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Commit 7659150c authored by Pierre Ossman's avatar Pierre Ossman
Browse files

sdhci: highmem capable PIO routines 



Improve the PIO handling so that it can service highmem pages.

Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 137d3edb

drivers/mmc/host/sdhci.c

+72 −91
Original line number Diff line number Diff line
@@ -173,119 +173,95 @@ static void sdhci_led_control(struct led_classdev *led, 
 *                                                                           *

\*****************************************************************************/



static inline char* sdhci_sg_to_buffer(struct sdhci_host* host)

{

	return sg_virt(host->cur_sg);

}



static inline int sdhci_next_sg(struct sdhci_host* host)

{

	/*

	 * Skip to next SG entry.

	 */

	host->cur_sg++;

	host->num_sg--;



	/*

	 * Any entries left?

	 */

	if (host->num_sg > 0) {

		host->offset = 0;

		host->remain = host->cur_sg->length;

	}



	return host->num_sg;

}



static void sdhci_read_block_pio(struct sdhci_host *host)

{

	int blksize, chunk_remain;

	u32 data;

	char *buffer;

	int size;

	unsigned long flags;

	size_t blksize, len, chunk;

	u32 scratch;

	u8 *buf;



	DBG("PIO reading\n");



	blksize = host->data->blksz;

	chunk_remain = 0;

	data = 0;

	chunk = 0;



	buffer = sdhci_sg_to_buffer(host) + host->offset;

	local_irq_save(flags);



	while (blksize) {

		if (chunk_remain == 0) {

			data = readl(host->ioaddr + SDHCI_BUFFER);

			chunk_remain = min(blksize, 4);

		}

		if (!sg_miter_next(&host->sg_miter))

			BUG();



		size = min(host->remain, chunk_remain);

		len = min(host->sg_miter.length, blksize);



		chunk_remain -= size;

		blksize -= size;

		host->offset += size;

		host->remain -= size;

		blksize -= len;

		host->sg_miter.consumed = len;



		while (size) {

			*buffer = data & 0xFF;

			buffer++;

			data >>= 8;

			size--;

		}

		buf = host->sg_miter.addr;



		if (host->remain == 0) {

			if (sdhci_next_sg(host) == 0) {

				BUG_ON(blksize != 0);

				return;

		while (len) {

			if (chunk == 0) {

				scratch = readl(host->ioaddr + SDHCI_BUFFER);

				chunk = 4;

			}

			buffer = sdhci_sg_to_buffer(host);



			*buf = scratch & 0xFF;



			buf++;

			scratch >>= 8;

			chunk--;

			len--;

		}

	}



	sg_miter_stop(&host->sg_miter);



	local_irq_restore(flags);

}



static void sdhci_write_block_pio(struct sdhci_host *host)

{

	int blksize, chunk_remain;

	u32 data;

	char *buffer;

	int bytes, size;

	unsigned long flags;

	size_t blksize, len, chunk;

	u32 scratch;

	u8 *buf;



	DBG("PIO writing\n");



	blksize = host->data->blksz;

	chunk_remain = 4;

	data = 0;

	chunk = 0;

	scratch = 0;



	bytes = 0;

	buffer = sdhci_sg_to_buffer(host) + host->offset;

	local_irq_save(flags);



	while (blksize) {

		size = min(host->remain, chunk_remain);

		if (!sg_miter_next(&host->sg_miter))

			BUG();



		chunk_remain -= size;

		blksize -= size;

		host->offset += size;

		host->remain -= size;

		len = min(host->sg_miter.length, blksize);



		while (size) {

			data >>= 8;

			data |= (u32)*buffer << 24;

			buffer++;

			size--;

		}

		blksize -= len;

		host->sg_miter.consumed = len;



		if (chunk_remain == 0) {

			writel(data, host->ioaddr + SDHCI_BUFFER);

			chunk_remain = min(blksize, 4);

		}

		buf = host->sg_miter.addr;



		if (host->remain == 0) {

			if (sdhci_next_sg(host) == 0) {

				BUG_ON(blksize != 0);

				return;

		while (len) {

			scratch |= (u32)*buf << (chunk * 8);



			buf++;

			chunk++;

			len--;



			if ((chunk == 4) || ((len == 0) && (blksize == 0))) {

				writel(scratch, host->ioaddr + SDHCI_BUFFER);

				chunk = 0;

				scratch = 0;

			}

			buffer = sdhci_sg_to_buffer(host);

		}

	}



	sg_miter_stop(&host->sg_miter);



	local_irq_restore(flags);

}



static void sdhci_transfer_pio(struct sdhci_host *host)
@@ -294,7 +270,7 @@ static void sdhci_transfer_pio(struct sdhci_host *host) 


	BUG_ON(!host->data);



	if (host->num_sg == 0)

	if (host->blocks == 0)

		return;



	if (host->data->flags & MMC_DATA_READ)
@@ -308,7 +284,8 @@ static void sdhci_transfer_pio(struct sdhci_host *host) 
		else

			sdhci_write_block_pio(host);



		if (host->num_sg == 0)

		host->blocks--;

		if (host->blocks == 0)

			break;

	}
@@ -713,11 +690,9 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data) 
	}



	if (!(host->flags & SDHCI_REQ_USE_DMA)) {

		host->cur_sg = data->sg;

		host->num_sg = data->sg_len;



		host->offset = 0;

		host->remain = host->cur_sg->length;

		sg_miter_start(&host->sg_miter,

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

		host->blocks = data->blocks;

	}



	/* We do not handle DMA boundaries, so set it to max (512 KiB) */
@@ -1583,9 +1558,15 @@ int sdhci_add_host(struct sdhci_host *host) 
		}

	}



	/* XXX: Hack to get MMC layer to avoid highmem */

	if (!(host->flags & SDHCI_USE_DMA))

		mmc_dev(host->mmc)->dma_mask = NULL;

	/*

	 * If we use DMA, then it's up to the caller to set the DMA

	 * mask, but PIO does not need the hw shim so we set a new

	 * mask here in that case.

	 */

	if (!(host->flags & SDHCI_USE_DMA)) {

		host->dma_mask = DMA_BIT_MASK(64);

		mmc_dev(host->mmc)->dma_mask = &host->dma_mask;

	}



	host->max_clk =

		(caps & SDHCI_CLOCK_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;

drivers/mmc/host/sdhci.h

+3 −4
Original line number Diff line number Diff line
@@ -212,6 +212,7 @@ struct sdhci_host { 


	/* Internal data */

	struct mmc_host		*mmc;		/* MMC structure */

	u64			dma_mask;	/* custom DMA mask */



#ifdef CONFIG_LEDS_CLASS

	struct led_classdev	led;		/* LED control */
@@ -238,10 +239,8 @@ struct sdhci_host { 
	struct mmc_data		*data;		/* Current data request */

	unsigned int		data_early:1;	/* Data finished before cmd */



	struct scatterlist	*cur_sg;	/* We're working on this */

	int			num_sg;		/* Entries left */

	int			offset;		/* Offset into current sg */

	int			remain;		/* Bytes left in current */

	struct sg_mapping_iter	sg_miter;	/* SG state for PIO */

	unsigned int		blocks;		/* remaining PIO blocks */



	int			sg_count;	/* Mapped sg entries */