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mmc: mxcmmc: 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.

Since this driver is using a worker, no atomic trickery
is needed.

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-v2-6-d8e732aa97d1@linaro.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Linus Walleij 2024-01-27 01:19:53 +01:00 committed by Ulf Hansson
parent 2761822c00
commit 12658af54f
1 changed files with 33 additions and 20 deletions
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53
drivers/mmc/host/mxcmmc.c
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@ -266,11 +266,18 @@ static inline void buffer_swap32(u32 *buf, int len)
static void mxcmci_swap_buffers(struct mmc_data *data)
{
struct scatterlist *sg;
int i;
struct sg_mapping_iter sgm;
u32 *buf;
for_each_sg(data->sg, sg, data->sg_len, i)
buffer_swap32(sg_virt(sg), sg->length);
sg_miter_start(&sgm, data->sg, data->sg_len,
SG_MITER_TO_SG | SG_MITER_FROM_SG);
while (sg_miter_next(&sgm)) {
buf = sgm.addr;
buffer_swap32(buf, sgm.length);
}
sg_miter_stop(&sgm);
}
#else
static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
@ -526,10 +533,9 @@ static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
} while (1);
}
static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
static int mxcmci_pull(struct mxcmci_host *host, u32 *buf, int bytes)
{
unsigned int stat;
u32 *buf = _buf;
while (bytes > 3) {
stat = mxcmci_poll_status(host,
@ -555,10 +561,9 @@ static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
return 0;
}
static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
static int mxcmci_push(struct mxcmci_host *host, u32 *buf, int bytes)
{
unsigned int stat;
u32 *buf = _buf;
while (bytes > 3) {
stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
@ -586,31 +591,39 @@ static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
static int mxcmci_transfer_data(struct mxcmci_host *host)
{
struct mmc_data *data = host->req->data;
struct scatterlist *sg;
int stat, i;
struct sg_mapping_iter sgm;
int stat;
u32 *buf;
host->data = data;
host->datasize = 0;
sg_miter_start(&sgm, data->sg, data->sg_len,
(data->flags & MMC_DATA_READ) ? SG_MITER_TO_SG : SG_MITER_FROM_SG);
if (data->flags & MMC_DATA_READ) {
for_each_sg(data->sg, sg, data->sg_len, i) {
stat = mxcmci_pull(host, sg_virt(sg), sg->length);
while (sg_miter_next(&sgm)) {
buf = sgm.addr;
stat = mxcmci_pull(host, buf, sgm.length);
if (stat)
return stat;
host->datasize += sg->length;
goto transfer_error;
host->datasize += sgm.length;
}
} else {
for_each_sg(data->sg, sg, data->sg_len, i) {
stat = mxcmci_push(host, sg_virt(sg), sg->length);
while (sg_miter_next(&sgm)) {
buf = sgm.addr;
stat = mxcmci_push(host, buf, sgm.length);
if (stat)
return stat;
host->datasize += sg->length;
goto transfer_error;
host->datasize += sgm.length;
}
stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
if (stat)
return stat;
goto transfer_error;
}
return 0;
transfer_error:
sg_miter_stop(&sgm);
return stat;
}
static void mxcmci_datawork(struct work_struct *work)