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mmc: davinci_mmc: Use sg_miter for PIO

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

Suggested-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-mmc/20240122073423.GA25859@lst.de/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240127-mmc-proper-kmap-v2-1-d8e732aa97d1@linaro.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Linus Walleij 2024-01-27 01:19:48 +01:00 committed by Ulf Hansson
parent 3a999e57cf
commit ed01d210fd
1 changed files with 28 additions and 33 deletions
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53
drivers/mmc/host/davinci_mmc.c
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@ -180,12 +180,6 @@ struct mmc_davinci_host {
#define DAVINCI_MMC_DATADIR_WRITE 2
unsigned char data_dir;
/* buffer is used during PIO of one scatterlist segment, and
* is updated along with buffer_bytes_left. bytes_left applies
* to all N blocks of the PIO transfer.
*/
u8 *buffer;
u32 buffer_bytes_left;
u32 bytes_left;
struct dma_chan *dma_tx;
@ -196,8 +190,8 @@ struct mmc_davinci_host {
bool active_request;
/* For PIO we walk scatterlists one segment at a time. */
struct sg_mapping_iter sg_miter;
unsigned int sg_len;
struct scatterlist *sg;
/* Version of the MMC/SD controller */
u8 version;
@ -213,30 +207,24 @@ struct mmc_davinci_host {
static irqreturn_t mmc_davinci_irq(int irq, void *dev_id);
/* PIO only */
static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host)
{
host->buffer_bytes_left = sg_dma_len(host->sg);
host->buffer = sg_virt(host->sg);
if (host->buffer_bytes_left > host->bytes_left)
host->buffer_bytes_left = host->bytes_left;
}
static void davinci_fifo_data_trans(struct mmc_davinci_host *host,
unsigned int n)
{
struct sg_mapping_iter *sgm = &host->sg_miter;
size_t sglen;
u8 *p;
unsigned int i;
if (host->buffer_bytes_left == 0) {
host->sg = sg_next(host->data->sg);
mmc_davinci_sg_to_buf(host);
/*
* By adjusting sgm->consumed this will give a pointer to the
* current index into the sgm.
*/
if (!sg_miter_next(sgm)) {
dev_err(mmc_dev(host->mmc), "ran out of sglist prematurely\n");
return;
}
p = host->buffer;
if (n > host->buffer_bytes_left)
n = host->buffer_bytes_left;
host->buffer_bytes_left -= n;
host->bytes_left -= n;
p = sgm->addr;
sglen = sgm->length;
/* NOTE: we never transfer more than rw_threshold bytes
* to/from the fifo here; there's no I/O overlap.
@ -261,7 +249,9 @@ static void davinci_fifo_data_trans(struct mmc_davinci_host *host,
p = p + (n & 3);
}
}
host->buffer = p;
sgm->consumed = n;
host->bytes_left -= n;
}
static void mmc_davinci_start_command(struct mmc_davinci_host *host,
@ -517,6 +507,7 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
int fifo_lev = (rw_threshold == 32) ? MMCFIFOCTL_FIFOLEV : 0;
int timeout;
struct mmc_data *data = req->data;
unsigned int flags = SG_MITER_ATOMIC; /* Used from IRQ */
if (host->version == MMC_CTLR_VERSION_2)
fifo_lev = (rw_threshold == 64) ? MMCFIFOCTL_FIFOLEV : 0;
@ -545,12 +536,14 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
/* Configure the FIFO */
if (data->flags & MMC_DATA_WRITE) {
flags |= SG_MITER_FROM_SG;
host->data_dir = DAVINCI_MMC_DATADIR_WRITE;
writel(fifo_lev | MMCFIFOCTL_FIFODIR_WR | MMCFIFOCTL_FIFORST,
host->base + DAVINCI_MMCFIFOCTL);
writel(fifo_lev | MMCFIFOCTL_FIFODIR_WR,
host->base + DAVINCI_MMCFIFOCTL);
} else {
flags |= SG_MITER_TO_SG;
host->data_dir = DAVINCI_MMC_DATADIR_READ;
writel(fifo_lev | MMCFIFOCTL_FIFODIR_RD | MMCFIFOCTL_FIFORST,
host->base + DAVINCI_MMCFIFOCTL);
@ -558,7 +551,6 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
host->base + DAVINCI_MMCFIFOCTL);
}
host->buffer = NULL;
host->bytes_left = data->blocks * data->blksz;
/* For now we try to use DMA whenever we won't need partial FIFO
@ -576,8 +568,7 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
} else {
/* Revert to CPU Copy */
host->sg_len = data->sg_len;
host->sg = host->data->sg;
mmc_davinci_sg_to_buf(host);
sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
}
}
@ -843,6 +834,8 @@ davinci_abort_data(struct mmc_davinci_host *host, struct mmc_data *data)
{
mmc_davinci_reset_ctrl(host, 1);
mmc_davinci_reset_ctrl(host, 0);
if (!host->do_dma)
sg_miter_stop(&host->sg_miter);
}
static irqreturn_t mmc_davinci_sdio_irq(int irq, void *dev_id)
@ -919,11 +912,13 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
if (qstatus & MMCST0_DATDNE) {
/* All blocks sent/received, and CRC checks passed */
if (data != NULL) {
if ((host->do_dma == 0) && (host->bytes_left > 0)) {
if (!host->do_dma) {
if (host->bytes_left > 0)
/* if datasize < rw_threshold
* no RX ints are generated
*/
davinci_fifo_data_trans(host, host->bytes_left);
sg_miter_stop(&host->sg_miter);
}
end_transfer = 1;
data->bytes_xfered = data->blocks * data->blksz;