[PATCH 2/2][v2] cpufreq: intel_pstate: Get percpu max freq via HWP MSR register if available

[Chen Yu]

Currently when turbo is disabled(either by BIOS or by the user), the 
intel_pstate
driver reads the max frequency from the package-wide MSR_PLATFORM_INFO(0xce) 
register.
However on asymmetric platforms it is possible in theory that small and big 
core with
HWP enabled might have different max cpu frequency, because the 
MSR_HWP_CAPABILITIES
is percpu scope according to Intel Software Developer Manual.

The turbo max freq is already percpu basis in current code, thus make similar 
change
to the max non-turbo frequency as well.

Reported-by: Wendy Wang <wendy.w...@intel.com>
Signed-off-by: Chen Yu <yu.c.c...@intel.com>
---
v2: per Srinivas' suggestion, avoid duplicated assignment of max_pstate.
--
 drivers/cpufreq/intel_pstate.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index bd3dd1be73ba..f2d18991d969 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1725,11 +1725,9 @@ static void intel_pstate_max_within_limits(struct 
cpudata *cpu)
 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 {
        cpu->pstate.min_pstate = pstate_funcs.get_min();
-       cpu->pstate.max_pstate = pstate_funcs.get_max();
        cpu->pstate.max_pstate_physical = pstate_funcs.get_max_physical();
        cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
        cpu->pstate.scaling = pstate_funcs.get_scaling();
-       cpu->pstate.max_freq = cpu->pstate.max_pstate * cpu->pstate.scaling;
 
        if (hwp_active && !hwp_mode_bdw) {
                unsigned int phy_max, current_max, guar_state;
@@ -1737,8 +1735,12 @@ static void intel_pstate_get_cpu_pstates(struct cpudata 
*cpu)
                intel_pstate_get_hwp_max(cpu, &phy_max, &current_max, 
&guar_state);
                cpu->pstate.turbo_freq = phy_max * cpu->pstate.scaling;
                cpu->pstate.turbo_pstate = phy_max;
+               cpu->pstate.max_pstate = guar_state;
+               cpu->pstate.max_freq = guar_state * cpu->pstate.scaling;
        } else {
                cpu->pstate.turbo_freq = cpu->pstate.turbo_pstate * 
cpu->pstate.scaling;
+               cpu->pstate.max_pstate = pstate_funcs.get_max();
+               cpu->pstate.max_freq = cpu->pstate.max_pstate * 
cpu->pstate.scaling;
        }
 
        if (pstate_funcs.get_aperf_mperf_shift)
-- 
2.17.1