1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * SCSI library functions depending on DMA 4*4882a593Smuzhiyun */ 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun #include <linux/blkdev.h> 7*4882a593Smuzhiyun #include <linux/device.h> 8*4882a593Smuzhiyun #include <linux/export.h> 9*4882a593Smuzhiyun #include <linux/kernel.h> 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun #include <scsi/scsi.h> 12*4882a593Smuzhiyun #include <scsi/scsi_cmnd.h> 13*4882a593Smuzhiyun #include <scsi/scsi_device.h> 14*4882a593Smuzhiyun #include <scsi/scsi_host.h> 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun /** 17*4882a593Smuzhiyun * scsi_dma_map - perform DMA mapping against command's sg lists 18*4882a593Smuzhiyun * @cmd: scsi command 19*4882a593Smuzhiyun * 20*4882a593Smuzhiyun * Returns the number of sg lists actually used, zero if the sg lists 21*4882a593Smuzhiyun * is NULL, or -ENOMEM if the mapping failed. 22*4882a593Smuzhiyun */ scsi_dma_map(struct scsi_cmnd * cmd)23*4882a593Smuzhiyunint scsi_dma_map(struct scsi_cmnd *cmd) 24*4882a593Smuzhiyun { 25*4882a593Smuzhiyun int nseg = 0; 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun if (scsi_sg_count(cmd)) { 28*4882a593Smuzhiyun struct device *dev = cmd->device->host->dma_dev; 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), 31*4882a593Smuzhiyun cmd->sc_data_direction); 32*4882a593Smuzhiyun if (unlikely(!nseg)) 33*4882a593Smuzhiyun return -ENOMEM; 34*4882a593Smuzhiyun } 35*4882a593Smuzhiyun return nseg; 36*4882a593Smuzhiyun } 37*4882a593Smuzhiyun EXPORT_SYMBOL(scsi_dma_map); 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun /** 40*4882a593Smuzhiyun * scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map 41*4882a593Smuzhiyun * @cmd: scsi command 42*4882a593Smuzhiyun */ scsi_dma_unmap(struct scsi_cmnd * cmd)43*4882a593Smuzhiyunvoid scsi_dma_unmap(struct scsi_cmnd *cmd) 44*4882a593Smuzhiyun { 45*4882a593Smuzhiyun if (scsi_sg_count(cmd)) { 46*4882a593Smuzhiyun struct device *dev = cmd->device->host->dma_dev; 47*4882a593Smuzhiyun 48*4882a593Smuzhiyun dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), 49*4882a593Smuzhiyun cmd->sc_data_direction); 50*4882a593Smuzhiyun } 51*4882a593Smuzhiyun } 52*4882a593Smuzhiyun EXPORT_SYMBOL(scsi_dma_unmap); 53