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x86, sched: Fix the AMD CPPC maximum performance value on certain AMD…
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… Ryzen generations

commit 3743d55 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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huangrui authored and gregkh committed May 19, 2021
1 parent 86d9a6b commit 8942128
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Showing 4 changed files with 24 additions and 2 deletions.
2 changes: 2 additions & 0 deletions arch/x86/include/asm/processor.h
Original file line number Diff line number Diff line change
Expand Up @@ -804,8 +804,10 @@ DECLARE_PER_CPU(u64, msr_misc_features_shadow);

#ifdef CONFIG_CPU_SUP_AMD
extern u32 amd_get_nodes_per_socket(void);
extern u32 amd_get_highest_perf(void);
#else
static inline u32 amd_get_nodes_per_socket(void) { return 0; }
static inline u32 amd_get_highest_perf(void) { return 0; }
#endif

static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
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16 changes: 16 additions & 0 deletions arch/x86/kernel/cpu/amd.c
Original file line number Diff line number Diff line change
Expand Up @@ -1170,3 +1170,19 @@ void set_dr_addr_mask(unsigned long mask, int dr)
break;
}
}

u32 amd_get_highest_perf(void)
{
struct cpuinfo_x86 *c = &boot_cpu_data;

if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
(c->x86_model >= 0x70 && c->x86_model < 0x80)))
return 166;

if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
(c->x86_model >= 0x40 && c->x86_model < 0x70)))
return 166;

return 255;
}
EXPORT_SYMBOL_GPL(amd_get_highest_perf);
2 changes: 1 addition & 1 deletion arch/x86/kernel/smpboot.c
Original file line number Diff line number Diff line change
Expand Up @@ -2046,7 +2046,7 @@ static bool amd_set_max_freq_ratio(void)
return false;
}

highest_perf = perf_caps.highest_perf;
highest_perf = amd_get_highest_perf();
nominal_perf = perf_caps.nominal_perf;

if (!highest_perf || !nominal_perf) {
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6 changes: 5 additions & 1 deletion drivers/cpufreq/acpi-cpufreq.c
Original file line number Diff line number Diff line change
Expand Up @@ -646,7 +646,11 @@ static u64 get_max_boost_ratio(unsigned int cpu)
return 0;
}

highest_perf = perf_caps.highest_perf;
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
highest_perf = amd_get_highest_perf();
else
highest_perf = perf_caps.highest_perf;

nominal_perf = perf_caps.nominal_perf;

if (!highest_perf || !nominal_perf) {
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