On 11/26/14 14:43, Ulf Hansson wrote:
On 26 November 2014 at 12:07, Avinash Patil<patila@xxxxxxxxxxx> wrote:
From: Bing Zhao<bzhao@xxxxxxxxxxx>
This patch adds new API to handle scatter gather aggregation.
Why is this needed?
One thing I can imagine is that the receiving device has specific
scatter-gather alignment requirements that are not covered in
mmc_io_rw_extended(). So the new API does not so much handle
scatter-gather, but leaves that up to the caller. Question is whether
mmc_io_rw_extended() could be changed to accommodate those requirements
instead of duplicating big part of it. Without knowing the exact
requirements that is difficult to answer.
Regards,
Arend
Signed-off-by: Bing Zhao<bzhao@xxxxxxxxxxx>
Signed-off-by: Avinash Patil<patila@xxxxxxxxxxx>
Signed-off-by: Xinming Hu<huxm@xxxxxxxxxxx>
Signed-off-by: Cathy Luo<cluo@xxxxxxxxxxx>
---
drivers/mmc/core/sdio_ops.c | 65 +++++++++++++++++++++++++++++++++++++++++++
include/linux/mmc/sdio_func.h | 5 ++++
2 files changed, 70 insertions(+)
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index 62508b4..4c5e362 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -15,6 +15,7 @@
#include<linux/mmc/card.h>
#include<linux/mmc/mmc.h>
#include<linux/mmc/sdio.h>
+#include<linux/export.h>
#include "core.h"
#include "sdio_ops.h"
@@ -204,6 +205,70 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
return 0;
}
+int mmc_io_rw_extended_sg(struct mmc_card *card, int write, unsigned fn,
+ unsigned addr, int incr_addr,
+ struct sg_table *sgt, unsigned blksz)
+{
+ struct mmc_request mrq = {NULL};
+ struct mmc_command cmd = {0};
+ struct mmc_data data = {0};
+ struct scatterlist *sg_ptr;
+ unsigned blocks = 0;
+ int i;
+
+ BUG_ON(!card || !card->host);
+ BUG_ON(fn> 7);
+ BUG_ON(!blksz);
No BUG_ON() here please. Better to return an error.
+ for_each_sg(sgt->sgl, sg_ptr, sgt->nents, i) {
+ WARN_ON(sg_ptr->length> card->host->max_seg_size);
+ blocks += DIV_ROUND_UP(sg_ptr->length, blksz);
+ }
+
+ /* sanity check */
+ if (addr& ~0x1FFFF)
+ return -EINVAL;
+
+ mrq.cmd =&cmd;
+ mrq.data =&data;
+
+ cmd.opcode = SD_IO_RW_EXTENDED;
+ cmd.arg = write ? 0x80000000 : 0x00000000;
+ cmd.arg |= fn<< 28;
+ cmd.arg |= incr_addr ? 0x04000000 : 0x00000000;
+ cmd.arg |= addr<< 9;
+ cmd.arg |= 0x08000000 | blocks;
+ cmd.flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_ADTC;
+
+ data.blksz = blksz;
+ data.blocks = blocks;
+ data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
+
+ data.sg = sgt->sgl;
+ data.sg_len = sgt->nents;
+
+ mmc_set_data_timeout(&data, card);
+ mmc_wait_for_req(card->host,&mrq);
+
+ if (cmd.error)
+ return cmd.error;
+ if (data.error)
+ return data.error;
+
+ if (mmc_host_is_spi(card->host)) {
+ /* host driver already reported errors */
+ } else {
+ if (cmd.resp[0]& R5_ERROR)
+ return -EIO;
+ if (cmd.resp[0]& R5_FUNCTION_NUMBER)
+ return -EINVAL;
+ if (cmd.resp[0]& R5_OUT_OF_RANGE)
+ return -ERANGE;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mmc_io_rw_extended_sg);
+
int sdio_reset(struct mmc_host *host)
{
int ret;
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index 50f0bc9..927ea8f 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -14,6 +14,7 @@
#include<linux/device.h>
#include<linux/mod_devicetable.h>
+#include<linux/scatterlist.h>
#include<linux/mmc/pm.h>
@@ -153,6 +154,10 @@ extern int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr,
extern int sdio_writesb(struct sdio_func *func, unsigned int addr,
void *src, int count);
+int mmc_io_rw_extended_sg(struct mmc_card *card, int write, unsigned fn,
+ unsigned addr, int incr_addr,
+ struct sg_table *sgt, unsigned blksz);
+
extern unsigned char sdio_f0_readb(struct sdio_func *func,
unsigned int addr, int *err_ret);
extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
--
1.8.1.4
Kind regards
Uffe
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