scsi_lib_dma.c

Go to the documentation of this file.

/*
 * SCSI library functions depending on DMA
 */

#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/kernel.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>

int scsi_dma_map(struct scsi_cmnd *cmd)
{
    int nseg = 0;

    if (scsi_sg_count(cmd)) {
        struct device *dev = cmd->device->host->dma_dev;

        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);

void scsi_dma_unmap(struct scsi_cmnd *cmd)
{
    if (scsi_sg_count(cmd)) {
        struct device *dev = cmd->device->host->dma_dev;

        dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
                 cmd->sc_data_direction);
    }
}
EXPORT_SYMBOL(scsi_dma_unmap);