[PATCH 02/02] mmc/sdhci: use PIO - scatterlist wrappers

From: Michał Mirosław
Date: Fri Feb 06 2009 - 15:44:54 EST


Use sg_dwiter_*_io() in sdhci_*_block_pio(). This assumes that
buffer sizes are multiple of 4 when transferring more than one
block consecutively.

Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>

diff -urN b/drivers/mmc/host/sdhci.c c/drivers/mmc/host/sdhci.c
--- b/drivers/mmc/host/sdhci.c 2008-12-25 00:26:37.000000000 +0100
+++ c/drivers/mmc/host/sdhci.c 2009-02-03 00:12:23.000000000 +0100
@@ -176,44 +176,17 @@
static void sdhci_read_block_pio(struct sdhci_host *host)
{
unsigned long flags;
- size_t blksize, len, chunk;
- u32 uninitialized_var(scratch);
- u8 *buf;
+ size_t blksize;

DBG("PIO reading\n");

- blksize = host->data->blksz;
- chunk = 0;
+ blksize = (host->data->blksz + 3) >> 2;

local_irq_save(flags);

- while (blksize) {
- if (!sg_miter_next(&host->sg_miter))
- BUG();
-
- len = min(host->sg_miter.length, blksize);
-
- blksize -= len;
- host->sg_miter.consumed = len;
-
- buf = host->sg_miter.addr;
-
- while (len) {
- if (chunk == 0) {
- scratch = readl(host->ioaddr + SDHCI_BUFFER);
- chunk = 4;
- }
-
- *buf = scratch & 0xFF;
-
- buf++;
- scratch >>= 8;
- chunk--;
- len--;
- }
- }
-
- sg_miter_stop(&host->sg_miter);
+ sg_dwiter_write_from_io(&host->sg_miter,
+ host->ioaddr + SDHCI_BUFFER, blksize);
+ sg_miter_stop_writing(&host->sg_miter);

local_irq_restore(flags);
}
@@ -221,44 +194,16 @@
static void sdhci_write_block_pio(struct sdhci_host *host)
{
unsigned long flags;
- size_t blksize, len, chunk;
- u32 scratch;
- u8 *buf;
+ size_t blksize;

DBG("PIO writing\n");

- blksize = host->data->blksz;
- chunk = 0;
- scratch = 0;
+ blksize = (host->data->blksz + 3) >> 2;

local_irq_save(flags);

- while (blksize) {
- if (!sg_miter_next(&host->sg_miter))
- BUG();
-
- len = min(host->sg_miter.length, blksize);
-
- blksize -= len;
- host->sg_miter.consumed = len;
-
- buf = host->sg_miter.addr;
-
- while (len) {
- scratch |= (u32)*buf << (chunk * 8);
-
- buf++;
- chunk++;
- len--;
-
- if ((chunk == 4) || ((len == 0) && (blksize == 0))) {
- writel(scratch, host->ioaddr + SDHCI_BUFFER);
- chunk = 0;
- scratch = 0;
- }
- }
- }
-
+ sg_dwiter_read_to_io(&host->sg_miter,
+ host->ioaddr + SDHCI_BUFFER, blksize);
sg_miter_stop(&host->sg_miter);

local_irq_restore(flags);
--
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