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>
diff --git a/drivers/mmc/tifm_sd.c b/drivers/mmc/tifm_sd.c
index d20ccfc..8e69514e 100644
--- a/drivers/mmc/tifm_sd.c
+++ b/drivers/mmc/tifm_sd.c
@@ -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 @@
#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 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
| (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 @@
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 @@
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 @@
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);