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>
2017-11-01 14:07:57 +00:00
|
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/* SPDX-License-Identifier: GPL-2.0 */
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2010-09-17 15:09:00 +00:00
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#ifndef _LINUX_JUMP_LABEL_H
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#define _LINUX_JUMP_LABEL_H
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2012-01-26 12:32:15 +00:00
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/*
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* Jump label support
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*
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* Copyright (C) 2009-2012 Jason Baron <jbaron@redhat.com>
|
2015-11-16 10:08:45 +00:00
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* Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra
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2012-01-26 12:32:15 +00:00
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*
|
2015-07-30 03:59:48 +00:00
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* DEPRECATED API:
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*
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* The use of 'struct static_key' directly, is now DEPRECATED. In addition
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* static_key_{true,false}() is also DEPRECATED. IE DO NOT use the following:
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*
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* struct static_key false = STATIC_KEY_INIT_FALSE;
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* struct static_key true = STATIC_KEY_INIT_TRUE;
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* static_key_true()
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* static_key_false()
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*
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* The updated API replacements are:
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*
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* DEFINE_STATIC_KEY_TRUE(key);
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* DEFINE_STATIC_KEY_FALSE(key);
|
2016-09-05 17:25:47 +00:00
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* DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count);
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* DEFINE_STATIC_KEY_ARRAY_FALSE(keys, count);
|
2015-09-14 23:11:05 +00:00
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* static_branch_likely()
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* static_branch_unlikely()
|
2015-07-30 03:59:48 +00:00
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*
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2012-01-26 12:32:15 +00:00
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* Jump labels provide an interface to generate dynamic branches using
|
2015-07-30 03:59:48 +00:00
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* self-modifying code. Assuming toolchain and architecture support, if we
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* define a "key" that is initially false via "DEFINE_STATIC_KEY_FALSE(key)",
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* an "if (static_branch_unlikely(&key))" statement is an unconditional branch
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* (which defaults to false - and the true block is placed out of line).
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* Similarly, we can define an initially true key via
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* "DEFINE_STATIC_KEY_TRUE(key)", and use it in the same
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* "if (static_branch_unlikely(&key))", in which case we will generate an
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* unconditional branch to the out-of-line true branch. Keys that are
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* initially true or false can be using in both static_branch_unlikely()
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* and static_branch_likely() statements.
|
2012-01-26 12:32:15 +00:00
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*
|
2015-07-30 03:59:48 +00:00
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* At runtime we can change the branch target by setting the key
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* to true via a call to static_branch_enable(), or false using
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* static_branch_disable(). If the direction of the branch is switched by
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* these calls then we run-time modify the branch target via a
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* no-op -> jump or jump -> no-op conversion. For example, for an
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* initially false key that is used in an "if (static_branch_unlikely(&key))"
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* statement, setting the key to true requires us to patch in a jump
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* to the out-of-line of true branch.
|
2012-01-26 12:32:15 +00:00
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*
|
2015-09-14 23:11:05 +00:00
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* In addition to static_branch_{enable,disable}, we can also reference count
|
2015-07-30 03:59:48 +00:00
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* the key or branch direction via static_branch_{inc,dec}. Thus,
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* static_branch_inc() can be thought of as a 'make more true' and
|
2015-09-14 23:11:05 +00:00
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* static_branch_dec() as a 'make more false'.
|
2015-07-30 03:59:48 +00:00
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*
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* Since this relies on modifying code, the branch modifying functions
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2012-01-26 12:32:15 +00:00
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* must be considered absolute slow paths (machine wide synchronization etc.).
|
2014-08-10 06:53:39 +00:00
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* OTOH, since the affected branches are unconditional, their runtime overhead
|
2012-01-26 12:32:15 +00:00
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* will be absolutely minimal, esp. in the default (off) case where the total
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* effect is a single NOP of appropriate size. The on case will patch in a jump
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* to the out-of-line block.
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*
|
2014-08-10 06:53:39 +00:00
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* When the control is directly exposed to userspace, it is prudent to delay the
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2012-01-26 12:32:15 +00:00
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* decrement to avoid high frequency code modifications which can (and do)
|
2012-02-24 07:31:31 +00:00
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* cause significant performance degradation. Struct static_key_deferred and
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* static_key_slow_dec_deferred() provide for this.
