1/* SPDX-License-Identifier: MIT */
 2/*
 3 * Copyright © 2024 Intel Corporation
 4 */
 5
 6#ifndef _ABI_GUC_LOG_ABI_H
 7#define _ABI_GUC_LOG_ABI_H
 8
 9#include <linux/types.h>
10
11/* GuC logging buffer types */
12enum guc_log_buffer_type {
13	GUC_LOG_BUFFER_CRASH_DUMP,
14	GUC_LOG_BUFFER_DEBUG,
15	GUC_LOG_BUFFER_CAPTURE,
16};
17
18#define GUC_LOG_BUFFER_TYPE_MAX		3
19
20/**
21 * struct guc_log_buffer_state - GuC log buffer state
22 *
23 * Below state structure is used for coordination of retrieval of GuC firmware
24 * logs. Separate state is maintained for each log buffer type.
25 * read_ptr points to the location where Xe read last in log buffer and
26 * is read only for GuC firmware. write_ptr is incremented by GuC with number
27 * of bytes written for each log entry and is read only for Xe.
28 * When any type of log buffer becomes half full, GuC sends a flush interrupt.
29 * GuC firmware expects that while it is writing to 2nd half of the buffer,
30 * first half would get consumed by Host and then get a flush completed
31 * acknowledgment from Host, so that it does not end up doing any overwrite
32 * causing loss of logs. So when buffer gets half filled & Xe has requested
33 * for interrupt, GuC will set flush_to_file field, set the sampled_write_ptr
34 * to the value of write_ptr and raise the interrupt.
35 * On receiving the interrupt Xe should read the buffer, clear flush_to_file
36 * field and also update read_ptr with the value of sample_write_ptr, before
37 * sending an acknowledgment to GuC. marker & version fields are for internal
38 * usage of GuC and opaque to Xe. buffer_full_cnt field is incremented every
39 * time GuC detects the log buffer overflow.
40 */
41struct guc_log_buffer_state {
42	/** @marker: buffer state start marker */
43	u32 marker[2];
44	/** @read_ptr: the last byte offset that was read by KMD previously */
45	u32 read_ptr;
46	/**
47	 * @write_ptr: the next byte offset location that will be written by
48	 * GuC
49	 */
50	u32 write_ptr;
51	/** @size: Log buffer size */
52	u32 size;
53	/**
54	 * @sampled_write_ptr: Log buffer write pointer
55	 * This is written by GuC to the byte offset of the next free entry in
56	 * the buffer on log buffer half full or state capture notification
57	 */
58	u32 sampled_write_ptr;
59	/**
60	 * @wrap_offset: wraparound offset
61	 * This is the byte offset of location 1 byte after last valid guc log
62	 * event entry written by Guc firmware before there was a wraparound.
63	 * This field is updated by guc firmware and should be used by Host
64	 * when copying buffer contents to file.
65	 */
66	u32 wrap_offset;
67	/** @flags: Flush to file flag and buffer full count */
68	u32 flags;
69#define	GUC_LOG_BUFFER_STATE_FLUSH_TO_FILE	GENMASK(0, 0)
70#define	GUC_LOG_BUFFER_STATE_BUFFER_FULL_CNT	GENMASK(4, 1)
71	/** @version: The Guc-Log-Entry format version */
72	u32 version;
73} __packed;
74
75#endif