info("Using PSCI v0.1 Function IDs from DT\n");
-
-       if (!of_property_read_u32(np, "cpu_suspend", &id)) {
-               psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
-               psci_ops.cpu_suspend = psci_cpu_suspend;
-       }
-
-       if (!of_property_read_u32(np, "cpu_off", &id)) {
-               psci_function_id[PSCI_FN_CPU_OFF] = id;
-               psci_ops.cpu_off = psci_cpu_off;
-       }
-
-       if (!of_property_read_u32(np, "cpu_on", &id)) {
-               psci_function_id[PSCI_FN_CPU_ON] = id;
-               psci_ops.cpu_on = psci_cpu_on;
-       }
-
-       if (!of_property_read_u32(np, "migrate", &id)) {
-               psci_function_id[PSCI_FN_MIGRATE] = id;
-               psci_ops.migrate = psci_migrate;
-       }
-
-out_put_node:
-       of_node_put(np);
-       return err;
-}
-
-static const struct of_device_id psci_of_match[] __initconst = {
-       { .compatible = "arm,psci", .data = psci_0_1_init},
-       { .compatible = "arm,psci-0.2", .data = psci_0_2_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);
-}

arch/arm/kernel/psci_smp.c +2 -0

index 28a1db4..2d4a7255 100644
@@ -17,6 +17,8 @@
 #include <linux/smp.h>
 #include <linux/of.h>
 #include <linux/delay.h>
+#include <linux/psci.h>
+
 #include <uapi/linux/psci.h>
 
 #include <asm/psci.h>

@@ -56,17 +58,29 @@ static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle)
 }
 
 #ifdef CONFIG_HOTPLUG_CPU

Quoted 415 lines · Mark Rutland

Now that the common PSCI client code has been factored out to drivers/firmware, and made safe for 32-bit use, move the 32-bit ARM code over to it. This results in a moderate reduction of duplicated lines, and will prevent further duplication as the PSCI client code is updated for PSCI 1.0 and beyond.

The two legacy platform users of the PSCI invocation code are updated to account for interface changes. In both cases the power state parameter is changed to an opaque u32 token in preparation for PSCI 1.0 power state changes.

Signed-off-by Mark Rutland <[email protected]>

Cc Ashwin Chaugule <[email protected]>

Cc Catalin Marinas <[email protected]>

Cc Lorenzo Pieralisi <[email protected]>

Cc Rob Herring <[email protected]>

Cc Will Deacon <[email protected]>

---
 arch/arm/Kconfig                  |   1 +
 arch/arm/include/asm/psci.h       |  23 ---
 arch/arm/kernel/Makefile          |   2 +-
 arch/arm/kernel/psci.c            | 299 --------------------------------------
 arch/arm/kernel/psci_smp.c        |  29 +++-
 arch/arm/kernel/setup.c           |   3 +-
 arch/arm/mach-highbank/highbank.c |   2 +-
 arch/arm/mach-highbank/pm.c       |   8 +-
 drivers/cpuidle/cpuidle-calxeda.c |   7 +-
 9 files changed, 32 insertions(+), 342 deletions(-)
 delete mode 100644 arch/arm/kernel/psci.c

arch/arm/Kconfig +1 -0

index 45df48b..191291f 100644
@@ -1465,6 +1465,7 @@ config HOTPLUG_CPU
 config ARM_PSCI
        bool "Support for the ARM Power State Coordination Interface (PSCI)"
        depends on CPU_V7
+       select ARM_PSCI_FW
        help
          Say Y here if you want Linux to communicate with system firmware
          implementing the PSCI specification for CPU-centric power

arch/arm/include/asm/psci.h +0 -23

index c25ef3e..68ee3ce 100644
@@ -14,34 +14,11 @@
 #ifndef __ASM_ARM_PSCI_H
 #define __ASM_ARM_PSCI_H
 
