Re: [PATCHv3 3/5] nvme: implement I/O Command Sets Command Set support

[Hannes Reinecke <hare@suse.de>]

On 6/22/20 6:25 PM, Keith Busch wrote:
> From: Niklas Cassel <niklas.cassel@wdc.com>
> 
> Implements support for the I/O Command Sets command set. The command set
> introduces a method to enumerate multiple command sets per namespace. If
> the command set is exposed, this method for enumeration will be used
> instead of the traditional method that uses the CC.CSS register command
> set register for command set identification.
> 
> For namespaces where the Command Set Identifier is not supported or
> recognized, the specific namespace will not be created.
> 
> Reviewed-by: Javier González <javier.gonz@samsung.com>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Reviewed-by: Matias Bjørling <matias.bjorling@wdc.com>
> Reviewed-by: Daniel Wagner <dwagner@suse.de>
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> ---
>   drivers/nvme/host/core.c | 48 +++++++++++++++++++++++++++++++++-------
>   drivers/nvme/host/nvme.h |  1 +
>   include/linux/nvme.h     | 19 ++++++++++++++--
>   3 files changed, 58 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 9491dbcfe81a..45a3cb5a35bd 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1056,8 +1056,13 @@ static int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
>   	return error;
>   }
>   
> +static bool nvme_multi_css(struct nvme_ctrl *ctrl)
> +{
> +	return (ctrl->ctrl_config & NVME_CC_CSS_MASK) == NVME_CC_CSS_CSI;
> +}
> +
>   static int nvme_process_ns_desc(struct nvme_ctrl *ctrl, struct nvme_ns_ids *ids,
> -		struct nvme_ns_id_desc *cur)
> +		struct nvme_ns_id_desc *cur, bool *csi_seen)
>   {
>   	const char *warn_str = "ctrl returned bogus length:";
>   	void *data = cur;
> @@ -1087,6 +1092,15 @@ static int nvme_process_ns_desc(struct nvme_ctrl *ctrl, struct nvme_ns_ids *ids,
>   		}
>   		uuid_copy(&ids->uuid, data + sizeof(*cur));
>   		return NVME_NIDT_UUID_LEN;
> +	case NVME_NIDT_CSI:
> +		if (cur->nidl != NVME_NIDT_CSI_LEN) {
> +			dev_warn(ctrl->device, "%s %d for NVME_NIDT_CSI\n",
> +				 warn_str, cur->nidl);
> +			return -1;
> +		}
> +		memcpy(&ids->csi, data + sizeof(*cur), NVME_NIDT_CSI_LEN);
> +		*csi_seen = true;
> +		return NVME_NIDT_CSI_LEN;
>   	default:
>   		/* Skip unknown types */
>   		return cur->nidl;
> @@ -1097,10 +1111,9 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>   		struct nvme_ns_ids *ids)
>   {
>   	struct nvme_command c = { };
> -	int status;
> +	bool csi_seen = false;
> +	int status, pos, len;
>   	void *data;
> -	int pos;
> -	int len;
>   
>   	c.identify.opcode = nvme_admin_identify;
>   	c.identify.nsid = cpu_to_le32(nsid);
> @@ -1130,13 +1143,19 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>   		if (cur->nidl == 0)
>   			break;
>   
> -		len = nvme_process_ns_desc(ctrl, ids, cur);
> +		len = nvme_process_ns_desc(ctrl, ids, cur, &csi_seen);
>   		if (len < 0)
>   			goto free_data;
>   
>   		len += sizeof(*cur);
>   	}
>   free_data:
> +	if (!status && nvme_multi_css(ctrl) && !csi_seen) {
> +		dev_warn(ctrl->device, "Command set not reported for nsid:%d\n",
> +			 nsid);
> +		status = -EINVAL;
> +	}
> +
>   	kfree(data);
>   	return status;
>   }
> @@ -1792,7 +1811,7 @@ static int nvme_report_ns_ids(struct nvme_ctrl *ctrl, unsigned int nsid,
>   		memcpy(ids->eui64, id->eui64, sizeof(id->eui64));
>   	if (ctrl->vs >= NVME_VS(1, 2, 0))
>   		memcpy(ids->nguid, id->nguid, sizeof(id->nguid));
> -	if (ctrl->vs >= NVME_VS(1, 3, 0))
> +	if (ctrl->vs >= NVME_VS(1, 3, 0) || nvme_multi_css(ctrl))
>   		return nvme_identify_ns_descs(ctrl, nsid, ids);
>   	return 0;
>   }

