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/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 5d8c573..74ef4a4 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -19,6 +19,10 @@
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/setup.h>
+#include <asm/processor-flags.h>
+
+/* Physical address */
+#define pa(X) ((X) - __PAGE_OFFSET)
/*
* References to members of the new_cpu_data structure.
@@ -80,10 +84,6 @@
*/
.section .text.head,"ax",@progbits
ENTRY(startup_32)
- /* check to see if KEEP_SEGMENTS flag is meaningful */
- cmpw $0x207, BP_version(%esi)
- jb 1f
-
/* test KEEP_SEGMENTS flag to see if the bootloader is asking
us to not reload segments */
testb $(1<<6), BP_loadflags(%esi)
@@ -92,7 +92,7 @@
/*
* Set segments to known values.
*/
-1: lgdt boot_gdt_descr - __PAGE_OFFSET
+ lgdt pa(boot_gdt_descr)
movl $(__BOOT_DS),%eax
movl %eax,%ds
movl %eax,%es
@@ -105,8 +105,8 @@
*/
cld
xorl %eax,%eax
- movl $__bss_start - __PAGE_OFFSET,%edi
- movl $__bss_stop - __PAGE_OFFSET,%ecx
+ movl $pa(__bss_start),%edi
+ movl $pa(__bss_stop),%ecx
subl %edi,%ecx
shrl $2,%ecx
rep ; stosl
@@ -118,31 +118,32 @@
* (kexec on panic case). Hence copy out the parameters before initializing
* page tables.
*/
- movl $(boot_params - __PAGE_OFFSET),%edi
+ movl $pa(boot_params),%edi
movl $(PARAM_SIZE/4),%ecx
cld
rep
movsl
- movl boot_params - __PAGE_OFFSET + NEW_CL_POINTER,%esi
+ movl pa(boot_params) + NEW_CL_POINTER,%esi
andl %esi,%esi
jz 1f # No comand line
- movl $(boot_command_line - __PAGE_OFFSET),%edi
+ movl $pa(boot_command_line),%edi
movl $(COMMAND_LINE_SIZE/4),%ecx
rep
movsl
1:
#ifdef CONFIG_PARAVIRT
- cmpw $0x207, (boot_params + BP_version - __PAGE_OFFSET)
+ /* This is can only trip for a broken bootloader... */
+ cmpw $0x207, pa(boot_params + BP_version)
jb default_entry
/* Paravirt-compatible boot parameters. Look to see what architecture
we're booting under. */
- movl (boot_params + BP_hardware_subarch - __PAGE_OFFSET), %eax
+ movl pa(boot_params + BP_hardware_subarch), %eax
cmpl $num_subarch_entries, %eax
jae bad_subarch
- movl subarch_entries - __PAGE_OFFSET(,%eax,4), %eax
+ movl pa(subarch_entries)(,%eax,4), %eax
subl $__PAGE_OFFSET, %eax
jmp *%eax
@@ -170,17 +171,68 @@
* Mappings are created both at virtual address 0 (identity mapping)
* and PAGE_OFFSET for up to _end+sizeof(page tables)+INIT_MAP_BEYOND_END.
*
- * Warning: don't use %esi or the stack in this code. However, %esp
- * can be used as a GPR if you really need it...
+ * Note that the stack is not yet set up!
*/
-page_pde_offset = (__PAGE_OFFSET >> 20);
+#define PTE_ATTR 0x007 /* PRESENT+RW+USER */
+#define PDE_ATTR 0x067 /* PRESENT+RW+USER+DIRTY+ACCESSED */
+#define PGD_ATTR 0x001 /* PRESENT (no other attributes) */
default_entry:
- movl $(pg0 - __PAGE_OFFSET), %edi
- movl $(swapper_pg_dir - __PAGE_OFFSET), %edx
- movl $0x007, %eax /* 0x007 = PRESENT+RW+USER */
+#ifdef CONFIG_X86_PAE
+
+ /*
+ * In PAE mode swapper_pg_dir is statically defined to contain enough
+ * entries to cover the VMSPLIT option (that is the top 1, 2 or 3
+ * entries). The identity mapping is handled by pointing two PGD
+ * entries to the first kernel PMD.
