1/* SPDX-License-Identifier: MIT */
 2/*
 3 * Copyright © 2016-2019 Intel Corporation
 4 */
 5
 6#ifndef _INTEL_GUC_CT_H_
 7#define _INTEL_GUC_CT_H_
 8
 9#include <linux/spinlock.h>
10#include <linux/workqueue.h>
11
12#include "intel_guc_fwif.h"
13
14struct i915_vma;
15struct intel_guc;
16
17/**
18 * DOC: Command Transport (CT).
19 *
20 * Buffer based command transport is a replacement for MMIO based mechanism.
21 * It can be used to perform both host-2-guc and guc-to-host communication.
22 */
23
24/** Represents single command transport buffer.
25 *
26 * A single command transport buffer consists of two parts, the header
27 * record (command transport buffer descriptor) and the actual buffer which
28 * holds the commands.
29 *
30 * @desc: pointer to the buffer descriptor
31 * @cmds: pointer to the commands buffer
32 */
33struct intel_guc_ct_buffer {
34	struct guc_ct_buffer_desc *desc;
35	u32 *cmds;
36};
37
38/** Represents pair of command transport buffers.
39 *
40 * Buffers go in pairs to allow bi-directional communication.
41 * To simplify the code we place both of them in the same vma.
42 * Buffers from the same pair must share unique owner id.
43 *
44 * @vma: pointer to the vma with pair of CT buffers
45 * @ctbs: buffers for sending(0) and receiving(1) commands
46 * @owner: unique identifier
47 * @next_fence: fence to be used with next send command
48 */
49struct intel_guc_ct_channel {
50	struct i915_vma *vma;
51	struct intel_guc_ct_buffer ctbs[2];
52	u32 owner;
53	u32 next_fence;
54	bool enabled;
55};
56
57/** Holds all command transport channels.
58 *
59 * @host_channel: main channel used by the host
60 */
61struct intel_guc_ct {
62	struct intel_guc_ct_channel host_channel;
63	/* other channels are tbd */
64
65	/** @lock: protects pending requests list */
66	spinlock_t lock;
67
68	/** @pending_requests: list of requests waiting for response */
69	struct list_head pending_requests;
70
71	/** @incoming_requests: list of incoming requests */
72	struct list_head incoming_requests;
73
74	/** @worker: worker for handling incoming requests */
75	struct work_struct worker;
76};
77
78void intel_guc_ct_init_early(struct intel_guc_ct *ct);
79int intel_guc_ct_init(struct intel_guc_ct *ct);
80void intel_guc_ct_fini(struct intel_guc_ct *ct);
81int intel_guc_ct_enable(struct intel_guc_ct *ct);
82void intel_guc_ct_disable(struct intel_guc_ct *ct);
83
84static inline void intel_guc_ct_stop(struct intel_guc_ct *ct)
85{
86	ct->host_channel.enabled = false;
87}
88
89int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len,
90		      u32 *response_buf, u32 response_buf_size);
91void intel_guc_to_host_event_handler_ct(struct intel_guc *guc);
92
93#endif /* _INTEL_GUC_CT_H_ */