@@ -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:
@@ -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 */