msm: pm-stats: refactor pm-stats into its own file

pm-stats records the time spent in each low power mode. The stats can be
accessed from /proc/msm_pm_stats. Refactor stats into pm-stats.c and
export only the required functions.

Also, remove CONFIG_MSM_IDLE_STATS blocks around code in pm-8x60.c and
pm2.c

pm-stats.c can optionally be compiled out completely.

Change-Id: Ie8fae1d0b2c53e2fbb92f3baf70efd9d33af27ae
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
Signed-off-by: Anji jonnala <anjir@codeaurora.org>
diff --git a/arch/arm/mach-msm/pm-stats.c b/arch/arm/mach-msm/pm-stats.c
new file mode 100644
index 0000000..936820a
--- /dev/null
+++ b/arch/arm/mach-msm/pm-stats.c
@@ -0,0 +1,305 @@
+/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/proc_fs.h>
+
+#include "pm.h"
+
+struct msm_pm_time_stats {
+	const char *name;
+	int64_t first_bucket_time;
+	int bucket[CONFIG_MSM_IDLE_STATS_BUCKET_COUNT];
+	int64_t min_time[CONFIG_MSM_IDLE_STATS_BUCKET_COUNT];
+	int64_t max_time[CONFIG_MSM_IDLE_STATS_BUCKET_COUNT];
+	int count;
+	int64_t total_time;
+	bool enabled;
+};
+
+struct msm_pm_cpu_time_stats {
+	struct msm_pm_time_stats stats[MSM_PM_STAT_COUNT];
+};
+
+static DEFINE_SPINLOCK(msm_pm_stats_lock);
+static DEFINE_PER_CPU_SHARED_ALIGNED(
+	struct msm_pm_cpu_time_stats, msm_pm_stats);
+
+/*
+ * Add the given time data to the statistics collection.
+ */
+void msm_pm_add_stat(enum msm_pm_time_stats_id id, int64_t t)
+{
+	unsigned long flags;
+	struct msm_pm_time_stats *stats;
+	int64_t bt;
+	int i;
+
+	spin_lock_irqsave(&msm_pm_stats_lock, flags);
+	stats = __get_cpu_var(msm_pm_stats).stats;
+
+	if (!stats[id].enabled)
+		goto add_bail;
+
+	stats[id].total_time += t;
+	stats[id].count++;
+
+	bt = t;
+	do_div(bt, stats[id].first_bucket_time);
+
+	if (bt < 1ULL << (CONFIG_MSM_IDLE_STATS_BUCKET_SHIFT *
+				(CONFIG_MSM_IDLE_STATS_BUCKET_COUNT - 1)))
+		i = DIV_ROUND_UP(fls((uint32_t)bt),
+					CONFIG_MSM_IDLE_STATS_BUCKET_SHIFT);
+	else
+		i = CONFIG_MSM_IDLE_STATS_BUCKET_COUNT - 1;
+
+	if (i >= CONFIG_MSM_IDLE_STATS_BUCKET_COUNT)
+		i = CONFIG_MSM_IDLE_STATS_BUCKET_COUNT - 1;
+
+	stats[id].bucket[i]++;
+
+	if (t < stats[id].min_time[i] || !stats[id].max_time[i])
+		stats[id].min_time[i] = t;
+	if (t > stats[id].max_time[i])
+		stats[id].max_time[i] = t;
+
+add_bail:
+	spin_unlock_irqrestore(&msm_pm_stats_lock, flags);
+}
+
+/*
+ * Helper function of snprintf where buf is auto-incremented, size is auto-
+ * decremented, and there is no return value.
+ *
+ * NOTE: buf and size must be l-values (e.g. variables)
+ */
+#define SNPRINTF(buf, size, format, ...) \
+	do { \
+		if (size > 0) { \
+			int ret; \
+			ret = snprintf(buf, size, format, ## __VA_ARGS__); \
+			if (ret > size) { \
+				buf += size; \
+				size = 0; \
+			} else { \
+				buf += ret; \
+				size -= ret; \
+			} \
+		} \
+	} while (0)
+
+/*
+ * Write out the power management statistics.
+ */
+static int msm_pm_read_proc
+	(char *page, char **start, off_t off, int count, int *eof, void *data)
+{
+	unsigned int cpu = off / MSM_PM_STAT_COUNT;
+	int id = off % MSM_PM_STAT_COUNT;
+	char *p = page;
+
+	if (count < 1024) {
+		*start = (char *) 0;
+		*eof = 0;
+		return 0;
+	}
+
+	if (cpu < num_possible_cpus()) {
+		unsigned long flags;
+		struct msm_pm_time_stats *stats;
+		int i;
+		int64_t bucket_time;
+		int64_t s;
+		uint32_t ns;
+
+		spin_lock_irqsave(&msm_pm_stats_lock, flags);
+		stats = per_cpu(msm_pm_stats, cpu).stats;
+
+		/* Skip the disabled ones */
+		if (!stats[id].enabled) {
+			*p = '\0';
+			p++;
+			goto again;
+		}
+
+		s = stats[id].total_time;
+		ns = do_div(s, NSEC_PER_SEC);
+		SNPRINTF(p, count,
+			"[cpu %u] %s:\n"
+			"  count: %7d\n"
+			"  total_time: %lld.%09u\n",
+			cpu, stats[id].name,
+			stats[id].count,
+			s, ns);
+
+		bucket_time = stats[id].first_bucket_time;
+		for (i = 0; i < CONFIG_MSM_IDLE_STATS_BUCKET_COUNT - 1; i++) {
+			s = bucket_time;
+			ns = do_div(s, NSEC_PER_SEC);
+			SNPRINTF(p, count,
+				"   <%6lld.%09u: %7d (%lld-%lld)\n",
