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Commit 348487cb authored by Haibo Chen's avatar Haibo Chen Committed by Ulf Hansson
Browse files

mmc: sdhci: use pipeline mmc requests to improve performance 



This patch is based on the patches by Per Forlin, Tony Lin and Ryan QIAN.

This patch complete the API 'post_req' and 'pre_req' in sdhci host side,

Test Env:
1. i.MX6Q-SABREAUTO board, CPU @ 996MHz, use ADMA in uSDHC controller.
2. Test command:
		$ echo 1 > /proc/sys/vm/drop_caches
	write to sd card:
		$ dd if=/dev/zero of=/dev/mmcblk0 bs=1M count=2000 conv=fsync
	read the sd card:
		$ dd if=/dev/mmcblk0 of=/dev/null bs=1M count=2000

3. TOSHIBA 16GB SD3.0 card, running at 4 bit, SDR104 @ 198MHZ
	Performance with and without this patch:
      -------------------------------------------------
	  |                    | read speed | write speed |
	  |------------------------------------------------
	  | with this patch    | ~76.7 MB/s |  ~23.3 MB/s |
	  |------------------------------------------------
	  |without this patch  | ~60.5 MB/s |  ~22.5 MB/s |
	  -------------------------------------------------

4. SanDisk 8GB SD3.0 card, running at 4 bit, DDR50 @ 50MHZ
	Performance with and without this patch:
      -------------------------------------------------
	  |                    | read speed | write speed |
	  |------------------------------------------------
	  | with this patch    | ~40.5 MB/s |  ~15.6 MB/s |
	  |------------------------------------------------
	  |without this patch  | ~36.1 MB/s |  ~14.1 MB/s |
	  -------------------------------------------------

5. Kingston 8GB SD2.0 card, running at 4 bit, High-speed @ 50MHZ
	Performance with and without this patch:
      -------------------------------------------------
	  |                    | read speed | write speed |
	  |------------------------------------------------
	  | with this patch    | ~22.7 MB/s |  ~8.2 MB/s  |
	  |------------------------------------------------
	  |without this patch  | ~21.3 MB/s |  ~8.0 MB/s  |
	  -------------------------------------------------

6. About eMMC, Sandisk 8GB eMMC on i.MX6DL-sabresd board, CPU @ 792MHZ,
   eMMC running at 8 bit, DDR52 @ 52MHZ.
	Performance with and without this patch:
      -------------------------------------------------
	  |                    | read speed | write speed |
	  |------------------------------------------------
	  | with this patch    | ~37.3 MB/s |  ~10.5 MB/s |
	  |------------------------------------------------
	  |without this patch  | ~33.4 MB/s |  ~10.5 MB/s |
	  -------------------------------------------------

Signed-off-by: default avatarHaibo Chen <haibo.chen@freescale.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 2070d805

drivers/mmc/host/sdhci.c

+87 −12
Original line number Diff line number Diff line
@@ -53,6 +53,9 @@ static void sdhci_finish_command(struct sdhci_host *); 
static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);

static void sdhci_tuning_timer(unsigned long data);

static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);

static int sdhci_pre_dma_transfer(struct sdhci_host *host,

					struct mmc_data *data,

					struct sdhci_host_next *next);



#ifdef CONFIG_PM

static int sdhci_runtime_pm_get(struct sdhci_host *host);
@@ -505,9 +508,8 @@ static int sdhci_adma_table_pre(struct sdhci_host *host, 
		goto fail;

	BUG_ON(host->align_addr & host->align_mask);



	host->sg_count = dma_map_sg(mmc_dev(host->mmc),

		data->sg, data->sg_len, direction);

	if (host->sg_count == 0)

	host->sg_count = sdhci_pre_dma_transfer(host, data, NULL);

	if (host->sg_count < 0)

		goto unmap_align;



	desc = host->adma_table;
@@ -645,6 +647,7 @@ static void sdhci_adma_table_post(struct sdhci_host *host, 
		}

	}



	if (!data->host_cookie)

		dma_unmap_sg(mmc_dev(host->mmc), data->sg,

			data->sg_len, direction);

}
@@ -842,11 +845,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd) 
		} else {

			int sg_cnt;



			sg_cnt = dma_map_sg(mmc_dev(host->mmc),

					data->sg, data->sg_len,

					(data->flags & MMC_DATA_READ) ?

