gator: Version 5.75.7

Signed-off-by: Drew Richardson <drew.richardson@arm.com>

1 files changed, 80 insertions, 106 deletions

diff --git a/driver/gator_events_armv7.c b/driver/gator_events_armv7.c
index 0f0d7ef..58855f8 100644
--- a/driver/gator_events_armv7.c
+++ b/driver/gator_events_armv7.c
@@ -6,129 +6,116 @@
  * published by the Free Software Foundation.
  */
 
-#include "gator.h"
-
-#define CORTEX_A5	0xc05
-#define CORTEX_A8	0xc08
-#define CORTEX_A9	0xc09
-#define CORTEX_A15	0xc0f
-
-static const char *pmnc_name;
-static int pmnc_count;
-
-// Per-CPU PMNC: config reg
-#define PMNC_E		(1 << 0)	/* Enable all counters */
-#define PMNC_P		(1 << 1)	/* Reset all counters */
-#define PMNC_C		(1 << 2)	/* Cycle counter reset */
-#define	PMNC_MASK	0x3f		/* Mask for writable bits */
+/*  Disabling interrupts
+ *    Many of the functions below disable interrupts via local_irq_save(). This disabling of interrupts is done to prevent any race conditions
+ *    between multiple entities (e.g. hrtimer interrupts and event based interrupts) calling the same functions. As accessing the pmu involves
+ *    several steps (disable, select, read, enable), these steps must be performed atomically. Normal synchronization routines cannot be used
+ *    as these functions are being called from interrupt context.
+ */
 
-// ccnt reg
-#define CCNT_REG	(1 << 31)
+#include "gator.h"
+#include "gator_events_armv7.h"
 
-#define CCNT 		0
-#define CNT0		1
-#define CNTMAX 		(6+1)
+const char *pmnc_name;
+int pmnc_counters;
 
-static unsigned long pmnc_enabled[CNTMAX];
-static unsigned long pmnc_event[CNTMAX];
-static unsigned long pmnc_key[CNTMAX];
+unsigned long pmnc_enabled[CNTMAX];
+unsigned long pmnc_event[CNTMAX];
+unsigned long pmnc_count[CNTMAX];
+unsigned long pmnc_key[CNTMAX];
 
 static DEFINE_PER_CPU(int[CNTMAX], perfPrev);
 static DEFINE_PER_CPU(int[CNTMAX * 2], perfCnt);
 
-static inline void armv7_pmnc_write(u32 val)
+inline void armv7_pmnc_write(u32 val)
 {
 	val &= PMNC_MASK;
 	asm volatile("mcr p15, 0, %0, c9, c12, 0" : : "r" (val));
 }
 
-static inline u32 armv7_pmnc_read(void)
+inline u32 armv7_pmnc_read(void)
 {
 	u32 val;
 	asm volatile("mrc p15, 0, %0, c9, c12, 0" : "=r" (val));
 	return val;
 }
 
-static inline u32 armv7_ccnt_read(void)
+inline u32 armv7_ccnt_read(u32 reset_value)
 {
-	u32 zero = 0;
+	unsigned long flags;
+	u32 newval = -reset_value;
 	u32 den = CCNT_REG;
 	u32 val;
 
+	local_irq_save(flags);
 	asm volatile("mcr p15, 0, %0, c9, c12, 2" : : "r" (den));	// disable
 	asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (val));	// read
-	asm volatile("mcr p15, 0, %0, c9, c13, 0" : : "r" (zero));	// zero
+	asm volatile("mcr p15, 0, %0, c9, c13, 0" : : "r" (newval));// new value
 	asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r" (den));	// enable
+	local_irq_restore(flags);
 
 	return val;
 }
 
-static inline u32 armv7_cntn_read(unsigned int cnt)
+inline u32 armv7_cntn_read(unsigned int cnt, u32 reset_value)
 {
-	u32 zero = 0;
+	unsigned long flags;
+	u32 newval = -reset_value;
 	u32 sel = (cnt - CNT0);
 	u32 den = 1 << sel;
-	u32 val;
+	u32 oldval;
 
+	local_irq_save(flags);
 	asm volatile("mcr p15, 0, %0, c9, c12, 2" : : "r" (den));	// disable
 	asm volatile("mcr p15, 0, %0, c9, c12, 5" : : "r" (sel));	// select
-	asm volatile("mrc p15, 0, %0, c9, c13, 2" : "=r" (val));	// read
-    asm volatile("mcr p15, 0, %0, c9, c13, 2" : : "r" (zero));	// zero
+	asm volatile("mrc p15, 0, %0, c9, c13, 2" : "=r" (oldval));	// read
+    asm volatile("mcr p15, 0, %0, c9, c13, 2" : : "r" (newval));// new value
 	asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r" (den));	// enable
+	local_irq_restore(flags);
 
