17 Mar, 2020
2 commits
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Move the get_unaligned_be24(), get_unaligned_le24() and
put_unaligned_le24() definitions from various drivers into
include/linux/unaligned/generic.h. Add a put_unaligned_be24()
implementation.Link: https://lore.kernel.org/r/20200313203102.16613-4-bvanassche@acm.org
Cc: Keith Busch
Cc: Sagi Grimberg
Cc: Jens Axboe
Cc: Harvey Harrison
Cc: Martin K. Petersen
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: H. Peter Anvin
Cc: Andrew Morton
Reviewed-by: Christoph Hellwig
Reviewed-by: Andy Shevchenko
Reviewed-by: Greg Kroah-Hartman # For drivers/usb
Reviewed-by: Felipe Balbi # For drivers/usb/gadget
Signed-off-by: Bart Van Assche
Signed-off-by: Martin K. Petersen -
The C language supports implicitly casting a void pointer into a non-void
pointer. Remove explicit void pointer to non-void pointer casts because
these are superfluous.Link: https://lore.kernel.org/r/20200313203102.16613-2-bvanassche@acm.org
Cc: Harvey Harrison
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: H. Peter Anvin
Cc: Andrew Morton
Reviewed-by: Christoph Hellwig
Signed-off-by: Bart Van Assche
Signed-off-by: Martin K. Petersen
02 Nov, 2017
1 commit
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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
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
18 Mar, 2016
1 commit
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Sometimes gcc mysteriously doesn't inline
very small functions we expect to be inlined. Seehttps://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122
With this .config:
http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os,
the following functions get deinlined many times.
Examples of disassembly:(24 copies, 108 calls):
66 8b 07 mov (%rdi),%ax
55 push %rbp
48 89 e5 mov %rsp,%rbp
86 e0 xchg %ah,%al
5d pop %rbp
c3 retq(25 copies, 181 calls):
8b 07 mov (%rdi),%eax
55 push %rbp
48 89 e5 mov %rsp,%rbp
0f c8 bswap %eax
5d pop %rbp
c3 retq(23 copies, 94 calls):
48 8b 07 mov (%rdi),%rax
55 push %rbp
48 89 e5 mov %rsp,%rbp
48 0f c8 bswap %rax
5d pop %rbp
c3 retq(2 copies, 11 calls):
89 f8 mov %edi,%eax
55 push %rbp
c1 ef 08 shr $0x8,%edi
c1 e0 08 shl $0x8,%eax
09 c7 or %eax,%edi
48 89 e5 mov %rsp,%rbp
66 89 3e mov %di,(%rsi)(8 copies, 43 calls):
55 push %rbp
0f cf bswap %edi
89 3e mov %edi,(%rsi)
48 89 e5 mov %rsp,%rbp
5d pop %rbp
c3 retq(26 copies, 157 calls):
55 push %rbp
48 0f cf bswap %rdi
48 89 3e mov %rdi,(%rsi)
48 89 e5 mov %rsp,%rbp
5d pop %rbp
c3 retqThis patch fixes this via s/inline/__always_inline/.
It only affects arches with efficient unaligned access insns, such as x86.
