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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: 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-v2-4-d8e732aa97d1@linaro.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Linus Walleij 2024-01-27 01:19:51 +01:00 committed by Ulf Hansson
parent 54fd8cd617
commit 3ee0e7c3e6
1 changed files with 34 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
drivers/mmc/host/moxart-mmc.c
View File

@ -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);
}