[PATCH 00/12] arm/arm64: Unify PSCI client support

[PATCH 00/12] arm/arm64: Unify PSCI client support

[Mark Rutland]

This series unifies the 32-bit and 64-bit PSCI client code, moving the bulk of
the FW invocation and probing out to a common locaiton in drivers/firmware.
As part of this, the remaining edge cases for PSCI 0.2 (Trusted OSs rejecting
CPU_OFF) are accounted for, maknig both 32-bit adn 64-bit clients more robust.

This results in a reasonable saving in terms of lines of code, and will allow
for PSCI 1.0 support to be unified form the beginning, avoiding further
duplication.

The series is based on v4.0-rc2.

Thanks,
Mark.

Mark Rutland (12):
  arm/arm64: kvm: add missing PSCI include
  arm64: smp_plat: add get_logical_index
  arm64: smp: consistently use error codes
  arm64: psci: remove unnecessary id indirection
  arm64: psci: support unsigned return values
  arm64: psci: account for Trusted OS instances
  arm64: psci: kill psci_power_state
  arm64: psci: remove ACPI coupling
  arm64: psci: factor invocation code to drivers
  drivers: psci: support native SMC{32,64} calls
  ARM: migrate to common PSCI client code
  MAINTAINERS: add PSCI entry

 MAINTAINERS                       |   9 +
 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/kvm/psci.c               |   2 +
 arch/arm/mach-highbank/highbank.c |   2 +-
 arch/arm/mach-highbank/pm.c       |   8 +-
 arch/arm64/Kconfig                |   1 +
 arch/arm64/include/asm/acpi.h     |  14 --
 arch/arm64/include/asm/psci.h     |  20 --
 arch/arm64/include/asm/smp_plat.h |  16 ++
 arch/arm64/kernel/acpi.c          |  11 ++
 arch/arm64/kernel/psci.c          | 398 ++++----------------------------------
 arch/arm64/kernel/setup.c         |   2 +-
 arch/arm64/kernel/smp.c           |  10 +-
 drivers/cpuidle/cpuidle-calxeda.c |   7 +-
 drivers/firmware/Kconfig          |   3 +
 drivers/firmware/Makefile         |   1 +
 drivers/firmware/psci.c           | 377 ++++++++++++++++++++++++++++++++++++
 include/linux/psci.h              |  48 +++++
 23 files changed, 541 insertions(+), 745 deletions(-)
 delete mode 100644 arch/arm/kernel/psci.c
 delete mode 100644 arch/arm64/include/asm/psci.h
 create mode 100644 drivers/firmware/psci.c
 create mode 100644 include/linux/psci.h

-- 
1.9.1

[PATCH 01/12] arm/arm64: kvm: add missing PSCI include

[Mark Rutland]

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 <mark.rutland@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/kvm/psci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 02fa8ef..7e9398c 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -24,6 +24,8 @@
 #include <asm/kvm_psci.h>
 #include <asm/kvm_host.h>
 
+#include <uapi/linux/psci.h>
+
 /*
  * This is an implementation of the Power State Coordination Interface
  * as described in ARM document number ARM DEN 0022A.
-- 
1.9.1

[PATCH 02/12] arm64: smp_plat: add get_logical_index

[Mark Rutland]

The PSCI MIGRATE_INFO_UP_CPU call returns a physical ID, which we will
need to map back to a Linux logical ID.

Implement a reusable get_logical_index to map from a physical ID to a
logical ID.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/smp_plat.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/arm64/include/asm/smp_plat.h b/arch/arm64/include/asm/smp_plat.h
index 8dcd61e..7abf757 100644
--- a/arch/arm64/include/asm/smp_plat.h
+++ b/arch/arm64/include/asm/smp_plat.h
@@ -19,6 +19,8 @@
 #ifndef __ASM_SMP_PLAT_H
 #define __ASM_SMP_PLAT_H
 
+#include <linux/cpumask.h>
+
 #include <asm/types.h>
 
 struct mpidr_hash {
@@ -39,6 +41,20 @@ static inline u32 mpidr_hash_size(void)
  */
 extern u64 __cpu_logical_map[NR_CPUS];
 #define cpu_logical_map(cpu)    __cpu_logical_map[cpu]
+/*
+ * Retrieve logical cpu index corresponding to a given MPIDR.Aff*
+ *  - mpidr: MPIDR.Aff* bits to be used for the look-up
+ *
+ * Returns the cpu logical index or -EINVAL on look-up error
+ */
+static inline int get_logical_index(u64 mpidr)
+{
+	int cpu;
+	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+		if (cpu_logical_map(cpu) == mpidr)
+			return cpu;
+	return -EINVAL;
+}
 
 void __init do_post_cpus_up_work(void);
 
-- 
1.9.1

[PATCH 03/12] arm64: smp: consistently use error codes

[Mark Rutland]

cpu_kill currently returns one for success and zero for failure, which
is unlike all the other cpu_operations, which return zero for success
and an error code upon failure. This difference is unnecessarily
confusing.