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2012-01-26 12:32:15 +00:00
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*
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2015-07-30 03:59:48 +00:00
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* Lacking toolchain and or architecture support, static keys fall back to a
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* simple conditional branch.
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2012-02-24 07:31:31 +00:00
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*
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2015-07-30 03:59:48 +00:00
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* Additional babbling in: Documentation/static-keys.txt
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2014-08-10 06:53:39 +00:00
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*/
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2012-01-26 12:32:15 +00:00
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2015-04-09 03:51:31 +00:00
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#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
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# define HAVE_JUMP_LABEL
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#endif
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#ifndef __ASSEMBLY__
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2011-03-16 21:29:47 +00:00
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#include <linux/types.h>
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#include <linux/compiler.h>
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2013-10-19 19:48:53 +00:00
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extern bool static_key_initialized;
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2017-10-18 15:24:28 +00:00
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#define STATIC_KEY_CHECK_USE(key) WARN(!static_key_initialized, \
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"%s(): static key '%pS' used before call to jump_label_init()", \
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__func__, (key))
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2011-03-16 21:29:47 +00:00
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2015-04-09 03:51:31 +00:00
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#ifdef HAVE_JUMP_LABEL
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2011-03-16 21:29:47 +00:00
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2012-02-24 07:31:31 +00:00
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struct static_key {
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2011-03-16 21:29:47 +00:00
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atomic_t enabled;
|
jump_label: Reduce the size of struct static_key
The static_key->next field goes mostly unused. The field is used for
associating module uses with a static key. Most uses of struct static_key
define a static key in the core kernel and make use of it entirely within
the core kernel, or define the static key in a module and make use of it
only from within that module. In fact, of the ~3,000 static keys defined,
I found only about 5 or so that did not fit this pattern.
Thus, we can remove the static_key->next field entirely and overload
the static_key->entries field. That is, when all the static_key uses
are contained within the same module, static_key->entries continues
to point to those uses. However, if the static_key uses are not contained
within the module where the static_key is defined, then we allocate a
struct static_key_mod, store a pointer to the uses within that
struct static_key_mod, and have the static key point at the static_key_mod.
This does incur some extra memory usage when a static_key is used in a
module that does not define it, but since there are only a handful of such
cases there is a net savings.
In order to identify if the static_key->entries pointer contains a
struct static_key_mod or a struct jump_entry pointer, bit 1 of
static_key->entries is set to 1 if it points to a struct static_key_mod and
is 0 if it points to a struct jump_entry. We were already using bit 0 in a
similar way to store the initial value of the static_key. This does mean
that allocations of struct static_key_mod and that the struct jump_entry
tables need to be at least 4-byte aligned in memory. As far as I can tell
all arches meet this criteria.
For my .config, the patch increased the text by 778 bytes, but reduced
the data + bss size by 14912, for a net savings of 14,134 bytes.
text data bss dec hex filename
8092427 5016512 790528 13899467 d416cb vmlinux.pre
8093205 5001600 790528 13885333 d3df95 vmlinux.post
Link: http://lkml.kernel.org/r/1486154544-4321-1-git-send-email-jbaron@akamai.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-02-03 20:42:24 +00:00
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|
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/*
|
2017-03-02 22:28:45 +00:00
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|
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* Note:
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|
* To make anonymous unions work with old compilers, the static
|
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* initialization of them requires brackets. This creates a dependency
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* on the order of the struct with the initializers. If any fields
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* are added, STATIC_KEY_INIT_TRUE and STATIC_KEY_INIT_FALSE may need
|
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* to be modified.
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*
|
jump_label: Reduce the size of struct static_key
The static_key->next field goes mostly unused. The field is used for
associating module uses with a static key. Most uses of struct static_key
define a static key in the core kernel and make use of it entirely within
the core kernel, or define the static key in a module and make use of it
only from within that module. In fact, of the ~3,000 static keys defined,
I found only about 5 or so that did not fit this pattern.
