On Fri, Apr 23, 2021 at 11:19:46PM +0800, Rafael J. Wysocki wrote:
On Wed, Apr 21, 2021 at 4:38 AM Huang Rui ray.huang@amd.com wrote:
Some AMD Ryzen generations has different calculation method on maximum perf. 255 is not for all asics, some specific generations should use 166 as the maximum perf. Otherwise, it will report incorrect frequency value like below:
~ $B"*(B lscpu | grep MHz CPU MHz: 3400.000 CPU max MHz: 7228.3198 CPU min MHz: 2200.0000
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@gmail.com Tested-by: Jason Bagavatsingham jason.bagavatsingham@gmail.com Bugzilla: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.k... Signed-off-by: Huang Rui ray.huang@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Nathan Fontenot nathan.fontenot@amd.com Cc: Rafael J. Wysocki rafael.j.wysocki@intel.com Cc: Borislav Petkov bp@suse.de Cc: x86@kernel.org Cc: stable@vger.kernel.org
Changes from V1 -> V2:
- Enhance the commit message.
- Move amd_get_highest_perf() into amd.c.
- Refine the implementation of switch-case.
- Cc stable mail list.
arch/x86/include/asm/processor.h | 2 ++ arch/x86/kernel/cpu/amd.c | 22 ++++++++++++++++++++++ arch/x86/kernel/smpboot.c | 2 +- drivers/cpufreq/acpi-cpufreq.c | 19 +++++++++++++++++++ 4 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index f1b9ed5efaa9..908bcaea1361 100644 --- 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_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) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 347a956f71ca..aadb691d9357 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -1170,3 +1170,25 @@ void set_dr_addr_mask(unsigned long mask, int dr) break; } }
+u32 amd_get_highest_perf(void) +{
struct cpuinfo_x86 *c = &boot_cpu_data;u32 cppc_max_perf = 225;The extra local variable is redundant.
switch (c->x86) {case 0x17:if ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||(c->x86_model >= 0x70 && c->x86_model < 0x80))cppc_max_perf = 166;break;Also it would be cleaner to write this as
if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) || (c->x86_model >= 0x70 && c->x86_model < 0x80)) return 166;
And analogously below.
case 0x19:if ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||(c->x86_model >= 0x40 && c->x86_model < 0x70))cppc_max_perf = 166;break;}return cppc_max_perf;And here
return 225;
+} +EXPORT_SYMBOL_GPL(amd_get_highest_perf); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 02813a7f3a7c..7bec57d04a87 100644 --- 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) {diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index d1bbc16fba4b..3f0a19dd658c 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -630,6 +630,22 @@ static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c) #endif
#ifdef CONFIG_ACPI_CPPC_LIB
+static u64 get_amd_max_boost_ratio(unsigned int cpu, u64 nominal_perf) +{
u64 boost_ratio, cppc_max_perf;if (!nominal_perf)return 0;cppc_max_perf = amd_get_highest_perf();boost_ratio = div_u64(cppc_max_perf << SCHED_CAPACITY_SHIFT,nominal_perf);return boost_ratio;+}
The function above is not necessary if I'm not mistaken.
Yes, right.
static u64 get_max_boost_ratio(unsigned int cpu) { struct cppc_perf_caps perf_caps; @@ -646,6 +662,9 @@ static u64 get_max_boost_ratio(unsigned int cpu) return 0; }
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)return get_amd_max_boost_ratio(cpu, perf_caps.nominal_perf);highest_perf = perf_caps.highest_perf;The above can be written as
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) highest_perf = amd_get_highest_perf(); else highest_perf = perf_caps.highest_perf;
Thanks to simplify the implementation. Will update it in V4.
Best Regards, Ray