linux/drivers/mmc/core/core.h
Konstantin Dorfman 2220eedfd7 mmc: fix async request mechanism for sequential read scenarios
When current request is running on the bus and if next request fetched
by mmcqd is NULL, mmc context (mmcqd thread) gets blocked until the
current request completes. This means that if new request comes in while
the mmcqd thread is blocked, this new request can not be prepared in
parallel to current ongoing request. This may result in delaying the new
request execution and increase it's latency.

This change allows to wake up the MMC thread on new request arrival.
Now once the MMC thread is woken up, a new request can be fetched and
prepared in parallel to the current running request which means this new
request can be started immediately after the current running request
completes.

With this change read throughput is improved by 16%.

Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2013-02-11 13:28:49 -05:00

82 lines
2.4 KiB
C

/*
* linux/drivers/mmc/core/core.h
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
* Copyright 2007 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _MMC_CORE_CORE_H
#define _MMC_CORE_CORE_H
#include <linux/delay.h>
#define MMC_CMD_RETRIES 3
struct mmc_bus_ops {
int (*awake)(struct mmc_host *);
int (*sleep)(struct mmc_host *);
void (*remove)(struct mmc_host *);
void (*detect)(struct mmc_host *);
int (*suspend)(struct mmc_host *);
int (*resume)(struct mmc_host *);
int (*power_save)(struct mmc_host *);
int (*power_restore)(struct mmc_host *);
int (*alive)(struct mmc_host *);
};
void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
void mmc_detach_bus(struct mmc_host *host);
void mmc_init_erase(struct mmc_card *card);
void mmc_set_chip_select(struct mmc_host *host, int mode);
void mmc_set_clock(struct mmc_host *host, unsigned int hz);
void mmc_gate_clock(struct mmc_host *host);
void mmc_ungate_clock(struct mmc_host *host);
void mmc_set_ungated(struct mmc_host *host);
void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode);
void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
bool cmd11);
void mmc_set_timing(struct mmc_host *host, unsigned int timing);
void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
void mmc_power_off(struct mmc_host *host);
static inline void mmc_delay(unsigned int ms)
{
if (ms < 1000 / HZ) {
cond_resched();
mdelay(ms);
} else {
msleep(ms);
}
}
void mmc_rescan(struct work_struct *work);
void mmc_start_host(struct mmc_host *host);
void mmc_stop_host(struct mmc_host *host);
int _mmc_detect_card_removed(struct mmc_host *host);
int mmc_attach_mmc(struct mmc_host *host);
int mmc_attach_sd(struct mmc_host *host);
int mmc_attach_sdio(struct mmc_host *host);
/* Module parameters */
extern bool use_spi_crc;
/* Debugfs information for hosts and cards */
void mmc_add_host_debugfs(struct mmc_host *host);
void mmc_remove_host_debugfs(struct mmc_host *host);
void mmc_add_card_debugfs(struct mmc_card *card);
void mmc_remove_card_debugfs(struct mmc_card *card);
void mmc_init_context_info(struct mmc_host *host);
#endif