Thus, we can remove the static_key->next field entirely and overload
the static_key->entries field. That is, when all the static_key uses
are contained within the same module, static_key->entries continues
to point to those uses. However, if the static_key uses are not contained
within the module where the static_key is defined, then we allocate a
struct static_key_mod, store a pointer to the uses within that
struct static_key_mod, and have the static key point at the static_key_mod.
This does incur some extra memory usage when a static_key is used in a
module that does not define it, but since there are only a handful of such
cases there is a net savings.
In order to identify if the static_key->entries pointer contains a
struct static_key_mod or a struct jump_entry pointer, bit 1 of
static_key->entries is set to 1 if it points to a struct static_key_mod and
is 0 if it points to a struct jump_entry. We were already using bit 0 in a
similar way to store the initial value of the static_key. This does mean
that allocations of struct static_key_mod and that the struct jump_entry
tables need to be at least 4-byte aligned in memory. As far as I can tell
all arches meet this criteria.
For my .config, the patch increased the text by 778 bytes, but reduced
the data + bss size by 14912, for a net savings of 14,134 bytes.
text data bss dec hex filename
8092427 5016512 790528 13899467 d416cb vmlinux.pre
8093205 5001600 790528 13885333 d3df95 vmlinux.post
Link: http://lkml.kernel.org/r/1486154544-4321-1-git-send-email-jbaron@akamai.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-02-03 20:42:24 +00:00
|
|
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* bit 0 => 1 if key is initially true
|
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* 0 if initially false
|
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* bit 1 => 1 if points to struct static_key_mod
|
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* 0 if points to struct jump_entry
|
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|
*/
|
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union {
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unsigned long type;
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struct jump_entry *entries;
|
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struct static_key_mod *next;
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};
|
2011-03-16 21:29:47 +00:00
|
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};
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|
2014-06-04 23:10:07 +00:00
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#else
|
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struct static_key {
|
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atomic_t enabled;
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};
|
2015-04-09 03:51:31 +00:00
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#endif /* HAVE_JUMP_LABEL */
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#endif /* __ASSEMBLY__ */
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#ifdef HAVE_JUMP_LABEL
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#include <asm/jump_label.h>
|
|
|
|
#endif
|
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#ifndef __ASSEMBLY__
|
2010-09-17 15:09:00 +00:00
|
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enum jump_label_type {
|
2015-07-24 12:45:44 +00:00
|
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|
JUMP_LABEL_NOP = 0,
|
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|
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JUMP_LABEL_JMP,
|
2010-09-17 15:09:00 +00:00
|
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|
};
|
|
|
|
|
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struct module;
|
|
|
|
|
2016-06-21 16:52:17 +00:00
|
|
|
#ifdef HAVE_JUMP_LABEL
|
|
|
|
|
jump_label: Reduce the size of struct static_key
The static_key->next field goes mostly unused. The field is used for
associating module uses with a static key. Most uses of struct static_key
define a static key in the core kernel and make use of it entirely within
the core kernel, or define the static key in a module and make use of it
only from within that module. In fact, of the ~3,000 static keys defined,
I found only about 5 or so that did not fit this pattern.
Thus, we can remove the static_key->next field entirely and overload
the static_key->entries field. That is, when all the static_key uses
are contained within the same module, static_key->entries continues
to point to those uses. However, if the static_key uses are not contained
within the module where the static_key is defined, then we allocate a
struct static_key_mod, store a pointer to the uses within that
struct static_key_mod, and have the static key point at the static_key_mod.
This does incur some extra memory usage when a static_key is used in a
module that does not define it, but since there are only a handful of such
cases there is a net savings.
In order to identify if the static_key->entries pointer contains a
struct static_key_mod or a struct jump_entry pointer, bit 1 of
static_key->entries is set to 1 if it points to a struct static_key_mod and
is 0 if it points to a struct jump_entry. We were already using bit 0 in a
similar way to store the initial value of the static_key. This does mean
that allocations of struct static_key_mod and that the struct jump_entry
tables need to be at least 4-byte aligned in memory. As far as I can tell
all arches meet this criteria.
