cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx()

Pointer subtraction is slow and tedious. Therefore, replace all instances
where cpufreq_for_each_{valid_,}entry loops contained such substractions
with an iteration macro providing an index to the frequency_table entry.

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 79 insertions, 46 deletions

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 065f3a8eb486..21e8d248d956 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -629,6 +629,18 @@ static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 	for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
 
 /*
+ * cpufreq_for_each_entry_idx -	iterate over a cpufreq_frequency_table
+ *	with index
+ * @pos:	the cpufreq_frequency_table * to use as a loop cursor.
+ * @table:	the cpufreq_frequency_table * to iterate over.
+ * @idx:	the table entry currently being processed
+ */
+
+#define cpufreq_for_each_entry_idx(pos, table, idx)	\
+	for (pos = table, idx = 0; pos->frequency != CPUFREQ_TABLE_END; \
+		pos++, idx++)
+
+/*
  * cpufreq_for_each_valid_entry -     iterate over a cpufreq_frequency_table
  *	excluding CPUFREQ_ENTRY_INVALID frequencies.
  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
@@ -641,6 +653,21 @@ static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 			continue;					\
 		else
 
+/*
+ * cpufreq_for_each_valid_entry_idx -     iterate with index over a cpufreq
+ *	frequency_table excluding CPUFREQ_ENTRY_INVALID frequencies.
+ * @pos:	the cpufreq_frequency_table * to use as a loop cursor.
+ * @table:	the cpufreq_frequency_table * to iterate over.
+ * @idx:	the table entry currently being processed
+ */
+
+#define cpufreq_for_each_valid_entry_idx(pos, table, idx)		\
+	cpufreq_for_each_entry_idx(pos, table, idx)			\
+		if (pos->frequency == CPUFREQ_ENTRY_INVALID)		\
+			continue;					\
+		else
+
+
 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 				    struct cpufreq_frequency_table *table);
 
@@ -667,19 +694,20 @@ static inline int cpufreq_table_find_index_al(struct cpufreq_policy *policy,
 					      unsigned int target_freq)
 {
 	struct cpufreq_frequency_table *table = policy->freq_table;
-	struct cpufreq_frequency_table *pos, *best = table - 1;
+	struct cpufreq_frequency_table *pos;
 	unsigned int freq;
+	int idx, best = -1;
 
-	cpufreq_for_each_valid_entry(pos, table) {
+	cpufreq_for_each_valid_entry_idx(pos, table, idx) {
 		freq = pos->frequency;
 
 		if (freq >= target_freq)
-			return pos - table;
+			return idx;
 
-		best = pos;
+		best = idx;
 	}
 
-	return best - table;
+	return best;
 }
 
 /* Find lowest freq at or above target in a table in descending order */
@@ -687,28 +715,29 @@ static inline int cpufreq_table_find_index_dl(struct cpufreq_policy *policy,
 					      unsigned int target_freq)
 {
 	struct cpufreq_frequency_table *table = policy->freq_table;
-	struct cpufreq_frequency_table *pos, *best = table - 1;
+	struct cpufreq_frequency_table *pos;
 	unsigned int freq;
+	int idx, best = -1;
 
-	cpufreq_for_each_valid_entry(pos, table) {
+	cpufreq_for_each_valid_entry_idx(pos, table, idx) {
 		freq = pos->frequency;
 
 		if (freq == target_freq)
-			return pos - table;
+			return idx;
 
 		if (freq > target_freq) {
-			best = pos;
+			best = idx;
 			continue;
 		}
 
 		/* No freq found above target_freq */
-		if (best == table - 1)
-			return pos - table;
+		if (best == -1)
+			return idx;
 
-		return best - table;
+		return best;
 	}
 
-	return best - table;
+	return best;
 }
 
 /* Works only on sorted freq-tables */
@@ -728,28 +757,29 @@ static inline int cpufreq_table_find_index_ah(struct cpufreq_policy *policy,
 					      unsigned int target_freq)
 {
 	struct cpufreq_frequency_table *table = policy->freq_table;
-	struct cpufreq_frequency_table *pos, *best = table - 1;
+	struct cpufreq_frequency_table *pos;
 	unsigned int freq;
+	int idx, best = -1;
 
