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Commit 795f99b6 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Tejun Heo
Browse files

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: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 11e3a840

arch/x86/xen/enlighten.c

+3 −0
Original line number Diff line number Diff line
@@ -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 */

arch/x86/xen/smp.c

+4 −1
Original line number Diff line number Diff line
@@ -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 */