Re: [PATCH v3 7/7] nvme: LightNVM support

From: Matias Bjorling
Date: Tue May 05 2015 - 14:52:04 EST


--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -39,6 +39,7 @@
#include <linux/slab.h>
#include <linux/t10-pi.h>
#include <linux/types.h>
+#include <linux/lightnvm.h>
#include <scsi/sg.h>
#include <asm-generic/io-64-nonatomic-lo-hi.h>

@@ -134,6 +135,11 @@ static inline void _nvme_check_size(void)
BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
+ BUILD_BUG_ON(sizeof(struct nvme_nvm_hb_rw) != 64);
+ BUILD_BUG_ON(sizeof(struct nvme_nvm_l2ptbl) != 64);
+ BUILD_BUG_ON(sizeof(struct nvme_nvm_bbtbl) != 64);
+ BUILD_BUG_ON(sizeof(struct nvme_nvm_set_resp) != 64);
+ BUILD_BUG_ON(sizeof(struct nvme_nvm_erase_blk) != 64);
}

Keith, should I move the lightnvm definition into the nvme-lightnvm.c file as well?

static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod,
struct nvme_ns *ns)
{
@@ -888,12 +937,29 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
}
}

+ if (ns->type == NVME_NS_NVM) {
+ switch (nvm_prep_rq(req, &iod->nvm_rqdata)) {
+ case NVM_PREP_DONE:
+ goto done_cmd;
+ case NVM_PREP_REQUEUE:
+ blk_mq_requeue_request(req);
+ blk_mq_kick_requeue_list(hctx->queue);
+ goto done_cmd;
+ case NVM_PREP_BUSY:
+ goto retry_cmd;
+ case NVM_PREP_ERROR:
+ goto error_cmd;
+ }
+ }
+

Regarding the prep part. I'm not 100% satisfied with it. I can refactor it into a function and clean it up. There is still a need for the jumping, as it depends on the iod.

Another possibility is to only call it on lightnvm capable controllers. With its own queue_rq function. It would be global for all namespaces. The flow would then look like

register -> nvme_nvm_queue_rq

nvme_nvm_queue_rq()
if (ns is normal command set)
return nvme_queue_rq();

__nvme_nvm_queue_rq()

Any thoughts?

index aef9a81..5292906 100644
--- a/include/uapi/linux/nvme.h
+++ b/include/uapi/linux/nvme.h
@@ -85,6 +85,35 @@ struct nvme_id_ctrl {
__u8 vs[1024];
};

+struct nvme_nvm_id_chnl {
+ __le64 laddr_begin;
+ __le64 laddr_end;
+ __le32 oob_size;
+ __le32 queue_size;
+ __le32 gran_read;
+ __le32 gran_write;
+ __le32 gran_erase;
+ __le32 t_r;
+ __le32 t_sqr;
+ __le32 t_w;
+ __le32 t_sqw;
+ __le32 t_e;
+ __le16 chnl_parallelism;
+ __u8 io_sched;
+ __u8 reserved[133];
+} __attribute__((packed));
+
+struct nvme_nvm_id {
+ __u8 ver_id;
+ __u8 nvm_type;
+ __le16 nchannels;
+ __u8 reserved[252];
+ struct nvme_nvm_id_chnl chnls[];
+} __attribute__((packed));
+
+#define NVME_NVM_CHNLS_PR_REQ ((4096U - sizeof(struct nvme_nvm_id)) \
+ / sizeof(struct nvme_nvm_id_chnl))
+
enum {
NVME_CTRL_ONCS_COMPARE = 1 << 0,
NVME_CTRL_ONCS_WRITE_UNCORRECTABLE = 1 << 1,
@@ -130,6 +159,7 @@ struct nvme_id_ns {

enum {
NVME_NS_FEAT_THIN = 1 << 0,
+ NVME_NS_FEAT_NVM = 1 << 3,
NVME_NS_FLBAS_LBA_MASK = 0xf,
NVME_NS_FLBAS_META_EXT = 0x10,
NVME_LBAF_RP_BEST = 0,
@@ -146,6 +176,8 @@ enum {
NVME_NS_DPS_PI_TYPE1 = 1,
NVME_NS_DPS_PI_TYPE2 = 2,
NVME_NS_DPS_PI_TYPE3 = 3,
+
+ NVME_NS_NVM = 1,
};

struct nvme_smart_log {
@@ -229,6 +261,12 @@ enum nvme_opcode {
nvme_cmd_resv_report = 0x0e,
nvme_cmd_resv_acquire = 0x11,
nvme_cmd_resv_release = 0x15,
+
+ nvme_nvm_cmd_hb_write = 0x81,
+ nvme_nvm_cmd_hb_read = 0x02,
+ nvme_nvm_cmd_phys_write = 0x91,
+ nvme_nvm_cmd_phys_read = 0x92,
+ nvme_nvm_cmd_erase = 0x90,
};

struct nvme_common_command {
@@ -261,6 +299,74 @@ struct nvme_rw_command {
__le16 appmask;
};

