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>

diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt
index 434c49cc7330aa5273ca1e018ff912fa8c32b7c4..61546ac578d6079a56aecc643989647ed7261399 100644 (file)
--- a/Documentation/cpu-freq/cpu-drivers.txt
+++ b/Documentation/cpu-freq/cpu-drivers.txt
@@ -291,3 +291,7 @@ For example:
                /* Do something with pos */
                pos->frequency = ...
        }
+
+If you need to work with the position of pos within driver_freq_table,
+do not subtract the pointers, as it is quite costly. Instead, use the
+macros cpufreq_for_each_entry_idx() and cpufreq_for_each_valid_entry_idx().

diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
index b6b369c2227265640b606fbf4c9d8a4c43dda1db..932caa386ecec43a62b10e2af7b0168e10fcd8fb 100644 (file)
--- a/drivers/cpufreq/exynos5440-cpufreq.c
+++ b/drivers/cpufreq/exynos5440-cpufreq.c
@@ -115,10 +115,10 @@ static struct cpufreq_freqs freqs;
 static int init_div_table(void)
 {
        struct cpufreq_frequency_table *pos, *freq_tbl = dvfs_info->freq_table;
-       unsigned int tmp, clk_div, ema_div, freq, volt_id;
+       unsigned int tmp, clk_div, ema_div, freq, volt_id, idx;
        struct dev_pm_opp *opp;
 
-       cpufreq_for_each_entry(pos, freq_tbl) {
+       cpufreq_for_each_entry_idx(pos, freq_tbl, idx) {
                opp = dev_pm_opp_find_freq_exact(dvfs_info->dev,
                                        pos->frequency * 1000, true);
                if (IS_ERR(opp)) {
@@ -154,8 +154,7 @@ static int init_div_table(void)
                tmp = (clk_div | ema_div | (volt_id << P0_7_VDD_SHIFT)
                        | ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT));
 
-               __raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 *
-                                               (pos - freq_tbl));
+               __raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * idx);
                dev_pm_opp_put(opp);
        }
 

diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 3bbbf9e6960cdf12d939d3d88c5dc5ba4a89d070..6d007f824ca74b05d096950dc246fcdf48d22031 100644 (file)
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -143,10 +143,9 @@ int cpufreq_table_index_unsorted(struct cpufreq_policy *policy,
                break;
        }
 
-       cpufreq_for_each_valid_entry(pos, table) {
+       cpufreq_for_each_valid_entry_idx(pos, table, i) {
                freq = pos->frequency;
 
-               i = pos - table;
                if ((freq < policy->min) || (freq > policy->max))
                        continue;
                if (freq == target_freq) {
@@ -211,15 +210,16 @@ int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
                unsigned int freq)
 {
        struct cpufreq_frequency_table *pos, *table = policy->freq_table;
+       int idx;
 
        if (unlikely(!table)) {
                pr_debug("%s: Unable to find frequency table\n", __func__);
                return -ENOENT;
        }
 
-       cpufreq_for_each_valid_entry(pos, table)
+       cpufreq_for_each_valid_entry_idx(pos, table, idx)
                if (pos->frequency == freq)
-                       return pos - table;
+                       return idx;
 
        return -EINVAL;
 }

diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
index 5faa37c5b0910e8614b2327b63e86d1c9a30ac42..942632a27b50fb458f927ed69406eafab99511e3 100644 (file)
--- a/drivers/cpufreq/longhaul.c
+++ b/drivers/cpufreq/longhaul.c
@@ -600,7 +600,7 @@ static void longhaul_setup_voltagescaling(void)
        /* Calculate kHz for one voltage step */
        kHz_step = (highest_speed - min_vid_speed) / numvscales;
 
-       cpufreq_for_each_entry(freq_pos, longhaul_table) {
+       cpufreq_for_each_entry_idx(freq_pos, longhaul_table, j) {
                speed = freq_pos->frequency;
                if (speed > min_vid_speed)
                        pos = (speed - min_vid_speed) / kHz_step + minvid.pos;
@@ -609,7 +609,7 @@ static void longhaul_setup_voltagescaling(void)
                freq_pos->driver_data |= mV_vrm_table[pos] << 8;
                vid = vrm_mV_table[mV_vrm_table[pos]];
                pr_info("f: %d kHz, index: %d, vid: %d mV\n",
-                       speed, (int)(freq_pos - longhaul_table), vid.mV);
+                       speed, j, vid.mV);
        }
 
        can_scale_voltage = 1;

diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
index b257fc7d520410c7090851399e253ae19a756d4d..75dfbd2a58ea6f1df8db4e89a8d47883e29ecfea 100644 (file)
--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -139,7 +139,7 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
        struct cpufreq_frequency_table *pos;
        const u32 *max_freqp;
        u32 max_freq;
-       int cur_astate;
+       int cur_astate, idx;
        struct resource res;
        struct device_node *cpu, *dn;
        int err = -ENODEV;
@@ -198,9 +198,9 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
        pr_debug("initializing frequency table\n");
 
        /* initialize frequency table */
-       cpufreq_for_each_entry(pos, pas_freqs) {
+       cpufreq_for_each_entry_idx(pos, pas_freqs, idx) {
                pos->frequency = get_astate_freq(pos->driver_data) * 100000;
-               pr_debug("%d: %d\n", (int)(pos - pas_freqs), pos->frequency);
+               pr_debug("%d: %d\n", idx, pos->frequency);
        }
 
        cur_astate = get_cur_astate(policy->cpu);

diff --git a/drivers/sh/clk/core.c b/drivers/sh/clk/core.c
index 92863e3818e5c726ec739b66d430c613e65a6f67..9475353f49d6c55455ead3ebcec759d55ce4a922 100644 (file)
--- a/drivers/sh/clk/core.c
+++ b/drivers/sh/clk/core.c
@@ -197,10 +197,11 @@ int clk_rate_table_find(struct clk *clk,
                        unsigned long rate)
 {
        struct cpufreq_frequency_table *pos;
+       int idx;
 
-       cpufreq_for_each_valid_entry(pos, freq_table)
+       cpufreq_for_each_valid_entry_idx(pos, freq_table, idx)
                if (pos->frequency == rate)
-                       return pos - freq_table;
+                       return idx;
 
        return -ENOENT;
 }

diff --git a/drivers/staging/irda/drivers/sh_sir.c b/drivers/staging/irda/drivers/sh_sir.c
index fede6864c737bd2710a842845bccc306cc6d2b7b..0d0687cc454abbd3ccdf7cecad72b4a20a3e27eb 100644 (file)
--- a/drivers/staging/irda/drivers/sh_sir.c
+++ b/drivers/staging/irda/drivers/sh_sir.c
@@ -226,7 +226,7 @@ static u32 sh_sir_find_sclk(struct clk *irda_clk)
        clk_put(pclk);
 
        /* IrDA can not set over peripheral_clk */
-       cpufreq_for_each_valid_entry(pos, freq_table) {
+       cpufreq_for_each_valid_entry_idx(pos, freq_table, index) {
                u32 freq = pos->frequency;
 
                /* IrDA should not over peripheral_clk */
@@ -236,7 +236,7 @@ static u32 sh_sir_find_sclk(struct clk *irda_clk)
                tmp = freq % SCLK_BASE;
                if (tmp < min) {
                        min = tmp;
-                       index = pos - freq_table;
+                       break;
                }
        }
 

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 065f3a8eb48615becdb299e0b50241794799facf..21e8d248d9564510011a3d0b12c94f5cf963fdcb 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -628,6 +628,18 @@ static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 #define cpufreq_for_each_entry(pos, table)     \
        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.
@@ -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 */