Commit 68cfdeb4 authored by Linus Walleij's avatar Linus Walleij Committed by Ulf Hansson
Browse files

mmc: omap: Use sg_miter for PIO 



Use the scatterlist memory iterator instead of just
dereferencing virtual memory using sg_virt().
This make highmem references work properly.

Suggested-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-mmc/20240122073423.GA25859@lst.de/


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240127-mmc-proper-kmap-v2-7-d8e732aa97d1@linaro.org


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 12658af5

drivers/mmc/host/omap.c

+24 −29
Original line number Diff line number Diff line
@@ -148,10 +148,8 @@ struct mmc_omap_host { 
	struct work_struct      send_stop_work;

	struct mmc_data		*stop_data;



	struct sg_mapping_iter	sg_miter;

	unsigned int		sg_len;

	int			sg_idx;

	u16 *			buffer;

	u32			buffer_bytes_left;

	u32			total_bytes_left;



	unsigned		features;
@@ -456,6 +454,8 @@ mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data) 
{

	if (host->dma_in_use)

		mmc_omap_release_dma(host, data, data->error);

	else

		sg_miter_stop(&host->sg_miter);



	host->data = NULL;

	host->sg_len = 0;
@@ -651,19 +651,6 @@ mmc_omap_cmd_timer(struct timer_list *t) 
	spin_unlock_irqrestore(&host->slot_lock, flags);

}



/* PIO only */

static void

mmc_omap_sg_to_buf(struct mmc_omap_host *host)

{

	struct scatterlist *sg;



	sg = host->data->sg + host->sg_idx;

	host->buffer_bytes_left = sg->length;

	host->buffer = sg_virt(sg);

	if (host->buffer_bytes_left > host->total_bytes_left)

		host->buffer_bytes_left = host->total_bytes_left;

}



static void

mmc_omap_clk_timer(struct timer_list *t)

{
@@ -676,33 +663,37 @@ mmc_omap_clk_timer(struct timer_list *t) 
static void

mmc_omap_xfer_data(struct mmc_omap_host *host, int write)

{

	struct sg_mapping_iter *sgm = &host->sg_miter;

	int n, nwords;

	u16 *buffer;



	if (host->buffer_bytes_left == 0) {

		host->sg_idx++;

		BUG_ON(host->sg_idx == host->sg_len);

		mmc_omap_sg_to_buf(host);

	if (!sg_miter_next(sgm)) {

		/* This should not happen */

		dev_err(mmc_dev(host->mmc), "ran out of scatterlist prematurely\n");

		return;

	}

	buffer = sgm->addr;



	n = 64;

	if (n > host->buffer_bytes_left)

		n = host->buffer_bytes_left;

	if (n > sgm->length)

		n = sgm->length;

	if (n > host->total_bytes_left)

		n = host->total_bytes_left;



	/* Round up to handle odd number of bytes to transfer */

	nwords = DIV_ROUND_UP(n, 2);



	host->buffer_bytes_left -= n;

	sgm->consumed = n;

	host->total_bytes_left -= n;

	host->data->bytes_xfered += n;



	if (write) {

		__raw_writesw(host->virt_base + OMAP_MMC_REG(host, DATA),

			      host->buffer, nwords);

			      buffer, nwords);

	} else {

		__raw_readsw(host->virt_base + OMAP_MMC_REG(host, DATA),

			     host->buffer, nwords);

			     buffer, nwords);

	}



	host->buffer += nwords;

}



#ifdef CONFIG_MMC_DEBUG
@@ -956,6 +947,7 @@ static inline void set_data_timeout(struct mmc_omap_host *host, struct mmc_reque 
static void

mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)

{

	unsigned int miter_flags = SG_MITER_ATOMIC; /* Used from IRQ */

	struct mmc_data *data = req->data;

	int i, use_dma = 1, block_size;

	struct scatterlist *sg;
@@ -990,7 +982,6 @@ mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req) 
		}

	}



	host->sg_idx = 0;

	if (use_dma) {

		enum dma_data_direction dma_data_dir;

		struct dma_async_tx_descriptor *tx;
@@ -1071,7 +1062,11 @@ mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req) 
	OMAP_MMC_WRITE(host, BUF, 0x1f1f);

	host->total_bytes_left = data->blocks * block_size;

	host->sg_len = sg_len;

	mmc_omap_sg_to_buf(host);

	if (data->flags & MMC_DATA_READ)

		miter_flags |= SG_MITER_TO_SG;

	else

		miter_flags |= SG_MITER_FROM_SG;

	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, miter_flags);

	host->dma_in_use = 0;

}