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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - include/linux/stm.h
1 // SPDX-License-Identifier: GPL-2.0
3 * System Trace Module (STM) infrastructure apis
4 * Copyright (C) 2014 Intel Corporation.
10 #include <linux/device.h>
13 * enum stp_packet_type - STP packets that an STM driver sends
15 enum stp_packet_type
{
26 * enum stp_packet_flags - STP packet modifiers
28 enum stp_packet_flags
{
29 STP_PACKET_MARKED
= 0x1,
30 STP_PACKET_TIMESTAMPED
= 0x2,
38 * struct stm_data - STM device description and callbacks
40 * @stm: internal structure, only used by stm class code
41 * @sw_start: first STP master available to software
42 * @sw_end: last STP master available to software
43 * @sw_nchannels: number of STP channels per master
44 * @sw_mmiosz: size of one channel's IO space, for mmap, optional
45 * @hw_override: masters in the STP stream will not match the ones
46 * assigned by software, but are up to the STM hardware
47 * @packet: callback that sends an STP packet
48 * @mmio_addr: mmap callback, optional
49 * @link: called when a new stm_source gets linked to us, optional
50 * @unlink: likewise for unlinking, again optional
51 * @set_options: set device-specific options on a channel
53 * Fill out this structure before calling stm_register_device() to create
54 * an STM device and stm_unregister_device() to destroy it. It will also be
55 * passed back to @packet(), @mmio_addr(), @link(), @unlink() and @set_options()
58 * Normally, an STM device will have a range of masters available to software
59 * and the rest being statically assigned to various hardware trace sources.
60 * The former is defined by the the range [@sw_start..@sw_end] of the device
61 * description. That is, the lowest master that can be allocated to software
62 * writers is @sw_start and data from this writer will appear is @sw_start
63 * master in the STP stream.
65 * The @packet callback should adhere to the following rules:
66 * 1) it must return the number of bytes it consumed from the payload;
67 * 2) therefore, if it sent a packet that does not have payload (like FLAG),
68 * it must return zero;
69 * 3) if it does not support the requested packet type/flag combination,
70 * it must return -ENOTSUPP.
72 * The @unlink callback is called when there are no more active writers so
73 * that the master/channel can be quiesced.
77 struct stm_device
*stm
;
78 unsigned int sw_start
;
80 unsigned int sw_nchannels
;
81 unsigned int sw_mmiosz
;
82 unsigned int hw_override
;
83 ssize_t (*packet
)(struct stm_data
*, unsigned int,
84 unsigned int, unsigned int,
85 unsigned int, unsigned int,
86 const unsigned char *);
87 phys_addr_t (*mmio_addr
)(struct stm_data
*, unsigned int,
88 unsigned int, unsigned int);
89 int (*link
)(struct stm_data
*, unsigned int,
91 void (*unlink
)(struct stm_data
*, unsigned int,
93 long (*set_options
)(struct stm_data
*, unsigned int,
94 unsigned int, unsigned int,
98 int stm_register_device(struct device
*parent
, struct stm_data
*stm_data
,
99 struct module
*owner
);
100 void stm_unregister_device(struct stm_data
*stm_data
);
102 struct stm_source_device
;
105 * struct stm_source_data - STM source device description and callbacks
106 * @name: device name, will be used for policy lookup
107 * @src: internal structure, only used by stm class code
108 * @nr_chans: number of channels to allocate
109 * @link: called when this source gets linked to an STM device
110 * @unlink: called when this source is about to get unlinked from its STM
112 * Fill in this structure before calling stm_source_register_device() to
113 * register a source device. Also pass it to unregister and write calls.
115 struct stm_source_data
{
117 struct stm_source_device
*src
;
119 unsigned int nr_chans
;
120 int (*link
)(struct stm_source_data
*data
);
121 void (*unlink
)(struct stm_source_data
*data
);
124 int stm_source_register_device(struct device
*parent
,
125 struct stm_source_data
*data
);
126 void stm_source_unregister_device(struct stm_source_data
*data
);
128 int notrace
stm_source_write(struct stm_source_data
*data
, unsigned int chan
,
129 const char *buf
, size_t count
);