nvmet: implement rotational media information log

Most of the information is stubbed. Supporting these commands is a
requirement for supporting rotational media.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/core.c

@@ -5002,6 +5002,7 @@ static inline void _nvme_check_size(void)
 	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_endurance_group_log) != 512);
+	BUILD_BUG_ON(sizeof(struct nvme_rotational_media_log) != 512);
 	BUILD_BUG_ON(sizeof(struct nvme_dbbuf) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_directive_cmd) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_feat_host_behavior) != 512);

drivers/nvme/target/admin-cmd.c

@@ -91,6 +91,7 @@ static void nvmet_execute_get_supported_log_pages(struct nvmet_req *req)
 	logs->lids[NVME_LOG_ENDURANCE_GROUP] = cpu_to_le32(NVME_LIDS_LSUPP);
 	logs->lids[NVME_LOG_ANA] = cpu_to_le32(NVME_LIDS_LSUPP);
 	logs->lids[NVME_LOG_FEATURES] = cpu_to_le32(NVME_LIDS_LSUPP);
+	logs->lids[NVME_LOG_RMI] = cpu_to_le32(NVME_LIDS_LSUPP);
 	logs->lids[NVME_LOG_RESERVATION] = cpu_to_le32(NVME_LIDS_LSUPP);
 
 	status = nvmet_copy_to_sgl(req, 0, logs, sizeof(*logs));
@@ -158,6 +159,45 @@ static u16 nvmet_get_smart_log_all(struct nvmet_req *req,
 	return NVME_SC_SUCCESS;
 }
 
+static void nvmet_execute_get_log_page_rmi(struct nvmet_req *req)
+{
+	struct nvme_rotational_media_log *log;
+	struct gendisk *disk;
+	u16 status;
+
+	req->cmd->common.nsid = cpu_to_le32(le16_to_cpu(
+					    req->cmd->get_log_page.lsi));
+	status = nvmet_req_find_ns(req);
+	if (status)
+		goto out;
+
+	if (!req->ns->bdev || bdev_nonrot(req->ns->bdev)) {
+		status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
+		goto out;
+	}
+
+	if (req->transfer_len != sizeof(*log)) {
+		status = NVME_SC_SGL_INVALID_DATA | NVME_STATUS_DNR;
+		goto out;
+	}
+
+	log = kzalloc(sizeof(*log), GFP_KERNEL);
+	if (!log)
+		goto out;
+
+	log->endgid = req->cmd->get_log_page.lsi;
+	disk = req->ns->bdev->bd_disk;
+	if (disk && disk->ia_ranges)
+		log->numa = cpu_to_le16(disk->ia_ranges->nr_ia_ranges);
+	else
+		log->numa = cpu_to_le16(1);
+
+	status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
+	kfree(log);
+out:
+	nvmet_req_complete(req, status);
+}
+
 static void nvmet_execute_get_log_page_smart(struct nvmet_req *req)
 {
 	struct nvme_smart_log *log;
@@ -451,6 +491,8 @@ static void nvmet_execute_get_log_page(struct nvmet_req *req)
 		return nvmet_execute_get_log_page_ana(req);
 	case NVME_LOG_FEATURES:
 		return nvmet_execute_get_log_page_features(req);
+	case NVME_LOG_RMI:
+		return nvmet_execute_get_log_page_rmi(req);
 	case NVME_LOG_RESERVATION:
 		return nvmet_execute_get_log_page_resv(req);
 	}

include/linux/nvme.h

@@ -642,6 +642,18 @@ struct nvme_endurance_group_log {
 	__u8	rsvd192[320];
 };
 
+struct nvme_rotational_media_log {
+	__le16	endgid;
+	__le16	numa;
+	__le16	nrs;
+	__u8	rsvd6[2];
+	__le32	spinc;
+	__le32	fspinc;
+	__le32	ldc;
+	__le32	fldc;
+	__u8	rsvd24[488];
+};
+
 struct nvme_smart_log {
 	__u8			critical_warning;
 	__u8			temperature[2];
@@ -1281,6 +1293,7 @@ enum {
 	NVME_LOG_ENDURANCE_GROUP = 0x09,
 	NVME_LOG_ANA		= 0x0c,
 	NVME_LOG_FEATURES	= 0x12,
+	NVME_LOG_RMI		= 0x16,
 	NVME_LOG_DISC		= 0x70,
 	NVME_LOG_RESERVATION	= 0x80,
 	NVME_FWACT_REPL		= (0 << 3),
@@ -1435,7 +1448,7 @@ struct nvme_get_log_page_command {
 	__u8			lsp; /* upper 4 bits reserved */
 	__le16			numdl;
 	__le16			numdu;
-	__u16			rsvd11;
+	__le16			lsi;
 	union {
 		struct {
 			__le32 lpol;