Hmm? Are command sets even defined for something earlier than 1.3?

> @@ -1808,7 +1827,8 @@ static bool nvme_ns_ids_equal(struct nvme_ns_ids *a, struct nvme_ns_ids *b)
>   {
>   	return uuid_equal(&a->uuid, &b->uuid) &&
>   		memcmp(&a->nguid, &b->nguid, sizeof(a->nguid)) == 0 &&
> -		memcmp(&a->eui64, &b->eui64, sizeof(a->eui64)) == 0;
> +		memcmp(&a->eui64, &b->eui64, sizeof(a->eui64)) == 0 &&
> +		a->csi == b->csi;
>   }
>   
>   static int nvme_setup_streams_ns(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
> @@ -1930,6 +1950,15 @@ static int __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id)
>   	if (ns->lba_shift == 0)
>   		ns->lba_shift = 9;
>   
> +	switch (ns->head->ids.csi) {
> +	case NVME_CSI_NVM:
> +		break;
> +	default:
> +		dev_warn(ctrl->device, "unknown csi:%d ns:%d\n",
> +			ns->head->ids.csi, ns->head->ns_id);
> +		return -ENODEV;
> +	}
> +
>   	if ((ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) &&
>   	    is_power_of_2(ctrl->max_hw_sectors))
>   		iob = ctrl->max_hw_sectors;
> @@ -2264,7 +2293,10 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
>   
>   	ctrl->page_size = 1 << page_shift;
>   
> -	ctrl->ctrl_config = NVME_CC_CSS_NVM;
> +	if (NVME_CAP_CSS(ctrl->cap) & NVME_CAP_CSS_CSI)
> +		ctrl->ctrl_config = NVME_CC_CSS_CSI;
> +	else
> +		ctrl->ctrl_config = NVME_CC_CSS_NVM;
>   	ctrl->ctrl_config |= (page_shift - 12) << NVME_CC_MPS_SHIFT;
>   	ctrl->ctrl_config |= NVME_CC_AMS_RR | NVME_CC_SHN_NONE;
>   	ctrl->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index c0f4226d3299..a84f71459caa 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -339,6 +339,7 @@ struct nvme_ns_ids {
>   	u8	eui64[8];
>   	u8	nguid[16];
>   	uuid_t	uuid;
> +	u8	csi;
>   };
>   
>   /*
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index 5ce51ab4c50e..81ffe5247505 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -132,6 +132,7 @@ enum {
>   #define NVME_CAP_TIMEOUT(cap)	(((cap) >> 24) & 0xff)
>   #define NVME_CAP_STRIDE(cap)	(((cap) >> 32) & 0xf)
>   #define NVME_CAP_NSSRC(cap)	(((cap) >> 36) & 0x1)
> +#define NVME_CAP_CSS(cap)	(((cap) >> 37) & 0xff)
>   #define NVME_CAP_MPSMIN(cap)	(((cap) >> 48) & 0xf)
>   #define NVME_CAP_MPSMAX(cap)	(((cap) >> 52) & 0xf)
>   

Indentation?

