cregit-Linux how code gets into the kernel

Release 4.12 include/linux/stm.h

Directory: include/linux
 * System Trace Module (STM) infrastructure apis
 * Copyright (C) 2014 Intel Corporation.
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.

#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 {

 * enum stp_packet_flags - STP packet modifiers

enum stp_packet_flags {

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_ */

Overall Contributors

Alexander Shishkin32099.69%266.67%
Chunyan Zhang10.31%133.33%
Directory: include/linux
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