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tifm_sd: implement software scatter-gather 

It was found that delays associated with issue and completion of the commands
severely limit performance of the new, fast SD cards. To alleviate this issue
scatter-gather emulation in software is implemented for both dma and pio
transfer modes. Non-block aligned and high memory sg entries are accounted
for.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
Alex Dubov 2007-04-12 17:05:25 +10:00 committed by Pierre Ossman
parent 5897d657b5
commit 13cdf48ef1
2 changed files with 299 additions and 149 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

447
drivers/mmc/tifm_sd.c
View File

@ -14,6 +14,7 @@
#include <linux/mmc/protocol.h>
#include <linux/mmc/host.h>
#include <linux/highmem.h>
#include <linux/scatterlist.h>
#include <asm/io.h>
#define DRIVER_NAME "tifm_sd"
@ -69,6 +70,8 @@ module_param(fixed_timeout, bool, 0644);
#define TIFM_MMCSD_CMD_AC 0x2000
#define TIFM_MMCSD_CMD_ADTC 0x3000
#define TIFM_MMCSD_MAX_BLOCK_SIZE 0x0800UL
enum {
CMD_READY = 0x0001,
FIFO_READY = 0x0002,
@ -95,63 +98,227 @@ struct tifm_sd {
struct timer_list timer;
struct mmc_request *req;
size_t written_blocks;
size_t buffer_size;
size_t buffer_pos;
int sg_len;
int sg_pos;
unsigned int block_pos;
struct scatterlist bounce_buf;
unsigned char bounce_buf_data[TIFM_MMCSD_MAX_BLOCK_SIZE];
};
static char* tifm_sd_data_buffer(struct mmc_data *data)
/* for some reason, host won't respond correctly to readw/writew */
static void tifm_sd_read_fifo(struct tifm_sd *host, struct page *pg,
unsigned int off, unsigned int cnt)
{
return page_address(data->sg->page) + data->sg->offset;
struct tifm_dev *sock = host->dev;
unsigned char *buf;
unsigned int pos = 0, val;
buf = kmap_atomic(pg, KM_BIO_DST_IRQ) + off;
if (host->cmd_flags & DATA_CARRY) {
buf[pos++] = host->bounce_buf_data[0];
host->cmd_flags &= ~DATA_CARRY;
}
while (pos < cnt) {
val = readl(sock->addr + SOCK_MMCSD_DATA);
buf[pos++] = val & 0xff;
if (pos == cnt) {
host->bounce_buf_data[0] = (val >> 8) & 0xff;
host->cmd_flags |= DATA_CARRY;
break;
}
buf[pos++] = (val >> 8) & 0xff;
}
kunmap_atomic(buf - off, KM_BIO_DST_IRQ);
}
static int tifm_sd_transfer_data(struct tifm_dev *sock, struct tifm_sd *host,
unsigned int host_status)
static void tifm_sd_write_fifo(struct tifm_sd *host, struct page *pg,
unsigned int off, unsigned int cnt)
{
struct mmc_command *cmd = host->req->cmd;
unsigned int t_val = 0, cnt = 0;
char *buffer;
struct tifm_dev *sock = host->dev;
unsigned char *buf;
unsigned int pos = 0, val;
if (host_status & TIFM_MMCSD_BRS) {
/* in non-dma rx mode BRS fires when fifo is still not empty */
if (host->no_dma && (cmd->data->flags & MMC_DATA_READ)) {
