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/*
* Copyright (C) ST-Ericsson SA 2011
*
* License Terms: GNU General Public License v2
*
* Author: Johan Rudholm <johan.rudholm@stericsson.com>
* Author: Jonas Aaberg <jonas.aberg@stericsson.com>
*/
#include <linux/kernel.h>
#include <linux/genhd.h>
#include <linux/major.h>
#include <linux/cdev.h>
#include <linux/kernel_stat.h>
#include <linux/workqueue.h>
#include <linux/kernel.h>
#include <linux/mfd/dbx500-prcmu.h>
#include <linux/cpu.h>
#include <linux/pm_qos.h>
#include <mach/irqs.h>
#define WLAN_PROBE_DELAY 3000 /* 3 seconds */
#define WLAN_LIMIT (3000/3) /* If we have more than 1000 irqs per second */
/*
* MMC TODO:
* o Develop a more power-aware algorithm
* o Make the parameters visible through debugfs
* o Get the value of CONFIG_MMC_BLOCK_MINORS in runtime instead, since
* it may be altered by drivers/mmc/card/block.c
*/
/* Sample reads and writes every n ms */
#define PERF_MMC_PROBE_DELAY 1000
/* Read threshold, sectors/second */
#define PERF_MMC_LIMIT_READ 10240
/* Write threshold, sectors/second */
#define PERF_MMC_LIMIT_WRITE 8192
/* Nr of MMC devices */
#define PERF_MMC_HOSTS 8
/*
* Rescan for new MMC devices every
* PERF_MMC_PROBE_DELAY * PERF_MMC_RESCAN_CYCLES ms
*/
#define PERF_MMC_RESCAN_CYCLES 10
#ifdef CONFIG_MMC_BLOCK
static struct delayed_work work_mmc;
#endif
static struct delayed_work work_wlan_workaround;
static struct pm_qos_request wlan_pm_qos_latency;
static bool wlan_pm_qos_is_latency_0;
static void wlan_load(struct work_struct *work)
{
int cpu;
unsigned int num_irqs = 0;
static unsigned int old_num_irqs = UINT_MAX;
for_each_online_cpu(cpu)
num_irqs += kstat_irqs_cpu(IRQ_DB8500_SDMMC1, cpu);
if ((num_irqs > old_num_irqs) &&
(num_irqs - old_num_irqs) > WLAN_LIMIT) {
prcmu_qos_update_requirement(PRCMU_QOS_ARM_OPP,
"wlan", 125);
if (!wlan_pm_qos_is_latency_0) {
/*
* The wake up latency is set to 0 to prevent
* the system from going to sleep. This improves
* the wlan throughput in DMA mode.
* The wake up latency from sleep adds ~5% overhead
* for TX in some cases.
* This change doesn't increase performance for wlan
* PIO since the CPU usage prevents sleep in this mode.
*/
pm_qos_add_request(&wlan_pm_qos_latency,
PM_QOS_CPU_DMA_LATENCY, 0);
wlan_pm_qos_is_latency_0 = true;
}
} else {
prcmu_qos_update_requirement(PRCMU_QOS_ARM_OPP,
"wlan", 25);
if (wlan_pm_qos_is_latency_0) {
pm_qos_remove_request(&wlan_pm_qos_latency);
wlan_pm_qos_is_latency_0 = false;
}
}
old_num_irqs = num_irqs;
schedule_delayed_work_on(0,
&work_wlan_workaround,
msecs_to_jiffies(WLAN_PROBE_DELAY));
}
#ifdef CONFIG_MMC_BLOCK
/*
* Loop through every CONFIG_MMC_BLOCK_MINORS'th minor device for
* MMC_BLOCK_MAJOR, get the struct gendisk for each device. Returns
* nr of found disks. Populate mmc_disks.
*/
static int scan_mmc_devices(struct gendisk *mmc_disks[])
{
dev_t devnr;
int i, j = 0, part;
struct gendisk *mmc_devices[256 / CONFIG_MMC_BLOCK_MINORS];
memset(&mmc_devices, 0, sizeof(mmc_devices));
for (i = 0; i * CONFIG_MMC_BLOCK_MINORS < 256; i++) {
devnr = MKDEV(MMC_BLOCK_MAJOR, i * CONFIG_MMC_BLOCK_MINORS);
mmc_devices[i] = get_gendisk(devnr, &part);
/* Invalid capacity of device, do not add to list */
if (!mmc_devices[i] || !get_capacity(mmc_devices[i]))
continue;
mmc_disks[j] = mmc_devices[i];
j++;
if (j == PERF_MMC_HOSTS)
break;
}
return j;
}
/*
* Sample sectors read and written to any MMC devices, update PRCMU
* qos requirement
*/
static void mmc_load(struct work_struct *work)
{
static unsigned long long old_sectors_read[PERF_MMC_HOSTS];
static unsigned long long old_sectors_written[PERF_MMC_HOSTS];
static struct gendisk *mmc_disks[PERF_MMC_HOSTS];
static int cycle, nrdisk;
static bool old_mode;
unsigned long long sectors;
bool new_mode = false;
int i;
if (!cycle) {
memset(&mmc_disks, 0, sizeof(mmc_disks));
nrdisk = scan_mmc_devices(mmc_disks);
cycle = PERF_MMC_RESCAN_CYCLES;
}
cycle--;
for (i = 0; i < nrdisk; i++) {
sectors = part_stat_read(&(mmc_disks[i]->part0),
sectors[READ]);
if (old_sectors_read[i] &&
sectors > old_sectors_read[i] &&
(sectors - old_sectors_read[i]) >
PERF_MMC_LIMIT_READ)
new_mode = true;
old_sectors_read[i] = sectors;
sectors = part_stat_read(&(mmc_disks[i]->part0),
sectors[WRITE]);
if (old_sectors_written[i] &&
sectors > old_sectors_written[i] &&
(sectors - old_sectors_written[i]) >
PERF_MMC_LIMIT_WRITE)
new_mode = true;
old_sectors_written[i] = sectors;
}
if (!old_mode && new_mode)
prcmu_qos_update_requirement(PRCMU_QOS_ARM_OPP,
"mmc", 125);
if (old_mode && !new_mode)
prcmu_qos_update_requirement(PRCMU_QOS_ARM_OPP,
"mmc", 25);
old_mode = new_mode;
schedule_delayed_work(&work_mmc,
msecs_to_jiffies(PERF_MMC_PROBE_DELAY));
}
#endif /* CONFIG_MMC_BLOCK */
static int __init performance_register(void)
{
int ret;
#ifdef CONFIG_MMC_BLOCK
ret = prcmu_qos_add_requirement(PRCMU_QOS_ARM_OPP, "mmc", 25);
if (ret) {
pr_err("%s: Failed to add PRCMU req for mmc\n", __func__);
goto out;
}
INIT_DELAYED_WORK_DEFERRABLE(&work_mmc, mmc_load);
schedule_delayed_work(&work_mmc,
msecs_to_jiffies(PERF_MMC_PROBE_DELAY));
#endif
ret = prcmu_qos_add_requirement(PRCMU_QOS_ARM_OPP, "wlan", 25);
if (ret) {
pr_err("%s: Failed to add PRCMU req for wlan\n", __func__);
goto out;
}
INIT_DELAYED_WORK_DEFERRABLE(&work_wlan_workaround,
wlan_load);
schedule_delayed_work_on(0, &work_wlan_workaround,
msecs_to_jiffies(WLAN_PROBE_DELAY));
out:
return ret;
}
late_initcall(performance_register);
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