[PATCH v2 3/3] cpufreq/amd-pstate: Get Highest Freq for a CPU

[Mario Limonciello <mario.limonciello@amd.com>]

If the highest frequency is known for a CPU, use this instead of
trying to calculate by linear interpolation.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Use fallback method if no BIOS/quirk values
---
 drivers/cpufreq/amd-pstate.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index cf2d67f09fead..dbe08420b1df7 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1133,8 +1133,10 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 
 	WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
 
-	/* max_freq is calculated according to (nominal_freq * highest_perf)/nominal_perf */
-	max_freq = perf_to_freq(perf, nominal_freq, perf.highest_perf);
+	/* try to look up from BIOS/quirk first, fall back to (nominal_freq * highest_perf)/nominal_perf */
+	max_freq = amd_get_max_frequency(cpudata->cpu) * 1000;
+	if (!max_freq)
+		max_freq = perf_to_freq(perf, nominal_freq, perf.highest_perf);
 	WRITE_ONCE(cpudata->max_freq, max_freq);
 
 	lowest_nonlinear_freq = perf_to_freq(perf, nominal_freq, perf.lowest_nonlinear_perf);
-- 
2.43.0