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 
14 struct i915_vma;
15 struct 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  */
33 struct 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  */
49 struct 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  */
61 struct 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 
78 void intel_guc_ct_init_early(struct intel_guc_ct *ct);
79 int intel_guc_ct_init(struct intel_guc_ct *ct);
80 void intel_guc_ct_fini(struct intel_guc_ct *ct);
81 int intel_guc_ct_enable(struct intel_guc_ct *ct);
82 void intel_guc_ct_disable(struct intel_guc_ct *ct);
83 
84 static inline void intel_guc_ct_stop(struct intel_guc_ct *ct)
85 {
86 	ct->host_channel.enabled = false;
87 }
88 
89 int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len,
90 		      u32 *response_buf, u32 response_buf_size);
91 void intel_guc_to_host_event_handler_ct(struct intel_guc *guc);
92 
93 #endif /* _INTEL_GUC_CT_H_ */
94