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) */ |
14 | enum { |
15 | MSC_MODE_SINGLE = 0, |
16 | MSC_MODE_MULTI, |
17 | MSC_MODE_EXI, |
18 | MSC_MODE_DEBUG, |
19 | }; |
20 | |
21 | struct 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 | |
62 | int intel_th_msu_buffer_register(const struct msu_buffer *mbuf, |
63 | struct module *owner); |
64 | void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf); |
65 | void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt); |
66 | |
67 | #define module_intel_th_msu_buffer(__buffer) \ |
68 | static int __init __buffer##_init(void) \ |
69 | { \ |
70 | return intel_th_msu_buffer_register(&(__buffer), THIS_MODULE); \ |
71 | } \ |
72 | module_init(__buffer##_init); \ |
73 | static void __exit __buffer##_exit(void) \ |
74 | { \ |
75 | intel_th_msu_buffer_unregister(&(__buffer)); \ |
76 | } \ |
77 | module_exit(__buffer##_exit); |
78 | |
79 | #endif /* _INTEL_TH_H_ */ |
80 | |