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/*
* Copyright (c) 2010, 2011, 2012 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _X86_PMAP_H
#define _X86_PMAP_H
#include <kern/param.h>
#include <kern/types.h>
#include <lib/stdint.h>
/*
* Page directory/table properties.
*/
#ifdef PAE
#define PMAP_PDE_SHIFT 21
#define PMAP_PT_SHIFT 9
#define PMAP_NR_PDT 4
#define PMAP_PTE_PMASK 0x0000000ffffff000ULL
#else /* PAE */
#define PMAP_PDE_SHIFT 22
#define PMAP_PT_SHIFT 10
#define PMAP_NR_PDT 1
#define PMAP_PTE_PMASK (~PAGE_MASK)
#endif /* PAE */
#define PMAP_PTE_SHIFT 12
/*
* The amount of virtual memory described by a page directory/table entry.
*/
#define PMAP_PDE_MAPSIZE (1 << PMAP_PDE_SHIFT)
#define PMAP_PTE_MAPSIZE (1 << PMAP_PTE_SHIFT)
/*
* Number of entries in a page directory/table.
*/
#define PMAP_PTE_PER_PT (1 << PMAP_PT_SHIFT)
/*
* PDE/PTE flags.
*/
#define PMAP_PTE_PRESENT 0x001
#define PMAP_PTE_WRITE 0x002
#define PMAP_PTE_USER 0x004
#define PMAP_PTE_WRITE_THROUGH 0x008
#define PMAP_PTE_CACHE_DISABLE 0x010
#define PMAP_PTE_ACCESSED 0x020
#define PMAP_PTE_DIRTY 0x040
#define PMAP_PTE_GLOBAL 0x100
#define PMAP_PTE_AVAIL1 0x200
#define PMAP_PTE_AVAIL2 0x400
#define PMAP_PTE_AVAIL3 0x800
/*
* Flags related to page protection.
*/
#define PMAP_PTE_PROT_MASK PMAP_PTE_WRITE
/*
* Index of the first PDE for the kernel address space.
*/
#define PMAP_PDE_KERN (VM_MIN_KERNEL_ADDRESS >> PMAP_PDE_SHIFT)
/*
* PDE index for the page directory.
*/
#define PMAP_PDE_PTE (VM_MAX_KERNEL_ADDRESS >> PMAP_PDE_SHIFT)
/*
* Page table entry (also usable as a page directory entry or page directory
* pointer table entry).
*/
#ifdef PAE
typedef uint64_t pmap_pte_t;
#else /* PAE */
typedef uint32_t pmap_pte_t;
#endif /* PAE */
/*
* Base virtual address of the linear mapping of PTEs.
*/
#define PMAP_PTE_BASE ((pmap_pte_t *)(PMAP_PDE_PTE << PMAP_PDE_SHIFT))
/*
* Base virtual address of the page directory, in the linear mapping of PTEs.
*/
#define PMAP_PDP_BASE (PMAP_PTE_BASE + (PMAP_PDE_PTE * PMAP_PTE_PER_PT))
/*
* Virtual address of the PDE that points to the PDP.
*/
#define PMAP_PDP_PDE (PMAP_PDP_BASE + PMAP_PDE_PTE)
/*
* Number of pages to reserve for the pmap module after the kernel.
*
* This pool of pure virtual memory can be used to reserve virtual addresses
* before the VM system is initialized.
*/
#define PMAP_RESERVED_PAGES 2
/*
* Physical address map.
*/
struct pmap {
pmap_pte_t *pdir; /* Page directory virtual address */
vm_phys_t pdir_pa; /* Page directory physical address */
#ifdef PAE
pmap_pte_t *pdpt; /* Page directory pointer table physical address */
#endif /* PAE */
};
/*
* The kernel pmap.
*/
extern struct pmap *kernel_pmap;
/*
* Kernel page directory.
*/
extern pmap_pte_t pmap_kpdir[PMAP_NR_PDT * PMAP_PTE_PER_PT];
#ifdef PAE
/*
* Kernel page directory pointer table.
*/
extern pmap_pte_t pmap_kpdpt[PMAP_NR_PDT];
#endif /* PAE */
/*
* Address below which using the low level kernel pmap functions is safe.
* Its value is adjusted by calling pmap_growkernel().
*/
extern unsigned long pmap_klimit;
/*
* Early initialization of the pmap module.
*
* When this function is called, basic paging is enabled and the kernel
* already runs at virtual addresses.
*/
void pmap_bootstrap(void);
/*
* Allocate pure virtual memory.
*
* This memory is obtained from a very small pool of reserved pages located
* immediately after the kernel. Its purpose is to allow early mappings to
* be created before the VM system is available.
*/
unsigned long pmap_bootalloc(unsigned int nr_pages);
/*
* Return the available kernel virtual space in virt_start and virt_end.
*
* This function is called early, during initialization of the VM system, and
* can't be used after since the VM has taken control of the kernel address
* space.
*/
void pmap_virtual_space(unsigned long *virt_start, unsigned long *virt_end);
/*
* Preallocate resources so that addresses up to va can be mapped safely in
* the kernel pmap.
*/
void pmap_growkernel(unsigned long va);
/*
* Kernel specific mapping functions.
*
* Resources for the new mappings must be preallocated.
*/
void pmap_kenter(unsigned long va, vm_phys_t pa);
void pmap_kremove(unsigned long start, unsigned long end);
void pmap_kprotect(unsigned long start, unsigned long end, int prot);
vm_phys_t pmap_kextract(unsigned long va);
/*
* Zero a page at the given physical address.
*/
void pmap_zero_page(vm_phys_t pa);
#endif /* _X86_PMAP_H */
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