For my .config, the patch increased the text by 778 bytes, but reduced
the data + bss size by 14912, for a net savings of 14,134 bytes.
text data bss dec hex filename
8092427 5016512 790528 13899467 d416cb vmlinux.pre
8093205 5001600 790528 13885333 d3df95 vmlinux.post
Link: http://lkml.kernel.org/r/1486154544-4321-1-git-send-email-jbaron@akamai.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-02-03 20:42:24 +00:00
|
|
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#define JUMP_TYPE_FALSE 0UL
|
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#define JUMP_TYPE_TRUE 1UL
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#define JUMP_TYPE_LINKED 2UL
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#define JUMP_TYPE_MASK 3UL
|
2012-02-24 07:31:31 +00:00
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static __always_inline bool static_key_false(struct static_key *key)
|
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{
|
2015-07-24 13:09:55 +00:00
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return arch_static_branch(key, false);
|
2012-02-24 07:31:31 +00:00
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}
|
2011-03-16 21:29:47 +00:00
|
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|
2012-02-24 07:31:31 +00:00
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static __always_inline bool static_key_true(struct static_key *key)
|
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{
|
2015-07-24 13:09:55 +00:00
|
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return !arch_static_branch(key, true);
|
2012-02-24 07:31:31 +00:00
|
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}
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|
2010-09-17 15:09:00 +00:00
|
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extern struct jump_entry __start___jump_table[];
|
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|
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extern struct jump_entry __stop___jump_table[];
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|
|
2011-10-12 23:17:54 +00:00
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|
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extern void jump_label_init(void);
|
2010-10-01 21:23:48 +00:00
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extern void jump_label_lock(void);
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extern void jump_label_unlock(void);
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2010-09-17 15:09:00 +00:00
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|
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extern void arch_jump_label_transform(struct jump_entry *entry,
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2011-09-29 18:10:05 +00:00
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enum jump_label_type type);
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2011-10-03 18:01:46 +00:00
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|
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extern void arch_jump_label_transform_static(struct jump_entry *entry,
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enum jump_label_type type);
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2010-09-17 15:09:08 +00:00
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extern int jump_label_text_reserved(void *start, void *end);
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2012-02-24 07:31:31 +00:00
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|
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extern void static_key_slow_inc(struct static_key *key);
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extern void static_key_slow_dec(struct static_key *key);
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2011-03-16 21:29:47 +00:00
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extern void jump_label_apply_nops(struct module *mod);
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2016-08-03 20:46:36 +00:00
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extern int static_key_count(struct static_key *key);
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extern void static_key_enable(struct static_key *key);
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extern void static_key_disable(struct static_key *key);
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2017-08-01 08:02:56 +00:00
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extern void static_key_enable_cpuslocked(struct static_key *key);
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extern void static_key_disable_cpuslocked(struct static_key *key);
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2012-02-24 07:31:31 +00:00
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|
2016-08-03 20:46:36 +00:00
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|
|
/*
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|
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* We should be using ATOMIC_INIT() for initializing .enabled, but
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* the inclusion of atomic.h is problematic for inclusion of jump_label.h
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* in 'low-level' headers. Thus, we are initializing .enabled with a
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* raw value, but have added a BUILD_BUG_ON() to catch any issues in
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* jump_label_init() see: kernel/jump_label.c.
