Commit | Line | Data |
---|---|---|
7689e82e CH |
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 | */ | |
21 | int 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 | } | |
35 | EXPORT_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 | */ | |
41 | void 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 | } | |
50 | EXPORT_SYMBOL(scsi_dma_unmap); |