From 68055915c1c22489f9658bd2b7391bb11b2cf4e4 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 3 Nov 2014 17:00:28 -0800 Subject: [PATCH] perf/x86/intel/uncore: Fix boot crash on SBOX PMU on Haswell-EP There were several reports that on some systems writing the SBOX0 PMU initialization MSR would #GP at boot. This did not happen on all systems -- my two test systems booted fine. Writing the three initialization bits bit-by-bit seems to avoid the problem. So add a special callback to do just that. This replaces an earlier patch that disabled the SBOX. Reported-by: Alexei Starovoitov Reported-and-Tested-by: Patrick Lu Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/r/1415062828-19759-4-git-send-email-andi@firstfloor.org [ Fixed a whitespace error and added attribution tags that were left out inexplicably. ] Signed-off-by: Ingo Molnar --- .../cpu/perf_event_intel_uncore_snbep.c | 33 +++++++++++++++++-- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c b/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c index 0af1c932fa0f..f9ed429d6e4f 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c @@ -486,14 +486,17 @@ static struct attribute_group snbep_uncore_qpi_format_group = { .attrs = snbep_uncore_qpi_formats_attr, }; -#define SNBEP_UNCORE_MSR_OPS_COMMON_INIT() \ - .init_box = snbep_uncore_msr_init_box, \ +#define __SNBEP_UNCORE_MSR_OPS_COMMON_INIT() \ .disable_box = snbep_uncore_msr_disable_box, \ .enable_box = snbep_uncore_msr_enable_box, \ .disable_event = snbep_uncore_msr_disable_event, \ .enable_event = snbep_uncore_msr_enable_event, \ .read_counter = uncore_msr_read_counter +#define SNBEP_UNCORE_MSR_OPS_COMMON_INIT() \ + __SNBEP_UNCORE_MSR_OPS_COMMON_INIT(), \ + .init_box = snbep_uncore_msr_init_box \ + static struct intel_uncore_ops snbep_uncore_msr_ops = { SNBEP_UNCORE_MSR_OPS_COMMON_INIT(), }; @@ -1919,6 +1922,30 @@ static struct intel_uncore_type hswep_uncore_cbox = { .format_group = &hswep_uncore_cbox_format_group, }; +/* + * Write SBOX Initialization register bit by bit to avoid spurious #GPs + */ +static void hswep_uncore_sbox_msr_init_box(struct intel_uncore_box *box) +{ + unsigned msr = uncore_msr_box_ctl(box); + + if (msr) { + u64 init = SNBEP_PMON_BOX_CTL_INT; + u64 flags = 0; + int i; + + for_each_set_bit(i, (unsigned long *)&init, 64) { + flags |= (1ULL << i); + wrmsrl(msr, flags); + } + } +} + +static struct intel_uncore_ops hswep_uncore_sbox_msr_ops = { + __SNBEP_UNCORE_MSR_OPS_COMMON_INIT(), + .init_box = hswep_uncore_sbox_msr_init_box +}; + static struct attribute *hswep_uncore_sbox_formats_attr[] = { &format_attr_event.attr, &format_attr_umask.attr, @@ -1944,7 +1971,7 @@ static struct intel_uncore_type hswep_uncore_sbox = { .event_mask = HSWEP_S_MSR_PMON_RAW_EVENT_MASK, .box_ctl = HSWEP_S0_MSR_PMON_BOX_CTL, .msr_offset = HSWEP_SBOX_MSR_OFFSET, - .ops = &snbep_uncore_msr_ops, + .ops = &hswep_uncore_sbox_msr_ops, .format_group = &hswep_uncore_sbox_format_group, }; -- 2.30.2