intel_pstate: Knights Landing support

1. Add Knights Landing (KNL) CPUID to the list of CPUIDs supported by
    the intel_pstate driver.

 2. Add a new cpu_default structure for KNL since KNL has a slightly
    different mechanism to get turbo pstates from MSRs.

Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Dasaratharaman Chandramouli 2015-04-10 10:22:18 -07:00 committed by Rafael J. Wysocki
parent 5f97899d78
commit b34ef932d7

View File

@ -614,6 +614,19 @@ static void core_set_pstate(struct cpudata *cpudata, int pstate)
wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
}
static int knl_get_turbo_pstate(void)
{
u64 value;
int nont, ret;
rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
nont = core_get_max_pstate();
ret = (((value) >> 8) & 0xFF);
if (ret <= nont)
ret = nont;
return ret;
}
static struct cpu_defaults core_params = {
.pid_policy = {
.sample_rate_ms = 10,
@ -651,6 +664,23 @@ static struct cpu_defaults byt_params = {
},
};
static struct cpu_defaults knl_params = {
.pid_policy = {
.sample_rate_ms = 10,
.deadband = 0,
.setpoint = 97,
.p_gain_pct = 20,
.d_gain_pct = 0,
.i_gain_pct = 0,
},
.funcs = {
.get_max = core_get_max_pstate,
.get_min = core_get_min_pstate,
.get_turbo = knl_get_turbo_pstate,
.set = core_set_pstate,
},
};
static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
{
int max_perf = cpu->pstate.turbo_pstate;
@ -865,6 +895,7 @@ static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
ICPU(0x4e, core_params),
ICPU(0x4f, core_params),
ICPU(0x56, core_params),
ICPU(0x57, knl_params),
{}
};
MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);