buffer = tifm_sd_data_buffer(host->req->data);
while (host->buffer_size > host->buffer_pos) {
t_val = readl(sock->addr + SOCK_MMCSD_DATA);
buffer[host->buffer_pos++] = t_val & 0xff;
buffer[host->buffer_pos++] =
(t_val >> 8) & 0xff;
}
}
return 1;
} else if (host->no_dma) {
buffer = tifm_sd_data_buffer(host->req->data);
if ((cmd->data->flags & MMC_DATA_READ) &&
(host_status & TIFM_MMCSD_AF)) {
for (cnt = 0; cnt < TIFM_MMCSD_FIFO_SIZE; cnt++) {
t_val = readl(sock->addr + SOCK_MMCSD_DATA);
if (host->buffer_size > host->buffer_pos) {
buffer[host->buffer_pos++] =
t_val & 0xff;
buffer[host->buffer_pos++] =
(t_val >> 8) & 0xff;
}
}
} else if ((cmd->data->flags & MMC_DATA_WRITE)
&& (host_status & TIFM_MMCSD_AE)) {
for (cnt = 0; cnt < TIFM_MMCSD_FIFO_SIZE; cnt++) {
if (host->buffer_size > host->buffer_pos) {
t_val = buffer[host->buffer_pos++]
& 0x00ff;
t_val |= ((buffer[host->buffer_pos++])
<< 8) & 0xff00;
writel(t_val,
sock->addr + SOCK_MMCSD_DATA);
}
}
}
buf = kmap_atomic(pg, KM_BIO_SRC_IRQ) + off;
if (host->cmd_flags & DATA_CARRY) {
val = host->bounce_buf_data[0] | ((buf[pos++] << 8) & 0xff00);
writel(val, sock->addr + SOCK_MMCSD_DATA);
host->cmd_flags &= ~DATA_CARRY;
}
while (pos < cnt) {
val = buf[pos++];
if (pos == cnt) {
host->bounce_buf_data[0] = val & 0xff;
host->cmd_flags |= DATA_CARRY;
break;
}
val |= (buf[pos++] << 8) & 0xff00;
writel(val, sock->addr + SOCK_MMCSD_DATA);
}
kunmap_atomic(buf - off, KM_BIO_SRC_IRQ);
}
static void tifm_sd_transfer_data(struct tifm_sd *host)
{
struct mmc_data *r_data = host->req->cmd->data;
struct scatterlist *sg = r_data->sg;
unsigned int off, cnt, t_size = TIFM_MMCSD_FIFO_SIZE * 2;
unsigned int p_off, p_cnt;
struct page *pg;
if (host->sg_pos == host->sg_len)
return;
while (t_size) {
cnt = sg[host->sg_pos].length - host->block_pos;
if (!cnt) {
host->block_pos = 0;
host->sg_pos++;
if (host->sg_pos == host->sg_len) {
if ((r_data->flags & MMC_DATA_WRITE)
&& DATA_CARRY)
writel(host->bounce_buf_data[0],
host->dev->addr
+ SOCK_MMCSD_DATA);
return;
}
cnt = sg[host->sg_pos].length;
}
off = sg[host->sg_pos].offset + host->block_pos;
pg = nth_page(sg[host->sg_pos].page, off >> PAGE_SHIFT);
p_off = offset_in_page(off);
p_cnt = PAGE_SIZE - p_off;
p_cnt = min(p_cnt, cnt);
p_cnt = min(p_cnt, t_size);
if (r_data->flags & MMC_DATA_READ)
tifm_sd_read_fifo(host, pg, p_off, p_cnt);
else if (r_data->flags & MMC_DATA_WRITE)
tifm_sd_write_fifo(host, pg, p_off, p_cnt);
t_size -= p_cnt;
host->block_pos += p_cnt;
}
}
static void tifm_sd_copy_page(struct page *dst, unsigned int dst_off,
struct page *src, unsigned int src_off,
unsigned int count)
{
unsigned char *src_buf = kmap_atomic(src, KM_BIO_SRC_IRQ) + src_off;
