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authorBenjamin Romer <benjamin.romer@unisys.com>2007-02-13 15:26:25 +0300
committerAndi Kleen <andi@basil.nowhere.org>2007-02-13 15:26:25 +0300
commitee4eff6ff6cbfc8ce38131058a18802bf6206879 (patch)
tree7cb9e7f7072fee788284c099f6f3f229bfefc20a /include/asm-x86_64
parenta4af60aa64c828b7c047e7a67b2f896d4bfbd700 (diff)
downloadlinux-ee4eff6ff6cbfc8ce38131058a18802bf6206879.tar.xz
[PATCH] x86-64: update IO-APIC dest field to 8-bit for xAPIC
On the Unisys ES7000/ONE system, we encountered a problem where performing a kexec reboot or dump on any cell other than cell 0 causes the system timer to stop working, resulting in a hang during timer calibration in the new kernel. We traced the problem to one line of code in disable_IO_APIC(), which needs to restore the timer's IO-APIC configuration before rebooting. The code is currently using the 4-bit physical destination field, rather than using the 8-bit logical destination field, and it cuts off the upper 4 bits of the timer's APIC ID. If we change this to use the logical destination field, the timer works and we can kexec on the upper cells. This was tested on two different cells (0 and 2) in an ES7000/ONE system. For reference, the relevant Intel xAPIC spec is kept at ftp://download.intel.com/design/chipsets/e8501/datashts/30962001.pdf, specifically on page 334. Signed-off-by: Benjamin M Romer <benjamin.romer@unisys.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/asm-x86_64')
-rw-r--r--include/asm-x86_64/io_apic.h14
1 files changed, 2 insertions, 12 deletions
diff --git a/include/asm-x86_64/io_apic.h b/include/asm-x86_64/io_apic.h
index 561ecbfd4cb5..f4fb238c89f1 100644
--- a/include/asm-x86_64/io_apic.h
+++ b/include/asm-x86_64/io_apic.h
@@ -85,18 +85,8 @@ struct IO_APIC_route_entry {
mask : 1, /* 0: enabled, 1: disabled */
__reserved_2 : 15;
- union { struct { __u32
- __reserved_1 : 24,
- physical_dest : 4,
- __reserved_2 : 4;
- } physical;
-
- struct { __u32
- __reserved_1 : 24,
- logical_dest : 8;
- } logical;
- } dest;
-
+ __u32 __reserved_3 : 24,
+ dest : 8;
} __attribute__ ((packed));
/*