1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Intel(R) Trace Hub data structures for implementing buffer sinks.
4 *
5 * Copyright (C) 2019 Intel Corporation.
6 */
7
8#ifndef _INTEL_TH_H_
9#define _INTEL_TH_H_
10
11#include <linux/scatterlist.h>
12
13/* MSC operating modes (MSC_MODE) */
14enum {
15	MSC_MODE_SINGLE	= 0,
16	MSC_MODE_MULTI,
17	MSC_MODE_EXI,
18	MSC_MODE_DEBUG,
19};
20
21struct msu_buffer {
22	const char	*name;
23	/*
24	 * ->assign() called when buffer 'mode' is set to this driver
25	 *   (aka mode_store())
26	 * @device:	struct device * of the msc
27	 * @mode:	allows the driver to set HW mode (see the enum above)
28	 * Returns:	a pointer to a private structure associated with this
29	 *		msc or NULL in case of error. This private structure
30	 *		will then be passed into all other callbacks.
31	 */
32	void	*(*assign)(struct device *dev, int *mode);
33	/* ->unassign():	some other mode is selected, clean up */
34	void	(*unassign)(void *priv);
35	/*
36	 * ->alloc_window(): allocate memory for the window of a given
37	 *		size
38	 * @sgt:	pointer to sg_table, can be overridden by the buffer
39	 *		driver, or kept intact
40	 * Returns:	number of sg table entries <= number of pages;
41	 *		0 is treated as an allocation failure.
42	 */
43	int	(*alloc_window)(void *priv, struct sg_table **sgt,
44				size_t size);
45	void	(*free_window)(void *priv, struct sg_table *sgt);
46	/* ->activate():	trace has started */
47	void	(*activate)(void *priv);
48	/* ->deactivate():	trace is about to stop */
49	void	(*deactivate)(void *priv);
50	/*
51	 * ->ready():	window @sgt is filled up to the last block OR
52	 *		tracing is stopped by the user; this window contains
53	 *		@bytes data. The window in question transitions into
54	 *		the "LOCKED" state, indicating that it can't be used
55	 *		by hardware. To clear this state and make the window
56	 *		available to the hardware again, call
57	 *		intel_th_msc_window_unlock().
58	 */
59	int	(*ready)(void *priv, struct sg_table *sgt, size_t bytes);
60};
61
62int intel_th_msu_buffer_register(const struct msu_buffer *mbuf,
63				 struct module *owner);
64void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf);
65void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt);
66
67#define module_intel_th_msu_buffer(__buffer) \
68static int __init __buffer##_init(void) \
69{ \
70	return intel_th_msu_buffer_register(&(__buffer), THIS_MODULE); \
71} \
72module_init(__buffer##_init); \
73static void __exit __buffer##_exit(void) \
74{ \
75	intel_th_msu_buffer_unregister(&(__buffer)); \
76} \
77module_exit(__buffer##_exit);
78
79#endif /* _INTEL_TH_H_ */
80