diff options
Diffstat (limited to 'include/linux/stm.h')
| -rw-r--r-- | include/linux/stm.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/include/linux/stm.h b/include/linux/stm.h new file mode 100644 index 000000000..3b2268951 --- /dev/null +++ b/include/linux/stm.h @@ -0,0 +1,131 @@ +// 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 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_ */ |