1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/mana/shadow_queue.h b/drivers/infiniband/hw/mana/shadow_queue.h
new file mode 100644
index 000000000000..a4b3818f9c39
--- /dev/null
+++ b/drivers/infiniband/hw/mana/shadow_queue.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/*
+ * Copyright (c) 2024, Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _MANA_SHADOW_QUEUE_H_
+#define _MANA_SHADOW_QUEUE_H_
+
+struct shadow_wqe_header {
+	u16 opcode;
+	u16 error_code;
+	u32 posted_wqe_size;
+	u64 wr_id;
+};
+
+struct ud_rq_shadow_wqe {
+	struct shadow_wqe_header header;
+	u32 byte_len;
+	u32 src_qpn;
+};
+
+struct ud_sq_shadow_wqe {
+	struct shadow_wqe_header header;
+};
+
+struct shadow_queue {
+	/* Unmasked producer index, Incremented on wqe posting */
+	u64 prod_idx;
+	/* Unmasked consumer index, Incremented on cq polling */
+	u64 cons_idx;
+	/* Unmasked index of next-to-complete (from HW) shadow WQE */
+	u64 next_to_complete_idx;
+	/* queue size in wqes */
+	u32 length;
+	/* distance between elements in bytes */
+	u32 stride;
+	/* ring buffer holding wqes */
+	void *buffer;
+};
+
+static inline int create_shadow_queue(struct shadow_queue *queue, uint32_t length, uint32_t stride)
+{
+	queue->buffer = kvmalloc_array(length, stride, GFP_KERNEL);
+	if (!queue->buffer)
+		return -ENOMEM;
+
+	queue->length = length;
+	queue->stride = stride;
+
+	return 0;
+}
+
+static inline void destroy_shadow_queue(struct shadow_queue *queue)
+{
+	kvfree(queue->buffer);
+}
+
+static inline bool shadow_queue_full(struct shadow_queue *queue)
+{
+	return (queue->prod_idx - queue->cons_idx) >= queue->length;
+}
+
+static inline bool shadow_queue_empty(struct shadow_queue *queue)
+{
+	return queue->prod_idx == queue->cons_idx;
+}
+
+static inline void *
+shadow_queue_get_element(const struct shadow_queue *queue, u64 unmasked_index)
+{
+	u32 index = unmasked_index % queue->length;
+
+	return ((u8 *)queue->buffer + index * queue->stride);
+}
+
+static inline void *
+shadow_queue_producer_entry(struct shadow_queue *queue)
+{
+	return shadow_queue_get_element(queue, queue->prod_idx);
+}
+
+static inline void *
+shadow_queue_get_next_to_consume(const struct shadow_queue *queue)
+{
+	if (queue->cons_idx == queue->next_to_complete_idx)
+		return NULL;
+
+	return shadow_queue_get_element(queue, queue->cons_idx);
+}
+
+static inline void *
+shadow_queue_get_next_to_complete(struct shadow_queue *queue)
+{
+	if (queue->next_to_complete_idx == queue->prod_idx)
+		return NULL;
+
+	return shadow_queue_get_element(queue, queue->next_to_complete_idx);
+}
+
+static inline void shadow_queue_advance_producer(struct shadow_queue *queue)
+{
+	queue->prod_idx++;
+}
+
+static inline void shadow_queue_advance_consumer(struct shadow_queue *queue)
+{
+	queue->cons_idx++;
+}
+
+static inline void shadow_queue_advance_next_to_complete(struct shadow_queue *queue)
+{
+	queue->next_to_complete_idx++;
+}
+
+#endif