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Commit 0e5e4f0e authored by Keith Busch's avatar Keith Busch Committed by Matthew Wilcox
Browse files

NVMe: Add discard support for capable devices 



This adds discard support to block queues if the nvme device is capable of
deallocating blocks as indicated by the controller's optional command support.
A discard flagged bio request will submit an NVMe deallocate Data Set
Management command for the requested blocks.

Signed-off-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarMatthew Wilcox <matthew.r.wilcox@intel.com>
parent a12183c6

drivers/block/nvme.c

+59 −1
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ struct nvme_dev { 
	char model[40];

	char firmware_rev[8];

	u32 max_hw_sectors;

	u16 oncs;

};



/*
@@ -510,6 +511,44 @@ static int nvme_map_bio(struct device *dev, struct nvme_iod *iod, 
	return length;

}



/*

 * We reuse the small pool to allocate the 16-byte range here as it is not

 * worth having a special pool for these or additional cases to handle freeing

 * the iod.

 */

static int nvme_submit_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,

		struct bio *bio, struct nvme_iod *iod, int cmdid)

{

	struct nvme_dsm_range *range;

	struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];



	range = dma_pool_alloc(nvmeq->dev->prp_small_pool, GFP_ATOMIC,

							&iod->first_dma);

	if (!range)

		return -ENOMEM;



	iod_list(iod)[0] = (__le64 *)range;

	iod->npages = 0;



	range->cattr = cpu_to_le32(0);

	range->nlb = cpu_to_le32(bio->bi_size >> ns->lba_shift);

	range->slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));



	memset(cmnd, 0, sizeof(*cmnd));

	cmnd->dsm.opcode = nvme_cmd_dsm;

	cmnd->dsm.command_id = cmdid;

	cmnd->dsm.nsid = cpu_to_le32(ns->ns_id);

	cmnd->dsm.prp1 = cpu_to_le64(iod->first_dma);

	cmnd->dsm.nr = 0;

	cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);



	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(struct nvme_queue *nvmeq, struct nvme_ns *ns,

								int cmdid)

{
@@ -567,6 +606,12 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns, 
	if (unlikely(cmdid < 0))

		goto free_iod;



	if (bio->bi_rw & REQ_DISCARD) {

		result = nvme_submit_discard(nvmeq, ns, bio, iod, cmdid);

		if (result)

			goto free_cmdid;

		return result;

	}

	if ((bio->bi_rw & REQ_FLUSH) && !psegs)

		return nvme_submit_flush(nvmeq, ns, cmdid);
@@ -1347,6 +1392,16 @@ static void nvme_put_ns_idx(int index) 
	spin_unlock(&dev_list_lock);

}



static void nvme_config_discard(struct nvme_ns *ns)

{

	u32 logical_block_size = queue_logical_block_size(ns->queue);

	ns->queue->limits.discard_zeroes_data = 0;

	ns->queue->limits.discard_alignment = logical_block_size;

	ns->queue->limits.discard_granularity = logical_block_size;

	ns->queue->limits.max_discard_sectors = 0xffffffff;

	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);

}



static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,

			struct nvme_id_ns *id, struct nvme_lba_range_type *rt)

{
@@ -1366,7 +1421,6 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid, 
	ns->queue->queue_flags = QUEUE_FLAG_DEFAULT;

	queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue);

	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);

/*	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue); */

	blk_queue_make_request(ns->queue, nvme_make_request);

	ns->dev = dev;

	ns->queue->queuedata = ns;
@@ -1392,6 +1446,9 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid, 
	sprintf(disk->disk_name, "nvme%dn%d", dev->instance, nsid);

	set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));



	if (dev->oncs & NVME_CTRL_ONCS_DSM)

		nvme_config_discard(ns);



	return ns;



 out_free_queue:
@@ -1520,6 +1577,7 @@ static int nvme_dev_add(struct nvme_dev *dev) 


	ctrl = mem;

	nn = le32_to_cpup(&ctrl->nn);

	dev->oncs = le16_to_cpup(&ctrl->oncs);

	memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));

	memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));

	memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));

include/linux/nvme.h

+32 −0
Original line number Diff line number Diff line
@@ -107,6 +107,12 @@ struct nvme_id_ctrl { 
	__u8			vs[1024];

};



enum {

	NVME_CTRL_ONCS_COMPARE			= 1 << 0,

	NVME_CTRL_ONCS_WRITE_UNCORRECTABLE	= 1 << 1,

	NVME_CTRL_ONCS_DSM			= 1 << 2,

};



struct nvme_lbaf {

	__le16			ms;

	__u8			ds;
@@ -246,6 +252,31 @@ enum { 
	NVME_RW_DSM_COMPRESSED		= 1 << 7,

};



struct nvme_dsm_cmd {

	__u8			opcode;

	__u8			flags;

	__u16			command_id;

	__le32			nsid;

	__u64			rsvd2[2];

	__le64			prp1;

	__le64			prp2;

	__le32			nr;

	__le32			attributes;

	__u32			rsvd12[4];

};



enum {

	NVME_DSMGMT_IDR		= 1 << 0,

	NVME_DSMGMT_IDW		= 1 << 1,

	NVME_DSMGMT_AD		= 1 << 2,

};



struct nvme_dsm_range {

	__le32			cattr;

	__le32			nlb;

	__le64			slba;

};



/* Admin commands */



enum nvme_admin_opcode {
@@ -372,6 +403,7 @@ struct nvme_command { 
		struct nvme_create_sq create_sq;

		struct nvme_delete_queue delete_queue;

		struct nvme_download_firmware dlfw;

		struct nvme_dsm_cmd dsm;

	};

};