linux/drivers/s390/net/fsm.h
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

267 lines
6.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FSM_H_
#define _FSM_H_
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/atomic.h>
/**
* Define this to get debugging messages.
*/
#define FSM_DEBUG 0
/**
* Define this to get debugging massages for
* timer handling.
*/
#define FSM_TIMER_DEBUG 0
/**
* Define these to record a history of
* Events/Statechanges and print it if a
* action_function is not found.
*/
#define FSM_DEBUG_HISTORY 0
#define FSM_HISTORY_SIZE 40
struct fsm_instance_t;
/**
* Definition of an action function, called by a FSM
*/
typedef void (*fsm_function_t)(struct fsm_instance_t *, int, void *);
/**
* Internal jump table for a FSM
*/
typedef struct {
fsm_function_t *jumpmatrix;
int nr_events;
int nr_states;
const char **event_names;
const char **state_names;
} fsm;
#if FSM_DEBUG_HISTORY
/**
* Element of State/Event history used for debugging.
*/
typedef struct {
int state;
int event;
} fsm_history;
#endif
/**
* Representation of a FSM
*/
typedef struct fsm_instance_t {
fsm *f;
atomic_t state;
char name[16];
void *userdata;
int userint;
wait_queue_head_t wait_q;
#if FSM_DEBUG_HISTORY
int history_index;
int history_size;
fsm_history history[FSM_HISTORY_SIZE];
#endif
} fsm_instance;
/**
* Description of a state-event combination
*/
typedef struct {
int cond_state;
int cond_event;
fsm_function_t function;
} fsm_node;
/**
* Description of a FSM Timer.
*/
typedef struct {
fsm_instance *fi;
struct timer_list tl;
int expire_event;
void *event_arg;
} fsm_timer;
/**
* Creates an FSM
*
* @param name Name of this instance for logging purposes.
* @param state_names An array of names for all states for logging purposes.
* @param event_names An array of names for all events for logging purposes.
* @param nr_states Number of states for this instance.
* @param nr_events Number of events for this instance.
* @param tmpl An array of fsm_nodes, describing this FSM.
* @param tmpl_len Length of the describing array.
* @param order Parameter for allocation of the FSM data structs.
*/
extern fsm_instance *
init_fsm(char *name, const char **state_names,
const char **event_names,
int nr_states, int nr_events, const fsm_node *tmpl,
int tmpl_len, gfp_t order);
/**
* Releases an FSM
*
* @param fi Pointer to an FSM, previously created with init_fsm.
*/
extern void kfree_fsm(fsm_instance *fi);
#if FSM_DEBUG_HISTORY
extern void
fsm_print_history(fsm_instance *fi);
extern void
fsm_record_history(fsm_instance *fi, int state, int event);
#endif
/**
* Emits an event to a FSM.
* If an action function is defined for the current state/event combination,
* this function is called.
*
* @param fi Pointer to FSM which should receive the event.
* @param event The event do be delivered.
* @param arg A generic argument, handed to the action function.
*
* @return 0 on success,
* 1 if current state or event is out of range
* !0 if state and event in range, but no action defined.
*/
static inline int
fsm_event(fsm_instance *fi, int event, void *arg)
{
fsm_function_t r;
int state = atomic_read(&fi->state);
if ((state >= fi->f->nr_states) ||
(event >= fi->f->nr_events) ) {
printk(KERN_ERR "fsm(%s): Invalid state st(%ld/%ld) ev(%d/%ld)\n",
fi->name, (long)state,(long)fi->f->nr_states, event,
(long)fi->f->nr_events);
#if FSM_DEBUG_HISTORY
fsm_print_history(fi);
#endif
return 1;
}
r = fi->f->jumpmatrix[fi->f->nr_states * event + state];
if (r) {
#if FSM_DEBUG
printk(KERN_DEBUG "fsm(%s): state %s event %s\n",
fi->name, fi->f->state_names[state],
fi->f->event_names[event]);
#endif
#if FSM_DEBUG_HISTORY
fsm_record_history(fi, state, event);
#endif
r(fi, event, arg);
return 0;
} else {
#if FSM_DEBUG || FSM_DEBUG_HISTORY
printk(KERN_DEBUG "fsm(%s): no function for event %s in state %s\n",
fi->name, fi->f->event_names[event],
fi->f->state_names[state]);
#endif
#if FSM_DEBUG_HISTORY
fsm_print_history(fi);
#endif
return !0;
}
}
/**
* Modifies the state of an FSM.
* This does <em>not</em> trigger an event or calls an action function.
*
* @param fi Pointer to FSM
* @param state The new state for this FSM.
*/
static inline void
fsm_newstate(fsm_instance *fi, int newstate)
{
atomic_set(&fi->state,newstate);
#if FSM_DEBUG_HISTORY
fsm_record_history(fi, newstate, -1);
#endif
#if FSM_DEBUG
printk(KERN_DEBUG "fsm(%s): New state %s\n", fi->name,
fi->f->state_names[newstate]);
#endif
wake_up(&fi->wait_q);
}
/**
* Retrieves the state of an FSM
*
* @param fi Pointer to FSM
*
* @return The current state of the FSM.
*/
static inline int
fsm_getstate(fsm_instance *fi)
{
return atomic_read(&fi->state);
}
/**
* Retrieves the name of the state of an FSM
*
* @param fi Pointer to FSM
*
* @return The current state of the FSM in a human readable form.
*/
extern const char *fsm_getstate_str(fsm_instance *fi);
/**
* Initializes a timer for an FSM.
* This prepares an fsm_timer for usage with fsm_addtimer.
*
* @param fi Pointer to FSM
* @param timer The timer to be initialized.
*/
extern void fsm_settimer(fsm_instance *fi, fsm_timer *);
/**
* Clears a pending timer of an FSM instance.
*
* @param timer The timer to clear.
*/
extern void fsm_deltimer(fsm_timer *timer);
/**
* Adds and starts a timer to an FSM instance.
*
* @param timer The timer to be added. The field fi of that timer
* must have been set to point to the instance.
* @param millisec Duration, after which the timer should expire.
* @param event Event, to trigger if timer expires.
* @param arg Generic argument, provided to expiry function.
*
* @return 0 on success, -1 if timer is already active.
*/
extern int fsm_addtimer(fsm_timer *timer, int millisec, int event, void *arg);
/**
* Modifies a timer of an FSM.
*
* @param timer The timer to modify.
* @param millisec Duration, after which the timer should expire.
* @param event Event, to trigger if timer expires.
* @param arg Generic argument, provided to expiry function.
*/
extern void fsm_modtimer(fsm_timer *timer, int millisec, int event, void *arg);
#endif /* _FSM_H_ */