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Code Issues Releases Wiki Activity

NVMe: Use PRP2 for the nvme_identify ioctl

Browse source 
DMA the result straight to userspace instead of bounce-buffering in the
kernel.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
This commit is contained in:
Matthew Wilcox 2011-01-24 07:52:07 -05:00
parent 53c9577e9c
commit 36c14ed9ca
1 changed files with 40 additions and 16 deletions
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56
drivers/block/nvme.c
View file

@ -647,33 +647,57 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
return result;
}
static int nvme_identify(struct nvme_ns *ns, void __user *addr, int cns)
static int nvme_identify(struct nvme_ns *ns, unsigned long addr, int cns)
{
struct nvme_dev *dev = ns->dev;
int status;
int i, err, count, nents, offset;
struct nvme_command c;
void *page;
dma_addr_t dma_addr;
struct scatterlist sg[2];
struct page *pages[2];
page = dma_alloc_coherent(&dev->pci_dev->dev, 4096, &dma_addr,
GFP_KERNEL);
if (addr & 3)
return -EINVAL;
offset = offset_in_page(addr);
count = offset ? 2 : 1;
err = get_user_pages_fast(addr, count, 1, pages);
if (err < count) {
count = err;
err = -EFAULT;
goto put_pages;
}
sg_init_table(sg, count);
for (i = 0; i < count; i++)
sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0);
nents = dma_map_sg(&dev->pci_dev->dev, sg, count, DMA_FROM_DEVICE);
if (!nents)
goto put_pages;
memset(&c, 0, sizeof(c));
c.identify.opcode = nvme_admin_identify;
c.identify.nsid = cns ? 0 : cpu_to_le32(ns->ns_id);
c.identify.prp1 = cpu_to_le64(dma_addr);
c.identify.prp1 = cpu_to_le64(sg_dma_address(&sg[0]) + offset);
if (count > 1) {
u64 dma_addr;
if (nents > 1)
dma_addr = sg_dma_address(&sg[1]);
else
dma_addr = sg_dma_address(&sg[0]) + PAGE_SIZE;
c.identify.prp2 = cpu_to_le64(dma_addr);
}
c.identify.cns = cpu_to_le32(cns);
status = nvme_submit_admin_cmd(dev, &c, NULL);
err = nvme_submit_admin_cmd(dev, &c, NULL);
if (status)
status = -EIO;
else if (copy_to_user(addr, page, 4096))
status = -EFAULT;
if (err)
err = -EIO;
dma_free_coherent(&dev->pci_dev->dev, 4096, page, dma_addr);
dma_unmap_sg(&dev->pci_dev->dev, sg, nents, DMA_FROM_DEVICE);
put_pages:
for (i = 0; i < count; i++)
put_page(pages[i]);
return status;
return err;
}
static int nvme_get_range_type(struct nvme_ns *ns, void __user *addr)
@ -713,9 +737,9 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
switch (cmd) {
case NVME_IOCTL_IDENTIFY_NS:
return nvme_identify(ns, (void __user *)arg, 0);
return nvme_identify(ns, arg, 0);
case NVME_IOCTL_IDENTIFY_CTRL:
return nvme_identify(ns, (void __user *)arg, 1);
return nvme_identify(ns, arg, 1);
case NVME_IOCTL_GET_RANGE_TYPE:
return nvme_get_range_type(ns, (void __user *)arg);
default: