unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
{
unsigned int orig_sz;
unsigned int blk_sz, byte_sz;
unsigned chunk_sz;
orig_sz = sz;
sz = mmc_align_data_size(func->card, sz);
if (sz <= sdio_max_byte_size(func))
return sz;
if (func->card->cccr.multi_block) {
if ((sz % func->cur_blksize) == 0)
return sz;
blk_sz = ((sz + func->cur_blksize - 1) /
func->cur_blksize) * func->cur_blksize;
blk_sz = mmc_align_data_size(func->card, blk_sz);
if ((blk_sz % func->cur_blksize) == 0)
return blk_sz;
byte_sz = mmc_align_data_size(func->card,
sz % func->cur_blksize);
if (byte_sz <= sdio_max_byte_size(func)) {
blk_sz = sz / func->cur_blksize;
return blk_sz * func->cur_blksize + byte_sz;
}
} else {
chunk_sz = mmc_align_data_size(func->card,
sdio_max_byte_size(func));
if (chunk_sz == sdio_max_byte_size(func)) {
byte_sz = orig_sz % chunk_sz;
if (byte_sz) {
byte_sz = mmc_align_data_size(func->card,
byte_sz);
}
return (orig_sz / chunk_sz) * chunk_sz + byte_sz;
}
}
return orig_sz;
}
/**
* sdio_align_size - pads a transfer size to a more optimal value
* @func: SDIO function
* @sz: original transfer size
*
* Pads the original data size with a number of extra bytes in
* order to avoid controller bugs and/or performance hits
* (e.g. some controllers revert to PIO for certain sizes).
*
* If possible, it will also adjust the size so that it can be
* handled in just a single request.
*
* Returns the improved size, which might be unmodified.
*/
unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
{
unsigned int orig_sz;
unsigned int blk_sz, byte_sz;
unsigned chunk_sz;
orig_sz = sz;
/*
* Do a first check with the controller, in case it
* wants to increase the size up to a point where it
* might need more than one block.
*/
sz = mmc_align_data_size(func->card, sz);
/*
* If we can still do this with just a byte transfer, then
* we're done.
*/
if (sz <= sdio_max_byte_size(func))
return sz;
if (func->card->cccr.multi_block) {
/*
* Check if the transfer is already block aligned
*/
if ((sz % func->cur_blksize) == 0)
return sz;
/*
* Realign it so that it can be done with one request,
* and recheck if the controller still likes it.
*/
blk_sz = ((sz + func->cur_blksize - 1) /
func->cur_blksize) * func->cur_blksize;
blk_sz = mmc_align_data_size(func->card, blk_sz);
/*
* This value is only good if it is still just
* one request.
*/
if ((blk_sz % func->cur_blksize) == 0)
return blk_sz;
/*
* We failed to do one request, but at least try to
* pad the remainder properly.
*/
byte_sz = mmc_align_data_size(func->card,
sz % func->cur_blksize);
if (byte_sz <= sdio_max_byte_size(func)) {
blk_sz = sz / func->cur_blksize;
return blk_sz * func->cur_blksize + byte_sz;
}
} else {
/*
* We need multiple requests, so first check that the
* controller can handle the chunk size;
*/
chunk_sz = mmc_align_data_size(func->card,
sdio_max_byte_size(func));
if (chunk_sz == sdio_max_byte_size(func)) {
/*
* Fix up the size of the remainder (if any)
*/
byte_sz = orig_sz % chunk_sz;
if (byte_sz) {
byte_sz = mmc_align_data_size(func->card,
byte_sz);
}
return (orig_sz / chunk_sz) * chunk_sz + byte_sz;
}
}
/*
* The controller is simply incapable of transferring the size
* we want in decent manner, so just return the original size.
*/
return orig_sz;
}
