+/* Split 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;
+ unsigned max_blocks;
+ int ret;
+
+ /* Do the bulk of the transfer using block mode (if supported). */
+ if (func->card->cccr.multi_block) {
+ /* Blocks per command is limited by host count, host transfer
+ * size (we only use a single sg entry) and the maximum for
+ * IO_RW_EXTENDED of 511 blocks. */
+ max_blocks = min(min(
+ func->card->host->max_blk_count,
+ func->card->host->max_seg_size / func->cur_blksize),
+ 511u);
+
+ while (remainder > func->cur_blksize) {
+ unsigned blocks;
+
+ blocks = remainder / func->cur_blksize;
+ if (blocks > max_blocks)
+ blocks = max_blocks;
+ size = blocks * func->cur_blksize;
+
+ ret = mmc_io_rw_extended(func->card, write,
+ func->num, addr, incr_addr, buf,
+ blocks, func->cur_blksize);
+ if (ret)
+ return ret;
+
+ remainder -= size;
+ buf += size;
+ if (incr_addr)
+ addr += size;
+ }
+ }
+
+ /* Write the remainder using byte mode. */
+ while (remainder > 0) {
+ size = remainder;
+ if (size > func->cur_blksize)
+ size = func->cur_blksize;
+ if (size > 512)
+ size = 512; /* maximum size for byte mode */
+
+ 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;
+}
+