// SPDX-License-Identifier: GPL-2.0 /* * System Trace Module (STM) infrastructure apis * Copyright (C) 2014 Intel Corporation. */ #ifndef _STM_H_ #define _STM_H_ #include <linux/device.h> /** * enum stp_packet_type - STP packets that an STM driver sends */ enum stp_packet_type { STP_PACKET_DATA = 0, STP_PACKET_FLAG, STP_PACKET_USER, STP_PACKET_MERR, STP_PACKET_GERR, STP_PACKET_TRIG, STP_PACKET_XSYNC, }; /** * enum stp_packet_flags - STP packet modifiers */ enum stp_packet_flags { STP_PACKET_MARKED = 0x1, STP_PACKET_TIMESTAMPED = 0x2, }; struct stp_policy; struct stm_device; /** * struct stm_data - STM device description and callbacks * @name: device name * @stm: internal structure, only used by stm class code * @sw_start: first STP master available to software * @sw_end: last STP master available to software * @sw_nchannels: number of STP channels per master * @sw_mmiosz: size of one channel's IO space, for mmap, optional * @hw_override: masters in the STP stream will not match the ones * assigned by software, but are up to the STM hardware * @packet: callback that sends an STP packet * @mmio_addr: mmap callback, optional * @link: called when a new stm_source gets linked to us, optional * @unlink: likewise for unlinking, again optional * @set_options: set device-specific options on a channel * * Fill out this structure before calling stm_register_device() to create * an STM device and stm_unregister_device() to destroy it. It will also be * passed back to @packet(), @mmio_addr(), @link(), @unlink() and @set_options() * callbacks. * * Normally, an STM device will have a range of masters available to software * and the rest being statically assigned to various hardware trace sources. * The former is defined by the the range [@sw_start..@sw_end] of the device * description. That is, the lowest master that can be allocated to software * writers is @sw_start and data from this writer will appear is @sw_start * master in the STP stream. * * The @packet callback should adhere to the following rules: * 1) it must return the number of bytes it consumed from the payload; * 2) therefore, if it sent a packet that does not have payload (like FLAG), * it must return zero; * 3) if it does not support the requested packet type/flag combination, * it must return -ENOTSUPP. * * The @unlink callback is called when there are no more active writers so * that the master/channel can be quiesced. */ struct stm_data { const char *name; struct stm_device *stm; unsigned int sw_start; unsigned int sw_end; unsigned int sw_nchannels; unsigned int sw_mmiosz; unsigned int hw_override; ssize_t (*packet)(struct stm_data *, unsigned int, unsigned int, unsigned int, unsigned int, unsigned int, const unsigned char *); phys_addr_t (*mmio_addr)(struct stm_data *, unsigned int, unsigned int, unsigned int); int (*link)(struct stm_data *, unsigned int, unsigned int); void (*unlink)(struct stm_data *, unsigned int, unsigned int); long (*set_options)(struct stm_data *, unsigned int, unsigned int, unsigned int, unsigned long); }; int stm_register_device(struct device *parent, struct stm_data *stm_data, struct module *owner); void stm_unregister_device(struct stm_data *stm_data); struct stm_source_device; /** * struct stm_source_data - STM source device description and callbacks * @name: device name, will be used for policy lookup * @src: internal structure, only used by stm class code * @nr_chans: number of channels to allocate * @link: called when this source gets linked to an STM device * @unlink: called when this source is about to get unlinked from its STM * * Fill in this structure before calling stm_source_register_device() to * register a source device. Also pass it to unregister and write calls. */ struct stm_source_data { const char *name; struct stm_source_device *src; unsigned int percpu; unsigned int nr_chans; int (*link)(struct stm_source_data *data); void (*unlink)(struct stm_source_data *data); }; int stm_source_register_device(struct device *parent, struct stm_source_data *data); void stm_source_unregister_device(struct stm_source_data *data); int notrace stm_source_write(struct stm_source_data *data, unsigned int chan, const char *buf, size_t count); #endif /* _STM_H_ */