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-rw-r--r--drivers/cpufreq/powernv-cpufreq.c85
1 files changed, 63 insertions, 22 deletions
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index f46b60fb3084..8e3dbcaee286 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -29,6 +29,7 @@
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/cpu.h>
+#include <linux/hashtable.h>
#include <trace/events/power.h>
#include <asm/cputhreads.h>
@@ -38,7 +39,8 @@
#include <asm/opal.h>
#include <linux/timer.h>
-#define POWERNV_MAX_PSTATES 256
+#define POWERNV_MAX_PSTATES_ORDER 8
+#define POWERNV_MAX_PSTATES (1UL << (POWERNV_MAX_PSTATES_ORDER))
#define PMSR_PSAFE_ENABLE (1UL << 30)
#define PMSR_SPR_EM_DISABLE (1UL << 31)
#define MAX_PSTATE_SHIFT 32
@@ -92,6 +94,27 @@ struct global_pstate_info {
};
static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
+
+DEFINE_HASHTABLE(pstate_revmap, POWERNV_MAX_PSTATES_ORDER);
+/**
+ * struct pstate_idx_revmap_data: Entry in the hashmap pstate_revmap
+ * indexed by a function of pstate id.
+ *
+ * @pstate_id: pstate id for this entry.
+ *
+ * @cpufreq_table_idx: Index into the powernv_freqs
+ * cpufreq_frequency_table for frequency
+ * corresponding to pstate_id.
+ *
+ * @hentry: hlist_node that hooks this entry into the pstate_revmap
+ * hashtable
+ */
+struct pstate_idx_revmap_data {
+ int pstate_id;
+ unsigned int cpufreq_table_idx;
+ struct hlist_node hentry;
+};
+
u32 pstate_sign_prefix;
static bool rebooting, throttled, occ_reset;
@@ -161,39 +184,47 @@ static inline int extract_pstate(u64 pmsr_val, unsigned int shift)
#define extract_global_pstate(x) extract_pstate(x, GPSTATE_SHIFT)
#define extract_max_pstate(x) extract_pstate(x, MAX_PSTATE_SHIFT)
-/* Use following macros for conversions between pstate_id and index */
+/* Use following functions for conversions between pstate_id and index */
+
+/**
+ * idx_to_pstate : Returns the pstate id corresponding to the
+ * frequency in the cpufreq frequency table
+ * powernv_freqs indexed by @i.
+ *
+ * If @i is out of bound, this will return the pstate
+ * corresponding to the nominal frequency.
+ */
static inline int idx_to_pstate(unsigned int i)
{
if (unlikely(i >= powernv_pstate_info.nr_pstates)) {
- pr_warn_once("index %u is out of bound\n", i);
+ pr_warn_once("idx_to_pstate: index %u is out of bound\n", i);
return powernv_freqs[powernv_pstate_info.nominal].driver_data;
}
return powernv_freqs[i].driver_data;
}
-static inline unsigned int pstate_to_idx(int pstate)
+/**
+ * pstate_to_idx : Returns the index in the cpufreq frequencytable
+ * powernv_freqs for the frequency whose corresponding
+ * pstate id is @pstate.
+ *
+ * If no frequency corresponding to @pstate is found,
+ * this will return the index of the nominal
+ * frequency.
+ */
+static unsigned int pstate_to_idx(int pstate)
{
- int min = powernv_freqs[powernv_pstate_info.min].driver_data;
- int max = powernv_freqs[powernv_pstate_info.max].driver_data;
+ unsigned int key = pstate % POWERNV_MAX_PSTATES;
+ struct pstate_idx_revmap_data *revmap_data;
- if (min > 0) {
- if (unlikely((pstate < max) || (pstate > min))) {
- pr_warn_once("pstate %d is out of bound\n", pstate);
- return powernv_pstate_info.nominal;
- }
- } else {
- if (unlikely((pstate > max) || (pstate < min))) {
- pr_warn_once("pstate %d is out of bound\n", pstate);
- return powernv_pstate_info.nominal;
- }
+ hash_for_each_possible(pstate_revmap, revmap_data, hentry, key) {
+ if (revmap_data->pstate_id == pstate)
+ return revmap_data->cpufreq_table_idx;
}
- /*
- * abs() is deliberately used so that is works with
- * both monotonically increasing and decreasing
- * pstate values
- */
- return abs(pstate - idx_to_pstate(powernv_pstate_info.max));
+
+ pr_warn_once("pstate_to_idx: pstate %d not found\n", pstate);
+ return powernv_pstate_info.nominal;
}
static inline void reset_gpstates(struct cpufreq_policy *policy)
@@ -297,11 +328,21 @@ next:
for (i = 0; i < nr_pstates; i++) {
u32 id = be32_to_cpu(pstate_ids[i]);
u32 freq = be32_to_cpu(pstate_freqs[i]);
+ struct pstate_idx_revmap_data *revmap_data;
+ unsigned int key;
pr_debug("PState id %d freq %d MHz\n", id, freq);
powernv_freqs[i].frequency = freq * 1000; /* kHz */
powernv_freqs[i].driver_data = id;
+ revmap_data = (struct pstate_idx_revmap_data *)
+ kmalloc(sizeof(*revmap_data), GFP_KERNEL);
+
+ revmap_data->pstate_id = id;
+ revmap_data->cpufreq_table_idx = i;
+ key = id % POWERNV_MAX_PSTATES;
+ hash_add(pstate_revmap, &revmap_data->hentry, key);
+
if (id == pstate_max)
powernv_pstate_info.max = i;
else if (id == pstate_nominal)