						DMA_FROM_DEVICE :

						DMA_TO_DEVICE);

			sg_cnt = sdhci_pre_dma_transfer(host, data, NULL);

			if (sg_cnt == 0) {

				/*

				 * This only happens when someone fed
@@ -959,8 +958,10 @@ static void sdhci_finish_data(struct sdhci_host *host) 
		if (host->flags & SDHCI_USE_ADMA)

			sdhci_adma_table_post(host, data);

		else {

			dma_unmap_sg(mmc_dev(host->mmc), data->sg,

				data->sg_len, (data->flags & MMC_DATA_READ) ?

			if (!data->host_cookie)

				dma_unmap_sg(mmc_dev(host->mmc),

					data->sg, data->sg_len,

					(data->flags & MMC_DATA_READ) ?

					DMA_FROM_DEVICE : DMA_TO_DEVICE);

		}

	}
@@ -2125,6 +2126,77 @@ static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable) 
	}

}



static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq,

				int err)

{

	struct sdhci_host *host = mmc_priv(mmc);

	struct mmc_data *data = mrq->data;



	if (host->flags & SDHCI_REQ_USE_DMA) {

		if (data->host_cookie)

			dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,

					 data->flags & MMC_DATA_WRITE ?

					 DMA_TO_DEVICE : DMA_FROM_DEVICE);

		mrq->data->host_cookie = 0;

	}

}



static int sdhci_pre_dma_transfer(struct sdhci_host *host,

				       struct mmc_data *data,

				       struct sdhci_host_next *next)

{

	int sg_count;



	if (!next && data->host_cookie &&

	    data->host_cookie != host->next_data.cookie) {

		pr_debug(DRIVER_NAME "[%s] invalid cookie: %d, next-cookie %d\n",

			__func__, data->host_cookie, host->next_data.cookie);

		data->host_cookie = 0;

	}



	/* Check if next job is already prepared */

	if (next ||

	    (!next && data->host_cookie != host->next_data.cookie)) {

		sg_count = dma_map_sg(mmc_dev(host->mmc), data->sg,

				     data->sg_len,

				     data->flags & MMC_DATA_WRITE ?

				     DMA_TO_DEVICE : DMA_FROM_DEVICE);



	} else {

		sg_count = host->next_data.sg_count;

		host->next_data.sg_count = 0;

	}





	if (sg_count == 0)

		return -EINVAL;



	if (next) {

		next->sg_count = sg_count;

		data->host_cookie = ++next->cookie < 0 ? 1 : next->cookie;

	} else

		host->sg_count = sg_count;



	return sg_count;

}



static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,

			       bool is_first_req)

{

	struct sdhci_host *host = mmc_priv(mmc);



	if (mrq->data->host_cookie) {

		mrq->data->host_cookie = 0;

		return;

	}



	if (host->flags & SDHCI_REQ_USE_DMA)

		if (sdhci_pre_dma_transfer(host,

					mrq->data,

					&host->next_data) < 0)

			mrq->data->host_cookie = 0;

}



static void sdhci_card_event(struct mmc_host *mmc)

{

	struct sdhci_host *host = mmc_priv(mmc);
@@ -2158,6 +2230,8 @@ static void sdhci_card_event(struct mmc_host *mmc) 


static const struct mmc_host_ops sdhci_ops = {

	.request	= sdhci_request,

	.post_req	= sdhci_post_req,

	.pre_req	= sdhci_pre_req,

	.set_ios	= sdhci_set_ios,

	.get_cd		= sdhci_get_cd,

	.get_ro		= sdhci_get_ro,
@@ -3015,6 +3089,7 @@ int sdhci_add_host(struct sdhci_host *host) 
		host->max_clk = host->ops->get_max_clock(host);

	}



	host->next_data.cookie = 1;

	/*

	 * In case of Host Controller v3.00, find out whether clock

	 * multiplier is supported.

include/linux/mmc/sdhci.h

+6 −0
Original line number Diff line number Diff line
@@ -17,6 +17,11 @@ 
#include <linux/io.h>

#include <linux/mmc/host.h>



struct sdhci_host_next {

	unsigned int	sg_count;

	s32		cookie;

};



struct sdhci_host {

	/* Data set by hardware interface driver */

	const char *hw_name;	/* Hardware bus name */
@@ -203,6 +208,7 @@ struct sdhci_host { 
#define SDHCI_TUNING_MODE_1	0

	struct timer_list	tuning_timer;	/* Timer for tuning */



	struct sdhci_host_next	next_data;

	unsigned long private[0] ____cacheline_aligned;

};

#endif /* LINUX_MMC_SDHCI_H */