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author | Yinghai Lu <yinghai@kernel.org> | 2009-05-02 10:40:57 -0700 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-05-11 11:29:23 +0200 |
commit | 4401da6111ac58f94234417427d06a72c4048c74 (patch) | |
tree | 8e42dbef7e8dcc9a82cc43971cdfb68f1a35e6fc | |
parent | 61fe91e1319556f32bebfd7ed2c68ef02e2c17f7 (diff) | |
download | linux-stable-4401da6111ac58f94234417427d06a72c4048c74.tar.gz linux-stable-4401da6111ac58f94234417427d06a72c4048c74.tar.bz2 linux-stable-4401da6111ac58f94234417427d06a72c4048c74.zip |
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
[ Impact: get correct apic id for bsp other than acpi path ]
Reported-by: Ed Swierk <eswierk@aristanetworks.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <49FC85A9.2070702@kernel.org>
[ v4: sanity-check in the ACPI case too ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r-- | arch/x86/kernel/apic/apic.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index e258bedce7cb..1ee966f4ae95 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1456,7 +1456,6 @@ static int __init detect_init_APIC(void) } mp_lapic_addr = APIC_DEFAULT_PHYS_BASE; - boot_cpu_physical_apicid = 0; return 0; } #else @@ -1570,6 +1569,8 @@ void __init early_init_lapic_mapping(void) */ void __init init_apic_mappings(void) { + unsigned int new_apicid; + if (x2apic_mode) { boot_cpu_physical_apicid = read_apic_id(); return; @@ -1586,21 +1587,31 @@ void __init init_apic_mappings(void) } else apic_phys = mp_lapic_addr; - 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; + } + + /* + * 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); - /* * Fetch the APIC ID of the BSP in case we have a * default configuration (or the MP table is broken). */ - if (boot_cpu_physical_apicid == -1U) - boot_cpu_physical_apicid = read_apic_id(); - - /* lets check if we may to NOP'ify apic operations */ - if (!cpu_has_apic) { - pr_info("APIC: disable apic facility\n"); - apic_disable(); + new_apicid = read_apic_id(); + if (boot_cpu_physical_apicid != new_apicid) { + boot_cpu_physical_apicid = new_apicid; + apic_version[new_apicid] = + GET_APIC_VERSION(apic_read(APIC_LVR)); } } |