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*/
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2015-07-24 13:09:55 +00:00
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#define STATIC_KEY_INIT_TRUE \
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2016-08-03 20:46:36 +00:00
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{ .enabled = { 1 }, \
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2017-02-28 16:32:22 +00:00
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{ .entries = (void *)JUMP_TYPE_TRUE } }
|
2015-07-24 13:09:55 +00:00
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|
#define STATIC_KEY_INIT_FALSE \
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2016-08-03 20:46:36 +00:00
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{ .enabled = { 0 }, \
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2017-02-28 16:32:22 +00:00
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{ .entries = (void *)JUMP_TYPE_FALSE } }
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2010-09-17 15:09:00 +00:00
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|
2011-10-12 23:17:54 +00:00
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#else /* !HAVE_JUMP_LABEL */
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2010-09-17 15:09:00 +00:00
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|
2016-08-03 20:46:36 +00:00
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#include <linux/atomic.h>
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#include <linux/bug.h>
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2016-06-21 16:52:17 +00:00
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static inline int static_key_count(struct static_key *key)
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{
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return atomic_read(&key->enabled);
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}
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2011-10-12 23:17:54 +00:00
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static __always_inline void jump_label_init(void)
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{
|
2013-10-19 19:48:53 +00:00
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static_key_initialized = true;
|
2011-10-12 23:17:54 +00:00
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|
}
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2012-02-24 07:31:31 +00:00
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static __always_inline bool static_key_false(struct static_key *key)
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{
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2014-06-04 23:10:07 +00:00
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|
if (unlikely(static_key_count(key) > 0))
|
2012-02-24 07:31:31 +00:00
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|
return true;
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|
return false;
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}
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static __always_inline bool static_key_true(struct static_key *key)
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2011-03-16 21:29:47 +00:00
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{
|
2014-06-04 23:10:07 +00:00
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|
if (likely(static_key_count(key) > 0))
|
2011-03-16 21:29:47 +00:00
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|
return true;
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return false;
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}
|
2010-09-17 15:09:00 +00:00
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|
2012-02-24 07:31:31 +00:00
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static inline void static_key_slow_inc(struct static_key *key)
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2011-03-16 21:29:47 +00:00
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|
{
|
2017-10-18 15:24:28 +00:00
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STATIC_KEY_CHECK_USE(key);
|
2011-03-16 21:29:47 +00:00
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atomic_inc(&key->enabled);
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}
|
2010-09-17 15:09:00 +00:00
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|
2012-02-24 07:31:31 +00:00
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static inline void static_key_slow_dec(struct static_key *key)
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2010-09-17 15:09:00 +00:00
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|
{
|
2017-10-18 15:24:28 +00:00
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|
|
STATIC_KEY_CHECK_USE(key);
|
2011-03-16 21:29:47 +00:00
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|
atomic_dec(&key->enabled);
|
2010-09-17 15:09:00 +00:00
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}
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|
2010-09-17 15:09:08 +00:00
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static inline int jump_label_text_reserved(void *start, void *end)
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|
{
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return 0;
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}
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|
2010-10-01 21:23:48 +00:00
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static inline void jump_label_lock(void) {}
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static inline void jump_label_unlock(void) {}
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2011-03-16 21:29:47 +00:00
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static inline int jump_label_apply_nops(struct module *mod)
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{
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|
return 0;
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}
|
2011-11-27 15:59:09 +00:00
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|
2015-07-24 13:03:40 +00:00
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static inline void static_key_enable(struct static_key *key)
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{
|
2017-10-18 15:24:28 +00:00
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STATIC_KEY_CHECK_USE(key);
|
2015-07-24 13:03:40 +00:00
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|
2017-08-01 15:24:04 +00:00
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|
if (atomic_read(&key->enabled) != 0) {
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WARN_ON_ONCE(atomic_read(&key->enabled) != 1);
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return;
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|
}
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|
atomic_set(&key->enabled, 1);
|
2015-07-24 13:03:40 +00:00
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|
}
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static inline void static_key_disable(struct static_key *key)
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{
|
2017-10-18 15:24:28 +00:00
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|
STATIC_KEY_CHECK_USE(key);
|
2015-07-24 13:03:40 +00:00
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|
|
2017-08-01 15:24:04 +00:00
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|
|
if (atomic_read(&key->enabled) != 1) {
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|
WARN_ON_ONCE(atomic_read(&key->enabled) != 0);
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|
|
return;
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|
|
}
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|
|
atomic_set(&key->enabled, 0);
|
2015-07-24 13:03:40 +00:00
|
|
|
}
|
|
|
|
|
2017-08-01 08:02:56 +00:00
|
|
|
#define static_key_enable_cpuslocked(k) static_key_enable((k))
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|
|
#define static_key_disable_cpuslocked(k) static_key_disable((k))
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|
|
|
2016-08-03 20:46:36 +00:00
|
|
|
#define STATIC_KEY_INIT_TRUE { .enabled = ATOMIC_INIT(1) }
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|
#define STATIC_KEY_INIT_FALSE { .enabled = ATOMIC_INIT(0) }
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|
#endif /* HAVE_JUMP_LABEL */
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#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE
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|
#define jump_label_enabled static_key_enabled
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|
|
2015-07-24 13:09:55 +00:00
|
|
|
/* -------------------------------------------------------------------------- */
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|
|
/*
|
|
|
|
* Two type wrappers around static_key, such that we can use compile time
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|
|
* type differentiation to emit the right code.
