From 078f194045f892a10f4a5406e7cb06a7f8d42c57 Mon Sep 17 00:00:00 2001 From: will schmidt Date: Wed, 27 Jun 2007 02:12:33 +1000 Subject: [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 cc: Maynard Johnson Signed-off-by: Paul Mackerras --- arch/powerpc/oprofile/op_model_power4.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'arch/powerpc/oprofile') 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 , IBM + * Added mmcra[slot] support: + * Copyright (C) 2006-2007 Will Schmidt , 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)) -- cgit v1.2.3