+ *
+ * Note the upper half of each PMD or PTE are always zero at
+ * this stage.
+ */
+
+#define KPMDS ((0x100000000-__PAGE_OFFSET) >> 30) /* Number of kernel PMDs */
+
+ xorl %ebx,%ebx /* %ebx is kept at zero */
+
+ movl $pa(pg0), %edi
+ movl $pa(swapper_pg_pmd), %edx
+ movl $PTE_ATTR, %eax
10:
- leal 0x007(%edi),%ecx /* Create PDE entry */
+ leal PDE_ATTR(%edi),%ecx /* Create PMD entry */
+ movl %ecx,(%edx) /* Store PMD entry */
+ /* Upper half already zero */
+ addl $8,%edx
+ movl $512,%ecx
+11:
+ stosl
+ xchgl %eax,%ebx
+ stosl
+ xchgl %eax,%ebx
+ addl $0x1000,%eax
+ loop 11b
+
+ /*
+ * End condition: we must map up to and including INIT_MAP_BEYOND_END
+ * bytes beyond the end of our own page tables.
+ */
+ leal (INIT_MAP_BEYOND_END+PTE_ATTR)(%edi),%ebp
+ cmpl %ebp,%eax
+ jb 10b
+1:
+ movl %edi,pa(init_pg_tables_end)
+
+ /* Do early initialization of the fixmap area */
+ movl $pa(swapper_pg_fixmap)+PDE_ATTR,%eax
+ movl %eax,pa(swapper_pg_pmd+0x1000*KPMDS-8)
+#else /* Not PAE */
+
+page_pde_offset = (__PAGE_OFFSET >> 20);
+
+ movl $pa(pg0), %edi
+ movl $pa(swapper_pg_dir), %edx
+ movl $PTE_ATTR, %eax
+10:
+ leal PDE_ATTR(%edi),%ecx /* Create PDE entry */
movl %ecx,(%edx) /* Store identity PDE entry */
movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */
addl $4,%edx
@@ -189,19 +241,20 @@
stosl
addl $0x1000,%eax
loop 11b
- /* End condition: we must map up to and including INIT_MAP_BEYOND_END */
- /* bytes beyond the end of our own page tables; the +0x007 is the attribute bits */
- leal (INIT_MAP_BEYOND_END+0x007)(%edi),%ebp
+ /*
+ * End condition: we must map up to and including INIT_MAP_BEYOND_END
+ * bytes beyond the end of our own page tables; the +0x007 is
+ * the attribute bits
+ */
+ leal (INIT_MAP_BEYOND_END+PTE_ATTR)(%edi),%ebp
cmpl %ebp,%eax
jb 10b
- movl %edi,(init_pg_tables_end - __PAGE_OFFSET)
+ movl %edi,pa(init_pg_tables_end)
- /* Do an early initialization of the fixmap area */
- movl $(swapper_pg_dir - __PAGE_OFFSET), %edx
- movl $(swapper_pg_pmd - __PAGE_OFFSET), %eax
- addl $0x67, %eax /* 0x67 == _PAGE_TABLE */
- movl %eax, 4092(%edx)
-
+ /* Do early initialization of the fixmap area */
+ movl $pa(swapper_pg_fixmap)+PDE_ATTR,%eax
+ movl %eax,pa(swapper_pg_dir+0xffc)
+#endif
jmp 3f
/*
* Non-boot CPU entry point; entered from trampoline.S
@@ -241,7 +294,7 @@
* NOTE! We have to correct for the fact that we're
* not yet offset PAGE_OFFSET..
