LXR linux/drivers/scsi/scsi_lib

   1/*
   2 * SCSI library functions depending on DMA
   3 */
   4
   5#include <linux/blkdev.h>
   6#include <linux/device.h>
   7#include <linux/kernel.h>
   8
   9#include <scsi/scsi.h>
  10#include <scsi/scsi_cmnd.h>
  11#include <scsi/scsi_device.h>
  12#include <scsi/scsi_host.h>
  13
  14/**
  15 * scsi_dma_map - perform DMA mapping against command's sg lists
  16 * @cmd:        scsi command
  17 *
  18 * Returns the number of sg lists actually used, zero if the sg lists
  19 * is NULL, or -ENOMEM if the mapping failed.
  20 */
  21int scsi_dma_map(struct scsi_cmnd *cmd)
  22{
  23        int nseg = 0;
  24
  25        if (scsi_sg_count(cmd)) {
  26                struct device *dev = cmd->device->host->shost_gendev.parent;
  27
  28                nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
  29                                  cmd->sc_data_direction);
  30                if (unlikely(!nseg))
  31                        return -ENOMEM;
  32        }
  33        return nseg;
  34}
  35EXPORT_SYMBOL(scsi_dma_map);
  36
  37/**
  38 * scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map
  39 * @cmd:        scsi command
  40 */
  41void scsi_dma_unmap(struct scsi_cmnd *cmd)
  42{
  43        if (scsi_sg_count(cmd)) {
  44                struct device *dev = cmd->device->host->shost_gendev.parent;
  45
  46                dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
  47                             cmd->sc_data_direction);
  48        }
  49}
  50EXPORT_SYMBOL(scsi_dma_unmap);
  51