Make cpu_kill consistent with the other cpu_operations.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/psci.c |  7 +++----
 arch/arm64/kernel/smp.c  | 10 +++++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index ea18cb5..10fa25e 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -498,7 +498,7 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
 	int err, i;
 
 	if (!psci_ops.affinity_info)
-		return 1;
+		return 0;
 	/*
 	 * cpu_kill could race with cpu_die and we can
 	 * potentially end up declaring this cpu undead
@@ -509,7 +509,7 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
 		err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
 		if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
 			pr_info("CPU%d killed.\n", cpu);
-			return 1;
+			return 0;
 		}
 
 		msleep(10);
@@ -518,8 +518,7 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
 
 	pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
 			cpu, err);
-	/* Make op_cpu_kill() fail. */
-	return 0;
+	return -ETIMEDOUT;
 }
 #endif
 #endif
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 2cb0081..3799df2 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -248,7 +248,7 @@ static int op_cpu_kill(unsigned int cpu)
 	 * time and hope that it's dead, so let's skip the wait and just hope.
 	 */
 	if (!cpu_ops[cpu]->cpu_kill)
-		return 1;
+		return 0;
 
 	return cpu_ops[cpu]->cpu_kill(cpu);
 }
@@ -261,6 +261,8 @@ static DECLARE_COMPLETION(cpu_died);
  */
 void __cpu_die(unsigned int cpu)
 {
+	int err;
+
 	if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
 		pr_crit("CPU%u: cpu didn't die\n", cpu);
 		return;
@@ -273,8 +275,10 @@ void __cpu_die(unsigned int cpu)
 	 * verify that it has really left the kernel before we consider
 	 * clobbering anything it might still be using.
 	 */
-	if (!op_cpu_kill(cpu))
-		pr_warn("CPU%d may not have shut down cleanly\n", cpu);
+	err = op_cpu_kill(cpu);
+	if (err)
+		pr_warn("CPU%d may not have shut down cleanly: %d\n",
+			cpu, err);
 }
 
 /*
-- 
1.9.1

[PATCH 04/12] arm64: psci: remove unnecessary id indirection

[Mark Rutland]

PSCI 0.1 did not define canonical IDs for CPU_ON, CPU_OFF, CPU_SUSPEND,
or MIGRATE, and so these need to be provided when using firmware
compliant to PSCI 0.1.

However, functions introduced in 0.2 or later have canonical IDs, and
these cannot be provided via DT. There's no need to indirect the IDs via
a table; they can be used directly at callsites (and already are for
SYSTEM_OFF and SYSTEM_RESET).

This patch removes the unnecessary function ID indirection for
AFFINITY_INFO and MIGRATE_INFO_TYPE.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/psci.c | 20 +++-----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 10fa25e..66b5b75 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -67,8 +67,6 @@ enum psci_function {
 	PSCI_FN_CPU_ON,
 	PSCI_FN_CPU_OFF,
 	PSCI_FN_MIGRATE,
-	PSCI_FN_AFFINITY_INFO,
-	PSCI_FN_MIGRATE_INFO_TYPE,
 	PSCI_FN_MAX,
 };
 
@@ -168,22 +166,13 @@ static int psci_migrate(unsigned long cpuid)
 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;
+	return invoke_psci_fn(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity,
+			      lowest_affinity_level, 0);
 }
 
 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;
+	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
 }
 
 static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
@@ -290,11 +279,8 @@ static void __init psci_0_2_set_functions(void)
 	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
 	psci_ops.migrate = psci_migrate;
 
-	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_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;
-- 
1.9.1

[PATCH 05/12] arm64: psci: support unsigned return values

[Mark Rutland]

PSCI_VERSION and MIGRATE_INFO_TYPE_UP_CPU return unsigned values, with
the latter returning a 64-bit value. However, the PSCI invocation
functions have prototypes returning int.

This patch upgrades the invocation functions to return unsigned long,
with a new typedef to keep things legible. As PSCI_VERSION cannot return
a negative value, the erroneous check against PSCI_RET_NOT_SUPPORTED is
also removed. The unrelated psci_initcall_t typedef is moved closer to
its first user, to avoid confusion with the invocation functions.

In preparation for sharing the code with ARM, unsigned long is used in
preference of u64. In the SMC32 calling convention, the relevant fields
will be 32 bits wide.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/psci.c | 43 ++++++++++++++++---------------------------
 1 file changed, 16 insertions(+), 27 deletions(-)

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 66b5b75..7324db9 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -56,11 +56,11 @@ struct psci_operations {
 
 static struct psci_operations psci_ops;
 
-static int (*invoke_psci_fn)(u64, u64, u64, u64);
-typedef int (*psci_initcall_t)(const struct device_node *);
-
-asmlinkage int __invoke_psci_fn_hvc(u64, u64, u64, u64);
-asmlinkage int __invoke_psci_fn_smc(u64, u64, u64, u64);
+typedef unsigned long (psci_fn)(unsigned long, unsigned long,
+				unsigned long, unsigned long);
+asmlinkage psci_fn __invoke_psci_fn_hvc;
+asmlinkage psci_fn __invoke_psci_fn_smc;
+static psci_fn *invoke_psci_fn;
 
 enum psci_function {
 	PSCI_FN_CPU_SUSPEND,
@@ -112,12 +112,9 @@ static void psci_power_state_unpack(u32 power_state,
 			PSCI_0_2_POWER_STATE_AFFL_SHIFT;
 }
 
-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,
@@ -295,23 +292,13 @@ static int __init psci_probe(void)
 {
 	int ver = psci_get_version();
 
-	if (ver == PSCI_RET_NOT_SUPPORTED) {
-		/*
-		 * PSCI versions >=0.2 mandates implementation of
-		 * PSCI_VERSION.
-		 */
-		pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
-		return -EOPNOTSUPP;
-	} 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) {
-			pr_err("Conflicting PSCI version detected.\n");
-			return -EINVAL;
-		}
+	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) {
+		pr_err("Conflicting PSCI version detected.\n");
+		return -EINVAL;
 	}
 
 	psci_0_2_set_functions();
@@ -319,6 +306,8 @@ static int __init psci_probe(void)
 	return 0;
 }
 
+typedef int (*psci_initcall_t)(const struct device_node *);
+
 /*
  * PSCI init function for PSCI versions >=0.2
  *
-- 
1.9.1

[PATCH 06/12] arm64: psci: account for Trusted OS instances

[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 <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 7324db9..25e2610 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -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();
+	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;
 }
 
@@ -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))
+		return -EPERM;
+
 	return 0;
 }
 
-- 
1.9.1

[PATCH 07/12] arm64: psci: kill psci_power_state

[Mark Rutland]

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 <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++----------------------------
 1 file changed, 37 insertions(+), 52 deletions(-)

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 25e2610..185174e 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -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);
-- 
1.9.1

[PATCH 08/12] arm64: psci: remove ACPI coupling

[Mark Rutland]

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 <mark.rutland@arm.com>
Cc: Al Stone <al.stone@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 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(-)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 59c05d8..b0fecad 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -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 */
 
diff --git a/arch/arm64/include/asm/psci.h b/arch/arm64/include/asm/psci.h
index 2454bc5..b5d4c1d 100644
--- a/arch/arm64/include/asm/psci.h
+++ b/arch/arm64/include/asm/psci.h
@@ -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 */
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 8b83955..fe56771b 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -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
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 185174e..ea89429 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -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

[PATCH 09/12] arm64: psci: factor invocation code to drivers

[Mark Rutland]

To enable sharing with arm, move the core PSCI framework code to
drivers/firmware. This results in a minor gain in lines of code, but
this will quickly be amortised by the removal of code currently
duplicated in arch/arm.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/Kconfig            |   1 +
 arch/arm64/include/asm/psci.h |  27 ----
 arch/arm64/kernel/psci.c      | 356 +----------------------------------------
 arch/arm64/kernel/setup.c     |   2 +-
 drivers/firmware/Kconfig      |   3 +
 drivers/firmware/Makefile     |   1 +
 drivers/firmware/psci.c       | 364 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/psci.h          |  48 ++++++
 8 files changed, 420 insertions(+), 382 deletions(-)
 delete mode 100644 arch/arm64/include/asm/psci.h
 create mode 100644 drivers/firmware/psci.c
 create mode 100644 include/linux/psci.h

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7796af4..d43ba0d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,6 +19,7 @@ config ARM64
 	select ARM_GIC_V2M if PCI_MSI
 	select ARM_GIC_V3
 	select ARM_GIC_V3_ITS if PCI_MSI
+	select ARM_PSCI_FW
 	select BUILDTIME_EXTABLE_SORT
 	select CLONE_BACKWARDS
 	select COMMON_CLK
diff --git a/arch/arm64/include/asm/psci.h b/arch/arm64/include/asm/psci.h
deleted file mode 100644
index b5d4c1d..0000000
--- a/arch/arm64/include/asm/psci.h
+++ /dev/null
@@ -1,27 +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) 2013 ARM Limited
- */
-
-#ifndef __ASM_PSCI_H
-#define __ASM_PSCI_H
-
-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 */
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index ea89429..8315d75 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -18,22 +18,17 @@
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/smp.h>
-#include <linux/reboot.h>
-#include <linux/pm.h>
 #include <linux/delay.h>
+#include <linux/psci.h>
 #include <linux/slab.h>
+
 #include <uapi/linux/psci.h>
 
 #include <asm/compiler.h>
 #include <asm/cpu_ops.h>
 #include <asm/errno.h>
-#include <asm/psci.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
-#include <asm/system_misc.h>
-
-#define PSCI_POWER_STATE_TYPE_STANDBY		0
-#define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
 
 static bool psci_power_state_loses_context(u32 state)
 {
@@ -49,128 +44,8 @@ static bool psci_power_state_is_valid(u32 state)
 	return !(state & ~valid_mask);
 }
 
-/*
- * 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)(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,
-			unsigned long lowest_affinity_level);
-	int (*migrate_info_type)(void);
-	unsigned long (*migrate_info_up_cpu)(void);
-};
-
-static struct psci_operations psci_ops;
-
-typedef unsigned long (psci_fn)(unsigned long, unsigned long,
-				unsigned long, unsigned long);
-asmlinkage psci_fn __invoke_psci_fn_hvc;
-asmlinkage psci_fn __invoke_psci_fn_smc;
-static psci_fn *invoke_psci_fn;
-
-enum psci_function {
-	PSCI_FN_CPU_SUSPEND,
-	PSCI_FN_CPU_ON,
-	PSCI_FN_CPU_OFF,
-	PSCI_FN_MIGRATE,
-	PSCI_FN_MAX,
-};
-
 static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
 
