mmc: cull sg list to match mmc request size
mmc layer may introduce additional (compared to block layer) limits on
request size. Culling of the sg list to match adjusted request size
simplifies the handling of such cases in the low level driver, allowing
it to skip block count checks while processing sg entries.
(fixes for wbsd and sdhci by Pierre Ossman)
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
index 05ccfc4..7a3e32e 100644
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -1,7 +1,7 @@
/*
* linux/drivers/mmc/wbsd.c - Winbond W83L51xD SD/MMC driver
*
- * Copyright (C) 2004-2006 Pierre Ossman, All Rights Reserved.
+ * Copyright (C) 2004-2007 Pierre Ossman, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -278,90 +278,36 @@
static inline void wbsd_sg_to_dma(struct wbsd_host *host, struct mmc_data *data)
{
- unsigned int len, i, size;
+ unsigned int len, i;
struct scatterlist *sg;
char *dmabuf = host->dma_buffer;
char *sgbuf;
- size = host->size;
-
sg = data->sg;
len = data->sg_len;
- /*
- * Just loop through all entries. Size might not
- * be the entire list though so make sure that
- * we do not transfer too much.
- */
for (i = 0; i < len; i++) {
sgbuf = page_address(sg[i].page) + sg[i].offset;
- if (size < sg[i].length)
- memcpy(dmabuf, sgbuf, size);
- else
- memcpy(dmabuf, sgbuf, sg[i].length);
+ memcpy(dmabuf, sgbuf, sg[i].length);
dmabuf += sg[i].length;
-
- if (size < sg[i].length)
- size = 0;
- else
- size -= sg[i].length;
-
- if (size == 0)
- break;
}
-
- /*
- * Check that we didn't get a request to transfer
- * more data than can fit into the SG list.
- */
-
- BUG_ON(size != 0);
-
- host->size -= size;
}
static inline void wbsd_dma_to_sg(struct wbsd_host *host, struct mmc_data *data)
{
- unsigned int len, i, size;
+ unsigned int len, i;
struct scatterlist *sg;
char *dmabuf = host->dma_buffer;
char *sgbuf;
- size = host->size;
-
sg = data->sg;
len = data->sg_len;
- /*
- * Just loop through all entries. Size might not
- * be the entire list though so make sure that
- * we do not transfer too much.
- */
for (i = 0; i < len; i++) {
sgbuf = page_address(sg[i].page) + sg[i].offset;
- if (size < sg[i].length)
- memcpy(sgbuf, dmabuf, size);
- else
- memcpy(sgbuf, dmabuf, sg[i].length);
+ memcpy(sgbuf, dmabuf, sg[i].length);
dmabuf += sg[i].length;
-
- if (size < sg[i].length)
- size = 0;
- else
- size -= sg[i].length;
-
- if (size == 0)
- break;
}
-
- /*
- * Check that we didn't get a request to transfer
- * more data than can fit into the SG list.
- */
-
- BUG_ON(size != 0);
-
- host->size -= size;
}
/*
@@ -484,7 +430,7 @@
/*
* Handle excessive data.
*/
- if (data->bytes_xfered == host->size)
+ if (host->num_sg == 0)
return;
buffer = wbsd_sg_to_buffer(host) + host->offset;
@@ -514,31 +460,14 @@
data->bytes_xfered++;
/*
- * Transfer done?
- */
- if (data->bytes_xfered == host->size)
- return;
-
- /*
* End of scatter list entry?
*/
if (host->remain == 0) {
/*
* Get next entry. Check if last.
*/
- if (!wbsd_next_sg(host)) {
- /*
- * We should never reach this point.
- * It means that we're trying to
- * transfer more blocks than can fit
- * into the scatter list.
- */
- BUG_ON(1);
-
- host->size = data->bytes_xfered;
-
+ if (!wbsd_next_sg(host))
return;
- }
buffer = wbsd_sg_to_buffer(host);
}
@@ -550,7 +479,7 @@
* hardware problem. The chip doesn't trigger
* FIFO threshold interrupts properly.
*/
- if ((host->size - data->bytes_xfered) < 16)
+ if ((data->blocks * data->blksz - data->bytes_xfered) < 16)
tasklet_schedule(&host->fifo_tasklet);
}
@@ -564,7 +493,7 @@
* Check that we aren't being called after the
* entire buffer has been transfered.
*/
- if (data->bytes_xfered == host->size)
+ if (host->num_sg == 0)
return;
buffer = wbsd_sg_to_buffer(host) + host->offset;
@@ -594,31 +523,14 @@
data->bytes_xfered++;
/*
- * Transfer done?
- */
- if (data->bytes_xfered == host->size)
- return;
-
- /*
* End of scatter list entry?
*/
if (host->remain == 0) {
/*
* Get next entry. Check if last.
*/
- if (!wbsd_next_sg(host)) {
- /*
- * We should never reach this point.
- * It means that we're trying to
- * transfer more blocks than can fit
- * into the scatter list.
- */
- BUG_ON(1);
-
- host->size = data->bytes_xfered;
-
+ if (!wbsd_next_sg(host))
return;
- }
buffer = wbsd_sg_to_buffer(host);
}
@@ -638,6 +550,7 @@
u16 blksize;
u8 setup;
unsigned long dmaflags;
+ unsigned int size;
DBGF("blksz %04x blks %04x flags %08x\n",
data->blksz, data->blocks, data->flags);
@@ -647,7 +560,7 @@
/*
* Calculate size.
*/
- host->size = data->blocks * data->blksz;
+ size = data->blocks * data->blksz;
/*
* Check timeout values for overflow.
@@ -705,8 +618,8 @@
/*
* The buffer for DMA is only 64 kB.
*/
- BUG_ON(host->size > 0x10000);
- if (host->size > 0x10000) {
+ BUG_ON(size > 0x10000);
+ if (size > 0x10000) {
data->error = MMC_ERR_INVALID;
return;
}
@@ -729,7 +642,7 @@
else
set_dma_mode(host->dma, DMA_MODE_WRITE & ~0x40);
set_dma_addr(host->dma, host->dma_addr);
- set_dma_count(host->dma, host->size);
+ set_dma_count(host->dma, size);
enable_dma(host->dma);
release_dma_lock(dmaflags);
@@ -812,6 +725,10 @@
count = get_dma_residue(host->dma);
release_dma_lock(dmaflags);
+ data->bytes_xfered = host->mrq->data->blocks *
+ host->mrq->data->blksz - count;
+ data->bytes_xfered -= data->bytes_xfered % data->blksz;
+
/*
* Any leftover data?
*/
@@ -820,7 +737,8 @@
"%d bytes left.\n",
mmc_hostname(host->mmc), count);
- data->error = MMC_ERR_FAILED;
+ if (data->error == MMC_ERR_NONE)
+ data->error = MMC_ERR_FAILED;
} else {
/*
* Transfer data from DMA buffer to
@@ -828,8 +746,11 @@
*/
if (data->flags & MMC_DATA_READ)
wbsd_dma_to_sg(host, data);
+ }
- data->bytes_xfered = host->size;
+ if (data->error != MMC_ERR_NONE) {
+ if (data->bytes_xfered)
+ data->bytes_xfered -= data->blksz;
}
}
@@ -1167,7 +1088,7 @@
/*
* Done?
*/
- if (host->size == data->bytes_xfered) {
+ if (host->num_sg == 0) {
wbsd_write_index(host, WBSD_IDX_FIFOEN, 0);
tasklet_schedule(&host->finish_tasklet);
}