1
linux/drivers/scsi/scsi_lib_dma.c
Cornelia Huck 7689e82efd [SCSI] don't build scsi_dma_{map,unmap} for !HAS_DMA
With

 dma-mapping-prevent-dma-dependent-code-from-linking-on.patch

scsi fails to build on !HAS_DMA architectures:

drivers/built-in.o(.text+0x20af6): In function `scsi_dma_map':
: undefined reference to `dma_map_sg'
drivers/built-in.o(.text+0x20b5c): In function `scsi_dma_unmap':
: undefined reference to `dma_unmap_sg'

I split those functions out into a new file. Builds on s390 and i386.

Move scsi_dma_{map,unmap} into scsi_lib_dma.c which is only build if
HAS_DMA is set.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2007-07-14 19:28:10 -05:00

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);