-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_get_version(void)
-{
-	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
-}
-
-static int psci_cpu_suspend(u32 state, unsigned long entry_point)
-{
-	int err;
-	u32 fn;
-
-	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
-	err = invoke_psci_fn(fn, state, entry_point, 0);
-	return psci_to_linux_errno(err);
-}
-
-static int psci_cpu_off(u32 state)
-{
-	int err;
-	u32 fn;
-
-	fn = psci_function_id[PSCI_FN_CPU_OFF];
-	err = invoke_psci_fn(fn, 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)
-{
-	return invoke_psci_fn(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity,
-			      lowest_affinity_level, 0);
-}
-
-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)
 {
@@ -232,233 +107,6 @@ free_mem:
 	return ret;
 }
 
-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);
-}
-
-/*
- * 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();
-	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");
-	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_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_FN64_CPU_ON;
-	psci_ops.cpu_on = psci_cpu_on;
-
-	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
-	psci_ops.migrate = psci_migrate;
-
-	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;
-
-	pm_power_off = psci_sys_poweroff;
-}
-
-/*
- * Probe function for PSCI firmware versions >= 0.2
- */
-static int __init psci_probe(void)
-{
-	int ver = psci_get_version();
-
-	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) {
-		pr_err("Conflicting PSCI version detected.\n");
-		return -EINVAL;
-	}
-
-	psci_0_2_set_functions();
-
-	psci_init_migrate();
-
-	return 0;
-}
-
-typedef int (*psci_initcall_t)(const struct device_node *);
-
-/*
- * PSCI init function for PSCI versions >=0.2
- *
- * Probe based on PSCI PSCI_VERSION function
- */
-static int __init psci_0_2_init(struct device_node *np)
-{
-	int err;
-
-	err = get_set_conduit_method(np);
-
-	if (err)
-		goto out_put_node;
-	/*
-	 * Starting with v0.2, the PSCI specification introduced a call
-	 * (PSCI_VERSION) that allows probing the firmware version, so
-	 * that PSCI function IDs and version specific initialization
-	 * can be carried out according to the specific version reported
-	 * by firmware
-	 */
-	err = psci_probe();
-
-out_put_node:
-	of_node_put(np);
-	return err;
-}
-
-/*
- * PSCI < v0.2 get PSCI Function IDs via DT.
- */
-static int __init 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_dt_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_ACPI
-/*
- * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
- * explicitly clarified in SBBR
- */
-int __init psci_acpi_init(void)
-{
-	if (!acpi_psci_present()) {
-		pr_info("is not implemented in ACPI.\n");
-		return -EOPNOTSUPP;
-	}
-
-	pr_info("probing for conduit method from ACPI.\n");
-
-	if (acpi_psci_use_hvc())
-		invoke_psci_fn = __invoke_psci_fn_hvc;
-	else
-		invoke_psci_fn = __invoke_psci_fn_smc;
-
-	return psci_probe();
-}
-#endif
-
 #ifdef CONFIG_SMP
 
 static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 7475313..be98a03 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -46,6 +46,7 @@
 #include <linux/of_platform.h>
 #include <linux/efi.h>
 #include <linux/personality.h>
+#include <linux/psci.h>
 
 #include <asm/acpi.h>
 #include <asm/fixmap.h>
@@ -61,7 +62,6 @@
 #include <asm/tlbflush.h>
 #include <asm/traps.h>
 #include <asm/memblock.h>
-#include <asm/psci.h>
 #include <asm/efi.h>
 #include <asm/virt.h>
 
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 6517132..24be7a3 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -5,6 +5,9 @@
 
 menu "Firmware Drivers"
 
+config ARM_PSCI_FW
+	bool
+
 config EDD
 	tristate "BIOS Enhanced Disk Drive calls determine boot disk"
 	depends on X86
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 3fdd391..6b05129 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -1,6 +1,7 @@
 #
 # Makefile for the linux kernel.
 #
+obj-$(CONFIG_ARM_PSCI_FW)	+= psci.o
 obj-$(CONFIG_DMI)		+= dmi_scan.o
 obj-$(CONFIG_DMI_SYSFS)		+= dmi-sysfs.o
 obj-$(CONFIG_EDD)		+= edd.o
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
new file mode 100644
index 0000000..1eaa5d7
--- /dev/null
+++ b/drivers/firmware/psci.c
@@ -0,0 +1,364 @@
+/*
+ * 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) 2015 ARM Limited
+ */
+
+#define pr_fmt(fmt) "psci: " fmt
+
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/printk.h>
+#include <linux/psci.h>
+#include <linux/reboot.h>
+
+#include <uapi/linux/psci.h>
+
+#include <asm/system_misc.h>
+#include <asm/smp_plat.h>
+
+/*
+ * 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;
+
+bool psci_tos_resident_on(int cpu)
+{
+	return cpu == resident_cpu;
+}
+
+struct psci_operations psci_ops;
+
+typedef unsigned long (psci_fn)(unsigned long, unsigned long,
+				unsigned long, unsigned long);
+asmlinkage psci_fn __invoke_psci_fn_hvc;
+asmlinkage psci_fn __invoke_psci_fn_smc;
+static psci_fn *invoke_psci_fn;
+
+enum psci_function {
+	PSCI_FN_CPU_SUSPEND,
+	PSCI_FN_CPU_ON,
+	PSCI_FN_CPU_OFF,
+	PSCI_FN_MIGRATE,
+	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_get_version(void)
+{
+	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+}
+
+static int psci_cpu_suspend(u32 state, unsigned long entry_point)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
+	err = invoke_psci_fn(fn, state, entry_point, 0);
+	return psci_to_linux_errno(err);
+}
+
+static int psci_cpu_off(u32 state)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_CPU_OFF];
+	err = invoke_psci_fn(fn, 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)
+{
+	return invoke_psci_fn(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity,
+			      lowest_affinity_level, 0);
+}
+
+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 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);
+}
+
+/*
+ * 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();
+	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");
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_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_FN64_CPU_ON;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
+	psci_ops.migrate = psci_migrate;
+
+	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;
+
+	pm_power_off = psci_sys_poweroff;
+}
+
+/*
+ * Probe function for PSCI firmware versions >= 0.2
+ */
+static int __init psci_probe(void)
+{
+	int ver = psci_get_version();
+
+	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) {
+		pr_err("Conflicting PSCI version detected.\n");
+		return -EINVAL;
+	}
+
+	psci_0_2_set_functions();
+
+	psci_init_migrate();
+
+	return 0;
+}
+
+typedef int (*psci_initcall_t)(const struct device_node *);
+
+/*
+ * PSCI init function for PSCI versions >=0.2
+ *
+ * Probe based on PSCI PSCI_VERSION function
+ */
+static int __init psci_0_2_init(struct device_node *np)
+{
+	int err;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
+		goto out_put_node;
+	/*
+	 * Starting with v0.2, the PSCI specification introduced a call
+	 * (PSCI_VERSION) that allows probing the firmware version, so
+	 * that PSCI function IDs and version specific initialization
+	 * can be carried out according to the specific version reported
+	 * by firmware
+	 */
+	err = psci_probe();
+
+out_put_node:
+	of_node_put(np);
+	return err;
+}
+
+/*
+ * PSCI < v0.2 get PSCI Function IDs via DT.
+ */
+static int __init 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_dt_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_ACPI
+/*
+ * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
+ * explicitly clarified in SBBR
+ */
+int __init psci_acpi_init(void)
+{
+	if (!acpi_psci_present()) {
+		pr_info("is not implemented in ACPI.\n");
+		return -EOPNOTSUPP;
+	}
+
+	pr_info("probing for conduit method from ACPI.\n");
+
+	if (acpi_psci_use_hvc())
+		invoke_psci_fn = __invoke_psci_fn_hvc;
+	else
+		invoke_psci_fn = __invoke_psci_fn_smc;
+
+	return psci_probe();
+}
+#endif
+
diff --git a/include/linux/psci.h b/include/linux/psci.h
new file mode 100644
index 0000000..dc620e2
--- /dev/null
+++ b/include/linux/psci.h
@@ -0,0 +1,48 @@
+/*
+ * 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) 2015 ARM Limited
+ */
+
+#ifndef __LINUX_PSCI_H
+#define __LINUX_PSCI_H
+
+#include <linux/init.h>
+#include <linux/types.h>
+
+#define PSCI_POWER_STATE_TYPE_STANDBY		0
+#define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
+
+bool psci_tos_resident_on(int cpu);
+
+struct psci_operations {
+	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,
+			unsigned long lowest_affinity_level);
+	int (*migrate_info_type)(void);
+	unsigned long (*migrate_info_up_cpu)(void);
+};
+
+extern struct psci_operations psci_ops;
+
+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 /* __LINUX_PSCI_H */
-- 
1.9.1

[PATCH 10/12] drivers: psci: support native SMC{32,64} calls

[Mark Rutland]

A 32-bit OS cannot make calls with SMC64 IDs, while a 64-bit OS must
invoke some PSCI functions with SMC64 IDs.

This patch introduces and makes use of a new macro to choose the
appropriate IDs based on the register width of the OS, which will allow
32-bit callers to use the PSCI client code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/firmware/psci.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 1eaa5d7..88e2249 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -27,6 +27,18 @@
 #include <asm/smp_plat.h>
 
