1 files changed, 132 insertions, 0 deletions
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
new file mode 100644
index 000000000..7cb3e0453
--- /dev/null
+++ b/arch/arm/oprofile/common.c
@@ -0,0 +1,132 @@
+/**
+ * @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/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <asm/stacktrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/perf_event.h>
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_HW_PERF_EVENTS
+
+/*
+ * 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[] = {
+	{ "armv5_xscale1",	"arm/xscale1"	},
+	{ "armv5_xscale2",	"arm/xscale2"	},
+	{ "armv6_1136",		"arm/armv6"	},
+	{ "armv6_1156",		"arm/armv6"	},
+	{ "armv6_1176",		"arm/armv6"	},
+	{ "armv6_11mpcore",	"arm/mpcore"	},
+	{ "armv7_cortex_a8",	"arm/armv7"	},
+	{ "armv7_cortex_a9",	"arm/armv7-ca9"	},
+};
+
+char *op_name_from_perf_id(void)
+{
+	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;
+	}
+
+	return NULL;
+}
+#endif
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+	unsigned int *depth = d;
+
+	if (*depth) {
+		oprofile_add_trace(frame->pc);
+		(*depth)--;
+	}
+
+	return *depth == 0;
+}
+
+/*
+ * 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 struct frame_tail* user_backtrace(struct frame_tail *tail)
+{
+	struct frame_tail buftail[2];
+
+	/* Also check accessibility of one struct frame_tail beyond */
+	if (!access_ok(tail, sizeof(buftail)))
+		return NULL;
+	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
+		return NULL;
+
+	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;
+
+	return buftail[0].fp-1;
+}
+
+static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
+{
+	struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
+
+	if (!user_mode(regs)) {
+		struct stackframe frame;
+		arm_get_current_stackframe(regs, &frame);
+		walk_stackframe(&frame, report_trace, &depth);
+		return;
+	}
+
+	while (depth-- && tail && !((unsigned long) tail & 3))
+		tail = user_backtrace(tail);
+}
+
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+	/* provide backtrace support also in timer mode: */
+	ops->backtrace		= arm_backtrace;
+
+	return oprofile_perf_init(ops);
+}
+
+void oprofile_arch_exit(void)
+{
+	oprofile_perf_exit();
+}