x86-32, mm: Add an initial page table for core bootstrapping

This patch adds an initial page table with low mappings used exclusively
for booting APs/resuming after ACPI suspend/machine restart. After this,
there's no need to add low mappings to swapper_pg_dir and zap them later
or create own swsusp PGD page solely for ACPI sleep needs - we have
initial_page_table for that.

Signed-off-by: Borislav Petkov <bp@alien8.de>
LKML-Reference: <20101020070526.GA9588@liondog.tnic>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 0 insertions, 45 deletions

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 558f2d332076..1aeac2d9df80 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -548,48 +548,6 @@ static void __init pagetable_init(void)
         permanent_kmaps_init(pgd_base);
 }
 
-#ifdef CONFIG_ACPI_SLEEP
-/*
- * ACPI suspend needs this for resume, because things like the intel-agp
- * driver might have split up a kernel 4MB mapping.
- */
-char swsusp_pg_dir[PAGE_SIZE]
-        __attribute__ ((aligned(PAGE_SIZE)));
-
-static inline void save_pg_dir(void)
-{
-        copy_page(swsusp_pg_dir, swapper_pg_dir);
-}
-#else /* !CONFIG_ACPI_SLEEP */
-static inline void save_pg_dir(void)
-{
-}
-#endif /* !CONFIG_ACPI_SLEEP */
-
-void zap_low_mappings(bool early)
-{
-        int i;
-
-        /*
-         * Zap initial low-memory mappings.
-         *
-         * Note that "pgd_clear()" doesn't do it for
-         * us, because pgd_clear() is a no-op on i386.
-         */
-        for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) {
-#ifdef CONFIG_X86_PAE
-                set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
-#else
-                set_pgd(swapper_pg_dir+i, __pgd(0));
-#endif
-        }
-
-        if (early)
-                __flush_tlb();
-        else
-                flush_tlb_all();
-}
-
 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 
@@ -958,9 +916,6 @@ void __init mem_init(void)
 
         if (boot_cpu_data.wp_works_ok < 0)
                 test_wp_bit();
-
-        save_pg_dir();
-        zap_low_mappings(true);
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG