-/*
- * Function: void merge_contiguous_buffers(struct scsi_cmnd *cmd)
- *
- * Purpose: Try to merge several scatter-gather requests into one DMA
- * transfer. This is possible if the scatter buffers lie on
- * physical contiguous addresses.
- *
- * Parameters: struct scsi_cmnd *cmd
- * The command to work on. The first scatter buffer's data are
- * assumed to be already transferred into ptr/this_residual.
- */
-
-static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
-{
- unsigned long endaddr;
-#if (NDEBUG & NDEBUG_MERGING)
- unsigned long oldlen = cmd->SCp.this_residual;
- int cnt = 1;
-#endif
-
- for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
- cmd->SCp.buffers_residual &&
- virt_to_phys(SGADDR(&(cmd->SCp.buffer[1]))) == endaddr; ) {
-
- MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
- SGADDR(&(cmd->SCp.buffer[1])), endaddr);
-#if (NDEBUG & NDEBUG_MERGING)
- ++cnt;
-#endif
- ++cmd->SCp.buffer;
- --cmd->SCp.buffers_residual;
- cmd->SCp.this_residual += cmd->SCp.buffer->length;
- endaddr += cmd->SCp.buffer->length;
- }
-#if (NDEBUG & NDEBUG_MERGING)
- if (oldlen != cmd->SCp.this_residual)
- MER_PRINTK("merged %d buffers from %p, new length %08x\n",
- cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
-#endif
-}
-