+struct nvme_nvm_hb_rw {
+ __u8 opcode;
+ __u8 flags;
+ __u16 command_id;
+ __le32 nsid;
+ __u64 rsvd2;
+ __le64 metadata;
+ __le64 prp1;
+ __le64 prp2;
+ __le64 slba;
+ __le16 length;
+ __le16 control;
+ __le32 dsmgmt;
+ __le64 phys_addr;
+};
+
+struct nvme_nvm_l2ptbl {
+ __u8 opcode;
+ __u8 flags;
+ __u16 command_id;
+ __le32 nsid;
+ __le32 cdw2[4];
+ __le64 prp1;
+ __le64 prp2;
+ __le64 slba;
+ __le32 nlb;
+ __u16 prp1_len;
+ __le16 cdw14[5];
+};
+
+struct nvme_nvm_bbtbl {
+ __u8 opcode;
+ __u8 flags;
+ __u16 command_id;
+ __le32 nsid;
+ __u64 rsvd[2];
+ __le64 prp1;
+ __le64 prp2;
+ __le32 prp1_len;
+ __le32 prp2_len;
+ __le32 lbb;
+ __u32 rsvd11[3];
+};
+
+struct nvme_nvm_set_resp {
+ __u8 opcode;
+ __u8 flags;
+ __u16 command_id;
+ __le32 nsid;
+ __u64 rsvd[2];
+ __le64 prp1;
+ __le64 prp2;
+ __le64 resp;
+ __u32 rsvd11[4];
+};
+
+struct nvme_nvm_erase_blk {
+ __u8 opcode;
+ __u8 flags;
+ __u16 command_id;
+ __le32 nsid;
+ __u64 rsvd[2];
+ __le64 prp1;
+ __le64 prp2;
+ __le64 blk_addr;
+ __u32 rsvd11[4];
+};
+
enum {
NVME_RW_LR = 1 << 15,
NVME_RW_FUA = 1 << 14,
@@ -328,6 +434,13 @@ enum nvme_admin_opcode {
nvme_admin_format_nvm = 0x80,
nvme_admin_security_send = 0x81,
nvme_admin_security_recv = 0x82,
+
+ nvme_nvm_admin_identify = 0xe2,
+ nvme_nvm_admin_get_features = 0xe6,
+ nvme_nvm_admin_set_resp = 0xe5,
+ nvme_nvm_admin_get_l2p_tbl = 0xea,
+ nvme_nvm_admin_get_bb_tbl = 0xf2,
+ nvme_nvm_admin_set_bb_tbl = 0xf1,
};

enum {
@@ -457,6 +570,18 @@ struct nvme_format_cmd {
__u32 rsvd11[5];
};

+struct nvme_nvm_identify {
+ __u8 opcode;
+ __u8 flags;
+ __u16 command_id;
+ __le32 nsid;
+ __u64 rsvd[2];
+ __le64 prp1;
+ __le64 prp2;
+ __le32 cns;
+ __u32 rsvd11[5];
+};
+
struct nvme_command {
union {
struct nvme_common_command common;
@@ -470,6 +595,13 @@ struct nvme_command {
struct nvme_format_cmd format;
struct nvme_dsm_cmd dsm;
struct nvme_abort_cmd abort;
+ struct nvme_nvm_identify nvm_identify;
+ struct nvme_nvm_hb_rw nvm_hb_rw;
+ struct nvme_nvm_l2ptbl nvm_l2p;
+ struct nvme_nvm_bbtbl nvm_get_bb;
+ struct nvme_nvm_bbtbl nvm_set_bb;
+ struct nvme_nvm_set_resp nvm_resp;
+ struct nvme_nvm_erase_blk nvm_erase;
};
};


All these could be moved into the nvme-lightnvm.c file. Taking the previous discussion with Christoph regarding exposing user headers with the protocol. It maybe shouldn't be exposed.

Should I push it into nvme-lightnvm.h? (there is still a need for struct nvme_nvm_hb_rw. The other defs can be moved)

Anything else?

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