x86: construct 32-bit boot time page tables in native format.
Specifically the boot time page tables in a CONFIG_X86_PAE=y enabled
kernel are in PAE format.
early_ioremap is updated to use the standard page table accessors.
Clear any mappings beyond max_low_pfn from the boot page tables in
native_pagetable_setup_start because the initial mappings can extend
beyond the range of physical memory and into the vmalloc area.
Derived from patches by Eric Biederman and H. Peter Anvin.
[ jeremy@goop.org: PAE swapper_pg_dir needs to be page-sized fix ]
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Mika Penttilä <mika.penttila@kolumbus.fi>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index d1bc040..54aba3c 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -46,6 +46,7 @@
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/paravirt.h>
+#include <asm/setup.h>
unsigned int __VMALLOC_RESERVE = 128 << 20;
@@ -328,44 +329,38 @@
void __init native_pagetable_setup_start(pgd_t *base)
{
-#ifdef CONFIG_X86_PAE
- int i;
+ unsigned long pfn, va;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
/*
- * Init entries of the first-level page table to the
- * zero page, if they haven't already been set up.
- *
- * In a normal native boot, we'll be running on a
- * pagetable rooted in swapper_pg_dir, but not in PAE
- * mode, so this will end up clobbering the mappings
- * for the lower 24Mbytes of the address space,
- * without affecting the kernel address space.
+ * Remove any mappings which extend past the end of physical
+ * memory from the boot time page table:
*/
- for (i = 0; i < USER_PTRS_PER_PGD; i++)
- set_pgd(&base[i],
- __pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
+ for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
+ va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
+ pgd = base + pgd_index(va);
+ if (!pgd_present(*pgd))
+ break;
- /* Make sure kernel address space is empty so that a pagetable
- will be allocated for it. */
- memset(&base[USER_PTRS_PER_PGD], 0,
- KERNEL_PGD_PTRS * sizeof(pgd_t));
-#else
+ pud = pud_offset(pgd, va);
+ pmd = pmd_offset(pud, va);
+ if (!pmd_present(*pmd))
+ break;
+
+ pte = pte_offset_kernel(pmd, va);
+ if (!pte_present(*pte))
+ break;
+
+ pte_clear(NULL, va, pte);
+ }
paravirt_alloc_pd(&init_mm, __pa(base) >> PAGE_SHIFT);
-#endif
}
void __init native_pagetable_setup_done(pgd_t *base)
{
-#ifdef CONFIG_X86_PAE
- /*
- * Add low memory identity-mappings - SMP needs it when
- * starting up on an AP from real-mode. In the non-PAE
- * case we already have these mappings through head.S.
- * All user-space mappings are explicitly cleared after
- * SMP startup.
- */
- set_pgd(&base[0], base[USER_PTRS_PER_PGD]);
-#endif
}
/*
@@ -374,9 +369,8 @@
* the boot process.
*
* If we're booting on native hardware, this will be a pagetable
- * constructed in arch/i386/kernel/head.S, and not running in PAE mode
- * (even if we'll end up running in PAE). The root of the pagetable
- * will be swapper_pg_dir.
+ * constructed in arch/x86/kernel/head_32.S. The root of the
+ * pagetable will be swapper_pg_dir.
*
* If we're booting paravirtualized under a hypervisor, then there are
* more options: we may already be running PAE, and the pagetable may
@@ -537,14 +531,6 @@
load_cr3(swapper_pg_dir);
-#ifdef CONFIG_X86_PAE
- /*
- * We will bail out later - printk doesn't work right now so
- * the user would just see a hanging kernel.
