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Diffstat (limited to 'drivers/cpufreq/powernv-cpufreq.c')
-rw-r--r--drivers/cpufreq/powernv-cpufreq.c47
1 files changed, 46 insertions, 1 deletions
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 2dfd4fdb5a52..ebef0d8279c7 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -34,9 +34,13 @@
#include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
#define POWERNV_MAX_PSTATES 256
+#define PMSR_PSAFE_ENABLE (1UL << 30)
+#define PMSR_SPR_EM_DISABLE (1UL << 31)
+#define PMSR_MAX(x) ((x >> 32) & 0xFF)
+#define PMSR_LP(x) ((x >> 48) & 0xFF)
static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
-static bool rebooting;
+static bool rebooting, throttled;
/*
* Note: The set of pstates consists of contiguous integers, the
@@ -294,6 +298,44 @@ static inline unsigned int get_nominal_index(void)
return powernv_pstate_info.max - powernv_pstate_info.nominal;
}
+static void powernv_cpufreq_throttle_check(unsigned int cpu)
+{
+ unsigned long pmsr;
+ int pmsr_pmax, pmsr_lp;
+
+ pmsr = get_pmspr(SPRN_PMSR);
+
+ /* Check for Pmax Capping */
+ pmsr_pmax = (s8)PMSR_MAX(pmsr);
+ if (pmsr_pmax != powernv_pstate_info.max) {
+ throttled = true;
+ pr_info("CPU %d Pmax is reduced to %d\n", cpu, pmsr_pmax);
+ pr_info("Max allowed Pstate is capped\n");
+ }
+
+ /*
+ * Check for Psafe by reading LocalPstate
+ * or check if Psafe_mode_active is set in PMSR.
+ */
+ pmsr_lp = (s8)PMSR_LP(pmsr);
+ if ((pmsr_lp < powernv_pstate_info.min) ||
+ (pmsr & PMSR_PSAFE_ENABLE)) {
+ throttled = true;
+ pr_info("Pstate set to safe frequency\n");
+ }
+
+ /* Check if SPR_EM_DISABLE is set in PMSR */
+ if (pmsr & PMSR_SPR_EM_DISABLE) {
+ throttled = true;
+ pr_info("Frequency Control disabled from OS\n");
+ }
+
+ if (throttled) {
+ pr_info("PMSR = %16lx\n", pmsr);
+ pr_crit("CPU Frequency could be throttled\n");
+ }
+}
+
/*
* powernv_cpufreq_target_index: Sets the frequency corresponding to
* the cpufreq table entry indexed by new_index on the cpus in the
@@ -307,6 +349,9 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
if (unlikely(rebooting) && new_index != get_nominal_index())
return 0;
+ if (!throttled)
+ powernv_cpufreq_throttle_check(smp_processor_id());
+
freq_data.pstate_id = powernv_freqs[new_index].driver_data;
/*