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authorMatthew Wilcox <matthew.r.wilcox@intel.com>2011-02-22 20:18:30 +0100
committerMatthew Wilcox <matthew.r.wilcox@intel.com>2011-11-04 20:52:59 +0100
commit00df5cb4eb927078850086f8becc3286a69ea12e (patch)
tree891011b1387ead32520ce86e75032c11509b80ec /drivers/block/nvme.c
parentNVMe: Mark CMD_CTX_CANCELLED as being unlikely (diff)
downloadlinux-00df5cb4eb927078850086f8becc3286a69ea12e.tar.xz
linux-00df5cb4eb927078850086f8becc3286a69ea12e.zip
NVMe: Implement Flush
Linux implements Flush as a bit in the bio. That means there may also be data associated with the flush; if so the flush should be sent before the data. To avoid completing the bio twice, I add CMD_CTX_FLUSH to indicate the completion routine should do nothing. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Diffstat (limited to 'drivers/block/nvme.c')
-rw-r--r--drivers/block/nvme.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index ce919b49b30d..d99b400ccd79 100644
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -191,10 +191,12 @@ enum {
bio_completion_id,
};
+/* Special values must be a multiple of 4, and less than 0x1000 */
#define CMD_CTX_BASE (POISON_POINTER_DELTA + sync_completion_id)
#define CMD_CTX_CANCELLED (0x30C + CMD_CTX_BASE)
#define CMD_CTX_COMPLETED (0x310 + CMD_CTX_BASE)
#define CMD_CTX_INVALID (0x314 + CMD_CTX_BASE)
+#define CMD_CTX_FLUSH (0x318 + CMD_CTX_BASE)
static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
{
@@ -416,6 +418,33 @@ static int nvme_map_bio(struct device *dev, struct nvme_bio *nbio,
return dma_map_sg(dev, nbio->sg, nbio->nents, dma_dir);
}
+static int nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
+ int cmdid)
+{
+ struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
+
+ memset(cmnd, 0, sizeof(*cmnd));
+ cmnd->common.opcode = nvme_cmd_flush;
+ cmnd->common.command_id = cmdid;
+ cmnd->common.nsid = cpu_to_le32(ns->ns_id);
+
+ if (++nvmeq->sq_tail == nvmeq->q_depth)
+ nvmeq->sq_tail = 0;
+ writel(nvmeq->sq_tail, nvmeq->q_db);
+
+ return 0;
+}
+
+static int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns)
+{
+ int cmdid = alloc_cmdid(nvmeq, (void *)CMD_CTX_FLUSH,
+ sync_completion_id, IO_TIMEOUT);
+ if (unlikely(cmdid < 0))
+ return cmdid;
+
+ return nvme_submit_flush(nvmeq, ns, cmdid);
+}
+
static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
struct bio *bio)
{
@@ -427,6 +456,12 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
u32 dsmgmt;
int psegs = bio_phys_segments(ns->queue, bio);
+ if ((bio->bi_rw & REQ_FLUSH) && psegs) {
+ result = nvme_submit_flush_data(nvmeq, ns);
+ if (result)
+ return result;
+ }
+
nbio = alloc_nbio(psegs, GFP_ATOMIC);
if (!nbio)
goto nomem;
@@ -437,6 +472,9 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
if (unlikely(cmdid < 0))
goto free_nbio;
+ if ((bio->bi_rw & REQ_FLUSH) && !psegs)
+ return nvme_submit_flush(nvmeq, ns, cmdid);
+
control = 0;
if (bio->bi_rw & REQ_FUA)
control |= NVME_RW_FUA;
@@ -520,6 +558,8 @@ static void sync_completion(struct nvme_queue *nvmeq, void *ctx,
struct sync_cmd_info *cmdinfo = ctx;
if (unlikely((unsigned long)cmdinfo == CMD_CTX_CANCELLED))
return;
+ if ((unsigned long)cmdinfo == CMD_CTX_FLUSH)
+ return;
if (unlikely((unsigned long)cmdinfo == CMD_CTX_COMPLETED)) {
dev_warn(nvmeq->q_dmadev,
"completed id %d twice on queue %d\n",