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Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
-rw-r--r--arch/x86/kernel/acpi/boot.c11
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)