Commit 1c2ad9fa authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

NVMe: Simplify nvme_unmap_user_pages 



By using the iod->nents field (the same way other I/O paths do), we can
avoid recalculating the number of sg entries at unmap time, and make
nvme_unmap_user_pages() easier to call.

Also, use the 'write' parameter instead of assuming DMA_FROM_DEVICE.

Signed-off-by: default avatarMatthew Wilcox <matthew.r.wilcox@intel.com>
parent fe304c43

drivers/block/nvme.c

+9 −10
Original line number Diff line number Diff line
@@ -1046,6 +1046,7 @@ static struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write, 
		offset = 0;

	}

	sg_mark_end(&sg[i - 1]);

	iod->nents = count;



	err = -ENOMEM;

	nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
@@ -1066,16 +1067,15 @@ static struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write, 
}



static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,

			unsigned long addr, int length, struct nvme_iod *iod)

			struct nvme_iod *iod)

{

	struct scatterlist *sg = iod->sg;

	int i, count;

	int i;



	count = DIV_ROUND_UP(offset_in_page(addr) + length, PAGE_SIZE);

	dma_unmap_sg(&dev->pci_dev->dev, sg, count, DMA_FROM_DEVICE);

	dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,

				write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);



	for (i = 0; i < count; i++)

		put_page(sg_page(&sg[i]));

	for (i = 0; i < iod->nents; i++)

		put_page(sg_page(&iod->sg[i]));

}



static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
@@ -1132,7 +1132,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio) 
	else

		status = nvme_submit_sync_cmd(nvmeq, &c, NULL, NVME_IO_TIMEOUT);



	nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, iod);

	nvme_unmap_user_pages(dev, io.opcode & 1, iod);

	nvme_free_iod(dev, iod);

	return status;

}
@@ -1180,8 +1180,7 @@ static int nvme_user_admin_cmd(struct nvme_ns *ns, 
		status = nvme_submit_admin_cmd(dev, &c, NULL);



	if (cmd.data_len) {

		nvme_unmap_user_pages(dev, cmd.opcode & 1, cmd.addr,

							cmd.data_len, iod);

		nvme_unmap_user_pages(dev, cmd.opcode & 1, iod);

		nvme_free_iod(dev, iod);

	}

	return status;

CRA Git | Maintained and supported by SUSTech CRA and CCSE