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;