1 /* 2 * System Trace Module (STM) infrastructure apis 3 * Copyright (C) 2014 Intel Corporation. 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms and conditions of the GNU General Public License, 7 * version 2, as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 */ 14 15 #ifndef _STM_H_ 16 #define _STM_H_ 17 18 #include <linux/device.h> 19 20 /** 21 * enum stp_packet_type - STP packets that an STM driver sends 22 */ 23 enum stp_packet_type { 24 STP_PACKET_DATA = 0, 25 STP_PACKET_FLAG, 26 STP_PACKET_USER, 27 STP_PACKET_MERR, 28 STP_PACKET_GERR, 29 STP_PACKET_TRIG, 30 STP_PACKET_XSYNC, 31 }; 32 33 /** 34 * enum stp_packet_flags - STP packet modifiers 35 */ 36 enum stp_packet_flags { 37 STP_PACKET_MARKED = 0x1, 38 STP_PACKET_TIMESTAMPED = 0x2, 39 }; 40 41 struct stp_policy; 42 43 struct stm_device; 44 45 /** 46 * struct stm_data - STM device description and callbacks 47 * @name: device name 48 * @stm: internal structure, only used by stm class code 49 * @sw_start: first STP master available to software 50 * @sw_end: last STP master available to software 51 * @sw_nchannels: number of STP channels per master 52 * @sw_mmiosz: size of one channel's IO space, for mmap, optional 53 * @packet: callback that sends an STP packet 54 * @mmio_addr: mmap callback, optional 55 * @link: called when a new stm_source gets linked to us, optional 56 * @unlink: likewise for unlinking, again optional 57 * @set_options: set device-specific options on a channel 58 * 59 * Fill out this structure before calling stm_register_device() to create 60 * an STM device and stm_unregister_device() to destroy it. It will also be 61 * passed back to @packet(), @mmio_addr(), @link(), @unlink() and @set_options() 62 * callbacks. 63 * 64 * Normally, an STM device will have a range of masters available to software 65 * and the rest being statically assigned to various hardware trace sources. 66 * The former is defined by the the range [@sw_start..@sw_end] of the device 67 * description. That is, the lowest master that can be allocated to software 68 * writers is @sw_start and data from this writer will appear is @sw_start 69 * master in the STP stream. 70 * 71 * The @packet callback should adhere to the following rules: 72 * 1) it must return the number of bytes it consumed from the payload; 73 * 2) therefore, if it sent a packet that does not have payload (like FLAG), 74 * it must return zero; 75 * 3) if it does not support the requested packet type/flag combination, 76 * it must return -ENOTSUPP. 77 * 78 * The @unlink callback is called when there are no more active writers so 79 * that the master/channel can be quiesced. 80 */ 81 struct stm_data { 82 const char *name; 83 struct stm_device *stm; 84 unsigned int sw_start; 85 unsigned int sw_end; 86 unsigned int sw_nchannels; 87 unsigned int sw_mmiosz; 88 ssize_t (*packet)(struct stm_data *, unsigned int, 89 unsigned int, unsigned int, 90 unsigned int, unsigned int, 91 const unsigned char *); 92 phys_addr_t (*mmio_addr)(struct stm_data *, unsigned int, 93 unsigned int, unsigned int); 94 int (*link)(struct stm_data *, unsigned int, 95 unsigned int); 96 void (*unlink)(struct stm_data *, unsigned int, 97 unsigned int); 98 long (*set_options)(struct stm_data *, unsigned int, 99 unsigned int, unsigned int, 100 unsigned long); 101 }; 102 103 int stm_register_device(struct device *parent, struct stm_data *stm_data, 104 struct module *owner); 105 void stm_unregister_device(struct stm_data *stm_data); 106 107 struct stm_source_device; 108 109 /** 110 * struct stm_source_data - STM source device description and callbacks 111 * @name: device name, will be used for policy lookup 112 * @src: internal structure, only used by stm class code 113 * @nr_chans: number of channels to allocate 114 * @link: called when this source gets linked to an STM device 115 * @unlink: called when this source is about to get unlinked from its STM 116 * 117 * Fill in this structure before calling stm_source_register_device() to 118 * register a source device. Also pass it to unregister and write calls. 119 */ 120 struct stm_source_data { 121 const char *name; 122 struct stm_source_device *src; 123 unsigned int percpu; 124 unsigned int nr_chans; 125 int (*link)(struct stm_source_data *data); 126 void (*unlink)(struct stm_source_data *data); 127 }; 128 129 int stm_source_register_device(struct device *parent, 130 struct stm_source_data *data); 131 void stm_source_unregister_device(struct stm_source_data *data); 132 133 int stm_source_write(struct stm_source_data *data, unsigned int chan, 134 const char *buf, size_t count); 135 136 #endif /* _STM_H_ */ 137