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SubjectRe: sdio: enhance IO_RW_EXTENDED support
This is essentially what I mean.

--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org
commit 8f9fca61fbacd15d1be4215584ed00aa1119d87f
Author: David Vrabel <david.vrabel@csr.com>
Date: Mon Aug 6 22:00:47 2007 +0200

sdio: extend sdio_readsb() and friends to handle any length of buffer

Extend sdio_readsb(), sdio_writesb(), sdio_memcpy_fromio(), and
sdio_memcpy_toio() to handle any length of buffer by splitting the transfer
into several IO_RW_EXTENDED commands. Typically, a transfer would be split
into a single block mode transfer followed by a byte mode transfer for the
remainder.

[ Automatic block size selection logic by Pierre Ossman ]

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 7f08ba5..e49b381 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -95,6 +95,9 @@ int sdio_enable_func(struct sdio_func *func)
goto err;
}

+ func->cur_blksz = 0;
+ func->forced_blksz = 0;
+
pr_debug("SDIO: Enabled device %s\n", sdio_func_id(func));

return 0;
@@ -202,6 +205,129 @@ void sdio_writeb(struct sdio_func *func, unsigned char b, unsigned int addr,

EXPORT_SYMBOL_GPL(sdio_writeb);

+/*
+ * Internal function. Sets the block size of the card.
+ */
+static int sdio_set_block_size(struct sdio_func *func, unsigned short blksz)
+{
+ int ret;
+
+ if (blksz == func->cur_blksz)
+ return 0;
+
+ /*
+ * We start by clearing the current block size as a failure
+ * will leave the size on the card in an unknown state.
+ */
+ func->cur_blksz = 0;
+
+ ret = mmc_io_rw_direct(func->card, 1, 0,
+ func->num * 0x100 + SDIO_FBR_BLKSIZE,
+ blksz & 0xff, NULL);
+ if (ret)
+ return ret;
+
+ ret = mmc_io_rw_direct(func->card, 1, 0,
+ func->num * 0x100 + SDIO_FBR_BLKSIZE + 1,
+ (blksz >> 8) & 0xff, NULL);
+ if (ret)
+ return ret;
+
+ func->cur_blksz = blksz;
+
+ return 0;
+}
+
+/*
+ * Internal function. Splits an arbitrarily sized data transfer
+ * into several IO_RW_EXTENDED commands.
+ */
+static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
+ unsigned addr, int incr_addr, u8 *buf, unsigned size)
+{
+ unsigned remainder = size;
+ int ret;
+ unsigned short blksz;
+ struct mmc_host *host = func->card->host;
+
+ if (func->forced_blksz)
+ blksz = func->forced_blksz;
+ else {
+ if (size <= 512)
+ goto byte_remainder;
+
+ blksz = size;
+ if (size > 0xffff)
+ blksz = 0xffff;
+
+ if (blksz > func->blksize)
+ blksz = func->blksize;
+ if (blksz > host->max_blk_size)
+ blksz = host->max_blk_size;
+
+ /* avoid changing blksize needlessly */
+ if (func->cur_blksz && ((blksz % func->cur_blksz) == 0))
+ blksz = func->cur_blksz;
+ }
+
+ ret = sdio_set_block_size(func, blksz);
+ if (ret)
+ return ret;
+
+ while (remainder >= blksz) {
+ unsigned blocks;
+
+ blocks = remainder / blksz;
+
+ if (blocks > 512)
+ blocks = 512;
+ if (blocks > host->max_blk_count)
+ blocks = host->max_blk_count;
+ if (blocks * blksz > host->max_req_size)
+ blocks = host->max_req_size / blksz;
+ if (blocks * blksz > host->max_seg_size)
+ blocks = host->max_seg_size / blksz;
+
+ size = blocks * blksz;
+
+ ret = mmc_io_rw_extended(func->card, write, func->num,
+ addr, incr_addr, buf, blocks, blksz);
+ if (ret)
+ return ret;
+
+ remainder -= size;
+ buf += size;
+ if (incr_addr)
+ addr += size;
+ }
+
+byte_remainder:
+ while (remainder) {
+ size = remainder;
+
+ if (size > 512)
+ size = 512;
+
+ /*
+ * We don't check host requirements as a block of 512
+ * bytes is the bare minimum support a host must
+ * provide.
+ */
+
+ ret = mmc_io_rw_extended(func->card, write, func->num,
+ addr, incr_addr, buf, 1, size);
+ if (ret)
+ return ret;
+
+ remainder -= size;
+ buf += size;
+ if (incr_addr)
+ addr += size;
+ }
+
+ return 0;
+}
+
/**
* sdio_memcpy_fromio - read a chunk of memory from a SDIO function
* @func: SDIO function to access
@@ -209,14 +335,13 @@ EXPORT_SYMBOL_GPL(sdio_writeb);
* @addr: address to begin reading from
* @count: number of bytes to read
*
- * Reads up to 512 bytes from the address space of a given SDIO
- * function. Return value indicates if the transfer succeeded or
- * not.
+ * Reads from the address space of a given SDIO function. Return
+ * value indicates if the transfer succeeded or not.
*/
int sdio_memcpy_fromio(struct sdio_func *func, void *dst,
unsigned int addr, int count)
{
- return mmc_io_rw_extended(func->card, 0, func->num, addr, 0, dst,
+ return sdio_io_rw_ext_helper(func, 0, addr, 1, dst,
count);
}

