From 00df5cb4eb927078850086f8becc3286a69ea12e Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 22 Feb 2011 14:18:30 -0500 Subject: [PATCH] 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 --- drivers/block/nvme.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) 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",