Hi Ulf,
We have decided to drop this patch.
Thanks,
Avinash
________________________________________
From: Avinash Patil
Sent: Tuesday, December 02, 2014 2:55 PM
To: Ulf Hansson
Cc: linux-mmc; linux-wirel...@vger.kernel.org; Amitkumar Karwar; Cathy Luo;
Marc Yang; Xinming Hu; bin9z...@gmail.com; Bing Zhao
Subject: RE: [PATCH] mmc: new API for data write using scatter gather DMA
Hi Ulf,
Purpose of patch is to offload scatter gather list population to host driver.
Patch provides MMC API using which host driver can directly use to program SG
DMA.
Thanks,
Avinash
________________________________________
From: Ulf Hansson [ulf.hans...@linaro.org]
Sent: Wednesday, November 26, 2014 7:13 PM
To: Avinash Patil
Cc: linux-mmc; linux-wirel...@vger.kernel.org; Amitkumar Karwar; Cathy Luo;
Marc Yang; Xinming Hu; bin9z...@gmail.com; Bing Zhao
Subject: Re: [PATCH] mmc: new API for data write using scatter gather DMA
On 26 November 2014 at 12:07, Avinash Patil <pat...@marvell.com> wrote:
> From: Bing Zhao <bz...@marvell.com>
>
> This patch adds new API to handle scatter gather aggregation.
Why is this needed?
>
> Signed-off-by: Bing Zhao <bz...@marvell.com>
> Signed-off-by: Avinash Patil <pat...@marvell.com>
> Signed-off-by: Xinming Hu <h...@marvell.com>
> Signed-off-by: Cathy Luo <c...@marvell.com>
> ---
> 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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