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authorJeremy Fitzhardinge <jeremy@goop.org>2009-02-02 13:55:31 -0800
committerH. Peter Anvin <hpa@linux.intel.com>2009-02-04 16:59:02 -0800
commit383414322b3b3ced0cbc146801e0cc6c60a6c5f4 (patch)
treef6abd0c09f3f15c1fd78d81a443ae4bf985bdc84
parent327641da8e3e227f42690479182b896fd19486be (diff)
xen: setup percpu data pointers
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. Also, set the kernel stack when bringing up secondary CPUs. If we don't they all end up sharing the same stack... Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-rw-r--r--arch/x86/xen/enlighten.c15
-rw-r--r--arch/x86/xen/smp.c6
-rw-r--r--arch/x86/xen/xen-ops.h2
3 files changed, 20 insertions, 3 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index cd022c43dfb..aed7ceeb4b6 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -66,6 +66,8 @@ EXPORT_SYMBOL_GPL(xen_start_info);
struct shared_info xen_dummy_shared_info;
+void *xen_initial_gdt;
+
/*
* Point at some empty memory to start with. We map the real shared_info
* page as soon as fixmap is up and running.
@@ -917,8 +919,19 @@ asmlinkage void __init xen_start_kernel(void)
have_vcpu_info_placement = 0;
#endif
- /* setup percpu state */
+#ifdef CONFIG_X86_64
+ /*
+ * Setup percpu state. We only need to do this for 64-bit
+ * because 32-bit already has %fs set properly.
+ */
load_percpu_segment(0);
+#endif
+ /*
+ * The only reliable way to retain the initial address of the
+ * percpu gdt_page is to remember it here, so we can go and
+ * mark it RW later, when the initial percpu area is freed.
+ */
+ xen_initial_gdt = &per_cpu(gdt_page, 0);
xen_smp_init();
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 88d5d5ec6be..035582ae815 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -170,8 +170,7 @@ 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_load +
- (unsigned long)&per_cpu_var(gdt_page));
+ make_lowmem_page_readwrite(xen_initial_gdt);
xen_setup_vcpu_info_placement();
}
@@ -287,6 +286,9 @@ static int __cpuinit xen_cpu_up(unsigned int cpu)
irq_ctx_init(cpu);
#else
clear_tsk_thread_flag(idle, TIF_FORK);
+ per_cpu(kernel_stack, cpu) =
+ (unsigned long)task_stack_page(idle) -
+ KERNEL_STACK_OFFSET + THREAD_SIZE;
#endif
xen_setup_timer(cpu);
xen_init_lock_cpu(cpu);
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 11913fc94c1..2f5ef2632ea 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -10,6 +10,8 @@
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
+extern void *xen_initial_gdt;
+
struct trap_info;
void xen_copy_trap_info(struct trap_info *traps);