mirror of
https://github.com/torvalds/linux.git
synced 2024-12-15 15:41:58 +00:00
51 lines
1.1 KiB
C
51 lines
1.1 KiB
C
|
/*
|
||
|
|
* SCSI library functions depending on DMA
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/blkdev.h>
|
||
|
|
#include <linux/device.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
|
||
|
|
#include <scsi/scsi.h>
|
||
|
|
#include <scsi/scsi_cmnd.h>
|
||
|
|
#include <scsi/scsi_device.h>
|
||
|
|
#include <scsi/scsi_host.h>
|
||
|
|
|
||
|
|
/**
|
||
|
|
* scsi_dma_map - perform DMA mapping against command's sg lists
|
||
|
|
* @cmd: scsi command
|
||
|
|
*
|
||
|
|
* Returns the number of sg lists actually used, zero if the sg lists
|
||
|
|
* is NULL, or -ENOMEM if the mapping failed.
|
||
|
|
*/
|
||
|
|
int scsi_dma_map(struct scsi_cmnd *cmd)
|
||
|
|
{
|
||
|
|
int nseg = 0;
|
||
|
|
|
||
|
|
if (scsi_sg_count(cmd)) {
|
||
|
|
struct device *dev = cmd->device->host->shost_gendev.parent;
|
||
|
|
|
||
|
|
nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
|
||
|
|
cmd->sc_data_direction);
|
||
|
|
if (unlikely(!nseg))
|
||
|
|
return -ENOMEM;
|
||
|
|
}
|
||
|
|
return nseg;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(scsi_dma_map);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map
|
||
|
|
* @cmd: scsi command
|
||
|
|
*/
|
||
|
|
void scsi_dma_unmap(struct scsi_cmnd *cmd)
|
||
|
|
{
|
||
|
|
if (scsi_sg_count(cmd)) {
|
||
|
|
struct device *dev = cmd->device->host->shost_gendev.parent;
|
||
|
|
|
||
|
|
dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
|
||
|
|
cmd->sc_data_direction);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(scsi_dma_unmap);
|