/* * 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);