From: "tip-bot2 for Kim Phillips" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Kim Phillips <kim.phillips@amd.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: perf/urgent] perf/x86/amd/ibs: Work around erratum #1197
Date: Thu, 26 Aug 2021 07:45:26 -0000 [thread overview]
Message-ID: <162996392634.25758.2619063727360581093.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210817221048.88063-3-kim.phillips@amd.com>
The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: 26db2e0c51fe83e1dd852c1321407835b481806e
Gitweb: https://git.kernel.org/tip/26db2e0c51fe83e1dd852c1321407835b481806e
Author: Kim Phillips <kim.phillips@amd.com>
AuthorDate: Tue, 17 Aug 2021 17:10:42 -05:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Thu, 26 Aug 2021 08:58:02 +02:00
perf/x86/amd/ibs: Work around erratum #1197
Erratum #1197 "IBS (Instruction Based Sampling) Register State May be
Incorrect After Restore From CC6" is published in a document:
"Revision Guide for AMD Family 19h Models 00h-0Fh Processors" 56683 Rev. 1.04 July 2021
https://bugzilla.kernel.org/show_bug.cgi?id=206537
Implement the erratum's suggested workaround and ignore IBS samples if
MSRC001_1031 == 0.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210817221048.88063-3-kim.phillips@amd.com
---
arch/x86/events/amd/ibs.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 40669ea..921f47b 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -90,6 +90,7 @@ struct perf_ibs {
unsigned long offset_mask[1];
int offset_max;
unsigned int fetch_count_reset_broken : 1;
+ unsigned int fetch_ignore_if_zero_rip : 1;
struct cpu_perf_ibs __percpu *pcpu;
struct attribute **format_attrs;
@@ -672,6 +673,10 @@ fail:
if (check_rip && (ibs_data.regs[2] & IBS_RIP_INVALID)) {
regs.flags &= ~PERF_EFLAGS_EXACT;
} else {
+ /* Workaround for erratum #1197 */
+ if (perf_ibs->fetch_ignore_if_zero_rip && !(ibs_data.regs[1]))
+ goto out;
+
set_linear_ip(®s, ibs_data.regs[1]);
regs.flags |= PERF_EFLAGS_EXACT;
}
@@ -769,6 +774,9 @@ static __init void perf_event_ibs_init(void)
if (boot_cpu_data.x86 >= 0x16 && boot_cpu_data.x86 <= 0x18)
perf_ibs_fetch.fetch_count_reset_broken = 1;
+ if (boot_cpu_data.x86 == 0x19 && boot_cpu_data.x86_model < 0x10)
+ perf_ibs_fetch.fetch_ignore_if_zero_rip = 1;
+
perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
if (ibs_caps & IBS_CAPS_OPCNT) {
next prev parent reply other threads:[~2021-08-26 7:45 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-17 22:10 [PATCH 0/8] perf/amd: Fixes, uncore as a module, new IBS header Kim Phillips
2021-08-17 22:10 ` [PATCH 1/8] perf/amd/ibs: Extend PERF_PMU_CAP_NO_EXCLUDE to IBS Op Kim Phillips
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 7:45 ` [tip: perf/urgent] perf/x86/amd/ibs: " tip-bot2 for Kim Phillips
2021-08-17 22:10 ` [PATCH 2/8] perf/x86/amd/ibs: Add workaround for erratum #1,197 Kim Phillips
2021-08-19 22:29 ` Namhyung Kim
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 7:45 ` tip-bot2 for Kim Phillips [this message]
2021-08-17 22:10 ` [PATCH 3/8] perf/x86/amd/power: Assign pmu.module Kim Phillips
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 7:45 ` [tip: perf/urgent] " tip-bot2 for Kim Phillips
2021-08-17 22:10 ` [PATCH 4/8] perf/amd/uncore: Use free_percpu's built-in check for null Kim Phillips
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 8:09 ` [tip: perf/core] perf/amd/uncore: Simplify code, use free_percpu()'s built-in check for NULL tip-bot2 for Kim Phillips
2021-08-17 22:10 ` [PATCH 5/8] perf/amd/uncore: Use linux/ include paths instead of asm/ Kim Phillips
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 8:09 ` [tip: perf/core] perf/amd/uncore: Clean up header use, use <linux/ include paths instead of <asm/ tip-bot2 for Kim Phillips
2021-08-17 22:10 ` [PATCH 6/8] x86/cpu: Add helper function get_llc_id Kim Phillips
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 8:09 ` [tip: perf/core] x86/cpu: Add get_llc_id() helper function tip-bot2 for Kim Phillips
2021-08-17 22:10 ` [PATCH 7/8] perf/amd/uncore: Allow the driver to be built as a module Kim Phillips
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 8:09 ` tip-bot2 for Kim Phillips
2021-08-17 22:10 ` [PATCH 8/8] perf/x86/amd/ibs: Add bitfield definitions in new header Kim Phillips
2021-08-19 22:56 ` Namhyung Kim
2021-08-23 9:32 ` [tip: perf/core] " tip-bot2 for Kim Phillips
2021-08-26 8:09 ` [tip: perf/core] perf/x86/amd/ibs: Add bitfield definitions in new <asm/amd-ibs.h> header tip-bot2 for Kim Phillips
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