xen: setup percpu data pointers

Impact: fix xen booting

We need to access percpu data fairly early, so set up the percpu
registers as soon as possible.  We only need to load the appropriate
segment register.  We already have a GDT, but its hard to change it
early because we need to manipulate the pagetable to do so, and that
hasn't been set up yet.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Jeremy Fitzhardinge 2009-01-30 17:47:54 +09:00 committed by Tejun Heo
parent 11e3a840cd
commit 795f99b61d
2 changed files with 7 additions and 1 deletions

View File

@ -1647,6 +1647,9 @@ asmlinkage void __init xen_start_kernel(void)
have_vcpu_info_placement = 0;
#endif
/* setup percpu state */
load_percpu_segment(0);
xen_smp_init();
/* Get mfn list */

View File

@ -170,7 +170,8 @@ static void __init xen_smp_prepare_boot_cpu(void)
/* We've switched to the "real" per-cpu gdt, so make sure the
old memory can be recycled */
make_lowmem_page_readwrite(&per_cpu_var(gdt_page));
make_lowmem_page_readwrite(__per_cpu_load +
(unsigned long)&per_cpu_var(gdt_page));
xen_setup_vcpu_info_placement();
}
@ -235,6 +236,8 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
ctxt->user_regs.ss = __KERNEL_DS;
#ifdef CONFIG_X86_32
ctxt->user_regs.fs = __KERNEL_PERCPU;
#else
ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */