NVMe: Add NVME_IOCTL_SUBMIT_IO

Allow userspace to submit synchronous I/O like the SCSI sg interface does.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index f44d6cd87ea2..40fb2e1bdfe4 100644
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -780,6 +780,47 @@ static int nvme_get_range_type(struct nvme_ns *ns, unsigned long addr)
         return nvme_submit_user_admin_command(ns->dev, addr, 4096, &c);
 }
 
+static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
+{
+        struct nvme_dev *dev = ns->dev;
+        struct nvme_queue *nvmeq;
+        struct nvme_user_io io;
+        struct nvme_command c;
+        unsigned length;
+        u32 result;
+        int nents, status;
+        struct scatterlist *sg;
+
+        if (copy_from_user(&io, uio, sizeof(io)))
+                return -EFAULT;
+        length = io.nblocks << io.block_shift;
+        nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length, &sg);
+        if (nents < 0)
+                return nents;
+
+        memset(&c, 0, sizeof(c));
+        c.rw.opcode = io.opcode;
+        c.rw.flags = io.flags;
+        c.rw.nsid = cpu_to_le32(io.nsid);
+        c.rw.slba = cpu_to_le64(io.slba);
+        c.rw.length = cpu_to_le16(io.nblocks - 1);
+        c.rw.control = cpu_to_le16(io.control);
+        c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);
+        c.rw.reftag = cpu_to_le32(io.reftag);   /* XXX: endian? */
+        c.rw.apptag = cpu_to_le16(io.apptag);
+        c.rw.appmask = cpu_to_le16(io.appmask);
+        /* XXX: metadata */
+        nvme_setup_prps(&c.common, sg, length);
+
+        nvmeq = get_nvmeq(ns);
+        status = nvme_submit_sync_cmd(nvmeq, &c, &result);
+        put_nvmeq(nvmeq);
+
+        nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg, nents);
+        put_user(result, &uio->result);
+        return status;
+}
+
 static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
                                                         unsigned long arg)
 {
@@ -792,6 +833,8 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
                 return nvme_identify(ns, arg, 1);
         case NVME_IOCTL_GET_RANGE_TYPE:
                 return nvme_get_range_type(ns, arg);
+        case NVME_IOCTL_SUBMIT_IO:
+                return nvme_submit_io(ns, (void __user *)arg);
         default:
                 return -ENOTTY;
         }