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| author | Andreas Herrmann <andreas.herrmann3@amd.com> | 2009-06-08 15:55:09 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-06-09 15:28:46 +0200 |
| commit | 42937e81a82b6bbc51a309c83da140b3a7ca5945 (patch) | |
| tree | c6562f38f91de06e00bd12280044e31733ff5ee4 /kernel/kfifo.c | |
| parent | c9690998ef48ffefeccb91c70a7739eebdea57f9 (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 'kernel/kfifo.c')
0 files changed, 0 insertions, 0 deletions