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52 lines
1.2 KiB
52 lines
1.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* SCSI library functions depending on DMA |
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*/ |
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#include <linux/blkdev.h> |
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#include <linux/device.h> |
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#include <linux/export.h> |
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#include <linux/kernel.h> |
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#include <scsi/scsi.h> |
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#include <scsi/scsi_cmnd.h> |
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#include <scsi/scsi_device.h> |
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#include <scsi/scsi_host.h> |
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/** |
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* scsi_dma_map - perform DMA mapping against command's sg lists |
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* @cmd: scsi command |
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* |
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* Returns the number of sg lists actually used, zero if the sg lists |
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* is NULL, or -ENOMEM if the mapping failed. |
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*/ |
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int scsi_dma_map(struct scsi_cmnd *cmd) |
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{ |
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int nseg = 0; |
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if (scsi_sg_count(cmd)) { |
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struct device *dev = cmd->device->host->dma_dev; |
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nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), |
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cmd->sc_data_direction); |
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if (unlikely(!nseg)) |
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return -ENOMEM; |
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} |
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return nseg; |
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} |
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EXPORT_SYMBOL(scsi_dma_map); |
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/** |
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* scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map |
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* @cmd: scsi command |
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*/ |
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void scsi_dma_unmap(struct scsi_cmnd *cmd) |
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{ |
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if (scsi_sg_count(cmd)) { |
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struct device *dev = cmd->device->host->dma_dev; |
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dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), |
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cmd->sc_data_direction); |
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} |
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} |
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EXPORT_SYMBOL(scsi_dma_unmap);
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