diff options
| author | Linus Torvalds | 2024-05-13 10:05:39 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2024-05-13 10:05:39 -0700 |
| commit | 2e57d1d6062af11420bc329ca004ebe3f3f6f0ee (patch) | |
| tree | 45d7c77f76bd77a2c6f71ac9dea2648b385f5cdd /include | |
| parent | c0b9620bc3f0a0f914996cc6631522d41870a9e0 (diff) | |
| parent | 5800e77d88c0cd98bc10460df148631afa7b5e4d (diff) | |
Merge tag 'cmpxchg.2024.05.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull cmpxchg updates from Paul McKenney:
"Provide one-byte and two-byte cmpxchg() support on sparc32, parisc,
and csky
This provides native one-byte and two-byte cmpxchg() support for
sparc32 and parisc, courtesy of Al Viro. This support is provided by
the same hashed-array-of-locks technique used for the other atomic
operations provided for these two platforms.
There is also emulated one-byte cmpxchg() support for csky using a new
cmpxchg_emu_u8() function that uses a four-byte cmpxchg() to emulate
the one-byte variant.
Similar patches for emulation of one-byte cmpxchg() for arc, sh, and
xtensa have not yet received maintainer acks, so they are slated for
the v6.11 merge window"
* tag 'cmpxchg.2024.05.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
csky: Emulate one-byte cmpxchg
lib: Add one-byte emulation function
parisc: add u16 support to cmpxchg()
parisc: add missing export of __cmpxchg_u8()
parisc: unify implementations of __cmpxchg_u{8,32,64}
parisc: __cmpxchg_u32(): lift conversion into the callers
sparc32: add __cmpxchg_u{8,16}() and teach __cmpxchg() to handle those sizes
sparc32: unify __cmpxchg_u{32,64}
sparc32: make the first argument of __cmpxchg_u64() volatile u64 *
sparc32: make __cmpxchg_u32() return u32
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cmpxchg-emu.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/cmpxchg-emu.h b/include/linux/cmpxchg-emu.h new file mode 100644 index 000000000000..998deec67740 --- /dev/null +++ b/include/linux/cmpxchg-emu.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Emulated 1-byte and 2-byte cmpxchg operations for architectures + * lacking direct support for these sizes. These are implemented in terms + * of 4-byte cmpxchg operations. + * + * Copyright (C) 2024 Paul E. McKenney. + */ + +#ifndef __LINUX_CMPXCHG_EMU_H +#define __LINUX_CMPXCHG_EMU_H + +uintptr_t cmpxchg_emu_u8(volatile u8 *p, uintptr_t old, uintptr_t new); + +#endif /* __LINUX_CMPXCHG_EMU_H */ |