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 333804d
("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>

arch/powerpc/include/uapi/asm/perf_regs.h

@@ -47,6 +47,7 @@ enum perf_event_powerpc_regs {
 	PERF_REG_POWERPC_DAR,
 	PERF_REG_POWERPC_DSISR,
 	PERF_REG_POWERPC_SIER,
+	PERF_REG_POWERPC_MMCRA,
 	PERF_REG_POWERPC_MAX,
 };
 #endif /* _UAPI_ASM_POWERPC_PERF_REGS_H */

arch/powerpc/perf/perf_regs.c

@@ -70,6 +70,7 @@ static unsigned int pt_regs_offset[PERF_REG_POWERPC_MAX] = {
 	PT_REGS_OFFSET(PERF_REG_POWERPC_DAR, dar),
 	PT_REGS_OFFSET(PERF_REG_POWERPC_DSISR, dsisr),
 	PT_REGS_OFFSET(PERF_REG_POWERPC_SIER, dar),
+	PT_REGS_OFFSET(PERF_REG_POWERPC_MMCRA, dsisr),
 };
 
 u64 perf_reg_value(struct pt_regs *regs, int idx)
@@ -83,6 +84,11 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
 	    !is_sier_available()))
 		return 0;
 
+	if (idx == PERF_REG_POWERPC_MMCRA &&
+	   (IS_ENABLED(CONFIG_FSL_EMB_PERF_EVENT) ||
+	    IS_ENABLED(CONFIG_PPC32)))
+		return 0;
+
 	return regs_get_register(regs, pt_regs_offset[idx]);
 }
 

tools/arch/powerpc/include/uapi/asm/perf_regs.h

@@ -47,6 +47,7 @@ enum perf_event_powerpc_regs {
 	PERF_REG_POWERPC_DAR,
 	PERF_REG_POWERPC_DSISR,
 	PERF_REG_POWERPC_SIER,
+	PERF_REG_POWERPC_MMCRA,
 	PERF_REG_POWERPC_MAX,
 };
 #endif /* _UAPI_ASM_POWERPC_PERF_REGS_H */

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
 };