@@ -559,6 +559,8 @@
#define AMD_CPPC_MIN_PERF(x) (((x) & 0xff) << 8)
#define AMD_CPPC_DES_PERF(x) (((x) & 0xff) << 16)
#define AMD_CPPC_ENERGY_PERF_PREF(x) (((x) & 0xff) << 24)
+#define AMD_CPPC_PRECISION_BOOST_BIT 25
+#define AMD_CPPC_PRECISION_BOOST_ENABLED BIT_ULL(AMD_CPPC_PRECISION_BOOST_BIT)
/* AMD Performance Counter Global Status and Control MSRs */
#define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS 0xc0000300
@@ -122,6 +122,7 @@ struct amd_cpudata {
u64 freq;
bool boost_supported;
+ u64 cppc_hw_conf_cached;
};
static inline int pstate_enable(bool enable)
@@ -438,18 +439,27 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
{
struct amd_cpudata *cpudata = policy->driver_data;
int ret;
+ u64 value;
if (!cpudata->boost_supported) {
pr_err("Boost mode is not supported by this processor or SBIOS\n");
return -EINVAL;
}
- if (state)
+ ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_HW_CTL, &value);
+ if (ret)
+ return ret;
+
+ if (state) {
+ value |= AMD_CPPC_PRECISION_BOOST_ENABLED;
policy->cpuinfo.max_freq = cpudata->max_freq;
- else
+ } else {
+ value &= ~AMD_CPPC_PRECISION_BOOST_ENABLED;
policy->cpuinfo.max_freq = cpudata->nominal_freq;
-
+ }
policy->max = policy->cpuinfo.max_freq;
+ WRITE_ONCE(cpudata->cppc_hw_conf_cached, value);
+ wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_HW_CTL, value);
ret = freq_qos_update_request(&cpudata->req[1],
policy->cpuinfo.max_freq);
@@ -478,6 +488,7 @@ 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;
+ u64 value;
dev = get_cpu_device(policy->cpu);
if (!dev)
@@ -542,6 +553,11 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
policy->driver_data = cpudata;
+ ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_HW_CTL, &value);
+ if (ret)
+ return ret;
+ WRITE_ONCE(cpudata->cppc_hw_conf_cached, value);
+
amd_pstate_boost_init(cpudata);
return 0;
Add support to switch AMD precision boost state to scale cpu max frequency that will help to improve the processor throughput. when set boost state to be enabled, user will need to execute below commands, the CPU will reach absolute maximum performance level or the highest perf which CPU physical support. This performance level may not be sustainable for long durations, it will help to improve the IO workload tasks. * turn on CPU boost state under root echo 1 > /sys/devices/system/cpu/cpufreq/boost If user set boost off,the CPU can reach to the maximum sustained performance level of the process, that level is the process can maintain continously working and definitely it can save some power compared to boost on mode. * turn off CPU boost state under root echo 0 > /sys/devices/system/cpu/cpufreq/boost Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> --- arch/x86/include/asm/msr-index.h | 2 ++ drivers/cpufreq/amd-pstate.c | 22 +++++++++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-)