x86: construct 32-bit boot time page tables in native format. (551889a6) · Commits · 戴 / test

arch/x86/kernel/head_32.S

+116 −35

Original line number	Diff line number	Diff line
		@@ -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 @@ INIT_MAP_BEYOND_END = BOOTBITMAP_SIZE + (PAGE_TABLE_SIZE + ALLOCATOR_SLOP)*PAGE_
		*/
		.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 @@ ENTRY(startup_32)
		/*
		* 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 @@ ENTRY(startup_32)
		*/
		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 @@ ENTRY(startup_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 @@ num_subarch_entries = (. - subarch_entries) / 4
		* 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 @@ default_entry:
		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)

		/* 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)
		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_dir+0xffc)
		#endif
		jmp 3f
		/*
		* Non-boot CPU entry point; entered from trampoline.S
		@@ -241,7 +294,7 @@ ENTRY(startup_32_smp)
		* 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 @@ ENTRY(startup_32_smp)
		/*
		* 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 @@ ENTRY(_stext)
		*/
		.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

arch/x86/kernel/setup_32.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -154,7 +154,11 @@ struct cpuinfo_x86 new_cpu_data __cpuinitdata = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
		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;

arch/x86/mm/init_32.c

+27 −45

Original line number	Diff line number	Diff line
		@@ -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 @@ pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC;

		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));

		/* 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
		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;

		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 @@ void __init native_pagetable_setup_done(pgd_t *base)
		* 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 @@ void __init paging_init(void)

		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 @@ void __init mem_init(void)
		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();

arch/x86/mm/ioremap.c

+31 −24

Original line number	Diff line number	Diff line
		@@ -260,37 +260,42 @@ static int __init early_ioremap_debug_setup(char *str)
		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));
		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n",
		@@ -304,28 +309,29 @@ void __init early_ioremap_init(void)

		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 @@ void __init early_ioremap_reset(void)
		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 @@ static void __init __early_set_fixmap(enum fixed_addresses idx,
		}
		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);
		}

include/asm-x86/page_32.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -48,7 +48,6 @@ typedef unsigned long pgprotval_t;
		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 */

Admin message