On Jun 13, 2017, at 11:15 AM, Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> This adds support for Directives in NVMe, particular for the Streams
> directive. We default to allocating 4 streams per name space, but
> it is configurable with the 'streams_per_ns' module option.
>
> If a write stream is set in a write, flag is as such before
> sending it to the device.
>
> Some debug stuff in this patch, dumping streams ID params when
> we load nvme.
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> drivers/nvme/host/core.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/nvme/host/nvme.h | 1 +
> include/linux/nvme.h | 48 ++++++++++++++++++
> 3 files changed, 173 insertions(+)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 903d5813023a..81225e7d4176 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -65,6 +65,10 @@ static bool force_apst;
> module_param(force_apst, bool, 0644);
> MODULE_PARM_DESC(force_apst, "allow APST for newly enumerated devices even if quirked off");
>
> +static char streams_per_ns = 4;
> +module_param(streams_per_ns, byte, 0644);
> +MODULE_PARM_DESC(streams_per_ns, "if available, allocate this many streams per NS");
Are there any limits here? For example, has to be a power-of-two value, or maximum
number per namespace, per device, etc?
> static LIST_HEAD(nvme_ctrl_list);
> static DEFINE_SPINLOCK(dev_list_lock);
>
> @@ -351,6 +355,15 @@ static inline void nvme_setup_rw(struct nvme_ns *ns, struct request *req,
> cmnd->rw.slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
> cmnd->rw.length = cpu_to_le16((blk_rq_bytes(req) >> ns->lba_shift) - 1);
>
> + if (req_op(req) == REQ_OP_WRITE) {
> + if (bio_stream_valid(req->bio) && ns->streams) {
> + unsigned stream = bio_stream(req->bio) & 0xffff;
> +
> + control |= NVME_RW_DTYPE_STREAMS;
> + dsmgmt |= (stream << 16);
It isn't really clear how this is converted from the 2^16 stream IDs masked
out of 2^32 possible streams in the bio into streams_per_ns = 4 streams per
NVMe device namespace. This appears to be implicitly dependent on upper
layers submitting only 4 distinct WRITE_FILE_* stream IDs, but IMHO that
should be handled transparently at this level. There isn't really any value
to mask the returned bio_stream with 0xffff, since either it will internally
be truncated by streams_per_ns (in which case we don't need to do anything),
or it should be explicitly folded into the accepted range, like:
dsmgmt |= (bio_stream(req->bio) % streams_per_ns) << 16;
or if we want to avoid a 32-bit modulus here, we could pre-compute a mask from
streams_per_ns and enforce that this be a power-of-two value?
Cheers, Andreas
> + }
> + }
> +
> if (ns->ms) {
> switch (ns->pi_type) {
> case NVME_NS_DPS_PI_TYPE3:
> @@ -1073,6 +1086,109 @@ static int nvme_revalidate_disk(struct gendisk *disk)
> return 0;
> }
>
> +static int nvme_enable_streams(struct nvme_ns *ns)
> +{
> + struct nvme_command c;
> +
> + memset(&c, 0, sizeof(c));
> +
> + c.directive.opcode = nvme_admin_directive_send;
> + c.directive.nsid = cpu_to_le32(ns->ns_id);
> + c.directive.doper = NVME_DIR_SND_ID_OP_ENABLE;
