linux_dsm_epyc7002/arch/x86/include/asm/pgtable_32.h
Jeremy Fitzhardinge ccf3fe02e3 x86-32: use brk segment for allocating initial kernel pagetable
Impact: use new interface instead of previous ad hoc implementation

Rather than having special purpose init_pg_table_start/end variables
to delimit the kernel pagetable built by head_32.S, just use the brk
mechanism to extend the bss for the new pagetable.

This patch removes init_pg_table_start/end and pg0, defines __brk_base
(which is page-aligned and immediately follows _end), initializes
the brk region to start there, and uses it for the 32-bit pagetable.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14 17:23:47 -07:00

94 lines
2.5 KiB
C

#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 <asm/fixmap.h>
#include <linux/threads.h>
#include <asm/paravirt.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/spinlock.h>
struct mm_struct;
struct vm_area_struct;
extern pgd_t swapper_pg_dir[1024];
static inline void pgtable_cache_init(void) { }
static inline void check_pgt_cache(void) { }
void paging_init(void);
extern void set_pmd_pfn(unsigned long, unsigned long, pgprot_t);
/*
* 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(VERIFY_WRITE,..)'
*/
#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_pte(pmd_page(*(dir)), KM_PTE0) + \
pte_index((address)))
#define pte_offset_map_nested(dir, address) \
((pte_t *)kmap_atomic_pte(pmd_page(*(dir)), KM_PTE1) + \
pte_index((address)))
#define pte_unmap(pte) kunmap_atomic((pte), KM_PTE0)
#define pte_unmap_nested(pte) kunmap_atomic((pte), KM_PTE1)
#else
#define pte_offset_map(dir, address) \
((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
#define pte_offset_map_nested(dir, address) pte_offset_map((dir), (address))
#define pte_unmap(pte) do { } while (0)
#define pte_unmap_nested(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((vaddr)); \
} while (0)
/*
* The i386 doesn't have any external MMU info: the kernel page
* tables contain all the necessary information.
*/
#define update_mmu_cache(vma, address, pte) do { } while (0)
#endif /* !__ASSEMBLY__ */
/*
* kern_addr_valid() is (1) for FLATMEM and (0) for
* SPARSEMEM and DISCONTIGMEM
*/
#ifdef CONFIG_FLATMEM
#define kern_addr_valid(addr) (1)
#else
#define kern_addr_valid(kaddr) (0)
#endif
#endif /* _ASM_X86_PGTABLE_32_H */