(arched which lack such ops do not include linux/unaligned/access_ok.h)Code size decrease after the patch is ~8.5k:
text data bss dec hex filename
92197848 20826112 36417536 149441496 8e84bd8 vmlinux
92189231 20826144 36417536 149432911 8e82a4f vmlinux6_unaligned_be_afterSigned-off-by: Denys Vlasenko
Acked-by: Ingo Molnar
Cc: Thomas Graf
Cc: Peter Zijlstra
Cc: David Rientjes
Cc: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Jan, 2011
1 commit
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Cc: Will Newton
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Dec, 2010
1 commit
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The current packed struct implementation of unaligned access adds the
packed attribute only to the field within the unaligned struct rather than
to the struct as a whole. This is not sufficient to enforce proper
behaviour on architectures with a default struct alignment of more than
one byte.For example, the current implementation of __get_unaligned_cpu16 when
compiled for arm with gcc -O1 -mstructure-size-boundary=32 assumes the
struct is on a 4 byte boundary so performs the load of the 16bit packed
field as if it were on a 4 byte boundary:__get_unaligned_cpu16:
ldrh r0, [r0, #0]
bx lrMoving the packed attribute to the struct rather than the field causes the
proper unaligned access code to be generated:__get_unaligned_cpu16:
ldrb r3, [r0, #0] @ zero_extendqisi2
ldrb r0, [r0, #1] @ zero_extendqisi2
orr r0, r3, r0, asl #8
bx lrSigned-off-by: Will Newton
Cc: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Sep, 2009
1 commit
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When unaligned accesses are required for uncompressing a kernel (such as
for LZO decompression on ARM in a patch that follows), including
causes issues as it brings in a lot of things that are
not available in the decompression environment.linux/kernel.h brings at least:
extern int console_printk[];
extern const char hex_asc[];
which causes errors at link-time as they are not available when
compiling the pre-boot environement. There are also a few others:arch/arm/boot/compressed/misc.o: In function `valid_user_regs':
arch/arm/include/asm/ptrace.h:158: undefined reference to `elf_hwcap'
arch/arm/boot/compressed/misc.o: In function `console_silent':
include/linux/kernel.h:292: undefined reference to `console_printk'
arch/arm/boot/compressed/misc.o: In function `console_verbose':
include/linux/kernel.h:297: undefined reference to `console_printk'
arch/arm/boot/compressed/misc.o: In function `pack_hex_byte':
include/linux/kernel.h:360: undefined reference to `hex_asc'
arch/arm/boot/compressed/misc.o: In function `hweight_long':
include/linux/bitops.h:45: undefined reference to `hweight32'
arch/arm/boot/compressed/misc.o: In function `__cmpxchg_local_generic':
include/asm-generic/cmpxchg-local.h:21: undefined reference to `wrong_size_cmpxchg'
include/asm-generic/cmpxchg-local.h:42: undefined reference to `wrong_size_cmpxchg'
arch/arm/boot/compressed/misc.o: In function `__xchg':
arch/arm/include/asm/system.h:309: undefined reference to `__bad_xchg'However, those files apparently use nothing from , all
they need is the declaration of types such as u32 or u64, so
should be enoughSigned-off-by: Albin Tonnerre
Cc: Sam Ravnborg
Cc: Russell King
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: "H. Peter Anvin"
Cc: Phillip Lougher
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
1 commit
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Create a linux/unaligned directory similar in spirit to the linux/byteorder
folder to hold generic implementations collected from various arches.Currently there are five implementations:
1) packed_struct.h: C-struct based, from asm-generic/unaligned.h
2) le_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
3) be_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
4) memmove.h: taken from multiple implementations in tree
5) access_ok.h: taken from x86 and others, unaligned access is ok.All of the new implementations checks for sizes not equal to 1,2,4,8
and will fail to link.API additions:
get_unaligned_{le16|le32|le64|be16|be32|be64}(p) which is meant to replace
code of the form:
le16_to_cpu(get_unaligned((__le16 *)p));put_unaligned_{le16|le32|le64|be16|be32|be64}(val, pointer) which is meant to
replace code of the form:
put_unaligned(cpu_to_le16(val), (__le16 *)p);The headers that arches should include from their asm/unaligned.h:
access_ok.h : Wrappers of the byteswapping functions in asm/byteorder
Choose a particular implementation for little-endian access:
le_byteshift.h
le_memmove.h (arch must be LE)
le_struct.h (arch must be LE)Choose a particular implementation for big-endian access:
be_byteshift.h
be_memmove.h (arch must be BE)
be_struct.h (arch must be BE)After including as needed from the above, include unaligned/generic.h and
define your arch's get/put_unaligned as (for LE):Signed-off-by: Harvey Harrison
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