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|
*
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|
|
* All the below code is macros in order to play type games.
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|
*/
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struct static_key_true {
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|
|
struct static_key key;
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|
};
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|
struct static_key_false {
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|
|
struct static_key key;
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|
};
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#define STATIC_KEY_TRUE_INIT (struct static_key_true) { .key = STATIC_KEY_INIT_TRUE, }
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|
#define STATIC_KEY_FALSE_INIT (struct static_key_false){ .key = STATIC_KEY_INIT_FALSE, }
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|
|
#define DEFINE_STATIC_KEY_TRUE(name) \
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|
|
struct static_key_true name = STATIC_KEY_TRUE_INIT
|
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|
|
2016-09-01 18:39:33 +00:00
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|
|
#define DECLARE_STATIC_KEY_TRUE(name) \
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|
|
extern struct static_key_true name
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|
|
|
2015-07-24 13:09:55 +00:00
|
|
|
#define DEFINE_STATIC_KEY_FALSE(name) \
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|
|
struct static_key_false name = STATIC_KEY_FALSE_INIT
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|
|
2016-09-01 18:39:33 +00:00
|
|
|
#define DECLARE_STATIC_KEY_FALSE(name) \
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|
|
|
extern struct static_key_false name
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|
|
|
|
2016-09-05 17:25:47 +00:00
|
|
|
#define DEFINE_STATIC_KEY_ARRAY_TRUE(name, count) \
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|
|
struct static_key_true name[count] = { \
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|
|
[0 ... (count) - 1] = STATIC_KEY_TRUE_INIT, \
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|
|
|
}
|
|
|
|
|
|
|
|
#define DEFINE_STATIC_KEY_ARRAY_FALSE(name, count) \
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|
|
struct static_key_false name[count] = { \
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|
|
|
[0 ... (count) - 1] = STATIC_KEY_FALSE_INIT, \
|
|
|
|
}
|
|
|
|
|
2015-09-18 15:56:28 +00:00
|
|
|
extern bool ____wrong_branch_error(void);
|
|
|
|
|
|
|
|
#define static_key_enabled(x) \
|
|
|
|
({ \
|
|
|
|
if (!__builtin_types_compatible_p(typeof(*x), struct static_key) && \
|
|
|
|
!__builtin_types_compatible_p(typeof(*x), struct static_key_true) &&\
|
|
|
|
!__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
|
|
|
|
____wrong_branch_error(); \
|
|
|
|
static_key_count((struct static_key *)x) > 0; \
|
|
|
|
})
|
|
|
|
|
2015-07-24 13:09:55 +00:00
|
|
|
#ifdef HAVE_JUMP_LABEL
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Combine the right initial value (type) with the right branch order
|
|
|
|
* to generate the desired result.
|
|
|
|
*
|
|
|
|
*
|
|
|
|
* type\branch| likely (1) | unlikely (0)
|
|
|
|
* -----------+-----------------------+------------------
|
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|
|
* | |
|
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|
|
* true (1) | ... | ...
|
|
|
|
* | NOP | JMP L
|
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|
|
* | <br-stmts> | 1: ...
|
|
|
|
* | L: ... |
|
|
|
|
* | |
|
|
|
|
* | | L: <br-stmts>
|
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|
|
* | | jmp 1b
|
|
|
|
* | |
|
|
|
|
* -----------+-----------------------+------------------
|
|
|
|
* | |
|
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|
|
* false (0) | ... | ...
|
|
|
|
* | JMP L | NOP
|
|
|
|
* | <br-stmts> | 1: ...