*/
-#define cr4_bits mmu_cr4_features-__PAGE_OFFSET
+#define cr4_bits pa(mmu_cr4_features)
movl cr4_bits,%edx
andl %edx,%edx
jz 6f
@@ -276,10 +329,10 @@
/*
* Enable paging
*/
- movl $swapper_pg_dir-__PAGE_OFFSET,%eax
+ movl $pa(swapper_pg_dir),%eax
movl %eax,%cr3 /* set the page table pointer.. */
movl %cr0,%eax
- orl $0x80000000,%eax
+ orl $X86_CR0_PG,%eax
movl %eax,%cr0 /* ..and set paging (PG) bit */
ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */
1:
@@ -552,16 +605,44 @@
*/
.section ".bss.page_aligned","wa"
.align PAGE_SIZE_asm
+#ifdef CONFIG_X86_PAE
+ENTRY(swapper_pg_pmd)
+ .fill 1024*KPMDS,4,0
+#else
ENTRY(swapper_pg_dir)
.fill 1024,4,0
-ENTRY(swapper_pg_pmd)
+#endif
+ENTRY(swapper_pg_fixmap)
.fill 1024,4,0
ENTRY(empty_zero_page)
.fill 4096,1,0
-
/*
* This starts the data section.
*/
+#ifdef CONFIG_X86_PAE
+.section ".data.page_aligned","wa"
+ /* Page-aligned for the benefit of paravirt? */
+ .align PAGE_SIZE_asm
+ENTRY(swapper_pg_dir)
+ .long pa(swapper_pg_pmd+PGD_ATTR),0 /* low identity map */
+# if KPMDS == 3
+ .long pa(swapper_pg_pmd+PGD_ATTR),0
+ .long pa(swapper_pg_pmd+PGD_ATTR+0x1000),0
+ .long pa(swapper_pg_pmd+PGD_ATTR+0x2000),0
+# elif KPMDS == 2
+ .long 0,0
+ .long pa(swapper_pg_pmd+PGD_ATTR),0
+ .long pa(swapper_pg_pmd+PGD_ATTR+0x1000),0
+# elif KPMDS == 1
+ .long 0,0
+ .long 0,0
+ .long pa(swapper_pg_pmd+PGD_ATTR),0
+# else
+# error "Kernel PMDs should be 1, 2 or 3"
+# endif
+ .align PAGE_SIZE_asm /* needs to be page-sized too */
+#endif
+
.data
ENTRY(stack_start)
.long init_thread_union+THREAD_SIZE
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index d1d8c34..691ab4c 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -154,7 +154,11 @@
struct cpuinfo_x86 boot_cpu_data __read_mostly = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
EXPORT_SYMBOL(boot_cpu_data);
+#ifndef CONFIG_X86_PAE
unsigned long mmu_cr4_features;
+#else
+unsigned long mmu_cr4_features = X86_CR4_PAE;
+#endif
/* for MCA, but anyone else can use it if they want */
unsigned int machine_id;
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);
}
diff --git a/include/asm-x86/page_32.h b/include/asm-x86/page_32.h
index 984998a..5f7257f 100644
--- a/include/asm-x86/page_32.h
+++ b/include/asm-x86/page_32.h
@@ -48,7 +48,6 @@
typedef unsigned long phys_addr_t;
typedef union { pteval_t pte, pte_low; } pte_t;
-typedef pte_t boot_pte_t;
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_X86_PAE */
diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h
index 80dd438..a842c72 100644
--- a/include/asm-x86/pgtable_32.h
+++ b/include/asm-x86/pgtable_32.h
@@ -52,10 +52,6 @@
#define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
#define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)
-#define TWOLEVEL_PGDIR_SHIFT 22
-#define BOOT_USER_PGD_PTRS (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT)
-#define BOOT_KERNEL_PGD_PTRS (1024-BOOT_USER_PGD_PTRS)
-
/* Just any arbitrary offset to the start of the vmalloc VM area: the
* current 8MB value just means that there will be a 8MB "hole" after the
* physical memory until the kernel virtual memory starts. That means that