[PATCH 5.12 261/363] x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 10:34:34 EST


From: Huang Rui <ray.huang@xxxxxxx>

commit 3743d55b289c203d8f77b7cd47c24926b9d186ae 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@xxxxxxxxx>: fix 225 -> 255 typo. ]

Fixes: 41ea667227ba ("x86, sched: Calculate frequency invariance for AMD systems")
Fixes: 3c55e94c0ade ("cpufreq: ACPI: Extend frequency tables to cover boost frequencies")
Reported-by: Jason Bagavatsingham <jason.bagavatsingham@xxxxxxxxx>
Fixed-by: Alexander Monakov <amonakov@xxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Jason Bagavatsingham <jason.bagavatsingham@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20210425073451.2557394-1-ray.huang@xxxxxxx
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211791
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 2 ++
arch/x86/kernel/cpu/amd.c | 16 ++++++++++++++++
arch/x86/kernel/smpboot.c | 2 +-
drivers/cpufreq/acpi-cpufreq.c | 6 +++++-
4 files changed, 24 insertions(+), 2 deletions(-)

--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -804,8 +804,10 @@ DECLARE_PER_CPU(u64, msr_misc_features_s

#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)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1170,3 +1170,19 @@ void set_dr_addr_mask(unsigned long mask
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);
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -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) {
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -646,7 +646,11 @@ static u64 get_max_boost_ratio(unsigned
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) {