|
|
|
|
* | L: ... |
|
|
|
|
* | |
|
|
|
|
* | | L: <br-stmts>
|
|
|
|
* | | jmp 1b
|
|
|
|
* | |
|
|
|
|
* -----------+-----------------------+------------------
|
|
|
|
*
|
|
|
|
* The initial value is encoded in the LSB of static_key::entries,
|
|
|
|
* type: 0 = false, 1 = true.
|
|
|
|
*
|
|
|
|
* The branch type is encoded in the LSB of jump_entry::key,
|
|
|
|
* branch: 0 = unlikely, 1 = likely.
|
|
|
|
*
|
|
|
|
* This gives the following logic table:
|
|
|
|
*
|
|
|
|
* enabled type branch instuction
|
|
|
|
* -----------------------------+-----------
|
|
|
|
* 0 0 0 | NOP
|
|
|
|
* 0 0 1 | JMP
|
|
|
|
* 0 1 0 | NOP
|
|
|
|
* 0 1 1 | JMP
|
|
|
|
*
|
|
|
|
* 1 0 0 | JMP
|
|
|
|
* 1 0 1 | NOP
|
|
|
|
* 1 1 0 | JMP
|
|
|
|
* 1 1 1 | NOP
|
|
|
|
*
|
|
|
|
* Which gives the following functions:
|
|
|
|
*
|
|
|
|
* dynamic: instruction = enabled ^ branch
|
|
|
|
* static: instruction = type ^ branch
|
|
|
|
*
|
|
|
|
* See jump_label_type() / jump_label_init_type().
|
|
|
|
*/
|
|
|
|
|
|
|
|
#define static_branch_likely(x) \
|
|
|
|
({ \
|
|
|
|
bool branch; \
|
|
|
|
if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \
|
|
|
|
branch = !arch_static_branch(&(x)->key, true); \
|
|
|
|
else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
|
|
|
|
branch = !arch_static_branch_jump(&(x)->key, true); \
|
|
|
|
else \
|
|
|
|
branch = ____wrong_branch_error(); \
|
|
|
|
branch; \
|
|
|
|
})
|
|
|
|
|
|
|
|
#define static_branch_unlikely(x) \
|
|
|
|
({ \
|
|
|
|
bool branch; \
|
|
|
|
if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \
|
|
|
|
branch = arch_static_branch_jump(&(x)->key, false); \
|
|
|
|
else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
|
|
|
|
branch = arch_static_branch(&(x)->key, false); \
|
|
|
|
else \
|
|
|
|
branch = ____wrong_branch_error(); \
|
|
|
|
branch; \
|
|
|
|
})
|
|
|
|
|
|
|
|
#else /* !HAVE_JUMP_LABEL */
|
|
|
|
|
|
|
|
#define static_branch_likely(x) likely(static_key_enabled(&(x)->key))
|
|
|
|
#define static_branch_unlikely(x) unlikely(static_key_enabled(&(x)->key))
|
|
|
|
|
|
|
|
#endif /* HAVE_JUMP_LABEL */
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Advanced usage; refcount, branch is enabled when: count != 0
|
|
|
|
*/
|
|
|
|
|
|
|
|
#define static_branch_inc(x) static_key_slow_inc(&(x)->key)
|
|
|
|
#define static_branch_dec(x) static_key_slow_dec(&(x)->key)
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Normal usage; boolean enable/disable.
|
|
|
|
*/
|
|
|
|
|
2017-08-01 08:02:56 +00:00
|
|
|
#define static_branch_enable(x) static_key_enable(&(x)->key)
|
|
|
|
#define static_branch_disable(x) static_key_disable(&(x)->key)
|
|
|
|
#define static_branch_enable_cpuslocked(x) static_key_enable_cpuslocked(&(x)->key)
|
|
|
|
#define static_branch_disable_cpuslocked(x) static_key_disable_cpuslocked(&(x)->key)
|
2015-07-24 13:09:55 +00:00
|
|
|
|
2015-04-09 03:51:31 +00:00
|
|
|
#endif /* __ASSEMBLY__ */
|
2017-01-18 17:38:04 +00:00
|
|
|
|
|
|
|
#endif /* _LINUX_JUMP_LABEL_H */
|