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| author | Ingo Molnar <mingo@elte.hu> | 2009-01-20 08:23:45 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-20 08:23:45 +0100 |
| commit | 8f5d36ed5bb6e33024619eaee15b7ce2e3d115b3 (patch) | |
| tree | 1a73934430a84fa926c7a12e1901d7e2639da4ff /arch/x86/kernel/head_64.S | |
| parent | 5cdc5e9e69d4dc3a3630ae1fa666401b2a8dcde6 (diff) | |
| parent | 6b7c38d55587f43bcd2cbce3a98b1c0826982090 (diff) | |
Merge branch 'tj-percpu' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/percpu
Diffstat (limited to 'arch/x86/kernel/head_64.S')
| -rw-r--r-- | arch/x86/kernel/head_64.S | 37 |
1 files changed, 13 insertions, 24 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index c8ace880661..a0a2b5ca9b7 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -207,19 +207,15 @@ ENTRY(secondary_startup_64) #ifdef CONFIG_SMP /* - * early_gdt_base should point to the gdt_page in static percpu init - * data area. Computing this requires two symbols - __per_cpu_load - * and per_cpu__gdt_page. As linker can't do no such relocation, do - * it by hand. As early_gdt_descr is manipulated by C code for - * secondary CPUs, this should be done only once for the boot CPU - * when early_gdt_descr_base contains zero. + * Fix up static pointers that need __per_cpu_load added. The assembler + * is unable to do this directly. This is only needed for the boot cpu. + * These values are set up with the correct base addresses by C code for + * secondary cpus. */ - movq early_gdt_descr_base(%rip), %rax - testq %rax, %rax - jnz 1f - movq $__per_cpu_load, %rax - addq $per_cpu__gdt_page, %rax - movq %rax, early_gdt_descr_base(%rip) + movq initial_gs(%rip), %rax + cmpl $0, per_cpu__cpu_number(%rax) + jne 1f + addq %rax, early_gdt_descr_base(%rip) 1: #endif /* @@ -246,13 +242,10 @@ ENTRY(secondary_startup_64) /* Set up %gs. * - * On SMP, %gs should point to the per-cpu area. For initial - * boot, make %gs point to the init data section. For a - * secondary CPU,initial_gs should be set to its pda address - * before the CPU runs this code. - * - * On UP, initial_gs points to PER_CPU_VAR(__pda) and doesn't - * change. + * The base of %gs always points to the bottom of the irqstack + * union. If the stack protector canary is enabled, it is + * located at %gs:40. Note that, on SMP, the boot cpu uses + * init data section till per cpu areas are set up. */ movl $MSR_GS_BASE,%ecx movq initial_gs(%rip),%rax @@ -285,7 +278,7 @@ ENTRY(secondary_startup_64) #ifdef CONFIG_SMP .quad __per_cpu_load #else - .quad PER_CPU_VAR(__pda) + .quad PER_CPU_VAR(irq_stack_union) #endif __FINITDATA @@ -431,12 +424,8 @@ NEXT_PAGE(level2_spare_pgt) .globl early_gdt_descr early_gdt_descr: .word GDT_ENTRIES*8-1 -#ifdef CONFIG_SMP early_gdt_descr_base: - .quad 0x0000000000000000 -#else .quad per_cpu__gdt_page -#endif ENTRY(phys_base) /* This must match the first entry in level2_kernel_pgt */ |