The following commit has been merged into the x86/apic branch of tip:
Commit-ID: 2906a67ac83b06b874b32bf6413a8d5e186fc33e
Gitweb: https://git.kernel.org/tip/2906a67ac83b06b874b32bf6413a8d5e186fc33e
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 08 Aug 2023 15:03:47 -07:00
Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
CommitterDate: Wed, 09 Aug 2023 11:58:19 -07:00
x86/of: Fix the APIC address registration
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>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Tested-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Tested-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
Tested-by: Juergen Gross <jgross@xxxxxxxx> # Xen PV (dom0 and unpriv. guest)
---
arch/x86/kernel/devicetree.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 56f6d59..8f94eb6 100644
--- 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 */
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