ARM: 6512/1: perf: fix warnings generated by sparse

Russell reported a number of warnings coming from sparse when
checking the ARM perf_event.c files:

| perf_event.c seems to also have problems too:
|
|   CHECK   arch/arm/kernel/perf_event.c
|   arch/arm/kernel/perf_event.c:37:1: warning: symbol 'pmu_lock' was not declared. Should it be static?
|   arch/arm/kernel/perf_event.c:70:1: warning: symbol 'cpu_hw_events' was not declared. Should it be static?
|   arch/arm/kernel/perf_event.c:1006:1: warning: symbol 'armv6pmu_enable_event' was not declared. Should it be static?
|   arch/arm/kernel/perf_event.c:1113:1: warning: symbol 'armv6pmu_stop' was not declared. Should it be static?
|   arch/arm/kernel/perf_event.c:1956:6: warning: symbol 'armv7pmu_enable_event' was not declared. Should it be static?
|   arch/arm/kernel/perf_event.c:3072:14: warning: incorrect type in argument 1 (different address spaces)
|   arch/arm/kernel/perf_event.c:3072:14:    expected void const volatile [noderef] <asn:1>*<noident>
|   arch/arm/kernel/perf_event.c:3072:14:    got struct frame_tail *tail
|   arch/arm/kernel/perf_event.c:3074:49: warning: incorrect type in argument 2 (different address spaces)
|   arch/arm/kernel/perf_event.c:3074:49:    expected void const [noderef] <asn:1>*from
|   arch/arm/kernel/perf_event.c:3074:49:    got struct frame_tail *tail

This patch resolves these issues so we can live in silence
again.

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/perf_event.c

@@ -32,7 +32,7 @@ static struct platform_device *pmu_device;
  * Hardware lock to serialize accesses to PMU registers. Needed for the
  * read/modify/write sequences.
  */
-DEFINE_SPINLOCK(pmu_lock);
+static DEFINE_SPINLOCK(pmu_lock);
 
 /*
  * ARMv6 supports a maximum of 3 events, starting from index 1. If we add
@@ -65,7 +65,7 @@ struct cpu_hw_events {
 	 */
 	unsigned long		active_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
 };
-DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
+static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
 
 struct arm_pmu {
 	enum arm_perf_pmu_ids id;
@@ -673,17 +673,17 @@ arch_initcall(init_hw_perf_events);
  * This code has been adapted from the ARM OProfile support.
  */
 struct frame_tail {
-	struct frame_tail   *fp;
-	unsigned long	    sp;
-	unsigned long	    lr;
+	struct frame_tail __user *fp;
+	unsigned long sp;
+	unsigned long lr;
 } __attribute__((packed));
 
 /*
  * Get the return address for a single stackframe and return a pointer to the
  * next frame tail.
  */
-static struct frame_tail *
-user_backtrace(struct frame_tail *tail,
+static struct frame_tail __user *
+user_backtrace(struct frame_tail __user *tail,
 	       struct perf_callchain_entry *entry)
 {
 	struct frame_tail buftail;
@@ -709,10 +709,10 @@ user_backtrace(struct frame_tail *tail,
 void
 perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
 {
-	struct frame_tail *tail;
+	struct frame_tail __user *tail;
 
 
-	tail = (struct frame_tail *)regs->ARM_fp - 1;
+	tail = (struct frame_tail __user *)regs->ARM_fp - 1;
 
 	while (tail && !((unsigned long)tail & 0x3))
 		tail = user_backtrace(tail, entry);

arch/arm/kernel/perf_event_v6.c

@@ -400,7 +400,7 @@ armv6pmu_write_counter(int counter,
 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
 }
 
-void
+static void
 armv6pmu_enable_event(struct hw_perf_event *hwc,
 		      int idx)
 {
@@ -625,7 +625,7 @@ static const struct arm_pmu armv6pmu = {
 	.max_period		= (1LLU << 32) - 1,
 };
 
-const struct arm_pmu *__init armv6pmu_init(void)
+static const struct arm_pmu *__init armv6pmu_init(void)
 {
 	return &armv6pmu;
 }
@@ -655,17 +655,17 @@ static const struct arm_pmu armv6mpcore_pmu = {
 	.max_period		= (1LLU << 32) - 1,
 };
 
-const struct arm_pmu *__init armv6mpcore_pmu_init(void)
+static const struct arm_pmu *__init armv6mpcore_pmu_init(void)
 {
 	return &armv6mpcore_pmu;
 }
 #else
-const struct arm_pmu *__init armv6pmu_init(void)
+static const struct arm_pmu *__init armv6pmu_init(void)
 {
 	return NULL;
 }
 
-const struct arm_pmu *__init armv6mpcore_pmu_init(void)
+static const struct arm_pmu *__init armv6mpcore_pmu_init(void)
 {
 	return NULL;
 }

arch/arm/kernel/perf_event_v7.c

@@ -681,7 +681,7 @@ static void armv7_pmnc_dump_regs(void)
 }
 #endif
 
-void armv7pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void armv7pmu_enable_event(struct hw_perf_event *hwc, int idx)
 {
 	unsigned long flags;
 
@@ -874,7 +874,7 @@ static u32 __init armv7_reset_read_pmnc(void)
 	return nb_cnt + 1;
 }
 
-const struct arm_pmu *__init armv7_a8_pmu_init(void)
+static const struct arm_pmu *__init armv7_a8_pmu_init(void)
 {
 	armv7pmu.id		= ARM_PERF_PMU_ID_CA8;
 	armv7pmu.name		= "ARMv7 Cortex-A8";
@@ -884,7 +884,7 @@ const struct arm_pmu *__init armv7_a8_pmu_init(void)
 	return &armv7pmu;
 }
 
-const struct arm_pmu *__init armv7_a9_pmu_init(void)
+static const struct arm_pmu *__init armv7_a9_pmu_init(void)
 {
 	armv7pmu.id		= ARM_PERF_PMU_ID_CA9;
 	armv7pmu.name		= "ARMv7 Cortex-A9";
@@ -894,12 +894,12 @@ const struct arm_pmu *__init armv7_a9_pmu_init(void)
 	return &armv7pmu;
 }
 #else
-const struct arm_pmu *__init armv7_a8_pmu_init(void)
+static const struct arm_pmu *__init armv7_a8_pmu_init(void)
 {
 	return NULL;
 }
 
-const struct arm_pmu *__init armv7_a9_pmu_init(void)
+static const struct arm_pmu *__init armv7_a9_pmu_init(void)
 {
 	return NULL;
 }

arch/arm/kernel/perf_event_xscale.c

@@ -428,7 +428,7 @@ static const struct arm_pmu xscale1pmu = {
 	.max_period	= (1LLU << 32) - 1,
 };
 
-const struct arm_pmu *__init xscale1pmu_init(void)
+static const struct arm_pmu *__init xscale1pmu_init(void)
 {
 	return &xscale1pmu;
 }
@@ -790,17 +790,17 @@ static const struct arm_pmu xscale2pmu = {
 	.max_period	= (1LLU << 32) - 1,
 };
 
-const struct arm_pmu *__init xscale2pmu_init(void)
+static const struct arm_pmu *__init xscale2pmu_init(void)
 {
 	return &xscale2pmu;
 }
 #else
-const struct arm_pmu *__init xscale1pmu_init(void)
+static const struct arm_pmu *__init xscale1pmu_init(void)
 {
 	return NULL;
 }
 
-const struct arm_pmu *__init xscale2pmu_init(void)
+static const struct arm_pmu *__init xscale2pmu_init(void)
 {
 	return NULL;
 }