powerpc/perf: Update perf_regs structure to include MMCRA

On each sample, Monitor Mode Control Register A (MMCRA) content is
saved in pt_regs. MMCRA does not have a entry as-is in the pt_regs but
instead, MMCRA content is saved in the "dsisr" register of pt_regs.

Patch adds another entry to the perf_regs structure to include the
"MMCRA" printing which internally maps to the "dsisr" of pt_regs.

It also check for the MMCRA availability in the platform and present
value accordingly

mpe: This was the 2nd patch in a series with commit 333804dc3b
("powerpc/perf: Update perf_regs structure to include SIER") but I
accidentally only merged the 1st patch, so merge this one now.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/perf/arch/powerpc/include/perf_regs.h

@@ -63,7 +63,8 @@ static const char *reg_names[] = {
 	[PERF_REG_POWERPC_TRAP] = "trap",
 	[PERF_REG_POWERPC_DAR] = "dar",
 	[PERF_REG_POWERPC_DSISR] = "dsisr",
-	[PERF_REG_POWERPC_SIER] = "sier"
+	[PERF_REG_POWERPC_SIER] = "sier",
+	[PERF_REG_POWERPC_MMCRA] = "mmcra"
 };
 
 static inline const char *perf_reg_name(int id)

tools/perf/arch/powerpc/util/perf_regs.c

@@ -53,6 +53,7 @@ const struct sample_reg sample_reg_masks[] = {
 	SMPL_REG(dar, PERF_REG_POWERPC_DAR),
 	SMPL_REG(dsisr, PERF_REG_POWERPC_DSISR),
 	SMPL_REG(sier, PERF_REG_POWERPC_SIER),
+	SMPL_REG(mmcra, PERF_REG_POWERPC_MMCRA),
 	SMPL_REG_END
 };