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| author | Tejun Heo <tj@kernel.org> | 2009-01-13 11:41:35 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-16 13:19:14 (GMT) |
| commit | 3e5d8f978435bb9ba4dfe3f4514e65e7885db1a9 (patch) | |
| tree | 1ce55b2ec16a0bd59a29857e05215960d463a1d8 /arch/x86/kernel/head64.c | |
| parent | a698c823e15149941b0f0281527d0c0d1daf2639 (diff) | |
| download | linux-3e5d8f978435bb9ba4dfe3f4514e65e7885db1a9.tar.xz | |
x86: make percpu symbols zerobased on SMP
[ Based on original patch from Christoph Lameter and Mike Travis. ]
This patch makes percpu symbols zerobased on x86_64 SMP by adding
PERCPU_VADDR() to vmlinux.lds.h which helps setting explicit vaddr on
the percpu output section and using it in vmlinux_64.lds.S. A new
PHDR is added as existing ones cannot contain sections near address
zero. PERCPU_VADDR() also adds a new symbol __per_cpu_load which
always points to the vaddr of the loaded percpu data.init region.
The following adjustments have been made to accomodate the address
change.
* code to locate percpu gdt_page in head_64.S is updated to add the
load address to the gdt_page offset.
* __per_cpu_load is used in places where access to the init data area
is necessary.
* pda->data_offset is initialized soon after C code is entered as zero
value doesn't work anymore.
This patch is mostly taken from Mike Travis' "x86_64: Base percpu
variables at zero" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index b9a4d8c..bc2900c 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -44,6 +44,8 @@ void __init x86_64_init_pda(void) { _cpu_pda = __cpu_pda; cpu_pda(0) = &_boot_cpu_pda; + cpu_pda(0)->data_offset = + (unsigned long)(__per_cpu_load - __per_cpu_start); pda_init(0); } |