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 * @hw_override: masters in the STP stream will not match the ones 54 * assigned by software, but are up to the STM hardware 55 * @packet: callback that sends an STP packet 56 * @mmio_addr: mmap callback, optional 57 * @link: called when a new stm_source gets linked to us, optional 58 * @unlink: likewise for unlinking, again optional 59 * @set_options: set device-specific options on a channel 60 * 61 * Fill out this structure before calling stm_register_device() to create 62 * an STM device and stm_unregister_device() to destroy it. It will also be 63 * passed back to @packet(), @mmio_addr(), @link(), @unlink() and @set_options() 64 * callbacks. 65 * 66 * Normally, an STM device will have a range of masters available to software 67 * and the rest being statically assigned to various hardware trace sources. 68 * The former is defined by the the range [@sw_start..@sw_end] of the device 69 * description. That is, the lowest master that can be allocated to software 70 * writers is @sw_start and data from this writer will appear is @sw_start 71 * master in the STP stream. 72 * 73 * The @packet callback should adhere to the following rules: 74 * 1) it must return the number of bytes it consumed from the payload; 75 * 2) therefore, if it sent a packet that does not have payload (like FLAG), 76 * it must return zero; 77 * 3) if it does not support the requested packet type/flag combination, 78 * it must return -ENOTSUPP. 79 * 80 * The @unlink callback is called when there are no more active writers so 81 * that the master/channel can be quiesced. 82 */ 83 struct stm_data { 84 const char *name; 85 struct stm_device *stm; 86 unsigned int sw_start; 87 unsigned int sw_end; 88 unsigned int sw_nchannels; 89 unsigned int sw_mmiosz; 90 unsigned int hw_override; 91 ssize_t (*packet)(struct stm_data *, unsigned int, 92 unsigned int, unsigned int, 93 unsigned int, unsigned int, 94 const unsigned char *); 95 phys_addr_t (*mmio_addr)(struct stm_data *, unsigned int, 96 unsigned int, unsigned int); 97 int (*link)(struct stm_data *, unsigned int, 98 unsigned int); 99 void (*unlink)(struct stm_data *, unsigned int, 100 unsigned int); 101 long (*set_options)(struct stm_data *, unsigned int, 102 unsigned int, unsigned int, 103 unsigned long); 104 }; 105 106 int stm_register_device(struct device *parent, struct stm_data *stm_data, 107 struct module *owner); 108 void stm_unregister_device(struct stm_data *stm_data); 109 110 struct stm_source_device; 111 112 /** 113 * struct stm_source_data - STM source device description and callbacks 114 * @name: device name, will be used for policy lookup 115 * @src: internal structure, only used by stm class code 116 * @nr_chans: number of channels to allocate 117 * @link: called when this source gets linked to an STM device 118 * @unlink: called when this source is about to get unlinked from its STM 119 * 120 * Fill in this structure before calling stm_source_register_device() to 121 * register a source device. Also pass it to unregister and write calls. 122 */ 123 struct stm_source_data { 124 const char *name; 125 struct stm_source_device *src; 126 unsigned int percpu; 127 unsigned int nr_chans; 128 int (*link)(struct stm_source_data *data); 129 void (*unlink)(struct stm_source_data *data); 130 }; 131 132 int stm_source_register_device(struct device *parent, 133 struct stm_source_data *data); 134 void stm_source_unregister_device(struct stm_source_data *data); 135 136 int notrace stm_source_write(struct stm_source_data *data, unsigned int chan, 137 const char *buf, size_t count); 138 139 #endif /* _STM_H_ */ 140