[PATCH RFC V2 2/7] nvme-core: function to check if a controller supports a specific I/O cmd

[Maurizio Lombardi]

Add a function (nvme_io_command_supported()) that checks if a
controller supports a specific I/O command.

Signed-off-by: Maurizio Lombardi <mlombard at redhat.com>
---
 drivers/nvme/host/core.c | 8 ++++++++
 drivers/nvme/host/nvme.h | 1 +
 2 files changed, 9 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 3768b1d778fb..d1e87d74c48b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1191,6 +1191,14 @@ u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u8 opcode)
 }
 EXPORT_SYMBOL_NS_GPL(nvme_command_effects, NVME_TARGET_PASSTHRU);
 
+bool nvme_io_command_supported(struct nvme_ctrl *ctrl, u8 opcode)
+{
+	u32 effects = le32_to_cpu(ctrl->effects->iocs[opcode]);
+
+	return effects & NVME_CMD_EFFECTS_CSUPP;
+}
+EXPORT_SYMBOL_GPL(nvme_io_command_supported);
+
 u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u8 opcode)
 {
 	u32 effects = nvme_command_effects(ctrl, ns, opcode);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index da57947130cc..c014192bd623 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -1153,6 +1153,7 @@ static inline void nvme_auth_free(struct nvme_ctrl *ctrl) {};
 
 u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 			 u8 opcode);
+bool nvme_io_command_supported(struct nvme_ctrl *ctrl, u8 opcode);
 u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u8 opcode);
 int nvme_execute_rq(struct request *rq, bool at_head);
 void nvme_passthru_end(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u32 effects,
-- 
2.43.5