-#define PSCI_POWER_STATE_TYPE_STANDBY          0
-#define PSCI_POWER_STATE_TYPE_POWER_DOWN       1
-
-struct psci_power_state {
-       u16     id;
-       u8      type;
-       u8      affinity_level;
-};
-
-struct psci_operations {
-       int (*cpu_suspend)(struct psci_power_state state,
-                          unsigned long entry_point);
-       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
-int psci_init(void);
 bool psci_smp_available(void);
 #else
-static inline int psci_init(void) { return 0; }
 static inline bool psci_smp_available(void) { return false; }
 #endif
 

arch/arm/kernel/Makefile +1 -1

index 752725d..2c06383 100644
@@ -86,7 +86,7 @@ obj-$(CONFIG_EARLY_PRINTK)    += early_printk.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)     += hyp-stub.o
 ifeq ($(CONFIG_ARM_PSCI),y)
-obj-y                          += psci.o psci-call.o
+obj-y                          += psci-call.o
 obj-$(CONFIG_SMP)              += psci_smp.o
 endif
 

arch/arm/kernel/psci.c deleted +0 -299

deleted file mode 100644
index f90fdf4..0000000
@@ -1,299 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * 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.
- *
- * Copyright (C) 2012 ARM Limited
- *
- * Author: Will Deacon <[email protected]>
- */
-
-#define pr_fmt(fmt) "psci: " fmt
-
-#include <linux/init.h>
-#include <linux/of.h>
-#include <linux/reboot.h>
-#include <linux/pm.h>
-#include <uapi/linux/psci.h>
-
-#include <asm/compiler.h>
-#include <asm/errno.h>
-#include <asm/psci.h>
-#include <asm/system_misc.h>
-
-struct psci_operations psci_ops;
-
-static int (*invoke_psci_fn)(u32, u32, u32, u32);
-typedef int (*psci_initcall_t)(const struct device_node *);
-
-asmlinkage int __invoke_psci_fn_hvc(u32, u32, u32, u32);
-asmlinkage int __invoke_psci_fn_smc(u32, u32, u32, u32);
-
-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,
-};
-
-static u32 psci_function_id[PSCI_FN_MAX];
-
-static int psci_to_linux_errno(int errno)
-{
-       switch (errno) {
-       case PSCI_RET_SUCCESS:
-               return 0;
-       case PSCI_RET_NOT_SUPPORTED:
-               return -EOPNOTSUPP;
-       case PSCI_RET_INVALID_PARAMS:
-               return -EINVAL;
-       case PSCI_RET_DENIED:
-               return -EPERM;
-       };
-
-       return -EINVAL;
-}
-
-static u32 psci_power_state_pack(struct psci_power_state state)
-{
-       return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
-                       & PSCI_0_2_POWER_STATE_ID_MASK) |
-               ((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
-                & PSCI_0_2_POWER_STATE_TYPE_MASK) |
-               ((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
-                & PSCI_0_2_POWER_STATE_AFFL_MASK);
-}
-
-static int psci_get_version(void)
-{
-       int err;
-
-       err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
-       return err;
-}
-
-static int psci_cpu_suspend(struct psci_power_state state,
-                           unsigned long entry_point)
-{
-       int err;
-       u32 fn, power_state;
-
-       fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
-       power_state = psci_power_state_pack(state);
-       err = invoke_psci_fn(fn, power_state, entry_point, 0);
-       return psci_to_linux_errno(err);
-}
-
-static int psci_cpu_off(struct psci_power_state state)
-{
-       int err;
-       u32 fn, power_state;
-
-       fn = psci_function_id[PSCI_FN_CPU_OFF];
-       power_state = psci_power_state_pack(state);
-       err = invoke_psci_fn(fn, power_state, 0, 0);
-       return psci_to_linux_errno(err);
-}
-
-static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
-{
-       int err;
-       u32 fn;
-
-       fn = psci_function_id[PSCI_FN_CPU_ON];
-       err = invoke_psci_fn(fn, cpuid, entry_point, 0);
-       return psci_to_linux_errno(err);
-}
-
-static int psci_migrate(unsigned long cpuid)
-{
-       int err;
-       u32 fn;
-
-       fn = psci_function_id[PSCI_FN_MIGRATE];
-       err = invoke_psci_fn(fn, cpuid, 0, 0);
-       return psci_to_linux_errno(err);
-}
-
-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;
-}
-
-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;
-}
-
-static int get_set_conduit_method(struct device_node *np)
