@@ -4,4 +4,5 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
endif
ifndef NO_LIBUNWIND
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o
endif
@@ -9,6 +9,8 @@
#define PERF_REG_IP PERF_REG_ARM64_PC
#define PERF_REG_SP PERF_REG_ARM64_SP
+void perf_regs_load(u64 *regs);
+
static inline const char *perf_reg_name(int id)
{
switch (id) {
new file mode 100644
@@ -0,0 +1,39 @@
+#include <linux/linkage.h>
+
+/*
+ * Implementation of void perf_regs_load(u64 *regs);
+ *
+ * This functions fills in the 'regs' buffer from the actual registers values,
+ * in the way the perf built-in unwinding test expects them:
+ * - the PC at the time at the call to this function. Since this function
+ * is called using a bl instruction, the PC value is taken from LR,
+ * - the current SP (not touched by this function),
+ * - the current value of LR is merely retrieved and stored because the
+ * value before the call to this function is unknown at this time; it will
+ * be unwound from the dwarf information in unwind__get_entries.
+ */
+
+.text
+.type perf_regs_load,%function
+ENTRY(perf_regs_load)
+ stp x0, x1, [x0], #16 // store x0..x29
+ stp x2, x3, [x0], #16
+ stp x4, x5, [x0], #16
+ stp x6, x7, [x0], #16
+ stp x8, x9, [x0], #16
+ stp x10, x11, [x0], #16
+ stp x12, x13, [x0], #16
+ stp x14, x15, [x0], #16
+ stp x16, x17, [x0], #16
+ stp x18, x19, [x0], #16
+ stp x20, x21, [x0], #16
+ stp x22, x23, [x0], #16
+ stp x24, x25, [x0], #16
+ stp x26, x27, [x0], #16
+ stp x28, x29, [x0], #16
+ mov x1, sp
+ stp x30, x1, [x0], #16 // store lr and sp
+ str x30, [x0] // store pc as lr in order to skip the call
+ // to this function
+ ret
+ENDPROC(perf_regs_load)
Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches. It takes single argument as a pointer to the regs dump buffer and populates it with current registers values, as expected by the perf built-in unwinding test. Signed-off-by: Jean Pihet <jean.pihet@linaro.org> Cc: Steve Capper <steve.capper@linaro.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> --- tools/perf/arch/arm64/Makefile | 1 + tools/perf/arch/arm64/include/perf_regs.h | 2 ++ tools/perf/arch/arm64/tests/regs_load.S | 39 +++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+) create mode 100644 tools/perf/arch/arm64/tests/regs_load.S