From 4e3286818327453efd8e4c133928ba26a169567a Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Fri, 10 May 2024 13:40:59 -0400 Subject: [PATCH] Increase IOAPIC_MAX_ID to 255 (from 254) A test system provided by AMD panicked with "madt_parse_apics: I/O APIC ID 255 too high". I/O APIC ID 255 is acceptable, so increase the limit. Reviewed by: jhb, kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D45157 --- sys/x86/include/apicvar.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/sys/x86/include/apicvar.h b/sys/x86/include/apicvar.h index 10016e291b9..ac6a82659e3 100644 --- a/sys/x86/include/apicvar.h +++ b/sys/x86/include/apicvar.h @@ -78,7 +78,12 @@ #define MAX_APIC_ID 0x800 #define APIC_ID_ALL 0xffffffff -#define IOAPIC_MAX_ID xAPIC_MAX_APIC_ID +/* + * The 0xff ID is used for broadcast IPIs for local APICs when not using + * x2APIC. IPIs are not sent to I/O APICs so it's acceptable for an I/O APIC + * to use that ID. + */ +#define IOAPIC_MAX_ID 0xff /* I/O Interrupts are used for external devices such as ISA, PCI, etc. */ #define APIC_IO_INTS (IDT_IO_INTS + 16)