unsigned char *dst_buf = kmap_atomic(dst, KM_BIO_DST_IRQ) + dst_off;
memcpy(dst_buf, src_buf, count);
kunmap_atomic(dst_buf - dst_off, KM_BIO_DST_IRQ);
kunmap_atomic(src_buf - src_off, KM_BIO_SRC_IRQ);
}
static void tifm_sd_bounce_block(struct tifm_sd *host, struct mmc_data *r_data)
{
struct scatterlist *sg = r_data->sg;
unsigned int t_size = r_data->blksz;
unsigned int off, cnt;
unsigned int p_off, p_cnt;
struct page *pg;
dev_dbg(&host->dev->dev, "bouncing block\n");
while (t_size) {
cnt = sg[host->sg_pos].length - host->block_pos;
if (!cnt) {
host->block_pos = 0;
host->sg_pos++;
if (host->sg_pos == host->sg_len)
return;
cnt = sg[host->sg_pos].length;
}
off = sg[host->sg_pos].offset + host->block_pos;
pg = nth_page(sg[host->sg_pos].page, off >> PAGE_SHIFT);
p_off = offset_in_page(off);
p_cnt = PAGE_SIZE - p_off;
p_cnt = min(p_cnt, cnt);
p_cnt = min(p_cnt, t_size);
if (r_data->flags & MMC_DATA_WRITE)
tifm_sd_copy_page(host->bounce_buf.page,
r_data->blksz - t_size,
pg, p_off, p_cnt);
else if (r_data->flags & MMC_DATA_READ)
tifm_sd_copy_page(pg, p_off, host->bounce_buf.page,
r_data->blksz - t_size, p_cnt);
t_size -= p_cnt;
host->block_pos += p_cnt;
}
}
int tifm_sd_set_dma_data(struct tifm_sd *host, struct mmc_data *r_data)
{
struct tifm_dev *sock = host->dev;
unsigned int t_size = TIFM_DMA_TSIZE * r_data->blksz;
unsigned int dma_len, dma_blk_cnt, dma_off;
struct scatterlist *sg = NULL;
unsigned long flags;
if (host->sg_pos == host->sg_len)
return 1;
if (host->cmd_flags & DATA_CARRY) {
host->cmd_flags &= ~DATA_CARRY;
local_irq_save(flags);
tifm_sd_bounce_block(host, r_data);
local_irq_restore(flags);
if (host->sg_pos == host->sg_len)
return 1;
}
dma_len = sg_dma_len(&r_data->sg[host->sg_pos]) - host->block_pos;
if (!dma_len) {
host->block_pos = 0;
host->sg_pos++;
if (host->sg_pos == host->sg_len)
return 1;
dma_len = sg_dma_len(&r_data->sg[host->sg_pos]);
}
if (dma_len < t_size) {
dma_blk_cnt = dma_len / r_data->blksz;
dma_off = host->block_pos;
host->block_pos += dma_blk_cnt * r_data->blksz;
} else {
dma_blk_cnt = TIFM_DMA_TSIZE;
dma_off = host->block_pos;
host->block_pos += t_size;
}
if (dma_blk_cnt)
sg = &r_data->sg[host->sg_pos];
else if (dma_len) {
if (r_data->flags & MMC_DATA_WRITE) {
local_irq_save(flags);
tifm_sd_bounce_block(host, r_data);
local_irq_restore(flags);
} else
host->cmd_flags |= DATA_CARRY;
sg = &host->bounce_buf;
dma_off = 0;
dma_blk_cnt = 1;
} else
return 1;
dev_dbg(&sock->dev, "setting dma for %d blocks\n", dma_blk_cnt);
writel(sg_dma_address(sg) + dma_off, sock->addr + SOCK_DMA_ADDRESS);
if (r_data->flags & MMC_DATA_WRITE)
writel((dma_blk_cnt << 8) | TIFM_DMA_TX | TIFM_DMA_EN,
sock->addr + SOCK_DMA_CONTROL);
else
writel((dma_blk_cnt << 8) | TIFM_DMA_EN,
sock->addr + SOCK_DMA_CONTROL);
return 0;
}
@ -317,8 +484,10 @@ static void tifm_sd_data_event(struct tifm_dev *sock)
r_data = host->req->cmd->data;
if (r_data && (fifo_status & TIFM_FIFO_READY)) {
host->cmd_flags |= FIFO_READY;
tifm_sd_check_status(host);
if (tifm_sd_set_dma_data(host, r_data)) {
host->cmd_flags |= FIFO_READY;
tifm_sd_check_status(host);
}
}
}
@ -398,7 +567,7 @@ static void tifm_sd_card_event(struct tifm_dev *sock)
if (host_status & (TIFM_MMCSD_AE | TIFM_MMCSD_AF
| TIFM_MMCSD_BRS)) {
local_irq_save(flags);
tifm_sd_transfer_data(sock, host, host_status);
tifm_sd_transfer_data(host);
local_irq_restore(flags);
host_status &= ~TIFM_MMCSD_AE;
}
@ -416,38 +585,6 @@ done:
spin_unlock(&sock->lock);
}
static void tifm_sd_prepare_data(struct tifm_sd *host, struct mmc_command *cmd)
{
struct tifm_dev *sock = host->dev;
unsigned int dest_cnt;
/* DMA style IO */
dev_dbg(&sock->dev, "setting dma for %d blocks\n",
cmd->data->blocks);
writel(TIFM_FIFO_INT_SETALL,
sock->addr + SOCK_DMA_FIFO_INT_ENABLE_CLEAR);
writel(ilog2(cmd->data->blksz) - 2,
sock->addr + SOCK_FIFO_PAGE_SIZE);
writel(TIFM_FIFO_ENABLE, sock->addr + SOCK_FIFO_CONTROL);
writel(TIFM_FIFO_INTMASK, sock->addr + SOCK_DMA_FIFO_INT_ENABLE_SET);
dest_cnt = (cmd->data->blocks) << 8;
writel(sg_dma_address(cmd->data->sg), sock->addr + SOCK_DMA_ADDRESS);
writel(cmd->data->blocks - 1, sock->addr + SOCK_MMCSD_NUM_BLOCKS);
writel(cmd->data->blksz - 1, sock->addr + SOCK_MMCSD_BLOCK_LEN);
if (cmd->data->flags & MMC_DATA_WRITE) {
writel(TIFM_MMCSD_TXDE, sock->addr + SOCK_MMCSD_BUFFER_CONFIG);
writel(dest_cnt | TIFM_DMA_TX | TIFM_DMA_EN,
sock->addr + SOCK_DMA_CONTROL);
} else {
writel(TIFM_MMCSD_RXDE, sock->addr + SOCK_MMCSD_BUFFER_CONFIG);
writel(dest_cnt | TIFM_DMA_EN, sock->addr + SOCK_DMA_CONTROL);
}
}
static void tifm_sd_set_data_timeout(struct tifm_sd *host,
struct mmc_data *data)
{
@ -481,7 +618,6 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
struct tifm_sd *host = mmc_priv(mmc);
struct tifm_dev *sock = host->dev;
unsigned long flags;
int sg_count = 0;
struct mmc_data *r_data = mrq->cmd->data;
spin_lock_irqsave(&sock->lock, flags);
@ -496,13 +632,19 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
goto err_out;
}
host->cmd_flags = 0;
host->block_pos = 0;
host->sg_pos = 0;
if (r_data) {
tifm_sd_set_data_timeout(host, r_data);
if (host->no_dma) {
host->buffer_size = mrq->cmd->data->blocks
* mrq->cmd->data->blksz;
if ((r_data->flags & MMC_DATA_WRITE) && !mrq->stop)
writel(TIFM_MMCSD_EOFB
| readl(sock->addr + SOCK_MMCSD_INT_ENABLE),
sock->addr + SOCK_MMCSD_INT_ENABLE);
if (host->no_dma) {
writel(TIFM_MMCSD_BUFINT
| readl(sock->addr + SOCK_MMCSD_INT_ENABLE),
sock->addr + SOCK_MMCSD_INT_ENABLE);
