[PATCH RFC v3] 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 add Rotational media(RMEDIA) basic support to nvme host firstly.

Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
---
changelog of RFC v3
 - rename var based on comments.
   change is_rmedia to is_rotational;
   but keep RMEDIA of NVME_INDEP_NS_FEAT_RMEDIA to match NVME spec 2.0.

 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_rotational;
 };
 
 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_rotational = 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->rotational = info->is_rotational;
 	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_rotational)
+		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->rotational)
+		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			rotational;
 	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