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huangruiingomolnar
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x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations
Some AMD Ryzen generations has different calculation method on maximum performance. 255 is not for all ASICs, some specific generations should use 166 as the maximum performance. Otherwise, it will report incorrect frequency value like below: ~ → lscpu | grep MHz CPU MHz: 3400.000 CPU max MHz: 7228.3198 CPU min MHz: 2200.0000 [ mingo: Tidied up whitespace use. ] [ Alexander Monakov <amonakov@ispras.ru>: fix 225 -> 255 typo. ] Fixes: 41ea667 ("x86, sched: Calculate frequency invariance for AMD systems") Fixes: 3c55e94 ("cpufreq: ACPI: Extend frequency tables to cover boost frequencies") Reported-by: Jason Bagavatsingham <jason.bagavatsingham@gmail.com> Fixed-by: Alexander Monakov <amonakov@ispras.ru> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Huang Rui <ray.huang@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Jason Bagavatsingham <jason.bagavatsingham@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210425073451.2557394-1-ray.huang@amd.com Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211791 Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent 02dbb72 commit 3743d55

4 files changed

Lines changed: 24 additions & 2 deletions

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arch/x86/include/asm/processor.h

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@@ -787,8 +787,10 @@ DECLARE_PER_CPU(u64, msr_misc_features_shadow);
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#ifdef CONFIG_CPU_SUP_AMD
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extern u32 amd_get_nodes_per_socket(void);
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extern u32 amd_get_highest_perf(void);
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#else
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static inline u32 amd_get_nodes_per_socket(void) { return 0; }
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static inline u32 amd_get_highest_perf(void) { return 0; }
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#endif
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static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)

arch/x86/kernel/cpu/amd.c

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Original file line numberDiff line numberDiff line change
@@ -1165,3 +1165,19 @@ void set_dr_addr_mask(unsigned long mask, int dr)
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break;
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}
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}
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u32 amd_get_highest_perf(void)
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{
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struct cpuinfo_x86 *c = &boot_cpu_data;
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if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
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(c->x86_model >= 0x70 && c->x86_model < 0x80)))
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return 166;
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if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
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(c->x86_model >= 0x40 && c->x86_model < 0x70)))
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return 166;
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return 255;
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}
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EXPORT_SYMBOL_GPL(amd_get_highest_perf);

arch/x86/kernel/smpboot.c

Lines changed: 1 addition & 1 deletion
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@@ -2043,7 +2043,7 @@ static bool amd_set_max_freq_ratio(void)
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return false;
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}
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highest_perf = perf_caps.highest_perf;
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highest_perf = amd_get_highest_perf();
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nominal_perf = perf_caps.nominal_perf;
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if (!highest_perf || !nominal_perf) {

drivers/cpufreq/acpi-cpufreq.c

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -646,7 +646,11 @@ static u64 get_max_boost_ratio(unsigned int cpu)
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return 0;
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}
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highest_perf = perf_caps.highest_perf;
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if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
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highest_perf = amd_get_highest_perf();
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else
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highest_perf = perf_caps.highest_perf;
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nominal_perf = perf_caps.nominal_perf;
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if (!highest_perf || !nominal_perf) {

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