@ -510,34 +652,64 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
| (TIFM_MMCSD_FIFO_SIZE - 1),
sock->addr + SOCK_MMCSD_BUFFER_CONFIG);
host->written_blocks = 0;
host->cmd_flags &= ~CARD_BUSY;
host->buffer_pos = 0;
writel(r_data->blocks - 1,
sock->addr + SOCK_MMCSD_NUM_BLOCKS);
writel(r_data->blksz - 1,
sock->addr + SOCK_MMCSD_BLOCK_LEN);
host->sg_len = r_data->sg_len;
} else {
sg_count = tifm_map_sg(sock, r_data->sg, r_data->sg_len,
mrq->cmd->flags & MMC_DATA_WRITE
? PCI_DMA_TODEVICE
: PCI_DMA_FROMDEVICE);
if (sg_count != 1) {
printk(KERN_ERR DRIVER_NAME
": scatterlist map failed\n");
sg_init_one(&host->bounce_buf, host->bounce_buf_data,
r_data->blksz);
if(1 != tifm_map_sg(sock, &host->bounce_buf, 1,
r_data->flags & MMC_DATA_WRITE
? PCI_DMA_TODEVICE
: PCI_DMA_FROMDEVICE)) {
printk(KERN_ERR "%s : scatterlist map failed\n",
sock->dev.bus_id);
spin_unlock_irqrestore(&sock->lock, flags);
goto err_out;
}
host->sg_len = tifm_map_sg(sock, r_data->sg,
r_data->sg_len,
r_data->flags
& MMC_DATA_WRITE
? PCI_DMA_TODEVICE
: PCI_DMA_FROMDEVICE);
if (host->sg_len < 1) {
printk(KERN_ERR "%s : scatterlist map failed\n",
sock->dev.bus_id);
tifm_unmap_sg(sock, &host->bounce_buf, 1,
r_data->flags & MMC_DATA_WRITE
? PCI_DMA_TODEVICE
: PCI_DMA_FROMDEVICE);
spin_unlock_irqrestore(&sock->lock, flags);
goto err_out;
}
host->written_blocks = 0;
host->cmd_flags &= ~CARD_BUSY;
tifm_sd_prepare_data(host, mrq->cmd);
writel(TIFM_FIFO_INT_SETALL,
sock->addr + SOCK_DMA_FIFO_INT_ENABLE_CLEAR);
writel(ilog2(r_data->blksz) - 2,
sock->addr + SOCK_FIFO_PAGE_SIZE);
writel(TIFM_FIFO_ENABLE,
sock->addr + SOCK_FIFO_CONTROL);
writel(TIFM_FIFO_INTMASK,
sock->addr + SOCK_DMA_FIFO_INT_ENABLE_SET);
if (r_data->flags & MMC_DATA_WRITE)
writel(TIFM_MMCSD_TXDE,
sock->addr + SOCK_MMCSD_BUFFER_CONFIG);
else
writel(TIFM_MMCSD_RXDE,
sock->addr + SOCK_MMCSD_BUFFER_CONFIG);
tifm_sd_set_dma_data(host, r_data);
}
writel(r_data->blocks - 1,
sock->addr + SOCK_MMCSD_NUM_BLOCKS);
writel(r_data->blksz - 1,
sock->addr + SOCK_MMCSD_BLOCK_LEN);
}
host->req = mrq;
mod_timer(&host->timer, jiffies + host->timeout_jiffies);
host->cmd_flags = 0;
writel(TIFM_CTRL_LED | readl(sock->addr + SOCK_CONTROL),
sock->addr + SOCK_CONTROL);
tifm_sd_exec(host, mrq->cmd);
@ -545,11 +717,6 @@ static void tifm_sd_request(struct mmc_host *mmc, struct mmc_request *mrq)
return;
err_out:
if (sg_count > 0)
tifm_unmap_sg(sock, r_data->sg, r_data->sg_len,
(r_data->flags & MMC_DATA_WRITE)
? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
mrq->cmd->error = MMC_ERR_TIMEOUT;
mmc_request_done(mmc, mrq);
}
@ -578,40 +745,23 @@ static void tifm_sd_end_cmd(unsigned long data)
r_data = mrq->cmd->data;
if (r_data) {
if (host->no_dma) {