-	return val;
+	return oldval;
 }
 
-static inline u32 armv7_pmnc_enable_counter(unsigned int cnt)
+static inline void armv7_pmnc_enable_interrupt(unsigned int cnt)
 {
-	u32 val;
+	u32 val = cnt ? (1 << (cnt - CNT0)) : (1 << 31);
+	asm volatile("mcr p15, 0, %0, c9, c14, 1" : : "r" (val));
+}
 
-	if (cnt >= CNTMAX) {
-		pr_err("gator: CPU%u enabling wrong PMNC counter %d\n", smp_processor_id(), cnt);
-		return -1;
-	}
+static inline void armv7_pmnc_disable_interrupt(unsigned int cnt)
+{
+	u32 val = cnt ? (1 << (cnt - CNT0)) : (1 << 31);
+	asm volatile("mcr p15, 0, %0, c9, c14, 2" : : "r" (val));
+}
 
-	if (cnt == CCNT)
-		val = CCNT_REG;
-	else
-		val = (1 << (cnt - CNT0));
+inline u32 armv7_pmnc_reset_interrupt()
+{
+	// Get and reset overflow status flags
+	u32 flags;
+	asm volatile("mrc p15, 0, %0, c9, c12, 3" : "=r" (flags));
+	flags &= 0x8000003f;
+	asm volatile("mcr p15, 0, %0, c9, c12, 3" : : "r" (flags));
+	return flags;
+}
 
+static inline u32 armv7_pmnc_enable_counter(unsigned int cnt)
+{
+	u32 val = cnt ? (1 << (cnt - CNT0)) : CCNT_REG;
 	asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r" (val));
-
 	return cnt;
 }
 
 static inline u32 armv7_pmnc_disable_counter(unsigned int cnt)
 {
-	u32 val;
-
-	if (cnt >= CNTMAX) {
-		pr_err("gator: CPU%u disabling wrong PMNC counter %d\n", smp_processor_id(), cnt);
-		return -1;
-	}
-
-	if (cnt == CCNT)
-		val = CCNT_REG;
-	else
-		val = (1 << (cnt - CNT0));
-
+	u32 val = cnt ? (1 << (cnt - CNT0)) : CCNT_REG;
 	asm volatile("mcr p15, 0, %0, c9, c12, 2" : : "r" (val));
-
 	return cnt;
 }
 
 static inline int armv7_pmnc_select_counter(unsigned int cnt)
 {
-	u32 val;
-
-	if ((cnt == CCNT) || (cnt >= CNTMAX)) {
-		pr_err("gator: CPU%u selecting wrong PMNC counter %d\n", smp_processor_id(), cnt);
-		return -1;
-	}
-
-	val = (cnt - CNT0);
+	u32 val = (cnt - CNT0);
 	asm volatile("mcr p15, 0, %0, c9, c12, 5" : : "r" (val));
-
 	return cnt;
 }
 
@@ -139,37 +126,12 @@ static inline void armv7_pmnc_write_evtsel(unsigned int cnt, u32 val)
 	}
 }
 
-static void armv7_pmnc_reset_counter(unsigned int cnt)
-{
-	u32 val = 0;
-
-	if (cnt == CCNT) {
-		armv7_pmnc_disable_counter(cnt);
-
-		asm volatile("mcr p15, 0, %0, c9, c13, 0" : : "r" (val));
-
-		if (pmnc_enabled[cnt] != 0)
-		    armv7_pmnc_enable_counter(cnt);
-
-	} else if (cnt >= CNTMAX) {
-		pr_err("gator: CPU%u resetting wrong PMNC counter %d\n", smp_processor_id(), cnt);
-	} else {
-		armv7_pmnc_disable_counter(cnt);
-
-		if (armv7_pmnc_select_counter(cnt) == cnt)
-		    asm volatile("mcr p15, 0, %0, c9, c13, 2" : : "r" (val));
-
-		if (pmnc_enabled[cnt] != 0)
-		    armv7_pmnc_enable_counter(cnt);
-	}
-}
-
 static int gator_events_armv7_create_files(struct super_block *sb, struct dentry *root)
 {
 	struct dentry *dir;
 	int i;
 
