Return-path: Received: from mail-qa0-f52.google.com ([209.85.216.52]:38083 "EHLO mail-qa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750768AbaKZNnj (ORCPT ); Wed, 26 Nov 2014 08:43:39 -0500 Received: by mail-qa0-f52.google.com with SMTP id dc16so1870652qab.39 for ; Wed, 26 Nov 2014 05:43:38 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1417000056-16920-1-git-send-email-patila@marvell.com> References: <1417000056-16920-1-git-send-email-patila@marvell.com> Date: Wed, 26 Nov 2014 14:43:38 +0100 Message-ID: (sfid-20141126_144343_867943_2BCA05FF) Subject: Re: [PATCH] mmc: new API for data write using scatter gather DMA From: Ulf Hansson To: Avinash Patil Cc: linux-mmc , "linux-wireless@vger.kernel.org" , akarwar@marvell.com, cluo@marvell.com, yangyang@marvell.com, huxm@marvell.com, bin9zha0@gmail.com, Bing Zhao Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 26 November 2014 at 12:07, Avinash Patil wrote: > From: Bing Zhao > > This patch adds new API to handle scatter gather aggregation. Why is this needed? > > Signed-off-by: Bing Zhao > Signed-off-by: Avinash Patil > Signed-off-by: Xinming Hu > Signed-off-by: Cathy Luo > --- > 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 > #include > #include > +#include > > #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 > #include > +#include > > #include > > @@ -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