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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-25 10:05:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-25 10:05:00 -0700 |
| commit | 1699dbebf31f0b26a8408d24da3c7f3b113f0340 (patch) | |
| tree | 14c760c69bbc1c5e9544e2a30e45f203ef316116 /arch/x86/kernel/acpi/boot.c | |
| parent | d3464152e541b08fdc3c60664c01a28f8844a655 (diff) | |
| parent | 22767544e9763e82acb60c233051bc426381b61c (diff) | |
Merge tag 'x86_acpi_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 ACPI update from Borislav Petkov:
- Improve code generation in ACPI's global lock's acquisition function
* tag 'x86_acpi_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ACPI/boot: Improve __acpi_acquire_global_lock
Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
| -rw-r--r-- | arch/x86/kernel/acpi/boot.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 0dac4ab5b55b..21b542a6866c 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -1858,13 +1858,18 @@ early_param("acpi_sci", setup_acpi_sci); int __acpi_acquire_global_lock(unsigned int *lock) { - unsigned int old, new; + unsigned int old, new, val; old = READ_ONCE(*lock); do { - new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1)); + val = (old >> 1) & 0x1; + new = (old & ~0x3) + 2 + val; } while (!try_cmpxchg(lock, &old, new)); - return ((new & 0x3) < 3) ? -1 : 0; + + if (val) + return 0; + + return -1; } int __acpi_release_global_lock(unsigned int *lock) |