Commit 3ee0e7c3 authored by Linus Walleij's avatar Linus Walleij Committed by Ulf Hansson
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mmc: moxart-mmc: 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-v2-4-d8e732aa97d1@linaro.org


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 54fd8cd6

drivers/mmc/host/moxart-mmc.c

+34 −43
Original line number Diff line number Diff line
@@ -131,12 +131,10 @@ struct moxart_host { 
	struct dma_async_tx_descriptor	*tx_desc;

	struct mmc_host			*mmc;

	struct mmc_request		*mrq;

	struct scatterlist		*cur_sg;

	struct completion		dma_complete;

	struct completion		pio_complete;



	u32				num_sg;

	u32				data_remain;

	struct sg_mapping_iter		sg_miter;

	u32				data_len;

	u32				fifo_width;

	u32				timeout;
@@ -148,35 +146,6 @@ struct moxart_host { 
	bool				is_removed;

};



static inline void moxart_init_sg(struct moxart_host *host,

				  struct mmc_data *data)

{

	host->cur_sg = data->sg;

	host->num_sg = data->sg_len;

	host->data_remain = host->cur_sg->length;



	if (host->data_remain > host->data_len)

		host->data_remain = host->data_len;

}



static inline int moxart_next_sg(struct moxart_host *host)

{

	int remain;

	struct mmc_data *data = host->mrq->cmd->data;



	host->cur_sg++;

	host->num_sg--;



	if (host->num_sg > 0) {

		host->data_remain = host->cur_sg->length;

		remain = host->data_len - data->bytes_xfered;

		if (remain > 0 && remain < host->data_remain)

			host->data_remain = remain;

	}



	return host->num_sg;

}



static int moxart_wait_for_status(struct moxart_host *host,

				  u32 mask, u32 *status)

{
@@ -309,14 +278,28 @@ static void moxart_transfer_dma(struct mmc_data *data, struct moxart_host *host) 


static void moxart_transfer_pio(struct moxart_host *host)

{

	struct sg_mapping_iter *sgm = &host->sg_miter;

	struct mmc_data *data = host->mrq->cmd->data;

	u32 *sgp, len = 0, remain, status;



	if (host->data_len == data->bytes_xfered)

		return;



	sgp = sg_virt(host->cur_sg);

	remain = host->data_remain;

	/*

	 * By updating sgm->consumes this will get a proper pointer into the

	 * buffer at any time.

	 */

	if (!sg_miter_next(sgm)) {

		/* This shold not happen */

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

		data->error = -EINVAL;

		complete(&host->pio_complete);

		return;

	}

	sgp = sgm->addr;

	remain = sgm->length;

	if (remain > host->data_len)

		remain = host->data_len;



	if (data->flags & MMC_DATA_WRITE) {

		while (remain > 0) {
@@ -331,6 +314,7 @@ static void moxart_transfer_pio(struct moxart_host *host) 
				sgp++;

				len += 4;

			}

			sgm->consumed += len;

			remain -= len;

		}
@@ -347,22 +331,22 @@ static void moxart_transfer_pio(struct moxart_host *host) 
				sgp++;

				len += 4;

			}

			sgm->consumed += len;

			remain -= len;

		}

	}



	data->bytes_xfered += host->data_remain - remain;

	host->data_remain = remain;



	if (host->data_len != data->bytes_xfered)

		moxart_next_sg(host);

	else

	data->bytes_xfered += sgm->consumed;

	if (host->data_len == data->bytes_xfered) {

		complete(&host->pio_complete);

		return;

	}

}



static void moxart_prepare_data(struct moxart_host *host)

{

	struct mmc_data *data = host->mrq->cmd->data;

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

	u32 datactrl;

	int blksz_bits;
@@ -373,15 +357,19 @@ static void moxart_prepare_data(struct moxart_host *host) 
	blksz_bits = ffs(data->blksz) - 1;

	BUG_ON(1 << blksz_bits != data->blksz);



	moxart_init_sg(host, data);



	datactrl = DCR_DATA_EN | (blksz_bits & DCR_BLK_SIZE);



	if (data->flags & MMC_DATA_WRITE)

	if (data->flags & MMC_DATA_WRITE) {

		flags |= SG_MITER_FROM_SG;

		datactrl |= DCR_DATA_WRITE;

	} else {

		flags |= SG_MITER_TO_SG;

	}



	if (moxart_use_dma(host))

		datactrl |= DCR_DMA_EN;

	else

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



	writel(DCR_DATA_FIFO_RESET, host->base + REG_DATA_CONTROL);

	writel(MASK_DATA | FIFO_URUN | FIFO_ORUN, host->base + REG_CLEAR);
@@ -454,6 +442,9 @@ static void moxart_request(struct mmc_host *mmc, struct mmc_request *mrq) 
	}



request_done:

	if (!moxart_use_dma(host))

		sg_miter_stop(&host->sg_miter);



	spin_unlock_irqrestore(&host->lock, flags);

	mmc_request_done(host->mmc, mrq);

}