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Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
-rw-r--r--arch/x86/kernel/acpi/boot.c35
1 files changed, 24 insertions, 11 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 907cc98b1938..1c38174b5f01 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -188,6 +188,17 @@ static int acpi_register_lapic(int id, u32 acpiid, u8 enabled)
return cpu;
}
+static bool __init acpi_is_processor_usable(u32 lapic_flags)
+{
+ if (lapic_flags & ACPI_MADT_ENABLED)
+ return true;
+
+ if (acpi_support_online_capable && (lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
+ return true;
+
+ return false;
+}
+
static int __init
acpi_parse_x2apic(union acpi_subtable_headers *header, const unsigned long end)
{
@@ -212,6 +223,10 @@ acpi_parse_x2apic(union acpi_subtable_headers *header, const unsigned long end)
if (apic_id == 0xffffffff)
return 0;
+ /* don't register processors that cannot be onlined */
+ if (!acpi_is_processor_usable(processor->lapic_flags))
+ return 0;
+
/*
* We need to register disabled CPU as well to permit
* counting disabled CPUs. This allows us to size
@@ -250,9 +265,7 @@ acpi_parse_lapic(union acpi_subtable_headers * header, const unsigned long end)
return 0;
/* don't register processors that can not be onlined */
- if (acpi_support_online_capable &&
- !(processor->lapic_flags & ACPI_MADT_ENABLED) &&
- !(processor->lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
+ if (!acpi_is_processor_usable(processor->lapic_flags))
return 0;
/*
@@ -1840,23 +1853,23 @@ early_param("acpi_sci", setup_acpi_sci);
int __acpi_acquire_global_lock(unsigned int *lock)
{
- unsigned int old, new, val;
+ unsigned int old, new;
+
+ old = READ_ONCE(*lock);
do {
- old = *lock;
new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1));
- val = cmpxchg(lock, old, new);
- } while (unlikely (val != old));
+ } while (!try_cmpxchg(lock, &old, new));
return ((new & 0x3) < 3) ? -1 : 0;
}
int __acpi_release_global_lock(unsigned int *lock)
{
- unsigned int old, new, val;
+ unsigned int old, new;
+
+ old = READ_ONCE(*lock);
do {
- old = *lock;
new = old & ~0x3;
- val = cmpxchg(lock, old, new);
- } while (unlikely (val != old));
+ } while (!try_cmpxchg(lock, &old, new));
return old & 0x1;
}