nvme: LightNVM support

The first generation of Open-Channel SSDs is based on NVMe. The NVMe
driver is extended with support for the LightNVM command set.

Detection is made through PCI IDs. Current supported devices are the
qemu nvme simulator and CNEX Labs Westlake SSD. The qemu nvme enables
support through vendor specific bits in the namespace identification and
the CNEX Labs Westlake SSD implements a LightNVM compatible firmware and
is detected using the same method as qemu.

After detection, vendor specific codes are used to identify the device
and enumerate supported features.

Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Javier González <jg@lightnvm.io>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index c1f41bf..fdb4e5b 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -22,6 +22,11 @@
 extern unsigned char nvme_io_timeout;
 #define NVME_IO_TIMEOUT	(nvme_io_timeout * HZ)
 
+enum {
+	NVME_NS_LBA		= 0,
+	NVME_NS_LIGHTNVM	= 1,
+};
+
 /*
  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
  */
@@ -84,6 +89,7 @@
 	u16 ms;
 	bool ext;
 	u8 pi_type;
+	int type;
 	u64 mode_select_num_blocks;
 	u32 mode_select_block_len;
 };
@@ -130,4 +136,8 @@
 int nvme_sg_io32(struct nvme_ns *ns, unsigned long arg);
 int nvme_sg_get_version_num(int __user *ip);
 
+int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id);
+int nvme_nvm_register(struct request_queue *q, char *disk_name);
+void nvme_nvm_unregister(struct request_queue *q, char *disk_name);
+
 #endif /* _NVME_H */