1 files changed, 234 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/ionic/ionic_queue.h b/drivers/infiniband/hw/ionic/ionic_queue.h
new file mode 100644
index 000000000000..d18020d4cad5
--- /dev/null
+++ b/drivers/infiniband/hw/ionic/ionic_queue.h
@@ -0,0 +1,234 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */
+
+#ifndef _IONIC_QUEUE_H_
+#define _IONIC_QUEUE_H_
+
+#include <linux/io.h>
+#include <ionic_regs.h>
+
+#define IONIC_MAX_DEPTH		0xffff
+#define IONIC_MAX_CQ_DEPTH	0xffff
+#define IONIC_CQ_RING_ARM	IONIC_DBELL_RING_1
+#define IONIC_CQ_RING_SOL	IONIC_DBELL_RING_2
+
+/**
+ * struct ionic_queue - Ring buffer used between device and driver
+ * @size:	Size of the buffer, in bytes
+ * @dma:	Dma address of the buffer
+ * @ptr:	Buffer virtual address
+ * @prod:	Driver position in the queue
+ * @cons:	Device position in the queue
+ * @mask:	Capacity of the queue, subtracting the hole
+ *		This value is equal to ((1 << depth_log2) - 1)
+ * @depth_log2: Log base two size depth of the queue
+ * @stride_log2: Log base two size of an element in the queue
+ * @dbell:	Doorbell identifying bits
+ */
+struct ionic_queue {
+	size_t size;
+	dma_addr_t dma;
+	void *ptr;
+	u16 prod;
+	u16 cons;
+	u16 mask;
+	u8 depth_log2;
+	u8 stride_log2;
+	u64 dbell;
+};
+
+/**
+ * ionic_queue_init() - Initialize user space queue
+ * @q:		Uninitialized queue structure
+ * @dma_dev:	DMA device for mapping
+ * @depth:	Depth of the queue
+ * @stride:	Size of each element of the queue
+ *
+ * Return: status code
+ */
+int ionic_queue_init(struct ionic_queue *q, struct device *dma_dev,
+		     int depth, size_t stride);
+
+/**
+ * ionic_queue_destroy() - Destroy user space queue
+ * @q:		Queue structure
+ * @dma_dev:	DMA device for mapping
+ *
+ * Return: status code
+ */
+void ionic_queue_destroy(struct ionic_queue *q, struct device *dma_dev);
+
+/**
+ * ionic_queue_empty() - Test if queue is empty
+ * @q:		Queue structure
+ *
+ * This is only valid for to-device queues.
+ *
+ * Return: is empty
+ */
+static inline bool ionic_queue_empty(struct ionic_queue *q)
+{
+	return q->prod == q->cons;
+}
+
+/**
+ * ionic_queue_length() - Get the current length of the queue
+ * @q:		Queue structure
+ *
+ * This is only valid for to-device queues.
+ *
+ * Return: length
+ */
+static inline u16 ionic_queue_length(struct ionic_queue *q)
+{
+	return (q->prod - q->cons) & q->mask;
+}
+
+/**
+ * ionic_queue_length_remaining() - Get the remaining length of the queue
+ * @q:		Queue structure
+ *
+ * This is only valid for to-device queues.
+ *
+ * Return: length remaining
+ */
+static inline u16 ionic_queue_length_remaining(struct ionic_queue *q)
+{
+	return q->mask - ionic_queue_length(q);
+}
+
+/**
+ * ionic_queue_full() - Test if queue is full
+ * @q:		Queue structure
+ *
+ * This is only valid for to-device queues.
+ *
+ * Return: is full
+ */
+static inline bool ionic_queue_full(struct ionic_queue *q)
+{
+	return q->mask == ionic_queue_length(q);
+}
+
+/**
+ * ionic_color_wrap() - Flip the color if prod is wrapped
+ * @prod:	Queue index just after advancing
+ * @color:	Queue color just prior to advancing the index
+ *
+ * Return: color after advancing the index
+ */
+static inline bool ionic_color_wrap(u16 prod, bool color)
+{
+	/* logical xor color with (prod == 0) */
+	return color != (prod == 0);
+}
+
+/**
+ * ionic_queue_at() - Get the element at the given index
+ * @q:		Queue structure
+ * @idx:	Index in the queue
+ *
+ * The index must be within the bounds of the queue.  It is not checked here.
+ *
+ * Return: pointer to element at index
+ */
+static inline void *ionic_queue_at(struct ionic_queue *q, u16 idx)
+{
+	return q->ptr + ((unsigned long)idx << q->stride_log2);
+}
+
+/**
+ * ionic_queue_at_prod() - Get the element at the producer index
+ * @q:		Queue structure
+ *
+ * Return: pointer to element at producer index
+ */
+static inline void *ionic_queue_at_prod(struct ionic_queue *q)
+{
+	return ionic_queue_at(q, q->prod);
+}
+
+/**
+ * ionic_queue_at_cons() - Get the element at the consumer index
+ * @q:		Queue structure
+ *
+ * Return: pointer to element at consumer index
+ */
+static inline void *ionic_queue_at_cons(struct ionic_queue *q)
+{
+	return ionic_queue_at(q, q->cons);
+}
+
+/**
+ * ionic_queue_next() - Compute the next index
+ * @q:		Queue structure
+ * @idx:	Index
+ *
+ * Return: next index after idx
+ */
+static inline u16 ionic_queue_next(struct ionic_queue *q, u16 idx)
+{
+	return (idx + 1) & q->mask;
+}
+
+/**
+ * ionic_queue_produce() - Increase the producer index
+ * @q:		Queue structure
+ *
+ * Caller must ensure that the queue is not full.  It is not checked here.
+ */
+static inline void ionic_queue_produce(struct ionic_queue *q)
+{
+	q->prod = ionic_queue_next(q, q->prod);
+}
+
+/**
+ * ionic_queue_consume() - Increase the consumer index
+ * @q:		Queue structure
+ *
+ * Caller must ensure that the queue is not empty.  It is not checked here.
+ *
+ * This is only valid for to-device queues.
+ */
+static inline void ionic_queue_consume(struct ionic_queue *q)
+{
+	q->cons = ionic_queue_next(q, q->cons);
+}
+
+/**
+ * ionic_queue_consume_entries() - Increase the consumer index by entries
+ * @q:				Queue structure
+ * @entries:		Number of entries to increment
+ *
+ * Caller must ensure that the queue is not empty.  It is not checked here.
+ *
+ * This is only valid for to-device queues.
+ */
+static inline void ionic_queue_consume_entries(struct ionic_queue *q,
+					       u16 entries)
+{
+	q->cons = (q->cons + entries) & q->mask;
+}
+
+/**
+ * ionic_queue_dbell_init() - Initialize doorbell bits for queue id
+ * @q:		Queue structure
+ * @qid:	Queue identifying number
+ */
+static inline void ionic_queue_dbell_init(struct ionic_queue *q, u32 qid)
+{
+	q->dbell = IONIC_DBELL_QID(qid);
+}
+
+/**
+ * ionic_queue_dbell_val() - Get current doorbell update value
+ * @q:		Queue structure
+ *
+ * Return: current doorbell update value
+ */
+static inline u64 ionic_queue_dbell_val(struct ionic_queue *q)
+{
+	return q->dbell | q->prod;
+}
+
+#endif /* _IONIC_QUEUE_H_ */