aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/setup_percpu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/setup_percpu.c')
-rw-r--r--arch/x86/kernel/setup_percpu.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 11338b0b3ad2..bb1e8cc0bc84 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -288,4 +288,25 @@ void __init setup_per_cpu_areas(void)
/* Setup cpu initialized, callin, callout masks */
setup_cpu_local_masks();
+
+#ifdef CONFIG_X86_32
+ /*
+ * Sync back kernel address range. We want to make sure that
+ * all kernel mappings, including percpu mappings, are available
+ * in the smpboot asm. We can't reliably pick up percpu
+ * mappings using vmalloc_fault(), because exception dispatch
+ * needs percpu data.
+ */
+ clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ KERNEL_PGD_PTRS);
+
+ /*
+ * sync back low identity map too. It is used for example
+ * in the 32-bit EFI stub.
+ */
+ clone_pgd_range(initial_page_table,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
+#endif
}