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authorYinghai Lu <yinghai@kernel.org>2009-05-02 10:40:57 -0700
committerIngo Molnar <mingo@elte.hu>2009-05-11 11:29:23 +0200
commit4401da6111ac58f94234417427d06a72c4048c74 (patch)
tree8e42dbef7e8dcc9a82cc43971cdfb68f1a35e6fc /arch
parent61fe91e1319556f32bebfd7ed2c68ef02e2c17f7 (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/apic/apic.c31
1 files changed, 21 insertions, 10 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index e258bedce7c..1ee966f4ae9 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));
}
}