@@ -229,14 +354,13 @@ EXPORT_SYMBOL_GPL(sdio_memcpy_fromio);
* @src: buffer that contains the data to write
* @count: number of bytes to write
*
- * Writes up to 512 bytes to the address space of a given SDIO
- * function. Return value indicates if the transfer succeeded or
- * not.
+ * Writes to the address space of a given SDIO function. Return
+ * value indicates if the transfer succeeded or not.
*/
int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr,
void *src, int count)
{
- return mmc_io_rw_extended(func->card, 1, func->num, addr, 0, src,
+ return sdio_io_rw_ext_helper(func, 1, addr, 1, src,
count);
}

@@ -247,14 +371,13 @@ int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr,
* @addr: address of (single byte) FIFO
* @count: number of bytes to read
*
- * Reads up to 512 bytes from the specified FIFO of a given SDIO
- * function. Return value indicates if the transfer succeeded or
- * not.
+ * Reads from the specified FIFO of a given SDIO function. Return
+ * value indicates if the transfer succeeded or not.
*/
int sdio_readsb(struct sdio_func *func, void *dst, unsigned int addr,
int count)
{
- return mmc_io_rw_extended(func->card, 0, func->num, addr, 1, dst,
+ return sdio_io_rw_ext_helper(func, 0, addr, 0, dst,
count);
}

@@ -267,14 +390,13 @@ EXPORT_SYMBOL_GPL(sdio_readsb);
* @src: buffer that contains the data to write
* @count: number of bytes to write
*
- * Writes up to 512 bytes to the specified FIFO of a given SDIO
- * function. Return value indicates if the transfer succeeded or
- * not.
+ * Writes to the specified FIFO of a given SDIO function. Return
+ * value indicates if the transfer succeeded or not.
*/
int sdio_writesb(struct sdio_func *func, unsigned int addr, void *src,
int count)
{
- return mmc_io_rw_extended(func->card, 1, func->num, addr, 1, src,
+ return sdio_io_rw_ext_helper(func, 1, addr, 0, src,
count);
}

@@ -393,3 +515,28 @@ void sdio_writel(struct sdio_func *func, unsigned long b, unsigned int addr,

EXPORT_SYMBOL_GPL(sdio_writel);

+/**
+ * sdio_force_block_size - lock a certain block size
+ * @func: SDIO function to set block size for
+ * @size: block size in bytes, or 0 to remove any lock
+ *
+ * Locks the used block size for all multi-block sdio functions
+ * in order to satisfy transactions with precise requirements.
+ * This lock can be removed by specifying 0 (zero) as the block
+ * size. Returns failure if the selected block size isn't
+ * supported.
+ */
+int sdio_force_block_size(struct sdio_func *func, unsigned short size)
+{
+ if (size > func->blksize)
+ return -EINVAL;
+ if (size > func->card->host->max_blk_size)
+ return -EINVAL;
+
+ func->forced_blksz = size;
+
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(sdio_force_block_size);
+
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index 277870c..14bd244 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -88,7 +88,7 @@ int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
}

int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
- unsigned addr, int bang, u8 *buf, unsigned size)
+ unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz)
{
struct mmc_request mrq;
struct mmc_command cmd;
@@ -97,7 +97,7 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,

BUG_ON(!card);
BUG_ON(fn > 7);
- BUG_ON(size > 512);
+ BUG_ON(blocks > 512);

memset(&mrq, 0, sizeof(struct mmc_request));
memset(&cmd, 0, sizeof(struct mmc_command));
@@ -107,20 +107,27 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
mrq.data = &data;

cmd.opcode = SD_IO_RW_EXTENDED;
+
cmd.arg = write ? 0x80000000 : 0x00000000;
cmd.arg |= fn << 28;
- cmd.arg |= bang ? 0x00000000 : 0x04000000;
+ cmd.arg |= incr_addr ? 0x04000000 : 0x00000000;
cmd.arg |= addr << 9;
- cmd.arg |= (size == 512) ? 0 : size;
+
+ if ((blocks > 1) || (blksz > 512)) {
+ cmd.arg |= 0x08000000;
+ cmd.arg |= (blocks == 512) ? 0 : blocks;
+ } else
+ cmd.arg |= (blksz == 512) ? 0 : blksz;
+
cmd.flags = MMC_RSP_R5 | MMC_CMD_ADTC;

- data.blksz = size;
- data.blocks = 1;
+ data.blksz = blksz;
+ data.blocks = blocks;
data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;

- sg_init_one(&sg, buf, size);
+ sg_init_one(&sg, buf, blksz * blocks);

mmc_set_data_timeout(&data, card, 0);

diff --git a/drivers/mmc/core/sdio_ops.h b/drivers/mmc/core/sdio_ops.h
index 1d42e4f..e2e74b0 100644
--- a/drivers/mmc/core/sdio_ops.h
+++ b/drivers/mmc/core/sdio_ops.h
@@ -16,7 +16,7 @@ int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr);
int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
unsigned addr, u8 in, u8* out);
int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
- unsigned addr, int bang, u8 *data, unsigned size);
+ unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz);

#endif

diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index 14d9147..fded343 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -44,6 +44,8 @@ struct sdio_func {
unsigned short device; /* device id */

unsigned short blksize; /* maximum block size */
+ unsigned short cur_blksz; /* current block size */
+ unsigned short forced_blksz; /* driver forced block size */

unsigned int state; /* function state */
#define SDIO_STATE_PRESENT (1<<0) /* present in sysfs */
@@ -136,5 +138,7 @@ 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);

+extern int sdio_force_block_size(struct sdio_func *func, unsigned short size);
+
#endif
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