+				s, ns, stats[id].bucket[i],
+				stats[id].min_time[i],
+				stats[id].max_time[i]);
+
+			bucket_time <<= CONFIG_MSM_IDLE_STATS_BUCKET_SHIFT;
+		}
+
+		SNPRINTF(p, count, "  >=%6lld.%09u: %7d (%lld-%lld)\n",
+			s, ns, stats[id].bucket[i],
+			stats[id].min_time[i],
+			stats[id].max_time[i]);
+
+again:
+		*start = (char *) 1;
+		*eof = (off + 1 >= MSM_PM_STAT_COUNT * num_possible_cpus());
+
+		spin_unlock_irqrestore(&msm_pm_stats_lock, flags);
+	}
+
+	return p - page;
+}
+#undef SNPRINTF
+
+#define MSM_PM_STATS_RESET "reset"
+
+/*
+ * Reset the power management statistics values.
+ */
+static int msm_pm_write_proc(struct file *file, const char __user *buffer,
+	unsigned long count, void *data)
+{
+	char buf[sizeof(MSM_PM_STATS_RESET)];
+	int ret;
+	unsigned long flags;
+	unsigned int cpu;
+
+	if (count < sizeof(MSM_PM_STATS_RESET)) {
+		ret = -EINVAL;
+		goto write_proc_failed;
+	}
+
+	if (copy_from_user(buf, buffer, sizeof(MSM_PM_STATS_RESET))) {
+		ret = -EFAULT;
+		goto write_proc_failed;
+	}
+
+	if (memcmp(buf, MSM_PM_STATS_RESET, sizeof(MSM_PM_STATS_RESET))) {
+		ret = -EINVAL;
+		goto write_proc_failed;
+	}
+
+	spin_lock_irqsave(&msm_pm_stats_lock, flags);
+	for_each_possible_cpu(cpu) {
+		struct msm_pm_time_stats *stats;
+		int i;
+
+		stats = per_cpu(msm_pm_stats, cpu).stats;
+		for (i = 0; i < MSM_PM_STAT_COUNT; i++) {
+			memset(stats[i].bucket,
+				0, sizeof(stats[i].bucket));
+			memset(stats[i].min_time,
+				0, sizeof(stats[i].min_time));
+			memset(stats[i].max_time,
+				0, sizeof(stats[i].max_time));
+			stats[i].count = 0;
+			stats[i].total_time = 0;
+		}
+	}
+
+	spin_unlock_irqrestore(&msm_pm_stats_lock, flags);
+	return count;
+
+write_proc_failed:
+	return ret;
+}
+#undef MSM_PM_STATS_RESET
+
+void msm_pm_add_stats(enum msm_pm_time_stats_id *enable_stats, int size)
+{
+	unsigned int cpu;
+	struct proc_dir_entry *d_entry;
+	int i = 0;
+
+	for_each_possible_cpu(cpu) {
+		struct msm_pm_time_stats *stats =
+			per_cpu(msm_pm_stats, cpu).stats;
+
+		stats[MSM_PM_STAT_REQUESTED_IDLE].name = "idle-request";
+		stats[MSM_PM_STAT_REQUESTED_IDLE].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_IDLE_SPIN].name = "idle-spin";
+		stats[MSM_PM_STAT_IDLE_SPIN].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_IDLE_WFI].name = "idle-wfi";
+		stats[MSM_PM_STAT_IDLE_WFI].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_RETENTION].name = "retention";
+		stats[MSM_PM_STAT_RETENTION].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_IDLE_STANDALONE_POWER_COLLAPSE].name =
+			"idle-standalone-power-collapse";
+		stats[MSM_PM_STAT_IDLE_STANDALONE_POWER_COLLAPSE].
+			first_bucket_time = CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_IDLE_FAILED_STANDALONE_POWER_COLLAPSE].name =
+			"idle-failed-standalone-power-collapse";
+		stats[MSM_PM_STAT_IDLE_FAILED_STANDALONE_POWER_COLLAPSE].
+			first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_IDLE_POWER_COLLAPSE].name =
+			"idle-power-collapse";
+		stats[MSM_PM_STAT_IDLE_POWER_COLLAPSE].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_IDLE_FAILED_POWER_COLLAPSE].name =
+			"idle-failed-power-collapse";
+		stats[MSM_PM_STAT_IDLE_FAILED_POWER_COLLAPSE].
+			first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_SUSPEND].name = "suspend";
+		stats[MSM_PM_STAT_SUSPEND].first_bucket_time =
+			CONFIG_MSM_SUSPEND_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_FAILED_SUSPEND].name = "failed-suspend";
+		stats[MSM_PM_STAT_FAILED_SUSPEND].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		stats[MSM_PM_STAT_NOT_IDLE].name = "not-idle";
+		stats[MSM_PM_STAT_NOT_IDLE].first_bucket_time =
+			CONFIG_MSM_IDLE_STATS_FIRST_BUCKET;
+
+		for (i = 0; i < size; i++)
+			stats[enable_stats[i]].enabled = true;
+
+	}
+
+	d_entry = create_proc_entry("msm_pm_stats",
+			S_IRUGO | S_IWUSR | S_IWGRP, NULL);
+	if (d_entry) {
+		d_entry->read_proc = msm_pm_read_proc;
+		d_entry->write_proc = msm_pm_write_proc;
+		d_entry->data = NULL;
+	}
+}