Commit | Line | Data |
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7689e82e CH |
1 | /* |
2 | * SCSI library functions depending on DMA | |
3 | */ | |
4 | ||
5 | #include <linux/blkdev.h> | |
6 | #include <linux/device.h> | |
09703660 | 7 | #include <linux/export.h> |
7689e82e CH |
8 | #include <linux/kernel.h> |
9 | ||
10 | #include <scsi/scsi.h> | |
11 | #include <scsi/scsi_cmnd.h> | |
12 | #include <scsi/scsi_device.h> | |
13 | #include <scsi/scsi_host.h> | |
14 | ||
15 | /** | |
16 | * scsi_dma_map - perform DMA mapping against command's sg lists | |
17 | * @cmd: scsi command | |
18 | * | |
19 | * Returns the number of sg lists actually used, zero if the sg lists | |
20 | * is NULL, or -ENOMEM if the mapping failed. | |
21 | */ | |
22 | int scsi_dma_map(struct scsi_cmnd *cmd) | |
23 | { | |
24 | int nseg = 0; | |
25 | ||
26 | if (scsi_sg_count(cmd)) { | |
d139b9bd | 27 | struct device *dev = cmd->device->host->dma_dev; |
7689e82e CH |
28 | |
29 | nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), | |
30 | cmd->sc_data_direction); | |
31 | if (unlikely(!nseg)) | |
32 | return -ENOMEM; | |
33 | } | |
34 | return nseg; | |
35 | } | |
36 | EXPORT_SYMBOL(scsi_dma_map); | |
37 | ||
38 | /** | |
39 | * scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map | |
40 | * @cmd: scsi command | |
41 | */ | |
42 | void scsi_dma_unmap(struct scsi_cmnd *cmd) | |
43 | { | |
44 | if (scsi_sg_count(cmd)) { | |
d139b9bd | 45 | struct device *dev = cmd->device->host->dma_dev; |
7689e82e CH |
46 | |
47 | dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), | |
48 | cmd->sc_data_direction); | |
49 | } | |
50 | } | |
51 | EXPORT_SYMBOL(scsi_dma_unmap); |