[thirdparty/linux.git] / arch / x86 / include / asm / pgtable_32.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PGTABLE_32_H
#define _ASM_X86_PGTABLE_32_H

#include <asm/pgtable_32_types.h>

/*
 * The Linux memory management assumes a three-level page table setup. On
 * the i386, we use that, but "fold" the mid level into the top-level page
 * table, so that we physically have the same two-level page table as the
 * i386 mmu expects.
 *
 * This file contains the functions and defines necessary to modify and use
 * the i386 page table tree.
 */
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#include <linux/threads.h>
#include <asm/paravirt.h>

#include <linux/bitops.h>
#include <linux/list.h>
#include <linux/spinlock.h>

struct mm_struct;
struct vm_area_struct;

extern pgd_t swapper_pg_dir[1024];
extern pgd_t initial_page_table[1024];
extern pmd_t initial_pg_pmd[];

void paging_init(void);
void sync_initial_page_table(void);

/*
 * Define this if things work differently on an i386 and an i486:
 * it will (on an i486) warn about kernel memory accesses that are
 * done without a 'access_ok( ..)'
 */
#undef TEST_ACCESS_OK

#ifdef CONFIG_X86_PAE
# include <asm/pgtable-3level.h>
#else
# include <asm/pgtable-2level.h>
#endif

#if defined(CONFIG_HIGHPTE)
#define pte_offset_map(dir, address)					\
	((pte_t *)kmap_atomic(pmd_page(*(dir))) +		\
	 pte_index((address)))
#define pte_unmap(pte) kunmap_atomic((pte))
#else
#define pte_offset_map(dir, address)					\
	((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
#define pte_unmap(pte) do { } while (0)
#endif

/* Clear a kernel PTE and flush it from the TLB */
#define kpte_clear_flush(ptep, vaddr)		\
do {						\
	pte_clear(&init_mm, (vaddr), (ptep));	\
	__flush_tlb_one_kernel((vaddr));		\
} while (0)

#endif /* !__ASSEMBLY__ */

/*
 * kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM
 */
#ifdef CONFIG_FLATMEM
#define kern_addr_valid(addr)	(1)
#else
#define kern_addr_valid(kaddr)	(0)
#endif

/*
 * This is how much memory in addition to the memory covered up to
 * and including _end we need mapped initially.
 * We need:
 *     (KERNEL_IMAGE_SIZE/4096) / 1024 pages (worst case, non PAE)
 *     (KERNEL_IMAGE_SIZE/4096) / 512 + 4 pages (worst case for PAE)
 *
 * Modulo rounding, each megabyte assigned here requires a kilobyte of
 * memory, which is currently unreclaimed.
 *
 * This should be a multiple of a page.
 *
 * KERNEL_IMAGE_SIZE should be greater than pa(_end)
 * and small than max_low_pfn, otherwise will waste some page table entries
 */
#if PTRS_PER_PMD > 1
#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
#else
#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
#endif

/*
 * Number of possible pages in the lowmem region.
 *
 * We shift 2 by 31 instead of 1 by 32 to the left in order to avoid a
 * gas warning about overflowing shift count when gas has been compiled
 * with only a host target support using a 32-bit type for internal
 * representation.
 */
#define LOWMEM_PAGES ((((_ULL(2)<<31) - __PAGE_OFFSET) >> PAGE_SHIFT))

