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authorwill schmidt <will_schmidt@vnet.ibm.com>2007-06-27 02:12:33 +1000
committerPaul Mackerras <paulus@samba.org>2007-07-10 21:55:48 +1000
commit078f194045f892a10f4a5406e7cb06a7f8d42c57 (patch)
treec81b15e94d451cddf43c71657a86adf2e8773a11
parentf5e6a280d153bff3b0cd15651d29d409f8dea698 (diff)
downloadlinux-2.6.34-ux500-078f194045f892a10f4a5406e7cb06a7f8d42c57.tar.gz
[POWERPC] Oprofile enhanced instruction sampling support
Oprofile enhanced instruction sampling support. When performing instruction sampling, the mmcra[SLOT] field can be used to more accurately identify the address of the sampled instruction. Tested on power4, js20, power5 and power5+. Signed-off-by: Will Schmidt <will_schmidt@vnet.ibm.com> cc: Maynard Johnson <maynardj@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/oprofile/op_model_power4.c14
-rw-r--r--include/asm-powerpc/reg.h2
2 files changed, 16 insertions, 0 deletions
diff --git a/arch/powerpc/oprofile/op_model_power4.c b/arch/powerpc/oprofile/op_model_power4.c
index fe597a154d4..a7c206b665a 100644
--- a/arch/powerpc/oprofile/op_model_power4.c
+++ b/arch/powerpc/oprofile/op_model_power4.c
@@ -1,5 +1,7 @@
/*
* Copyright (C) 2004 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Added mmcra[slot] support:
+ * Copyright (C) 2006-2007 Will Schmidt <willschm@us.ibm.com>, IBM
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -181,11 +183,17 @@ static void __attribute_used__ kernel_unknown_bucket(void)
* On GQ and newer the MMCRA stores the HV and PR bits at the time
* the SIAR was sampled. We use that to work out if the SIAR was sampled in
* the hypervisor, our exception vectors or RTAS.
+ * If the MMCRA_SAMPLE_ENABLE bit is set, we can use the MMCRA[slot] bits
+ * to more accurately identify the address of the sampled instruction. The
+ * mmcra[slot] bits represent the slot number of a sampled instruction
+ * within an instruction group. The slot will contain a value between 1
+ * and 5 if MMCRA_SAMPLE_ENABLE is set, otherwise 0.
*/
static unsigned long get_pc(struct pt_regs *regs)
{
unsigned long pc = mfspr(SPRN_SIAR);
unsigned long mmcra;
+ unsigned long slot;
/* Cant do much about it */
if (!cur_cpu_spec->oprofile_mmcra_sihv)
@@ -193,6 +201,12 @@ static unsigned long get_pc(struct pt_regs *regs)
mmcra = mfspr(SPRN_MMCRA);
+ if (mmcra & MMCRA_SAMPLE_ENABLE) {
+ slot = ((mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT);
+ if (slot > 1)
+ pc += 4 * (slot - 1);
+ }
+
/* Were we in the hypervisor? */
if (firmware_has_feature(FW_FEATURE_LPAR) &&
(mmcra & cur_cpu_spec->oprofile_mmcra_sihv))
diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index 749c7f953b5..281011e953e 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -453,6 +453,8 @@
#define SPRN_MMCRA 0x312
#define MMCRA_SIHV 0x10000000UL /* state of MSR HV when SIAR set */
#define MMCRA_SIPR 0x08000000UL /* state of MSR PR when SIAR set */
+#define MMCRA_SLOT 0x07000000UL /* SLOT bits (37-39) */
+#define MMCRA_SLOT_SHIFT 24
#define MMCRA_SAMPLE_ENABLE 0x00000001UL /* enable sampling */
#define POWER6_MMCRA_SIHV 0x0000040000000000ULL
#define POWER6_MMCRA_SIPR 0x0000020000000000ULL