diff options
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/Kconfig.x86 | 2 | ||||
| -rw-r--r-- | drivers/cpufreq/amd-pstate.c | 49 |
2 files changed, 35 insertions, 16 deletions
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 index 310779b07daf..00476e94db90 100644 --- a/drivers/cpufreq/Kconfig.x86 +++ b/drivers/cpufreq/Kconfig.x86 @@ -35,7 +35,7 @@ config X86_PCC_CPUFREQ If in doubt, say N. config X86_AMD_PSTATE - tristate "AMD Processor P-State driver" + bool "AMD Processor P-State driver" depends on X86 && ACPI select ACPI_PROCESSOR select ACPI_CPPC_LIB if X86_64 diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index ace7d50cf2ac..204e39006dda 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -59,12 +59,8 @@ * we disable it by default to go acpi-cpufreq on these processors and add a * module parameter to be able to enable it manually for debugging. */ -static bool shared_mem = false; -module_param(shared_mem, bool, 0444); -MODULE_PARM_DESC(shared_mem, - "enable amd-pstate on processors with shared memory solution (false = disabled (default), true = enabled)"); - static struct cpufreq_driver amd_pstate_driver; +static int cppc_load __initdata; static inline int pstate_enable(bool enable) { @@ -424,12 +420,22 @@ static void amd_pstate_boost_init(struct amd_cpudata *cpudata) amd_pstate_driver.boost_enabled = true; } +static void amd_perf_ctl_reset(unsigned int cpu) +{ + wrmsrl_on_cpu(cpu, MSR_AMD_PERF_CTL, 0); +} + static int amd_pstate_cpu_init(struct cpufreq_policy *policy) { int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; struct device *dev; struct amd_cpudata *cpudata; + /* + * Resetting PERF_CTL_MSR will put the CPU in P0 frequency, + * which is ideal for initialization process. + */ + amd_perf_ctl_reset(policy->cpu); dev = get_cpu_device(policy->cpu); if (!dev) return -ENODEV; @@ -616,6 +622,15 @@ static int __init amd_pstate_init(void) if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) return -ENODEV; + /* + * by default the pstate driver is disabled to load + * enable the amd_pstate passive mode driver explicitly + * with amd_pstate=passive in kernel command line + */ + if (!cppc_load) { + pr_debug("driver load is disabled, boot with amd_pstate=passive to enable this\n"); + return -ENODEV; + } if (!acpi_cpc_valid()) { pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n"); @@ -630,13 +645,11 @@ static int __init amd_pstate_init(void) if (boot_cpu_has(X86_FEATURE_CPPC)) { pr_debug("AMD CPPC MSR based functionality is supported\n"); amd_pstate_driver.adjust_perf = amd_pstate_adjust_perf; - } else if (shared_mem) { + } else { + pr_debug("AMD CPPC shared memory based functionality is supported\n"); static_call_update(amd_pstate_enable, cppc_enable); static_call_update(amd_pstate_init_perf, cppc_init_perf); static_call_update(amd_pstate_update_perf, cppc_update_perf); - } else { - pr_info("This processor supports shared memory solution, you can enable it with amd_pstate.shared_mem=1\n"); - return -ENODEV; } /* enable amd pstate feature */ @@ -653,16 +666,22 @@ static int __init amd_pstate_init(void) return ret; } +device_initcall(amd_pstate_init); -static void __exit amd_pstate_exit(void) +static int __init amd_pstate_param(char *str) { - cpufreq_unregister_driver(&amd_pstate_driver); + if (!str) + return -EINVAL; - amd_pstate_enable(false); -} + if (!strcmp(str, "disable")) { + cppc_load = 0; + pr_info("driver is explicitly disabled\n"); + } else if (!strcmp(str, "passive")) + cppc_load = 1; -module_init(amd_pstate_init); -module_exit(amd_pstate_exit); + return 0; +} +early_param("amd_pstate", amd_pstate_param); MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>"); MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver"); |