#endif /* _ASM_X86_PGTABLE_32_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1965aae3 PA	2	#ifndef _ASM_X86_PGTABLE_32_H
1965aae3 PA	3	#define _ASM_X86_PGTABLE_32_H
1da177e4	4
f402a65f	5	#include <asm/pgtable_32_types.h>
1da177e4 LT	6
	7	/*
	8	* The Linux memory management assumes a three-level page table setup. On
	9	* the i386, we use that, but "fold" the mid level into the top-level page
	10	* table, so that we physically have the same two-level page table as the
	11	* i386 mmu expects.
	12	*
	13	* This file contains the functions and defines necessary to modify and use
	14	* the i386 page table tree.
	15	*/
	16	#ifndef __ASSEMBLY__
	17	#include <asm/processor.h>
1da177e4	18	#include <linux/threads.h>
da181a8b	19	#include <asm/paravirt.h>
1da177e4	20
1977f032	21	#include <linux/bitops.h>
1da177e4 LT	22	#include <linux/list.h>
	23	#include <linux/spinlock.h>
	24
8c65b4a6 TS	25	struct mm_struct;
	26	struct vm_area_struct;
	27
1da177e4	28	extern pgd_t swapper_pg_dir[1024];
b40827fa	29	extern pgd_t initial_page_table[1024];
1e620f9b	30	extern pmd_t initial_pg_pmd[];
1da177e4	31
1da177e4	32	void paging_init(void);
945fd17a	33	void sync_initial_page_table(void);
1da177e4	34
1da177e4 LT	35	/*
	36	* Define this if things work differently on an i386 and an i486:
	37	* it will (on an i486) warn about kernel memory accesses that are
96d4f267	38	* done without a 'access_ok( ..)'
1da177e4	39	*/
e49332bd	40	#undef TEST_ACCESS_OK
1da177e4	41
1da177e4 LT	42	#ifdef CONFIG_X86_PAE
	43	# include <asm/pgtable-3level.h>
	44	#else
	45	# include <asm/pgtable-2level.h>
	46	#endif
	47
1da177e4	48	#if defined(CONFIG_HIGHPTE)
cf840147	49	#define pte_offset_map(dir, address) \
ece0e2b6	50	((pte_t )kmap_atomic(pmd_page((dir))) + \
cf840147	51	pte_index((address)))
ece0e2b6	52	#define pte_unmap(pte) kunmap_atomic((pte))
1da177e4	53	#else
cf840147 JP	54	#define pte_offset_map(dir, address) \
cf840147 JP	55	((pte_t )page_address(pmd_page((dir))) + pte_index((address)))
1da177e4	56	#define pte_unmap(pte) do { } while (0)
1da177e4 LT	57	#endif
1da177e4 LT	58
23002d88	59	/* Clear a kernel PTE and flush it from the TLB */
cf840147 JP	60	#define kpte_clear_flush(ptep, vaddr) \
	61	do { \
	62	pte_clear(&init_mm, (vaddr), (ptep)); \
1299ef1d	63	__flush_tlb_one_kernel((vaddr)); \
23002d88 ZA	64	} while (0)
23002d88 ZA	65
1da177e4 LT	66	#endif /* !__ASSEMBLY__ */
1da177e4 LT	67
4757d7d8	68	/*
43173265	69	* kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM
4757d7d8	70	*/
05b79bdc	71	#ifdef CONFIG_FLATMEM
1da177e4	72	#define kern_addr_valid(addr) (1)
4757d7d8 TG	73	#else
	74	#define kern_addr_valid(kaddr) (0)
	75	#endif
1da177e4	76
1e620f9b BO	77	/*
	78	* This is how much memory in addition to the memory covered up to
	79	* and including _end we need mapped initially.
	80	* We need:
	81	* (KERNEL_IMAGE_SIZE/4096) / 1024 pages (worst case, non PAE)
	82	* (KERNEL_IMAGE_SIZE/4096) / 512 + 4 pages (worst case for PAE)
	83	*
	84	* Modulo rounding, each megabyte assigned here requires a kilobyte of
	85	* memory, which is currently unreclaimed.
	86	*
	87	* This should be a multiple of a page.
	88	*
	89	* KERNEL_IMAGE_SIZE should be greater than pa(_end)
	90	* and small than max_low_pfn, otherwise will waste some page table entries
	91	*/
	92	#if PTRS_PER_PMD > 1
	93	#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
	94	#else
	95	#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
	96	#endif
	97
	98	/*
	99	* Number of possible pages in the lowmem region.
	100	*
	101	* We shift 2 by 31 instead of 1 by 32 to the left in order to avoid a
	102	* gas warning about overflowing shift count when gas has been compiled
	103	* with only a host target support using a 32-bit type for internal
	104	* representation.
	105	*/
26515699	106	#define LOWMEM_PAGES ((((_ULL(2)<<31) - __PAGE_OFFSET) >> PAGE_SHIFT))
1e620f9b	107
1965aae3	108	#endif /* _ASM_X86_PGTABLE_32_H */