v4.19.13 snapshot.
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
new file mode 100644
index 0000000..cc649a1
--- /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(VERIFY_READ, 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();
+}