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>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bef941f6145140c2c8ceeb50b532a163f9cd58e6..fe19c88a502996707647cf5db146382822c7b6ea 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -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 */

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 7735e3dd359c5351ef33ef818368dff5ac16f6d8..88d5d5ec6bebbe01d913597c4e50f9aecc38a73b 100644 (file)
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -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 */