> @@ -162,7 +163,6 @@ enum {
>   
>   enum {
>   	NVME_CC_ENABLE		= 1 << 0,
> -	NVME_CC_CSS_NVM		= 0 << 4,
>   	NVME_CC_EN_SHIFT	= 0,
>   	NVME_CC_CSS_SHIFT	= 4,
>   	NVME_CC_MPS_SHIFT	= 7,
> @@ -170,6 +170,9 @@ enum {
>   	NVME_CC_SHN_SHIFT	= 14,
>   	NVME_CC_IOSQES_SHIFT	= 16,
>   	NVME_CC_IOCQES_SHIFT	= 20,
> +	NVME_CC_CSS_NVM		= 0 << NVME_CC_CSS_SHIFT,
> +	NVME_CC_CSS_CSI		= 6 << NVME_CC_CSS_SHIFT,
> +	NVME_CC_CSS_MASK	= 7 << NVME_CC_CSS_SHIFT,
>   	NVME_CC_AMS_RR		= 0 << NVME_CC_AMS_SHIFT,
>   	NVME_CC_AMS_WRRU	= 1 << NVME_CC_AMS_SHIFT,
>   	NVME_CC_AMS_VS		= 7 << NVME_CC_AMS_SHIFT,
> @@ -179,6 +182,8 @@ enum {
>   	NVME_CC_SHN_MASK	= 3 << NVME_CC_SHN_SHIFT,
>   	NVME_CC_IOSQES		= NVME_NVM_IOSQES << NVME_CC_IOSQES_SHIFT,
>   	NVME_CC_IOCQES		= NVME_NVM_IOCQES << NVME_CC_IOCQES_SHIFT,
> +	NVME_CAP_CSS_NVM	= 1 << 0,
> +	NVME_CAP_CSS_CSI	= 1 << 6,
>   	NVME_CSTS_RDY		= 1 << 0,
>   	NVME_CSTS_CFS		= 1 << 1,
>   	NVME_CSTS_NSSRO		= 1 << 4,
> @@ -374,6 +379,8 @@ enum {
>   	NVME_ID_CNS_CTRL		= 0x01,
>   	NVME_ID_CNS_NS_ACTIVE_LIST	= 0x02,
>   	NVME_ID_CNS_NS_DESC_LIST	= 0x03,
> +	NVME_ID_CNS_CS_NS		= 0x05,
> +	NVME_ID_CNS_CS_CTRL		= 0x06,
>   	NVME_ID_CNS_NS_PRESENT_LIST	= 0x10,
>   	NVME_ID_CNS_NS_PRESENT		= 0x11,
>   	NVME_ID_CNS_CTRL_NS_LIST	= 0x12,
> @@ -383,6 +390,10 @@ enum {
>   	NVME_ID_CNS_UUID_LIST		= 0x17,
>   };
>   
> +enum {
> +	NVME_CSI_NVM			= 0,
> +};
> +
>   enum {
>   	NVME_DIR_IDENTIFY		= 0x00,
>   	NVME_DIR_STREAMS		= 0x01,
> @@ -435,11 +446,13 @@ struct nvme_ns_id_desc {
>   #define NVME_NIDT_EUI64_LEN	8
>   #define NVME_NIDT_NGUID_LEN	16
>   #define NVME_NIDT_UUID_LEN	16
> +#define NVME_NIDT_CSI_LEN	1
>   
>   enum {
>   	NVME_NIDT_EUI64		= 0x01,
>   	NVME_NIDT_NGUID		= 0x02,
>   	NVME_NIDT_UUID		= 0x03,
> +	NVME_NIDT_CSI		= 0x04,
>   };
>   
>   struct nvme_smart_log {
> @@ -972,7 +985,9 @@ struct nvme_identify {
>   	__u8			cns;
>   	__u8			rsvd3;
>   	__le16			ctrlid;
> -	__u32			rsvd11[5];
> +	__u8			rsvd11[3];
> +	__u8			csi;
> +	__u32			rsvd12[4];
>   };
>   
>   #define NVME_IDENTIFY_DATA_SIZE 4096
> 
Otherwise looks okay.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
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