writel((~TIFM_MMCSD_BUFINT) &
readl(sock->addr + SOCK_MMCSD_INT_ENABLE),
sock->addr + SOCK_MMCSD_INT_ENABLE);
if (r_data->flags & MMC_DATA_WRITE) {
r_data->bytes_xfered = host->written_blocks
* r_data->blksz;
} else {
r_data->bytes_xfered = r_data->blocks -
readl(sock->addr + SOCK_MMCSD_NUM_BLOCKS)
- 1;
r_data->bytes_xfered *= r_data->blksz;
r_data->bytes_xfered += r_data->blksz
- readl(sock->addr + SOCK_MMCSD_BLOCK_LEN)
+ 1;
}
host->buffer_pos = 0;
host->buffer_size = 0;
writel((~TIFM_MMCSD_BUFINT)
& readl(sock->addr + SOCK_MMCSD_INT_ENABLE),
sock->addr + SOCK_MMCSD_INT_ENABLE);
} else {
if (r_data->flags & MMC_DATA_WRITE) {
r_data->bytes_xfered = host->written_blocks
* r_data->blksz;
} else {
r_data->bytes_xfered = r_data->blocks -
readl(sock->addr + SOCK_MMCSD_NUM_BLOCKS) - 1;
r_data->bytes_xfered *= r_data->blksz;
r_data->bytes_xfered += r_data->blksz -
readl(sock->addr + SOCK_MMCSD_BLOCK_LEN)
+ 1;
}
tifm_unmap_sg(sock, &host->bounce_buf, 1,
(r_data->flags & MMC_DATA_WRITE)
? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
tifm_unmap_sg(sock, r_data->sg, r_data->sg_len,
(r_data->flags & MMC_DATA_WRITE)
? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
}
r_data->bytes_xfered = r_data->blocks
- readl(sock->addr + SOCK_MMCSD_NUM_BLOCKS) - 1;
r_data->bytes_xfered *= r_data->blksz;
r_data->bytes_xfered += r_data->blksz
- readl(sock->addr + SOCK_MMCSD_BLOCK_LEN) + 1;
}
writel((~TIFM_CTRL_LED) & readl(sock->addr + SOCK_CONTROL),
@ -810,15 +960,14 @@ static int tifm_sd_probe(struct tifm_dev *sock)
mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_MULTIWRITE;
mmc->f_min = 20000000 / 60;
mmc->f_max = 24000000;
mmc->max_hw_segs = 1;
mmc->max_phys_segs = 1;
// limited by DMA counter - it's safer to stick with
// block counter has 11 bits though
mmc->max_blk_count = 256;
// 2k maximum hw block length
mmc->max_blk_size = 2048;
mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
mmc->max_seg_size = mmc->max_req_size;
mmc->max_blk_count = 2048;
mmc->max_hw_segs = mmc->max_blk_count;
mmc->max_blk_size = min(TIFM_MMCSD_MAX_BLOCK_SIZE, PAGE_SIZE);
mmc->max_seg_size = mmc->max_blk_count * mmc->max_blk_size;
mmc->max_req_size = mmc->max_seg_size;
mmc->max_phys_segs = mmc->max_hw_segs;
sock->card_event = tifm_sd_card_event;
sock->data_event = tifm_sd_data_event;
rc = tifm_sd_initialize_host(host);

1
include/linux/tifm.h
View File

@ -74,6 +74,7 @@ enum {
#define TIFM_DMA_RESET 0x00000002 /* Meaning of this constant is unverified */
#define TIFM_DMA_TX 0x00008000 /* Meaning of this constant is unverified */
#define TIFM_DMA_EN 0x00000001 /* Meaning of this constant is unverified */
#define TIFM_DMA_TSIZE 0x0000007f
#define TIFM_TYPE_XD 1
#define TIFM_TYPE_MS 2