as.h

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/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __AS_H__
#define __AS_H__

#define AS_AREA_READ            1
#define AS_AREA_WRITE           2
#define AS_AREA_EXEC            4
#define AS_AREA_CACHEABLE       8

#ifdef KERNEL

#include <arch/mm/page.h>
#include <arch/mm/as.h>
#include <arch/mm/asid.h>
#include <arch/types.h>
#include <typedefs.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <adt/list.h>
#include <adt/btree.h>
#include <elf.h>

#define KERNEL_ADDRESS_SPACE_SHADOWED   KERNEL_ADDRESS_SPACE_SHADOWED_ARCH

#define KERNEL_ADDRESS_SPACE_START      KERNEL_ADDRESS_SPACE_START_ARCH
#define KERNEL_ADDRESS_SPACE_END        KERNEL_ADDRESS_SPACE_END_ARCH
#define USER_ADDRESS_SPACE_START        USER_ADDRESS_SPACE_START_ARCH
#define USER_ADDRESS_SPACE_END          USER_ADDRESS_SPACE_END_ARCH

#define IS_KA(addr)     ((addr)>=KERNEL_ADDRESS_SPACE_START && (addr)<=KERNEL_ADDRESS_SPACE_END)

#define USTACK_ADDRESS  USTACK_ADDRESS_ARCH

#define FLAG_AS_KERNEL      (1 << 0)    
struct as {

        link_t inactive_as_with_asid_link;

        mutex_t lock;

        count_t refcount;

        count_t cpu_refcount;

        btree_t as_area_btree;

        pte_t *page_table;

        asid_t asid;
};

struct as_operations {
        pte_t *(* page_table_create)(int flags);
        void (* page_table_destroy)(pte_t *page_table);
        void (* page_table_lock)(as_t *as, bool lock);
        void (* page_table_unlock)(as_t *as, bool unlock);
};
typedef struct as_operations as_operations_t;

#define AS_AREA_ATTR_NONE       0
#define AS_AREA_ATTR_PARTIAL    1       
#define AS_PF_FAULT             0       
#define AS_PF_OK                1       
#define AS_PF_DEFER             2       
typedef struct {
        mutex_t lock;           
        count_t refcount;       
        btree_t pagemap;        
} share_info_t;

typedef struct {
        int (* page_fault)(as_area_t *area, __address addr, pf_access_t access);
        void (* frame_free)(as_area_t *area, __address page, __address frame);
        void (* share)(as_area_t *area);
} mem_backend_t;

typedef union {
        struct {        
                elf_header_t *elf;
                elf_segment_header_t *segment;
        };
        struct {        
                __address base;
                count_t frames;
        };
} mem_backend_data_t;

struct as_area {
        mutex_t lock;
        as_t *as;               
        int flags;              
        int attributes;         
        count_t pages;          
        __address base;         
        btree_t used_space;     
        share_info_t *sh_info;  
        mem_backend_t *backend; 
        mem_backend_data_t backend_data;
};

extern as_t *AS_KERNEL;
extern as_operations_t *as_operations;

extern spinlock_t inactive_as_with_asid_lock;
extern link_t inactive_as_with_asid_head;

extern void as_init(void);

extern as_t *as_create(int flags);
extern void as_destroy(as_t *as);
extern void as_switch(as_t *old, as_t *new);
extern int as_page_fault(__address page, pf_access_t access, istate_t *istate);

extern as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs,
        mem_backend_t *backend, mem_backend_data_t *backend_data);
extern int as_area_destroy(as_t *as, __address address);        
extern int as_area_resize(as_t *as, __address address, size_t size, int flags);
int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
                  as_t *dst_as, __address dst_base, int dst_flags_mask);

extern int as_area_get_flags(as_area_t *area);
extern bool as_area_check_access(as_area_t *area, pf_access_t access);
extern size_t as_get_size(__address base);
extern int used_space_insert(as_area_t *a, __address page, count_t count);
extern int used_space_remove(as_area_t *a, __address page, count_t count);

/* Interface to be implemented by architectures. */
#ifndef as_install_arch
extern void as_install_arch(as_t *as);
#endif /* !def as_install_arch */

/* Backend declarations. */
extern mem_backend_t anon_backend;
extern mem_backend_t elf_backend;
extern mem_backend_t phys_backend;

/* Address space area related syscalls. */
extern __native sys_as_area_create(__address address, size_t size, int flags);
extern __native sys_as_area_resize(__address address, size_t size, int flags);
extern __native sys_as_area_destroy(__address address);

#endif /* KERNEL */

#endif

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