-{
-       const char *method;
-
-       pr_info("probing for conduit method from DT.\n");
-
-       if (of_property_read_string(np, "method", &method)) {
-               pr_warn("missing \"method\" property\n");
-               return -ENXIO;
-       }
-
-       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);
-               return -EINVAL;
-       }
-       return 0;
-}
-
-static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
-{
-       invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
-}
-
-static void psci_sys_poweroff(void)
-{
-       invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
-}
-
-/*
- * PSCI Function IDs for v0.2+ are well defined so use
- * standard values.
- */
-static int psci_0_2_init(struct device_node *np)
-{
-       int err, ver;
-
-       err = get_set_conduit_method(np);
-
-       if (err)
-               goto out_put_node;
-
-       ver = psci_get_version();
-
-       if (ver == PSCI_RET_NOT_SUPPORTED) {
-               /* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
-               pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
-               err = -EOPNOTSUPP;
-               goto out_put_node;
-       } else {
-               pr_info("PSCIv%d.%d detected in firmware.\n",
-                               PSCI_VERSION_MAJOR(ver),
-                               PSCI_VERSION_MINOR(ver));
-
-               if (PSCI_VERSION_MAJOR(ver) == 0 &&
-                               PSCI_VERSION_MINOR(ver) < 2) {
-                       err = -EINVAL;
-                       pr_err("Conflicting PSCI version detected.\n");
-                       goto out_put_node;
-               }
-       }
-
-       pr_info("Using standard PSCI v0.2 function IDs\n");
-       psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_CPU_SUSPEND;
-       psci_ops.cpu_suspend = psci_cpu_suspend;
-
-       psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
-       psci_ops.cpu_off = psci_cpu_off;
-
-       psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_CPU_ON;
-       psci_ops.cpu_on = psci_cpu_on;
-
-       psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_MIGRATE;
-       psci_ops.migrate = psci_migrate;
-
-       psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN_AFFINITY_INFO;
-       psci_ops.affinity_info = psci_affinity_info;
-
-       psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
-               PSCI_0_2_FN_MIGRATE_INFO_TYPE;
-       psci_ops.migrate_info_type = psci_migrate_info_type;
-
-       arm_pm_restart = psci_sys_reset;
-
-       pm_power_off = psci_sys_poweroff;
-
-out_put_node:
-       of_node_put(np);
-       return err;
-}
-
-/*
- * PSCI < v0.2 get PSCI Function IDs via DT.
- */
-static int psci_0_1_init(struct device_node *np)
-{
-       u32 id;
-       int err;
-
-       err = get_set_conduit_method(np);
-
-       if (err)
-               goto out_put_node;
-
-       pr_info("Using PSCI v0.1 Function IDs from DT\n");
-
-       if (!of_property_read_u32(np, "cpu_suspend", &id)) {
-               psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
-               psci_ops.cpu_suspend = psci_cpu_suspend;
-       }
-
-       if (!of_property_read_u32(np, "cpu_off", &id)) {
-               psci_function_id[PSCI_FN_CPU_OFF] = id;
-               psci_ops.cpu_off = psci_cpu_off;
-       }
-
-       if (!of_property_read_u32(np, "cpu_on", &id)) {
-               psci_function_id[PSCI_FN_CPU_ON] = id;
-               psci_ops.cpu_on = psci_cpu_on;
-       }
-
-       if (!of_property_read_u32(np, "migrate", &id)) {
-               psci_function_id[PSCI_FN_MIGRATE] = id;
-               psci_ops.migrate = psci_migrate;
-       }
-
-out_put_node:
-       of_node_put(np);
-       return err;
-}
-
-static const struct of_device_id psci_of_match[] __initconst = {
-       { .compatible = "arm,psci", .data = psci_0_1_init},
-       { .compatible = "arm,psci-0.2", .data = psci_0_2_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);
-}

arch/arm/kernel/psci_smp.c +2 -0

index 28a1db4..2d4a7255 100644
@@ -17,6 +17,8 @@
 #include <linux/smp.h>
 #include <linux/of.h>
 #include <linux/delay.h>
+#include <linux/psci.h>
+
 #include <uapi/linux/psci.h>
 