> + c.directive.dtype = NVME_DIR_IDENTIFY;
> + c.directive.tdtype = NVME_DIR_STREAMS;
> + c.directive.endir = NVME_DIR_ENDIR;
> +
> + return nvme_submit_sync_cmd(ns->ctrl->admin_q, &c, NULL, 0);
> +}
> +
> +static int nvme_streams_params(struct nvme_ns *ns)
> +{
> + struct nvme_ctrl *ctrl = ns->ctrl;
> + struct streams_directive_params s;
> + struct nvme_command c;
> + int ret;
> +
> + memset(&c, 0, sizeof(c));
> + memset(&s, 0, sizeof(s));
> +
> + c.directive.opcode = nvme_admin_directive_recv;
> + c.directive.nsid = cpu_to_le32(ns->ns_id);
> + c.directive.numd = sizeof(s);
> + c.directive.doper = NVME_DIR_RCV_ST_OP_PARAM;
> + c.directive.dtype = NVME_DIR_STREAMS;
> +
> + ret = nvme_submit_sync_cmd(ctrl->admin_q, &c, &s, sizeof(s));
> + if (ret)
> + return ret;
> +
> + s.msl = le16_to_cpu(s.msl);
> + s.nssa = le16_to_cpu(s.nssa);
> + s.nsso = le16_to_cpu(s.nsso);
> + s.sws = le32_to_cpu(s.sws);
> + s.sgs = le16_to_cpu(s.sgs);
> + s.nsa = le16_to_cpu(s.nsa);
> + s.nso = le16_to_cpu(s.nso);
> +
> + dev_info(ctrl->device, "streams: msl=%u, nssa=%u, nsso=%u, sws=%u "
> + "sgs=%u, nsa=%u, nso=%u\n", s.msl, s.nssa,
> + s.nsso, s.sws, s.sgs, s.nsa, s.nso);
> + return 0;
> +}
> +
> +static int nvme_streams_allocate(struct nvme_ns *ns, unsigned int streams)
> +{
> + struct nvme_command c;
> +
> + memset(&c, 0, sizeof(c));
> +
> + c.directive.opcode = nvme_admin_directive_recv;
> + c.directive.nsid = cpu_to_le32(ns->ns_id);
> + c.directive.doper = NVME_DIR_RCV_ST_OP_RESOURCE;
> + c.directive.dtype = NVME_DIR_STREAMS;
> + c.directive.endir = streams;
> +
> + return nvme_submit_sync_cmd(ns->ctrl->admin_q, &c, NULL, 0);
> +}
> +
> +static int nvme_streams_deallocate(struct nvme_ns *ns)
> +{
> + struct nvme_command c;
> +
> + memset(&c, 0, sizeof(c));
> +
> + c.directive.opcode = nvme_admin_directive_send;
> + c.directive.nsid = cpu_to_le32(ns->ns_id);
> + c.directive.doper = NVME_DIR_SND_ST_OP_REL_RSC;
> + c.directive.dtype = NVME_DIR_STREAMS;
> +
> + return nvme_submit_sync_cmd(ns->ctrl->admin_q, &c, NULL, 0);
> +}
> +
> +static void nvme_config_streams(struct nvme_ns *ns)
> +{
> + int ret;
> +
> + ret = nvme_enable_streams(ns);
> + if (ret)
> + return;
> +
> + ret = nvme_streams_params(ns);
> + if (ret)
> + return;
> +
> + ret = nvme_streams_allocate(ns, streams_per_ns);
> + if (ret)
> + return;
> +
> + ret = nvme_streams_params(ns);
> + if (ret)
> + return;
> +
> + ns->streams = true;
> + dev_info(ns->ctrl->device, "successfully enabled streams\n");
> +}
> +
> static char nvme_pr_type(enum pr_type type)
> {
> switch (type) {
> @@ -1606,6 +1722,9 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
> ctrl->sgls = le32_to_cpu(id->sgls);
> ctrl->kas = le16_to_cpu(id->kas);
>
> + if (ctrl->oacs & NVME_CTRL_OACS_DIRECTIVES)
> + dev_info(ctrl->dev, "supports directives\n");
> +
> ctrl->npss = id->npss;
> prev_apsta = ctrl->apsta;
> if (ctrl->quirks & NVME_QUIRK_NO_APST) {
> @@ -2060,6 +2179,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
> goto out_free_id;
> }
>
> + if (ctrl->oacs & NVME_CTRL_OACS_DIRECTIVES)
