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[POWERPC] Oprofile enhanced instruction sampling support

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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>
This commit is contained in:
will schmidt 2007-06-27 02:12:33 +10:00 • committed by Paul Mackerras
parent f5e6a280d1
commit 078f194045
2 changed files with 16 additions and 0 deletions
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14
arch/powerpc/oprofile/op_model_power4.c
View file

@ -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))

2
include/asm-powerpc/reg.h
View file

@ -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