Messages in this thread Patch in this message | | | Subject | [PATCH 2/4] perf/x86/ibs: Use CPUID region helper | From | Dave Hansen <> | Date | Wed, 03 Apr 2024 08:35:11 -0700 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
IBS details are enumerated in an extended CPUID leaf. But the support has an open-coded CPUID region check. Use the new helper to trim down the code.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> --
Note: this cleanup could take another form:
if (boot_cpu_data->extended_cpuid_level >= IBS_CPUID_FEATURES) caps = cpuid_eax(IBS_CPUID_FEATURES);
that would be one fewer CPUID invocations, but one more line of code. ---
b/arch/x86/events/amd/ibs.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)
diff -puN arch/x86/events/amd/ibs.c~ibs-region-helpers arch/x86/events/amd/ibs.c --- a/arch/x86/events/amd/ibs.c~ibs-region-helpers 2024-04-02 15:22:59.262912595 -0700 +++ b/arch/x86/events/amd/ibs.c 2024-04-02 15:22:59.262912595 -0700 @@ -1278,18 +1278,13 @@ static __init int perf_event_ibs_init(vo static __init u32 __get_ibs_caps(void) { - u32 caps; - unsigned int max_level; + u32 caps = 0; if (!boot_cpu_has(X86_FEATURE_IBS)) return 0; - /* check IBS cpuid feature flags */ - max_level = cpuid_eax(0x80000000); - if (max_level < IBS_CPUID_FEATURES) - return IBS_CAPS_DEFAULT; + get_cpuid_region_leaf(IBS_CPUID_FEATURES, CPUID_EAX, &caps); - caps = cpuid_eax(IBS_CPUID_FEATURES); if (!(caps & IBS_CAPS_AVAIL)) /* cpuid flags not valid */ return IBS_CAPS_DEFAULT; _
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