1 files changed, 92 insertions, 115 deletions

diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index e57dde88289..99c63d4b6af 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -2,155 +2,132 @@
  * @file common.c
  *
  * @remark Copyright 2004 Oprofile Authors
+ * @remark Copyright 2010 ARM Ltd.
  * @remark Read the file COPYING
  *
  * @author Zwane Mwaikambo
+ * @author Will Deacon [move to perf]
  */
 
+#include <linux/cpumask.h>
 #include <linux/init.h>
+#include <linux/mutex.h>
 #include <linux/oprofile.h>
-#include <linux/errno.h>
-#include <asm/semaphore.h>
-#include <linux/sysdev.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <asm/stacktrace.h>
+#include <linux/uaccess.h>
 
-#include "op_counter.h"
-#include "op_arm_model.h"
+#include <asm/perf_event.h>
+#include <asm/ptrace.h>
 
-static struct op_arm_model_spec *pmu_model;
-static int pmu_enabled;
-static struct semaphore pmu_sem;
+#ifdef CONFIG_HW_PERF_EVENTS
 
-static int pmu_start(void);
-static int pmu_setup(void);
-static void pmu_stop(void);
-static int pmu_create_files(struct super_block *, struct dentry *);
+/*
+ * OProfile has a curious naming scheme for the ARM PMUs, but they are
+ * part of the user ABI so we need to map from the perf PMU name for
+ * supported PMUs.
+ */
+static struct op_perf_name {
+	char *perf_name;
+	char *op_name;
+} op_perf_name_map[] = {
+	{ "xscale1",		"arm/xscale1"	},
+	{ "xscale1",		"arm/xscale2"	},
+	{ "v6",			"arm/armv6"	},
+	{ "v6mpcore",		"arm/mpcore"	},
+	{ "ARMv7 Cortex-A8",	"arm/armv7"	},
+	{ "ARMv7 Cortex-A9",	"arm/armv7-ca9"	},
+};
 
-#ifdef CONFIG_PM
-static int pmu_suspend(struct sys_device *dev, pm_message_t state)
+char *op_name_from_perf_id(void)
 {
-	if (pmu_enabled)
-		pmu_stop();
-	return 0;
-}
+	int i;
+	struct op_perf_name names;
+	const char *perf_name = perf_pmu_name();
+
+	for (i = 0; i < ARRAY_SIZE(op_perf_name_map); ++i) {
+		names = op_perf_name_map[i];
+		if (!strcmp(names.perf_name, perf_name))
+			return names.op_name;
+	}
 
-static int pmu_resume(struct sys_device *dev)
-{
-	if (pmu_enabled)
-		pmu_start();
-	return 0;
+	return NULL;
 }
+#endif
 
-static struct sysdev_class oprofile_sysclass = {
-	set_kset_name("oprofile"),
-	.resume		= pmu_resume,
-	.suspend	= pmu_suspend,
-};
-
-static struct sys_device device_oprofile = {
-	.id		= 0,
-	.cls		= &oprofile_sysclass,
-};
-
-static int __init init_driverfs(void)
+static int report_trace(struct stackframe *frame, void *d)
 {
-	int ret;
+	unsigned int *depth = d;
 
-	if (!(ret = sysdev_class_register(&oprofile_sysclass)))
-		ret = sysdev_register(&device_oprofile);
-
-	return ret;
-}
+	if (*depth) {
+		oprofile_add_trace(frame->pc);
+		(*depth)--;
+	}
 
-static void  exit_driverfs(void)
-{
-	sysdev_unregister(&device_oprofile);
-	sysdev_class_unregister(&oprofile_sysclass);
+	return *depth == 0;
 }
-#else
-#define init_driverfs()	do { } while (0)
-#define exit_driverfs() do { } while (0)
-#endif /* CONFIG_PM */
 
-struct op_counter_config counter_config[OP_MAX_COUNTER];
+/*
+ * The registers we're interested in are at the end of the variable
+ * length saved register structure. The fp points at the end of this
+ * structure so the address of this struct is:
+ * (struct frame_tail *)(xxx->fp)-1
+ */
+struct frame_tail {
+	struct frame_tail *fp;
+	unsigned long sp;
+	unsigned long lr;
+} __attribute__((packed));
 
-static int pmu_create_files(struct super_block *sb, struct dentry *root)
+static struct frame_tail* user_backtrace(struct frame_tail *tail)
 {
-	unsigned int i;
-
-	for (i = 0; i < pmu_model->num_counters; i++) {
-		struct dentry *dir;
-		char buf[2];
-
-		snprintf(buf, sizeof buf, "%d", i);
-		dir = oprofilefs_mkdir(sb, root, buf);
-		oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
-		oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
-		oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
-		oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
-		oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
-		oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
-	}
+	struct frame_tail buftail[2];
 
-	return 0;
-}
+	/* Also check accessibility of one struct frame_tail beyond */
+	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+		return NULL;
+	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
+		return NULL;
 
-static int pmu_setup(void)
-{
-	int ret;
+	oprofile_add_trace(buftail[0].lr);
+
+	/* frame pointers should strictly progress back up the stack
+	 * (towards higher addresses) */
+	if (tail + 1 >= buftail[0].fp)
+		return NULL;
 
-	spin_lock(&oprofilefs_lock);
-	ret = pmu_model->setup_ctrs();
-	spin_unlock(&oprofilefs_lock);
-	return ret;
+	return buftail[0].fp-1;
 }
 
-static int pmu_start(void)
+static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
 {
-	int ret = -EBUSY;
-
-	down(&pmu_sem);
-	if (!pmu_enabled) {
-		ret = pmu_model->start();
-		pmu_enabled = !ret;
+	struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
+
+	if (!user_mode(regs)) {
+		struct stackframe frame;
+		frame.fp = regs->ARM_fp;
+		frame.sp = regs->ARM_sp;
+		frame.lr = regs->ARM_lr;
+		frame.pc = regs->ARM_pc;
+		walk_stackframe(&frame, report_trace, &depth);
+		return;
 	}
-	up(&pmu_sem);
-	return ret;
-}
 
-static void pmu_stop(void)
-{
-	down(&pmu_sem);
-	if (pmu_enabled)
-		pmu_model->stop();
-	pmu_enabled = 0;
-	up(&pmu_sem);
+	while (depth-- && tail && !((unsigned long) tail & 3))
+		tail = user_backtrace(tail);
 }
 
-int __init pmu_init(struct oprofile_operations *ops, struct op_arm_model_spec *spec)
+int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
-	init_MUTEX(&pmu_sem);
-
-	if (spec->init() < 0)
-		return -ENODEV;
-
-	pmu_model = spec;
-	init_driverfs();
-	ops->create_files = pmu_create_files;
-	ops->setup = pmu_setup;
-	ops->shutdown = pmu_stop;
-	ops->start = pmu_start;
-	ops->stop = pmu_stop;
-	ops->cpu_type = pmu_model->name;
-	printk(KERN_INFO "oprofile: using %s PMU\n", spec->name);
-
-	return 0;
+	/* provide backtrace support also in timer mode: */
+	ops->backtrace		= arm_backtrace;
+
+	return oprofile_perf_init(ops);
 }
 
-void pmu_exit(void)
+void oprofile_arch_exit(void)
 {
-	if (pmu_model) {
-		exit_driverfs();
-		pmu_model = NULL;
-	}
+	oprofile_perf_exit();
 }
-