 /*
+ * While a 64-bit OS can make calls with SMC32 calling conventions, for some
+ * calls it is necessary to use SMC64 to pass or return 64-bit values. For such
+ * calls PSCI_0_2_FN_NATIVE(x) will choose the appropriate (native-width)
+ * function ID.
+ */
+#ifdef CONFIG_64BIT
+#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN_##name
+#else
+#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN64_##name
+#endif
+
+/*
  * 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
@@ -121,8 +133,8 @@ static int psci_migrate(unsigned long cpuid)
 static int psci_affinity_info(unsigned long target_affinity,
 		unsigned long lowest_affinity_level)
 {
-	return invoke_psci_fn(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity,
-			      lowest_affinity_level, 0);
+	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(AFFINITY_INFO),
+			      target_affinity, lowest_affinity_level, 0);
 }
 
 static int psci_migrate_info_type(void)
@@ -132,7 +144,8 @@ static int psci_migrate_info_type(void)
 
 static unsigned long psci_migrate_info_up_cpu(void)
 {
-	return invoke_psci_fn(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, 0, 0, 0);
+	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(MIGRATE_INFO_UP_CPU),
+			      0, 0, 0);
 }
 
 static int get_set_conduit_method(struct device_node *np)
@@ -204,16 +217,16 @@ static void __init psci_init_migrate(void)
 static void __init psci_0_2_set_functions(void)
 {
 	pr_info("Using standard PSCI v0.2 function IDs\n");
-	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND;
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_NATIVE(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_FN64_CPU_ON;
+	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_NATIVE(CPU_ON);
 	psci_ops.cpu_on = psci_cpu_on;
 
-	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_NATIVE(MIGRATE);
 	psci_ops.migrate = psci_migrate;
 
 	psci_ops.affinity_info = psci_affinity_info;
-- 
1.9.1

[PATCH 11/12] ARM: migrate to common PSCI client code

[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 <mark.rutland@arm.com>
Cc: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
---
 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

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 45df48b..191291f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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
diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index c25ef3e..68ee3ce 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -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
 
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 752725d..2c06383 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -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
 
diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
deleted file mode 100644
index f90fdf4..0000000
--- a/arch/arm/kernel/psci.c
+++ /dev/null
@@ -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 <will.deacon@arm.com>
- */
-
-#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);
-}
diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
index 28a1db4..2d4a7255 100644
--- a/arch/arm/kernel/psci_smp.c
+++ b/arch/arm/kernel/psci_smp.c
@@ -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
+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;
+
+	return 1;
+}
+
 void __ref psci_cpu_die(unsigned int cpu)
 {
-       const struct psci_power_state ps = {
-               .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
-       };
+	u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
+		    PSCI_0_2_POWER_STATE_TYPE_SHIFT;
 
-       if (psci_ops.cpu_off)
-               psci_ops.cpu_off(ps);
+	if (psci_ops.cpu_off)
+		psci_ops.cpu_off(state);
 
-       /* We should never return */
-       panic("psci: cpu %d failed to shutdown\n", cpu);
+	/* We should never return */
+	panic("psci: cpu %d failed to shutdown\n", cpu);
 }
 
 int __ref psci_cpu_kill(unsigned int cpu)
@@ -109,6 +123,7 @@ bool __init psci_smp_available(void)
 struct smp_operations __initdata psci_smp_ops = {
 	.smp_boot_secondary	= psci_boot_secondary,
 #ifdef CONFIG_HOTPLUG_CPU
+	.cpu_disable		= psci_cpu_disable,
 	.cpu_die		= psci_cpu_die,
 	.cpu_kill		= psci_cpu_kill,
 #endif
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 6c777e9..3224680 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -31,6 +31,7 @@
 #include <linux/bug.h>
 #include <linux/compiler.h>
 #include <linux/sort.h>
+#include <linux/psci.h>
 
 #include <asm/unified.h>
 #include <asm/cp15.h>
@@ -950,7 +951,7 @@ void __init setup_arch(char **cmdline_p)
 	unflatten_device_tree();
 
 	arm_dt_init_cpu_maps();
-	psci_init();
+	psci_dt_init();
 #ifdef CONFIG_SMP
 	if (is_smp()) {
 		if (!mdesc->smp_init || !mdesc->smp_init()) {
diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c
index 231fba0..6050a14 100644
--- a/arch/arm/mach-highbank/highbank.c
+++ b/arch/arm/mach-highbank/highbank.c
@@ -28,8 +28,8 @@
 #include <linux/reboot.h>
 #include <linux/amba/bus.h>
 #include <linux/platform_device.h>
+#include <linux/psci.h>
 
-#include <asm/psci.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
diff --git a/arch/arm/mach-highbank/pm.c b/arch/arm/mach-highbank/pm.c
index 7f2bd85..014e96d 100644
--- a/arch/arm/mach-highbank/pm.c
+++ b/arch/arm/mach-highbank/pm.c
@@ -16,18 +16,14 @@
 
 #include <linux/cpu_pm.h>
 #include <linux/init.h>
+#include <linux/psci.h>
 #include <linux/suspend.h>
 
 #include <asm/suspend.h>
-#include <asm/psci.h>
 
 static int highbank_suspend_finish(unsigned long val)
 {
-	const struct psci_power_state ps = {
-		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
-		.affinity_level = 1,
-	};
-
+	u32 ps = 0x01010000; /* Aff1 power down */
 	return psci_ops.cpu_suspend(ps, __pa(cpu_resume));
 }
 
diff --git a/drivers/cpuidle/cpuidle-calxeda.c b/drivers/cpuidle/cpuidle-calxeda.c
index 9445e6c..d010da8f 100644
--- a/drivers/cpuidle/cpuidle-calxeda.c
+++ b/drivers/cpuidle/cpuidle-calxeda.c
@@ -25,15 +25,14 @@
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/platform_device.h>
+#include <linux/psci.h>
+
 #include <asm/cpuidle.h>
 #include <asm/suspend.h>
-#include <asm/psci.h>
 
 static int calxeda_idle_finish(unsigned long val)
 {
-	const struct psci_power_state ps = {
-		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
-	};
+	u32 ps = 0x00010000; /* Aff0 power down */
 	return psci_ops.cpu_suspend(ps, __pa(cpu_resume));
 }
 
-- 
1.9.1

[PATCH 12/12] MAINTAINERS: add PSCI entry

[Mark Rutland]

Add myself and Lorenzo as maintainers of the PSCI client code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 MAINTAINERS | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 781e099..ff8e577 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7761,6 +7761,15 @@ S:	Maintained
 F:	include/linux/power_supply.h
 F:	drivers/power/
 
+POWER STATE COORDINATION INTERFACE (PSCI)
+M:	Mark Rutland <mark.rutland@arm.com>
+M:	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+L:	linux-arm-kernel at lists.infradead.org
+S:	Maintained
+F:	drivers/firmware/psci.c
+F:	include/linux/psci.h
+F:	include/uapi/linux/psci.h
+
 PNP SUPPORT
 M:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 S:	Maintained
-- 
1.9.1

[PATCH 05/12] arm64: psci: support unsigned return values

[Lorenzo Pieralisi]

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

[...]

> -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,
> @@ -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.

Lorenzo

[PATCH 05/12] arm64: psci: support unsigned return values

[Mark Rutland]

On Mon, May 11, 2015 at 01:25:25PM +0100, Lorenzo Pieralisi wrote:
> On Fri, May 08, 2015 at 12:36:37PM +0100, Mark Rutland wrote:
> 
> [...]
> 
> > -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,
> > @@ -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 ?

No, I just missed it when propagating the type changes. It should be
corrected to a u32 as well.

> Other than that the patch looks fine.

Great!

Mark.

[PATCH 07/12] arm64: psci: kill psci_power_state

[Lorenzo Pieralisi]

On Fri, May 08, 2015 at 12:36:39PM +0100, Mark Rutland wrote:
> 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 <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++----------------------------
>  1 file changed, 37 insertions(+), 52 deletions(-)

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index 25e2610..185174e 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -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);
> -- 
> 1.9.1
> 

[PATCH 01/12] arm/arm64: kvm: add missing PSCI include

[Christoffer Dall]

On Fri, May 08, 2015 at 12:36:33PM +0100, Mark Rutland wrote:
> 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 <mark.rutland@arm.com>
> Cc: Christoffer Dall <christoffer.dall@linaro.org>
> Cc: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>

[PATCH 09/12] arm64: psci: factor invocation code to drivers

[Mark Rutland]

[...]

> +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

I've just realised this could result in a build failure with
CONFIG_ARM_PSCI_FW isn't selected. I've wrapped psci_dt_init in an ifdef
and tightened the checks for psci_acpi_init.

That's all pushed out to a branch [1] on kernel.org.

Mark.

[1] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git psci/unification

[PATCH 06/12] arm64: psci: account for Trusted OS instances

[Lorenzo Pieralisi]

On Fri, May 08, 2015 at 12:36:38PM +0100, Mark Rutland wrote:
> 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 <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 61 insertions(+)
> 
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index 7324db9..25e2610 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -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);

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.

>  };
>  
>  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);
> +}

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) ?

>  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;

Nit: cpu variable initialization is useless.

Apart from these minor comments patch is fine.

Lorenzo

[PATCH 06/12] arm64: psci: account for Trusted OS instances

[Ashwin Chaugule]

On 8 May 2015 at 07:36, Mark Rutland <mark.rutland@arm.com> wrote:
> 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 <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 61 insertions(+)
>
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index 7324db9..25e2610 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -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();

[..]

> +       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;
>  }
>
> @@ -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?

[PATCH 08/12] arm64: psci: remove ACPI coupling

[Ashwin Chaugule]

On 8 May 2015 at 07:36, Mark Rutland <mark.rutland@arm.com> wrote:
> 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 <mark.rutland@arm.com>
> Cc: Al Stone <al.stone@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  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(-)
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 59c05d8..b0fecad 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -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 */
>
> diff --git a/arch/arm64/include/asm/psci.h b/arch/arm64/include/asm/psci.h
> index 2454bc5..b5d4c1d 100644
> --- a/arch/arm64/include/asm/psci.h
> +++ b/arch/arm64/include/asm/psci.h
> @@ -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 */
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index 8b83955..fe56771b 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -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
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index 185174e..ea89429 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -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
>

Reviewed-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>

[PATCH 11/12] ARM: migrate to common PSCI client code

[Ashwin Chaugule]

On 8 May 2015 at 07:36, Mark Rutland <mark.rutland@arm.com> wrote:
> 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 <mark.rutland@arm.com>
> Cc: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  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
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 45df48b..191291f 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -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
> diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
> index c25ef3e..68ee3ce 100644
> --- a/arch/arm/include/asm/psci.h
> +++ b/arch/arm/include/asm/psci.h
> @@ -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
>
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index 752725d..2c06383 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -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
>
> diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
> deleted file mode 100644
> index f90fdf4..0000000
> --- a/arch/arm/kernel/psci.c
> +++ /dev/null
> @@ -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 <will.deacon@arm.com>
> - */
> -
> -#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);
> -}
> diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
> index 28a1db4..2d4a7255 100644
> --- a/arch/arm/kernel/psci_smp.c
> +++ b/arch/arm/kernel/psci_smp.c
> @@ -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
> +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.