 #include <asm/psci.h>

@@ -56,17 +58,29 @@ static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle)
 }
 

arch/arm/kernel/psci_smp.c static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle) · line 70

Quoted 11 lines

arch/arm/kernel/psci_smp.c +10 -0

 #ifdef CONFIG_HOTPLUG_CPU
+int psci_cpu_disable(unsigned int cpu)
+{
+       /* Fail early if we don't have CPU_OFF support */
+       if (!psci_ops.cpu_off)
+               return 0;
+
+       /* Trusted OS will deny CPU_OFF */
+       if (psci_tos_resident_on(cpu))
+               return 0;
+

Same question here. Seems like if MIGRATE_INFO_TYPE = 2 ( TOS is present or does not require migration), you should be able to call CPU_OFF. Otherwise the patch looks fine to me.

Quoted 6 lines

Quoted 6 lines

arch/arm/kernel/psci_smp.c +6 -0

+int psci_cpu_disable(unsigned int cpu)
+{
+       /* Fail early if we don't have CPU_OFF support */
+       if (!psci_ops.cpu_off)
+               return 0;
+

Quoted 8 lines

arch/arm/kernel/psci_smp.c static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle) · line 70

Quoted 4 lines

arch/arm/kernel/psci_smp.c +4 -0

+       /* Trusted OS will deny CPU_OFF */
+       if (psci_tos_resident_on(cpu))
+               return 0;
+

Same question here. Seems like if MIGRATE_INFO_TYPE = 2 ( TOS is present or does not require migration), you should be able to call CPU_OFF. Otherwise the patch looks fine to me.

err. Make that TOS is not present.

Quoted 15 lines

Quoted 14 lines

arch/arm/kernel/psci_smp.c static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle) · line 70

Quoted 10 lines

arch/arm/kernel/psci_smp.c +10 -0

+int psci_cpu_disable(unsigned int cpu)
+{
+       /* Fail early if we don't have CPU_OFF support */
+       if (!psci_ops.cpu_off)
+               return 0;
+
+       /* Trusted OS will deny CPU_OFF */
+       if (psci_tos_resident_on(cpu))
+               return 0;
+

Same question here. Seems like if MIGRATE_INFO_TYPE = 2 ( TOS is present or does not require migration), you should be able to call CPU_OFF. Otherwise the patch looks fine to me.

Quoted 1 line

err. Make that TOS is not present.

In the cases where migration is not required, resident_cpu == -1, and psci_tos_resident_on(cpu) will return false for any valid CPU. So I don't see that we would deny migration here.

Quoted 17 lines · Mark Rutland

Quoted 16 lines

Quoted 6 lines

Quoted 6 lines

arch/arm/kernel/psci_smp.c +6 -0

+int psci_cpu_disable(unsigned int cpu)
+{
+       /* Fail early if we don't have CPU_OFF support */
+       if (!psci_ops.cpu_off)
+               return 0;
+

Quoted 8 lines

arch/arm/kernel/psci_smp.c static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle) · line 70

Quoted 4 lines

arch/arm/kernel/psci_smp.c +4 -0

+       /* Trusted OS will deny CPU_OFF */
+       if (psci_tos_resident_on(cpu))
+               return 0;
+

Same question here. Seems like if MIGRATE_INFO_TYPE = 2 ( TOS is present or does not require migration), you should be able to call CPU_OFF. Otherwise the patch looks fine to me.

err. Make that TOS is not present.

Quoted 4 lines

In the cases where migration is not required, resident_cpu == -1, and psci_tos_resident_on(cpu) will return false for any valid CPU. So I don't see that we would deny migration here.

Hm. Perhaps I was confused by the "return -EPERM" in the arm64 version and "return 0" here. :)