- */
- if (cpu_has_pae)
- set_in_cr4(X86_CR4_PAE);
-#endif
__flush_tlb_all();
kmap_init();
@@ -675,10 +661,6 @@
BUG_ON((unsigned long)high_memory > VMALLOC_START);
#endif /* double-sanity-check paranoia */
-#ifdef CONFIG_X86_PAE
- if (!cpu_has_pae)
- panic("cannot execute a PAE-enabled kernel on a PAE-less CPU!");
-#endif
if (boot_cpu_data.wp_works_ok < 0)
test_wp_bit();
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index ee6648f..1106b7f 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -260,41 +260,46 @@
early_param("early_ioremap_debug", early_ioremap_debug_setup);
static __initdata int after_paging_init;
-static __initdata unsigned long bm_pte[1024]
+static __initdata pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)]
__attribute__((aligned(PAGE_SIZE)));
-static inline unsigned long * __init early_ioremap_pgd(unsigned long addr)
+static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
- return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
+ pgd_t *pgd = &swapper_pg_dir[pgd_index(addr)];
+ pud_t *pud = pud_offset(pgd, addr);
+ pmd_t *pmd = pmd_offset(pud, addr);
+
+ return pmd;
}
-static inline unsigned long * __init early_ioremap_pte(unsigned long addr)
+static inline pte_t * __init early_ioremap_pte(unsigned long addr)
{
- return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
+ return &bm_pte[pte_index(addr)];
}
void __init early_ioremap_init(void)
{
- unsigned long *pgd;
+ pmd_t *pmd;
if (early_ioremap_debug)
printk(KERN_INFO "early_ioremap_init()\n");
- pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
- *pgd = __pa(bm_pte) | _PAGE_TABLE;
+ pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
memset(bm_pte, 0, sizeof(bm_pte));
+ set_pmd(pmd, __pmd(__pa(bm_pte) | _PAGE_TABLE));
+
/*
- * The boot-ioremap range spans multiple pgds, for which
+ * The boot-ioremap range spans multiple pmds, for which
* we are not prepared:
*/
- if (pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))) {
+ if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
WARN_ON(1);
- printk(KERN_WARNING "pgd %p != %p\n",
- pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
+ printk(KERN_WARNING "pmd %p != %p\n",
+ pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
- fix_to_virt(FIX_BTMAP_BEGIN));
+ fix_to_virt(FIX_BTMAP_BEGIN));
printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n",
- fix_to_virt(FIX_BTMAP_END));
+ fix_to_virt(FIX_BTMAP_END));
printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n",
@@ -304,28 +309,29 @@
void __init early_ioremap_clear(void)
{
- unsigned long *pgd;
+ pmd_t *pmd;
if (early_ioremap_debug)
printk(KERN_INFO "early_ioremap_clear()\n");
- pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
- *pgd = 0;
- paravirt_release_pt(__pa(pgd) >> PAGE_SHIFT);
+ pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
+ pmd_clear(pmd);
+ paravirt_release_pt(__pa(pmd) >> PAGE_SHIFT);
__flush_tlb_all();
}
void __init early_ioremap_reset(void)
{
enum fixed_addresses idx;
- unsigned long *pte, phys, addr;
+ unsigned long addr, phys;
+ pte_t *pte;
after_paging_init = 1;
for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
addr = fix_to_virt(idx);
pte = early_ioremap_pte(addr);
- if (*pte & _PAGE_PRESENT) {
- phys = *pte & PAGE_MASK;
+ if (pte_present(*pte)) {
+ phys = pte_val(*pte) & PAGE_MASK;
set_fixmap(idx, phys);
}
}
@@ -334,7 +340,8 @@
static void __init __early_set_fixmap(enum fixed_addresses idx,
unsigned long phys, pgprot_t flags)
{
- unsigned long *pte, addr = __fix_to_virt(idx);
+ unsigned long addr = __fix_to_virt(idx);
+ pte_t *pte;
if (idx >= __end_of_fixed_addresses) {
BUG();
@@ -342,9 +349,9 @@
}
pte = early_ioremap_pte(addr);
if (pgprot_val(flags))
- *pte = (phys & PAGE_MASK) | pgprot_val(flags);
+ set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
else
- *pte = 0;
+ pte_clear(NULL, addr, pte);
__flush_tlb_one(addr);
}