[PATCH RFC 2/8] nvme: Add cdq data structure to nvme_ctrl

[Joel Granados <joel.granados@kernel.org>]

Add a CDQ xarray to nvme_ctrl allowing for several CDQs per controller
(as per specification). The structure will house a pointer to its
controller (*ctrl), a pointer to the entry memory (*entries), number and
size of entries, current entry and phase bit value, the location of the
phase bit value within an entry, dma address, CDQ id and the file
pointer where the reading will be taking place.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 drivers/nvme/host/core.c |  1 +
 drivers/nvme/host/nvme.h | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 7be6b42a1adcc3fdb3cec2e2d0e73fcf74244590..9b2de74d62f7a65aea2d28bbbed6681195d9afcd 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4868,6 +4868,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
 	mutex_init(&ctrl->scan_lock);
 	INIT_LIST_HEAD(&ctrl->namespaces);
 	xa_init(&ctrl->cels);
+	xa_init(&ctrl->cdqs);
 	ctrl->dev = dev;
 	ctrl->ops = ops;
 	ctrl->quirks = quirks;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 8fc4683418a3a6929311c7b56da90ebcbbe16d86..800970a0bb87f7a3b6e855f56a2493a7deed1ecd 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -411,6 +411,7 @@ struct nvme_ctrl {
 	enum nvme_ctrl_type cntrltype;
 	enum nvme_dctype dctype;
 	u16 awupf; /* 0's based value. */
+	struct xarray cdqs; /* Controller Data Queue */
 };
 
 static inline enum nvme_ctrl_state nvme_ctrl_state(struct nvme_ctrl *ctrl)
@@ -553,6 +554,20 @@ static inline bool nvme_ns_has_pi(struct nvme_ns_head *head)
 	return head->pi_type && head->ms == head->pi_size;
 }
 
+struct cdq_nvme_queue {
+	struct nvme_ctrl *ctrl;
+	void *entries;
+	u32 entry_nbyte;
+	u32 entry_nr;
+	u32 curr_entry;
+	u8 curr_cdqp;
+	uint cdqp_offset;
+	uint cdqp_mask;
+	dma_addr_t entries_dma_addr;
+	u16 cdq_id;
+	struct file *filep;
+};
+
 struct nvme_ctrl_ops {
 	const char *name;
 	struct module *module;

-- 
2.47.2