[PATCH RFC v2] nvme: basic RMEDIA support for host

[Wang Yugui <wangyugui@e16-tech.com>]

Rotational media(RMEDIA) support is added to the NVMe 2.0 specification.
We firstly add Rotational media(RMEDIA) support to nvme host, then we can add
the support to nvme target later if the backstore is a Rotational media(RMEDIA)
block device.

Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
---
 drivers/nvme/host/core.c      | 5 +++++
 drivers/nvme/host/multipath.c | 3 +++
 drivers/nvme/host/nvme.h      | 1 +
 include/linux/nvme.h          | 1 +
 4 files changed, 10 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 19917253ba7b..f4c41bf70b19 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -40,6 +40,7 @@ struct nvme_ns_info {
 	bool is_readonly;
 	bool is_ready;
 	bool is_removed;
+	bool is_rmedia;
 };
 
 unsigned int admin_timeout = 60;
@@ -1622,6 +1623,7 @@ static int nvme_ns_info_from_id_cs_indep(struct nvme_ctrl *ctrl,
 		info->is_shared = id->nmic & NVME_NS_NMIC_SHARED;
 		info->is_readonly = id->nsattr & NVME_NS_ATTR_RO;
 		info->is_ready = id->nstat & NVME_NSTAT_NRDY;
+		info->is_rmedia = id->nsfeat & NVME_INDEP_NS_FEAT_RMEDIA;
 	}
 	kfree(id);
 	return ret;
@@ -3613,6 +3618,7 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
 	head->ns_id = info->nsid;
 	head->ids = info->ids;
 	head->shared = info->is_shared;
+	head->rmedia = info->is_rmedia;
 	ratelimit_state_init(&head->rs_nuse, 5 * HZ, 1);
 	ratelimit_set_flags(&head->rs_nuse, RATELIMIT_MSG_ON_RELEASE);
 	kref_init(&head->ref);
@@ -3816,6 +3816,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, struct nvme_ns_info *info)
 
 	if (ctrl->opts && ctrl->opts->data_digest)
 		lim.features |= BLK_FEAT_STABLE_WRITES;
+	if (info->is_rmedia)
+		lim.features |= BLK_FEAT_ROTATIONAL;
 	if (ctrl->ops->supports_pci_p2pdma &&
 	    ctrl->ops->supports_pci_p2pdma(ctrl))
 		lim.features |= BLK_FEAT_PCI_P2PDMA;
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 91d9eb3c22ef..a3cd6525d24d 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -626,6 +626,9 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 	head->disk->private_data = head;
 	sprintf(head->disk->disk_name, "nvme%dn%d",
 			ctrl->subsys->instance, head->instance);
+
+	if(head->rmedia)
+		lim.features |= BLK_FEAT_ROTATIONAL;
 	return 0;
 }
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index f900e44243ae..9f2789c44249 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -465,6 +465,7 @@ struct nvme_ns_head {
 	struct list_head	entry;
 	struct kref		ref;
 	bool			shared;
+	bool			rmedia;
 	bool			passthru_err_log_enabled;
 	int			instance;
 	struct nvme_effects_log *effects;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index c12a329dd463..2c259d126f80 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -546,6 +546,7 @@ enum {
 	NVME_NS_FEAT_THIN	= 1 << 0,
 	NVME_NS_FEAT_ATOMICS	= 1 << 1,
 	NVME_NS_FEAT_IO_OPT	= 1 << 4,
+	NVME_INDEP_NS_FEAT_RMEDIA = 1 << 4,
 	NVME_NS_ATTR_RO		= 1 << 0,
 	NVME_NS_FLBAS_LBA_MASK	= 0xf,
 	NVME_NS_FLBAS_LBA_UMASK	= 0x60,
-- 
2.36.2