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authorAndreas Herrmann <andreas.herrmann3@amd.com>2009-06-08 15:55:09 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-09 15:28:46 +0200
commit42937e81a82b6bbc51a309c83da140b3a7ca5945 (patch)
treec6562f38f91de06e00bd12280044e31733ff5ee4 /arch/x86/include
parentc9690998ef48ffefeccb91c70a7739eebdea57f9 (diff)
x86: Detect use of extended APIC ID for AMD CPUs
Booting a 32-bit kernel on Magny-Cours results in the following panic: ... Using APIC driver default ... Overriding APIC driver with bigsmp ... Getting VERSION: 80050010 Getting VERSION: 80050010 Getting ID: 10000000 Getting ID: ef000000 Getting LVT0: 700 Getting LVT1: 10000 Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0) Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2 Call Trace: [<c05194da>] ? panic+0x38/0xd3 [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f [<c073b19d>] ? kernel_init+0x3e/0x141 [<c073b15f>] ? kernel_init+0x0/0x141 [<c020325f>] ? kernel_thread_helper+0x7/0x10 The reason is that default_get_apic_id handled extension of local APIC ID field just in case of XAPIC. Thus for this AMD CPU, default_get_apic_id() returns 0 and bigsmp_get_apic_id() returns 16 which leads to the respective kernel panic. This patch introduces a Linux specific feature flag to indicate support for extended APIC id (8 bits instead of 4 bits width) and sets the flag on AMD CPUs if applicable. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: <stable@kernel.org> LKML-Reference: <20090608135509.GA12431@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/apic.h2
-rw-r--r--arch/x86/include/asm/cpufeature.h1
2 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 42f2f837742..9b2c04910e0 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
{
unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
- if (APIC_XAPIC(ver))
+ if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
return (x >> 24) & 0xFF;
else
return (x >> 24) & 0x0F;
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb83b1c397a..78dee4f0f7a 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -94,6 +94,7 @@
#define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
#define X86_FEATURE_NONSTOP_TSC (3*32+24) /* TSC does not stop in C states */
#define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
+#define X86_FEATURE_EXTD_APICID (3*32+26) /* has extended APICID (8 bits) */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */