1 files changed, 50 insertions, 2 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 150e49723c15..5c2d2f1e7261 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -611,6 +611,22 @@ static blk_status_t nvme_setup_discard(struct nvme_ns *ns, struct request *req,
 	return BLK_STS_OK;
 }
 
+static inline blk_status_t nvme_setup_write_zeroes(struct nvme_ns *ns,
+		struct request *req, struct nvme_command *cmnd)
+{
+	if (ns->ctrl->quirks & NVME_QUIRK_DEALLOCATE_ZEROES)
+		return nvme_setup_discard(ns, req, cmnd);
+
+	cmnd->write_zeroes.opcode = nvme_cmd_write_zeroes;
+	cmnd->write_zeroes.nsid = cpu_to_le32(ns->head->ns_id);
+	cmnd->write_zeroes.slba =
+		cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
+	cmnd->write_zeroes.length =
+		cpu_to_le16((blk_rq_bytes(req) >> ns->lba_shift) - 1);
+	cmnd->write_zeroes.control = 0;
+	return BLK_STS_OK;
+}
+
 static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
 		struct request *req, struct nvme_command *cmnd)
 {
@@ -705,7 +721,8 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
 		nvme_setup_flush(ns, cmd);
 		break;
 	case REQ_OP_WRITE_ZEROES:
-		/* currently only aliased to deallocate for a few ctrls: */
+		ret = nvme_setup_write_zeroes(ns, req, cmd);
+		break;
 	case REQ_OP_DISCARD:
 		ret = nvme_setup_discard(ns, req, cmd);
 		break;
@@ -1509,6 +1526,37 @@ static void nvme_config_discard(struct nvme_ns *ns)
 		blk_queue_max_write_zeroes_sectors(queue, UINT_MAX);
 }
 
+static inline void nvme_config_write_zeroes(struct nvme_ns *ns)
+{
+	u32 max_sectors;
+	unsigned short bs = 1 << ns->lba_shift;
+
+	if (!(ns->ctrl->oncs & NVME_CTRL_ONCS_WRITE_ZEROES))
+		return;
+	/*
+	 * Even though NVMe spec explicitly states that MDTS is not
+	 * applicable to the write-zeroes:- "The restriction does not apply to
+	 * commands that do not transfer data between the host and the
+	 * controller (e.g., Write Uncorrectable ro Write Zeroes command).".
+	 * In order to be more cautious use controller's max_hw_sectors value
+	 * to configure the maximum sectors for the write-zeroes which is
+	 * configured based on the controller's MDTS field in the
+	 * nvme_init_identify() if available.
+	 */
+	if (ns->ctrl->max_hw_sectors == UINT_MAX)
+		max_sectors = ((u32)(USHRT_MAX + 1) * bs) >> 9;
+	else
+		max_sectors = ((u32)(ns->ctrl->max_hw_sectors + 1) * bs) >> 9;
+
+	blk_queue_max_write_zeroes_sectors(ns->queue, max_sectors);
+}
+
+static inline void nvme_ns_config_oncs(struct nvme_ns *ns)
+{
+	nvme_config_discard(ns);
+	nvme_config_write_zeroes(ns);
+}
+
 static void nvme_report_ns_ids(struct nvme_ctrl *ctrl, unsigned int nsid,
 		struct nvme_id_ns *id, struct nvme_ns_ids *ids)
 {
@@ -1562,7 +1610,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
 		capacity = 0;
 
 	set_capacity(disk, capacity);
-	nvme_config_discard(ns);
+	nvme_ns_config_oncs(ns);
 
 	if (id->nsattr & (1 << 0))
 		set_disk_ro(disk, true);