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author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2011-01-26 17:05:50 -0500 |
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committer | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2011-11-04 15:52:52 -0400 |
commit | 7fc3cdabba75c2516b8b645eb0ca7907aea70415 (patch) | |
tree | 67cf9f491410121bbf8c2418dcb05148258ad5cb /drivers/block | |
parent | bd38c5557cf482fc195e2264b32ea62eed60730a (diff) | |
download | blackbird-op-linux-7fc3cdabba75c2516b8b645eb0ca7907aea70415.tar.gz blackbird-op-linux-7fc3cdabba75c2516b8b645eb0ca7907aea70415.zip |
NVMe: Create nvme_map_user_pages() and nvme_unmap_user_pages()
These are generalisations of the code that was in
nvme_submit_user_admin_command().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/nvme.c | 68 |
1 files changed, 53 insertions, 15 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index b28d188d10f8..f44d6cd87ea2 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -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) { @@ -695,27 +700,60 @@ 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); + put_pages: + for (i = 0; i < count; i++) + put_page(pages[i]); + kfree(pages); + return err; +} - if (err) - err = -EIO; +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); - put_pages: + for (i = 0; i < count; i++) - put_page(pages[i]); + put_page(sg_page(&sg[i])); +} - return err; +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) |