From 4797f6b021a3fa399942245d07a1feb30df81bb8 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sat, 2 May 2009 10:40:57 -0700 Subject: [PATCH] x86: read apic ID in the !acpi_lapic case Ed found that on 32-bit, boot_cpu_physical_apicid is not read right, when the mptable is broken. Interestingly, actually three paths use/set it: 1. acpi: at that time that is already read from reg 2. mptable: only read from mptable 3. no madt, and no mptable, that use default apic id 0 for 64-bit, -1 for 32-bit so we could read the apic id for the 2/3 path. We trust the hardware register more than we trust a BIOS data structure (the mptable). We can also avoid the double set_fixmap() when acpi_lapic is used, and also need to move cpu_has_apic earlier and call apic_disable(). Also when need to update the apic id, we'd better read and set the apic version as well - so that quirks are applied precisely. v2: make path 3 with 64bit, use -1 as apic id, so could read it later. v3: fix whitespace problem pointed out by Ed Swierk v5: fix boot crash [ Impact: get correct apic id for bsp other than acpi path ] Reported-by: Ed Swierk Signed-off-by: Yinghai Lu Acked-by: Cyrill Gorcunov LKML-Reference: <49FC85A9.2070702@kernel.org> [ v4: sanity-check in the ACPI case too ] Signed-off-by: Ingo Molnar --- arch/x86/include/asm/smp.h | 2 +- arch/x86/kernel/apic/apic.c | 46 ++++++++++++++++------------------ arch/x86/kernel/apic/io_apic.c | 5 ++++ 3 files changed, 28 insertions(+), 25 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 19e0d88b966d..6a84ed166aec 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -180,7 +180,7 @@ extern int safe_smp_processor_id(void); static inline int logical_smp_processor_id(void) { /* we don't want to mark this access volatile - bad code generation */ - return GET_APIC_LOGICAL_ID(*(u32 *)(APIC_BASE + APIC_LDR)); + return GET_APIC_LOGICAL_ID(apic_read(APIC_LDR)); } #endif diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 07cffc1214cb..b0fd26442c41 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -242,17 +242,24 @@ static int modern_apic(void) * bare function to substitute write operation * and it's _that_ fast :) */ -void native_apic_write_dummy(u32 reg, u32 v) +static void native_apic_write_dummy(u32 reg, u32 v) { WARN_ON_ONCE((cpu_has_apic || !disable_apic)); } +static u32 native_apic_read_dummy(u32 reg) +{ + WARN_ON_ONCE((cpu_has_apic || !disable_apic)); + return 0; +} + /* - * right after this call apic->write doesn't do anything + * right after this call apic->write/read doesn't do anything * note that there is no restore operation it works one way */ void apic_disable(void) { + apic->read = native_apic_read_dummy; apic->write = native_apic_write_dummy; } @@ -1576,32 +1583,23 @@ void __init init_apic_mappings(void) return; } - /* - * If no local APIC can be found then set up a fake all - * zeroes page to simulate the local APIC and another - * one for the IO-APIC. - */ + /* If no local APIC can be found return early */ if (!smp_found_config && detect_init_APIC()) { - apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); - apic_phys = __pa(apic_phys); - } else + /* lets NOP'ify apic operations */ + pr_info("APIC: disable apic facility\n"); + apic_disable(); + } else { apic_phys = mp_lapic_addr; - /* - * acpi lapic path already maps that address in - * acpi_register_lapic_address() - */ - if (!acpi_lapic) - set_fixmap_nocache(FIX_APIC_BASE, apic_phys); - - apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n", - APIC_BASE, apic_phys); + /* + * acpi lapic path already maps that address in + * acpi_register_lapic_address() + */ + if (!acpi_lapic) + set_fixmap_nocache(FIX_APIC_BASE, apic_phys); - /* lets check if we may NOP'ify apic operations */ - if (!cpu_has_apic) { - pr_info("APIC: disable apic facility\n"); - apic_disable(); - return; + apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n", + APIC_BASE, apic_phys); } /* diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 1f3d3669dae8..74d2b480a20b 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1878,6 +1878,11 @@ __apicdebuginit(void) print_PIC(void) __apicdebuginit(int) print_all_ICs(void) { print_PIC(); + + /* don't print out if apic is not there */ + if (!cpu_has_apic || disable_apic) + return 0; + print_all_local_APICs(); print_IO_APIC(); -- 2.39.5