[PATCH 2/2] xen: setup percpu data pointers

[Jeremy Fitzhardinge]

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@xxxxxxxxxx>
---
arch/x86/xen/enlighten.c |    3 +++
arch/x86/xen/smp.c       |    5 ++++-
2 files changed, 7 insertions(+), 1 deletion(-)

===================================================================
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1646,6 +1640,9 @@
	have_vcpu_info_placement = 0;
#endif

+	/* setup percpu state */
+	load_percpu_segment(0);
+
	xen_smp_init();

	/* Get mfn list */
===================================================================
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -170,7 +170,8 @@

	/* 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 @@
	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 */


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/