-	for (i = 0; i < pmnc_count; i++) {
+	for (i = 0; i < pmnc_counters; i++) {
 		char buf[40];
 		if (i == 0) {
 			snprintf(buf, sizeof buf, "ARM_%s_ccnt", pmnc_name);
@@ -181,10 +143,11 @@ static int gator_events_armv7_create_files(struct super_block *sb, struct dentry
 			return -1;
 		}
 		gatorfs_create_ulong(sb, dir, "enabled", &pmnc_enabled[i]);
+		gatorfs_create_ulong(sb, dir, "count", &pmnc_count[i]);
+		gatorfs_create_ro_ulong(sb, dir, "key", &pmnc_key[i]);
 		if (i > 0) {
 			gatorfs_create_ulong(sb, dir, "event", &pmnc_event[i]);
 		}
-		gatorfs_create_ro_ulong(sb, dir, "key", &pmnc_key[i]);
 	}
 
 	return 0;
@@ -202,6 +165,9 @@ static void gator_events_armv7_online(void)
 	// Initialize & Reset PMNC: C bit and P bit
 	armv7_pmnc_write(PMNC_P | PMNC_C);
 
+	// Reset overflow flags
+	armv7_pmnc_reset_interrupt();
+
 	for (cnt = CCNT; cnt < CNTMAX; cnt++) {
 		unsigned long event;
 
@@ -219,10 +185,16 @@ static void gator_events_armv7_online(void)
 		if (cnt != CCNT)
 			armv7_pmnc_write_evtsel(cnt, event);
 
+		// Enable/disable interrupt
+		if (pmnc_count[cnt] > 0)
+			armv7_pmnc_enable_interrupt(cnt);
+		else
+			armv7_pmnc_disable_interrupt(cnt);
+
 		// Reset counter
-		armv7_pmnc_reset_counter(cnt);
+		cnt ? armv7_cntn_read(cnt, pmnc_count[cnt]) : armv7_ccnt_read(pmnc_count[cnt]);
 
-		// Enable counter, but do not enable interrupt for this counter
+		// Enable counter
 		armv7_pmnc_enable_counter(cnt);
 	}
 
@@ -242,6 +214,7 @@ static void gator_events_armv7_stop(void)
 	for (cnt = CCNT; cnt < CNTMAX; cnt++) {
 		pmnc_enabled[cnt] = 0;
 		pmnc_event[cnt] = 0;
+		pmnc_count[cnt] = 0;
 	}
 }
 
@@ -250,16 +223,16 @@ static int gator_events_armv7_read(int **buffer)
 	int cnt, len = 0;
 	int cpu = smp_processor_id();
 
-	if (!pmnc_count)
+	if (!pmnc_counters)
 		return 0;
 
-	for (cnt = 0; cnt < pmnc_count; cnt++) {
-		if (pmnc_enabled[cnt]) {
+	for (cnt = 0; cnt < pmnc_counters; cnt++) {
+		if (pmnc_enabled[cnt] && pmnc_count[cnt] == 0) {
 			int value;
 			if (cnt == CCNT) {
-				value = armv7_ccnt_read();
+				value = armv7_ccnt_read(0);
 			} else {
-				value = armv7_cntn_read(cnt);
+				value = armv7_cntn_read(cnt, 0);
 			}
 			if (value != per_cpu(perfPrev, cpu)[cnt]) {
 				per_cpu(perfPrev, cpu)[cnt] = value;
@@ -291,29 +264,30 @@ int gator_events_armv7_init(void)
 	switch (gator_cpuid()) {
 	case CORTEX_A5:
 		pmnc_name = "Cortex-A5";
-		pmnc_count = 2;
+		pmnc_counters = 2;
 		break;
 	case CORTEX_A8:
 		pmnc_name = "Cortex-A8";
-		pmnc_count = 4;
+		pmnc_counters = 4;
 		break;
 	case CORTEX_A9:
 		pmnc_name = "Cortex-A9";
-		pmnc_count = 6;
+		pmnc_counters = 6;
 		break;
 	case CORTEX_A15:
 		pmnc_name = "Cortex-A15";
-		pmnc_count = 6;
+		pmnc_counters = 6;
 		break;
 	default:
 		return -1;
 	}
 
-	pmnc_count++; // CNT[n] + CCNT
+	pmnc_counters++; // CNT[n] + CCNT
 
 	for (cnt = CCNT; cnt < CNTMAX; cnt++) {
 		pmnc_enabled[cnt] = 0;
 		pmnc_event[cnt] = 0;
+		pmnc_count[cnt] = 0;
 		pmnc_key[cnt] = gator_events_get_key();
 	}