alistair23-linux/drivers/mmc/core/sdio_ops.c
Kyoungil Kim 968a64ea63 mmc: sdio: Use multiple scatter/gather list
Before this patch, we always used only single sg entry for SDIO transfer.
This patch switches to using multiple sg entries. In the case of dwmci,
it supports only up to 4KB size per single sg entry. So if we want to
transfer more than 4KB, we should send more than 1 command.

When we tested before applying this patch, it took around 335 us for
5K(5120) bytes transfer with dwmci controller. After applying this patch,
it takes 242 us for 5K bytes. So this patch makes around 38% performance
improvement for 5K bytes transfer. If the transfer size is bigger, then
the performance improvement ratio will be increased.

Signed-off-by: Kyoungil Kim <ki0351.kim@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-12-06 13:54:43 -05:00

224 lines
4.8 KiB
C

/*
* linux/drivers/mmc/sdio_ops.c
*
* Copyright 2006-2007 Pierre Ossman
*
* 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
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*/
#include <linux/scatterlist.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sdio.h>
#include "core.h"
#include "sdio_ops.h"
int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
{
struct mmc_command cmd = {0};
int i, err = 0;
BUG_ON(!host);
cmd.opcode = SD_IO_SEND_OP_COND;
cmd.arg = ocr;
cmd.flags = MMC_RSP_SPI_R4 | MMC_RSP_R4 | MMC_CMD_BCR;
for (i = 100; i; i--) {
err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
if (err)
break;
/* if we're just probing, do a single pass */
if (ocr == 0)
break;
/* otherwise wait until reset completes */
if (mmc_host_is_spi(host)) {
/*
* Both R1_SPI_IDLE and MMC_CARD_BUSY indicate
* an initialized card under SPI, but some cards
* (Marvell's) only behave when looking at this
* one.
*/
if (cmd.resp[1] & MMC_CARD_BUSY)
break;
} else {
if (cmd.resp[0] & MMC_CARD_BUSY)
break;
}
err = -ETIMEDOUT;
mmc_delay(10);
}
if (rocr)
*rocr = cmd.resp[mmc_host_is_spi(host) ? 1 : 0];
return err;
}
static int mmc_io_rw_direct_host(struct mmc_host *host, int write, unsigned fn,
unsigned addr, u8 in, u8 *out)
{
struct mmc_command cmd = {0};
int err;
BUG_ON(!host);
BUG_ON(fn > 7);
/* sanity check */
if (addr & ~0x1FFFF)
return -EINVAL;
cmd.opcode = SD_IO_RW_DIRECT;
cmd.arg = write ? 0x80000000 : 0x00000000;
cmd.arg |= fn << 28;
cmd.arg |= (write && out) ? 0x08000000 : 0x00000000;
cmd.arg |= addr << 9;
cmd.arg |= in;
cmd.flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_AC;
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
return err;
if (mmc_host_is_spi(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;
}
if (out) {
if (mmc_host_is_spi(host))
*out = (cmd.resp[0] >> 8) & 0xFF;
else
*out = cmd.resp[0] & 0xFF;
}
return 0;
}
int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
unsigned addr, u8 in, u8 *out)
{
BUG_ON(!card);
return mmc_io_rw_direct_host(card->host, write, fn, addr, in, out);
}
int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz)
{
struct mmc_request mrq = {NULL};
struct mmc_command cmd = {0};
struct mmc_data data = {0};
struct scatterlist sg, *sg_ptr;
struct sg_table sgtable;
unsigned int nents, left_size, i;
unsigned int seg_size = card->host->max_seg_size;
BUG_ON(!card);
BUG_ON(fn > 7);
WARN_ON(blksz == 0);
/* 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;
if (blocks == 0)
cmd.arg |= (blksz == 512) ? 0 : blksz; /* byte mode */
else
cmd.arg |= 0x08000000 | blocks; /* block mode */
cmd.flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_ADTC;
data.blksz = blksz;
/* Code in host drivers/fwk assumes that "blocks" always is >=1 */
data.blocks = blocks ? blocks : 1;
data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
left_size = data.blksz * data.blocks;
nents = (left_size - 1) / seg_size + 1;
if (nents > 1) {
if (sg_alloc_table(&sgtable, nents, GFP_KERNEL))
return -ENOMEM;
data.sg = sgtable.sgl;
data.sg_len = nents;
for_each_sg(data.sg, sg_ptr, data.sg_len, i) {
sg_set_page(sg_ptr, virt_to_page(buf + (i * seg_size)),
min(seg_size, left_size),
offset_in_page(buf + (i * seg_size)));
left_size = left_size - seg_size;
}
} else {
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, buf, left_size);
}
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
if (nents > 1)
sg_free_table(&sgtable);
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;
}
int sdio_reset(struct mmc_host *host)
{
int ret;
u8 abort;
/* SDIO Simplified Specification V2.0, 4.4 Reset for SDIO */
ret = mmc_io_rw_direct_host(host, 0, 0, SDIO_CCCR_ABORT, 0, &abort);
if (ret)
abort = 0x08;
else
abort |= 0x08;
ret = mmc_io_rw_direct_host(host, 1, 0, SDIO_CCCR_ABORT, abort, NULL);
return ret;
}