From eb8b6c36820214df96e7e86d8614d93f6b028f28 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Thu, 25 Apr 2024 16:07:58 +0800 Subject: [PATCH] cpufreq: amd-pstate: Add quirk for the pstate CPPC capabilities missing Add quirks table to get CPPC capabilities issue fixed by providing correct perf or frequency values while driver loading. If CPPC capabilities are not defined in the ACPI tables or wrongly defined by platform firmware, it needs to use quick to get those issues fixed with correct workaround values to make pstate driver can be loaded even though there are CPPC capabilities errors. The workaround will match the broken BIOS which lack of CPPC capabilities nominal_freq and lowest_freq definition in the ACPI table. $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_freq 0 $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq 0 Acked-by: Huang Rui Reviewed-by: Mario Limonciello Reviewed-by: Gautham R. Shenoy Tested-by: Dhananjay Ugwekar Signed-off-by: Perry Yuan Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/amd-pstate.c | 53 ++++++++++++++++++++++++++++++++++-- include/linux/amd-pstate.h | 6 ++++ 2 files changed, 57 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 510b5aec42ea0..83a29b257794b 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver; static int cppc_state = AMD_PSTATE_UNDEFINED; static bool cppc_enabled; static bool amd_pstate_prefcore = true; +static struct quirk_entry *quirks; /* * AMD Energy Preference Performance (EPP) @@ -111,6 +112,41 @@ static unsigned int epp_values[] = { typedef int (*cppc_mode_transition_fn)(int); +static struct quirk_entry quirk_amd_7k62 = { + .nominal_freq = 2600, + .lowest_freq = 550, +}; + +static int __init dmi_matched_7k62_bios_bug(const struct dmi_system_id *dmi) +{ + /** + * match the broken bios for family 17h processor support CPPC V2 + * broken BIOS lack of nominal_freq and lowest_freq capabilities + * definition in ACPI tables + */ + if (boot_cpu_has(X86_FEATURE_ZEN2)) { + quirks = dmi->driver_data; + pr_info("Overriding nominal and lowest frequencies for %s\n", dmi->ident); + return 1; + } + + return 0; +} + +static const struct dmi_system_id amd_pstate_quirks_table[] __initconst = { + { + .callback = dmi_matched_7k62_bios_bug, + .ident = "AMD EPYC 7K62", + .matches = { + DMI_MATCH(DMI_BIOS_VERSION, "5.14"), + DMI_MATCH(DMI_BIOS_RELEASE, "12/12/2019"), + }, + .driver_data = &quirk_amd_7k62, + }, + {} +}; +MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table); + static inline int get_mode_idx_from_str(const char *str, size_t size) { int i; @@ -812,8 +848,16 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata) if (ret) return ret; - min_freq = cppc_perf.lowest_freq * 1000; - nominal_freq = cppc_perf.nominal_freq; + if (quirks && quirks->lowest_freq) + min_freq = quirks->lowest_freq * 1000; + else + min_freq = cppc_perf.lowest_freq * 1000; + + if (quirks && quirks->nominal_freq) + nominal_freq = quirks->nominal_freq ; + else + nominal_freq = cppc_perf.nominal_freq; + nominal_perf = READ_ONCE(cpudata->nominal_perf); highest_perf = READ_ONCE(cpudata->highest_perf); @@ -1662,6 +1706,11 @@ static int __init amd_pstate_init(void) if (cpufreq_get_current_driver()) return -EEXIST; + quirks = NULL; + + /* check if this machine need CPPC quirks */ + dmi_check_system(amd_pstate_quirks_table); + switch (cppc_state) { case AMD_PSTATE_UNDEFINED: /* Disable on the following configs by default: diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h index ec0b0fa3e9bb4..d58fc022ec466 100644 --- a/include/linux/amd-pstate.h +++ b/include/linux/amd-pstate.h @@ -128,4 +128,10 @@ static const char * const amd_pstate_mode_string[] = { [AMD_PSTATE_GUIDED] = "guided", NULL, }; + +struct quirk_entry { + u32 nominal_freq; + u32 lowest_freq; +}; + #endif /* _LINUX_AMD_PSTATE_H */