[PATCH 11/12] ARM: migrate to common PSCI client code

[Ashwin Chaugule]

On 15 May 2015 at 11:41, Ashwin Chaugule <ashwin.chaugule@linaro.org> wrote:
> On 8 May 2015 at 07:36, Mark Rutland <mark.rutland@arm.com> wrote:
>> 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 <mark.rutland@arm.com>
>> Cc: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Rob Herring <robh@kernel.org>
>> Cc: Will Deacon <will.deacon@arm.com>
>> ---
>>  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
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index 45df48b..191291f 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -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
>> diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
>> index c25ef3e..68ee3ce 100644
>> --- a/arch/arm/include/asm/psci.h
>> +++ b/arch/arm/include/asm/psci.h
>> @@ -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
>>
>> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
>> index 752725d..2c06383 100644
>> --- a/arch/arm/kernel/Makefile
>> +++ b/arch/arm/kernel/Makefile
>> @@ -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
>>
>> diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
>> deleted file mode 100644
>> index f90fdf4..0000000
>> --- a/arch/arm/kernel/psci.c
>> +++ /dev/null
>> @@ -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 <will.deacon@arm.com>
>> - */
>> -
>> -#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);
>> -}
>> diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
>> index 28a1db4..2d4a7255 100644
>> --- a/arch/arm/kernel/psci_smp.c
>> +++ b/arch/arm/kernel/psci_smp.c
>> @@ -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
>> +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.

err. Make that TOS is not present.

[PATCH 06/12] arm64: psci: account for Trusted OS instances

[Mark Rutland]

On Fri, May 15, 2015 at 04:06:39PM +0100, Ashwin Chaugule wrote:
> On 8 May 2015 at 07:36, Mark Rutland <mark.rutland@arm.com> wrote:
> > 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 <mark.rutland@arm.com>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > ---
> >  arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 61 insertions(+)
> >
> > diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> > index 7324db9..25e2610 100644
> > --- a/arch/arm64/kernel/psci.c
> > +++ b/arch/arm64/kernel/psci.c
> > @@ -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;
> > +}

[...]

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

[...]

> > @@ -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?
> 

Yes, though only for the CPU the TOS is resident on.

It's not clear what the right policy is w.r.t. migration, and it's
probably going to depend on the TOS and workload. It's also not clear
whether there are migrateable UP TOS instances out there.

So for the moment this just ensures we won't accidentally bring the
system down in the presence of a UP TOS (migrateable or otherwise).

Thanks.
Mark.

[PATCH 11/12] ARM: migrate to common PSCI client code

[Mark Rutland]

> >> +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.
> 
> 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.

What am I missing?

Thanks,
Mark.

[PATCH 06/12] arm64: psci: account for Trusted OS instances

[Mark Rutland]

On Wed, May 13, 2015 at 03:22:55PM +0100, Lorenzo Pieralisi wrote:
> On Fri, May 08, 2015 at 12:36:38PM +0100, Mark Rutland wrote:
> > 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 <mark.rutland@arm.com>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > ---
> >  arch/arm64/kernel/psci.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 61 insertions(+)
> > 
> > diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> > index 7324db9..25e2610 100644
> > --- a/arch/arm64/kernel/psci.c
> > +++ b/arch/arm64/kernel/psci.c
> > @@ -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);
> 
> 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.

Sure, I can drop migrate_info_up_cpu. I'll take a look at
migrate_info_type.

> 
> >  };
> >  
> >  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);
> > +}
> 
> 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) ?

True, I can't see why we'd query this again.

> >  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;
> 
> Nit: cpu variable initialization is useless.
> 
> Apart from these minor comments patch is fine.

Thanks, I'll fix these up and push out a v2 shortly.

Thanks,
Mark.

[PATCH 11/12] ARM: migrate to common PSCI client code

[Ashwin Chaugule]

On 18 May 2015 at 05:46, Mark Rutland <mark.rutland@arm.com> wrote:
>> >> +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.
>>
>> 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.
>

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

Ashwin

[PATCH 11/12] ARM: migrate to common PSCI client code

[Mark Rutland]

On Mon, May 18, 2015 at 08:14:51PM +0100, Ashwin Chaugule wrote:
> On 18 May 2015 at 05:46, Mark Rutland <mark.rutland@arm.com> wrote:
> >> >> +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.
> >>
> >> 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.
> >
> 
> Hm. Perhaps I was confused by the "return -EPERM" in the arm64 version
> and "return 0" here. :)

Looking at this again, you're absolutely right, and I'd gotten myself
confused about the expected return values. I'll respin this with
corrected return codes (-EPERM instead of 0 and 0 instead of 1).

Thanks for spotting that, and sorry for being so dense!

Mark.