> + nvme_config_streams(ns);
> +
> disk = alloc_disk_node(0, node);
> if (!disk)
> goto out_free_id;
> @@ -2112,6 +2234,8 @@ static void nvme_ns_remove(struct nvme_ns *ns)
> &nvme_ns_attr_group);
> if (ns->ndev)
> nvme_nvm_unregister_sysfs(ns);
> + if (ns->streams)
> + nvme_streams_deallocate(ns);
> del_gendisk(ns->disk);
> blk_cleanup_queue(ns->queue);
> }
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 9d6a070d4391..c2d8d23c90de 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -195,6 +195,7 @@ struct nvme_ns {
> int lba_shift;
> u16 ms;
> bool ext;
> + bool streams;
> u8 pi_type;
> unsigned long flags;
>
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index b625bacf37ef..8b2f5b140134 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -245,6 +245,7 @@ enum {
> NVME_CTRL_ONCS_WRITE_ZEROES = 1 << 3,
> NVME_CTRL_VWC_PRESENT = 1 << 0,
> NVME_CTRL_OACS_SEC_SUPP = 1 << 0,
> + NVME_CTRL_OACS_DIRECTIVES = 1 << 5,
> NVME_CTRL_OACS_DBBUF_SUPP = 1 << 7,
> };
>
> @@ -295,6 +296,19 @@ enum {
> };
>
> enum {
> + NVME_DIR_IDENTIFY = 0x00,
> + NVME_DIR_STREAMS = 0x01,
> + NVME_DIR_SND_ID_OP_ENABLE = 0x01,
> + NVME_DIR_SND_ST_OP_REL_ID = 0x01,
> + NVME_DIR_SND_ST_OP_REL_RSC = 0x02,
> + NVME_DIR_RCV_ID_OP_PARAM = 0x01,
> + NVME_DIR_RCV_ST_OP_PARAM = 0x01,
> + NVME_DIR_RCV_ST_OP_STATUS = 0x02,
> + NVME_DIR_RCV_ST_OP_RESOURCE = 0x03,
> + NVME_DIR_ENDIR = 0x01,
> +};
> +
> +enum {
> NVME_NS_FEAT_THIN = 1 << 0,
> NVME_NS_FLBAS_LBA_MASK = 0xf,
> NVME_NS_FLBAS_META_EXT = 0x10,
> @@ -535,6 +549,7 @@ enum {
> NVME_RW_PRINFO_PRCHK_APP = 1 << 11,
> NVME_RW_PRINFO_PRCHK_GUARD = 1 << 12,
> NVME_RW_PRINFO_PRACT = 1 << 13,
> + NVME_RW_DTYPE_STREAMS = 1 << 4,
> };
>
> struct nvme_dsm_cmd {
> @@ -604,6 +619,8 @@ enum nvme_admin_opcode {
> nvme_admin_download_fw = 0x11,
> nvme_admin_ns_attach = 0x15,
> nvme_admin_keep_alive = 0x18,
> + nvme_admin_directive_send = 0x19,
> + nvme_admin_directive_recv = 0x1a,
> nvme_admin_dbbuf = 0x7C,
> nvme_admin_format_nvm = 0x80,
> nvme_admin_security_send = 0x81,
> @@ -756,6 +773,24 @@ struct nvme_get_log_page_command {
> __u32 rsvd14[2];
> };
>
> +struct nvme_directive_cmd {
> + __u8 opcode;
> + __u8 flags;
> + __u16 command_id;
> + __le32 nsid;
> + __u64 rsvd2[2];
> + union nvme_data_ptr dptr;
> + __le32 numd;
> + __u8 doper;
> + __u8 dtype;
> + __le16 dspec;
> + __u8 endir;
> + __u8 tdtype;
> + __u16 rsvd15;
> +
> + __u32 rsvd16[3];
> +};
> +
> /*
> * Fabrics subcommands.
> */
> @@ -886,6 +921,18 @@ struct nvme_dbbuf {
> __u32 rsvd12[6];
> };
>
> +struct streams_directive_params {
> + __u16 msl;
> + __u16 nssa;
> + __u16 nsso;
> + __u8 rsvd[10];
> + __u32 sws;
> + __u16 sgs;
> + __u16 nsa;
> + __u16 nso;
> + __u8 rsvd2[6];
> +};
> +
> struct nvme_command {
> union {
> struct nvme_common_command common;
> @@ -906,6 +953,7 @@ struct nvme_command {
> struct nvmf_property_set_command prop_set;
> struct nvmf_property_get_command prop_get;
> struct nvme_dbbuf dbbuf;
> + struct nvme_directive_cmd directive;
> };
> };
>
> --
> 2.7.4
>
Cheers, Andreas
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