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NVMe: Simplify nvme_unmap_user_pages

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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: Matthew Wilcox <matthew.r.wilcox@intel.com>
This commit is contained in:
Matthew Wilcox 2012-01-06 13:52:56 -07:00
parent fe304c43c6
commit 1c2ad9faaf
1 changed files with 9 additions and 10 deletions
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19
drivers/block/nvme.c
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@ -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;