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Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
-rw-r--r--arch/x86/kernel/acpi/boot.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 1c38174b5f01..21b542a6866c 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -146,7 +146,11 @@ static int __init acpi_parse_madt(struct acpi_table_header *table)
pr_debug("Local APIC address 0x%08x\n", madt->address);
}
- if (madt->header.revision >= 5)
+
+ /* ACPI 6.3 and newer support the online capable bit. */
+ if (acpi_gbl_FADT.header.revision > 6 ||
+ (acpi_gbl_FADT.header.revision == 6 &&
+ acpi_gbl_FADT.minor_revision >= 3))
acpi_support_online_capable = true;
default_acpi_madt_oem_check(madt->header.oem_id,
@@ -193,7 +197,8 @@ 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))
+ if (!acpi_support_online_capable ||
+ (lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
return true;
return false;
@@ -1853,13 +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)