[patch 12/58] x86/of: Fix the APIC address registration

From: Thomas Gleixner
Date: Mon Jul 17 2023 - 19:15:29 EST


The device tree APIC parser tries to force enable the local APIC when it is
not set in CPUID. apic_force_enable() registers the boot CPU apic on
success.

If that succeeds then dtb_lapic_setup() registers the local APIC again
eventually with a different address.

Rewrite the code so that it only registers it once.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/devicetree.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -157,19 +157,15 @@ static void __init dtb_lapic_setup(void)

/* Did the boot loader setup the local APIC ? */
if (!boot_cpu_has(X86_FEATURE_APIC)) {
+ /* Try force enabling, which registers the APIC address */
if (apic_force_enable(lapic_addr))
return;
- }
- smp_found_config = 1;
- if (of_property_read_bool(dn, "intel,virtual-wire-mode")) {
- pr_info("Virtual Wire compatibility mode.\n");
- pic_mode = 0;
} else {
- pr_info("IMCR and PIC compatibility mode.\n");
- pic_mode = 1;
+ register_lapic_address(lapic_addr);
}
-
- register_lapic_address(lapic_addr);
+ smp_found_config = 1;
+ pic_mode = !of_property_read_bool(dn, "intel,virtual-wire-mode");
+ pr_info("%s compatibility mode.\n", pic_mode ? "IMCR and PIC" : "Virtual Wire");
}

#endif /* CONFIG_X86_LOCAL_APIC */