1 files changed, 44 insertions, 0 deletions

diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c
new file mode 100644
index 000000000000..f2d6f0a36d63
--- /dev/null
+++ b/arch/arm64/kernel/perf_regs.c
@@ -0,0 +1,44 @@
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <linux/bug.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+        if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM64_MAX))
+                return 0;
+
+        /*
+         * Compat (i.e. 32 bit) mode:
+         * - PC has been set in the pt_regs struct in kernel_entry,
+         * - Handle SP and LR here.
+         */
+        if (compat_user_mode(regs)) {
+                if ((u32)idx == PERF_REG_ARM64_SP)
+                        return regs->compat_sp;
+                if ((u32)idx == PERF_REG_ARM64_LR)
+                        return regs->compat_lr;
+        }
+
+        return regs->regs[idx];
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_ARM64_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+        if (!mask || mask & REG_RESERVED)
+                return -EINVAL;
+
+        return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+        if (is_compat_thread(task_thread_info(task)))
+                return PERF_SAMPLE_REGS_ABI_32;
+        else
+                return PERF_SAMPLE_REGS_ABI_64;
+}