-	cpufreq_for_each_valid_entry(pos, table) {
+	cpufreq_for_each_valid_entry_idx(pos, table, idx) {
 		freq = pos->frequency;
 
 		if (freq == target_freq)
-			return pos - table;
+			return idx;
 
 		if (freq < target_freq) {
-			best = pos;
+			best = idx;
 			continue;
 		}
 
 		/* No freq found below target_freq */
-		if (best == table - 1)
-			return pos - table;
+		if (best == -1)
+			return idx;
 
-		return best - table;
+		return best;
 	}
 
-	return best - table;
+	return best;
 }
 
 /* Find highest freq at or below target in a table in descending order */
@@ -757,19 +787,20 @@ static inline int cpufreq_table_find_index_dh(struct cpufreq_policy *policy,
 					      unsigned int target_freq)
 {
 	struct cpufreq_frequency_table *table = policy->freq_table;
-	struct cpufreq_frequency_table *pos, *best = table - 1;
+	struct cpufreq_frequency_table *pos;
 	unsigned int freq;
+	int idx, best = -1;
 
-	cpufreq_for_each_valid_entry(pos, table) {
+	cpufreq_for_each_valid_entry_idx(pos, table, idx) {
 		freq = pos->frequency;
 
 		if (freq <= target_freq)
-			return pos - table;
+			return idx;
 
-		best = pos;
+		best = idx;
 	}
 
-	return best - table;
+	return best;
 }
 
 /* Works only on sorted freq-tables */
@@ -789,32 +820,33 @@ static inline int cpufreq_table_find_index_ac(struct cpufreq_policy *policy,
 					      unsigned int target_freq)
 {
 	struct cpufreq_frequency_table *table = policy->freq_table;
-	struct cpufreq_frequency_table *pos, *best = table - 1;
+	struct cpufreq_frequency_table *pos;
 	unsigned int freq;
+	int idx, best = -1;
 
-	cpufreq_for_each_valid_entry(pos, table) {
+	cpufreq_for_each_valid_entry_idx(pos, table, idx) {
 		freq = pos->frequency;
 
 		if (freq == target_freq)
-			return pos - table;
+			return idx;
 
 		if (freq < target_freq) {
-			best = pos;
+			best = idx;
 			continue;
 		}
 
 		/* No freq found below target_freq */
-		if (best == table - 1)
-			return pos - table;
+		if (best == -1)
+			return idx;
 
 		/* Choose the closest freq */
-		if (target_freq - best->frequency > freq - target_freq)
-			return pos - table;
+		if (target_freq - table[best].frequency > freq - target_freq)
+			return idx;
 
-		return best - table;
+		return best;
 	}
 
-	return best - table;
+	return best;
 }
 
 /* Find closest freq to target in a table in descending order */
@@ -822,32 +854,33 @@ static inline int cpufreq_table_find_index_dc(struct cpufreq_policy *policy,
 					      unsigned int target_freq)
 {
 	struct cpufreq_frequency_table *table = policy->freq_table;
-	struct cpufreq_frequency_table *pos, *best = table - 1;
+	struct cpufreq_frequency_table *pos;
 	unsigned int freq;
+	int idx, best = -1;
 
-	cpufreq_for_each_valid_entry(pos, table) {
+	cpufreq_for_each_valid_entry_idx(pos, table, idx) {
 		freq = pos->frequency;
 
 		if (freq == target_freq)
-			return pos - table;
+			return idx;
 
 		if (freq > target_freq) {
-			best = pos;
+			best = idx;
 			continue;
 		}
 
 		/* No freq found above target_freq */
-		if (best == table - 1)
-			return pos - table;
+		if (best == -1)
+			return idx;
 
 		/* Choose the closest freq */
-		if (best->frequency - target_freq > target_freq - freq)
-			return pos - table;
+		if (table[best].frequency - target_freq > target_freq - freq)
+			return idx;
 
-		return best - table;
+		return best;
 	}
 
-	return best - table;
+	return best;
 }
 
 /* Works only on sorted freq-tables */