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NVMe: Create nvme_map_user_pages() and nvme_unmap_user_pages()

Browse source 
These are generalisations of the code that was in
nvme_submit_user_admin_command().

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
This commit is contained in:
Matthew Wilcox 2011-01-26 17:05:50 -05:00
parent bd38c5557c
commit 7fc3cdabba
1 changed files with 54 additions and 16 deletions
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70
drivers/block/nvme.c
View file

@ -677,17 +677,22 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
return result;
}
static int nvme_submit_user_admin_command(struct nvme_dev *dev, unsigned long addr,
unsigned length, struct nvme_command *cmd)
static int nvme_map_user_pages(struct nvme_dev *dev, int write,
unsigned long addr, unsigned length,
struct scatterlist **sgp)
{
int i, err, count, nents, offset;
struct scatterlist sg[2];
struct page *pages[2];
struct scatterlist *sg;
struct page **pages;
if (addr & 3)
return -EINVAL;
if (!length)
return -EINVAL;
offset = offset_in_page(addr);
count = ((offset + length) > PAGE_SIZE) ? 2 : 1;
count = DIV_ROUND_UP(offset + length, PAGE_SIZE);
pages = kcalloc(count, sizeof(*pages), GFP_KERNEL);
err = get_user_pages_fast(addr, count, 1, pages);
if (err < count) {
@ -695,29 +700,62 @@ static int nvme_submit_user_admin_command(struct nvme_dev *dev, unsigned long ad
err = -EFAULT;
goto put_pages;
}
sg = kcalloc(count, sizeof(*sg), GFP_KERNEL);
sg_init_table(sg, count);
sg_set_page(&sg[0], pages[0], PAGE_SIZE - offset, offset);
if (count > 1)
sg_set_page(&sg[1], pages[1], offset, 0);
nents = dma_map_sg(&dev->pci_dev->dev, sg, count, DMA_FROM_DEVICE);
length -= (PAGE_SIZE - offset);
for (i = 1; i < count; i++) {
sg_set_page(&sg[i], pages[i], min_t(int, length, PAGE_SIZE), 0);
length -= PAGE_SIZE;
}
err = -ENOMEM;
nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
if (!nents)
goto put_pages;
nvme_setup_prps(&cmd->common, sg, length);
kfree(pages);
*sgp = sg;
return nents;
err = nvme_submit_admin_cmd(dev, cmd, NULL);
if (err)
err = -EIO;
dma_unmap_sg(&dev->pci_dev->dev, sg, nents, DMA_FROM_DEVICE);
put_pages:
for (i = 0; i < count; i++)
put_page(pages[i]);
kfree(pages);
return err;
}
static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
unsigned long addr, int length,
struct scatterlist *sg, int nents)
{
int i, count;
count = DIV_ROUND_UP(offset_in_page(addr) + length, PAGE_SIZE);
dma_unmap_sg(&dev->pci_dev->dev, sg, nents, DMA_FROM_DEVICE);
for (i = 0; i < count; i++)
put_page(sg_page(&sg[i]));
}
static int nvme_submit_user_admin_command(struct nvme_dev *dev,
unsigned long addr, unsigned length,
struct nvme_command *cmd)
{
int err, nents;
struct scatterlist *sg;
nents = nvme_map_user_pages(dev, 0, addr, length, &sg);
if (nents < 0)
return nents;
nvme_setup_prps(&cmd->common, sg, length);
err = nvme_submit_admin_cmd(dev, cmd, NULL);
nvme_unmap_user_pages(dev, 0, addr, length, sg, nents);
return err ? -EIO : 0;
}
static int nvme_identify(struct nvme_ns *ns, unsigned long addr, int cns)
{
struct nvme_command c;