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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.
*/
/** @addtogroup genericmm
* @{
*/
/** @file
*/
#ifndef KERN_AS_H_
#define KERN_AS_H_
/** Address space area flags. */
#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 <synch/spinlock.h>
#include <synch/mutex.h>
#include <adt/list.h>
#include <adt/btree.h>
#include <lib/elf.h>
/**
* Defined to be true if user address space and kernel address space shadow each
* other.
*/
#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 USTACK_ADDRESS USTACK_ADDRESS_ARCH
/** Kernel address space. */
#define FLAG_AS_KERNEL (1 << 0)
/* Address space area attributes. */
#define AS_AREA_ATTR_NONE 0
#define AS_AREA_ATTR_PARTIAL 1 /**< Not fully initialized area. */
/** The page fault was not resolved by as_page_fault(). */
#define AS_PF_FAULT 0
/** The page fault was resolved by as_page_fault(). */
#define AS_PF_OK 1
/** The page fault was caused by memcpy_from_uspace() or memcpy_to_uspace(). */
#define AS_PF_DEFER 2
/** Address space structure.
*
* as_t contains the list of as_areas of userspace accessible
* pages for one or more tasks. Ranges of kernel memory pages are not
* supposed to figure in the list as they are shared by all tasks and
* set up during system initialization.
*/
typedef struct as {
/** Protected by asidlock. */
link_t inactive_as_with_asid_link;
/**
* Number of processors on wich is this address space active.
* Protected by asidlock.
*/
size_t cpu_refcount;
/**
* Address space identifier.
* Constant on architectures that do not support ASIDs.
* Protected by asidlock.
*/
asid_t asid;
/** Number of references (i.e tasks that reference this as). */
atomic_t refcount;
mutex_t lock;
/** B+tree of address space areas. */
btree_t as_area_btree;
/** Non-generic content. */
as_genarch_t genarch;
/** Architecture specific content. */
as_arch_t arch;
} as_t;
typedef struct {
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);
} as_operations_t;
/**
* This structure contains information associated with the shared address space
* area.
*/
typedef struct {
/** This lock must be acquired only when the as_area lock is held. */
mutex_t lock;
/** This structure can be deallocated if refcount drops to 0. */
size_t refcount;
/**
* B+tree containing complete map of anonymous pages of the shared area.
*/
btree_t pagemap;
} share_info_t;
/** Page fault access type. */
typedef enum {
PF_ACCESS_READ,
PF_ACCESS_WRITE,
PF_ACCESS_EXEC
} pf_access_t;
struct mem_backend;
/** Backend data stored in address space area. */
typedef union mem_backend_data {
struct { /**< elf_backend members */
elf_header_t *elf;
elf_segment_header_t *segment;
};
struct { /**< phys_backend members */
uintptr_t base;
size_t frames;
};
} mem_backend_data_t;
/** Address space area structure.
*
* Each as_area_t structure describes one contiguous area of virtual memory.
*/
typedef struct {
mutex_t lock;
/** Containing address space. */
as_t *as;
/**
* Flags related to the memory represented by the address space area.
*/
int flags;
/** Attributes related to the address space area itself. */
int attributes;
/** Size of this area in multiples of PAGE_SIZE. */
size_t pages;
/** Base address of this area. */
uintptr_t base;
/** Map of used space. */
btree_t used_space;
/**
* If the address space area has been shared, this pointer will
* reference the share info structure.
*/
share_info_t *sh_info;
/** Memory backend backing this address space area. */
struct mem_backend *backend;
/** Data to be used by the backend. */
mem_backend_data_t backend_data;
} as_area_t;
/** Address space area backend structure. */
typedef struct mem_backend {
int (* page_fault)(as_area_t *area, uintptr_t addr, pf_access_t access);
void (* frame_free)(as_area_t *area, uintptr_t page, uintptr_t frame);
void (* share)(as_area_t *area);
} mem_backend_t;
extern as_t *AS_KERNEL;
extern as_operations_t *as_operations;
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, as_t *new_as);
extern int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate);
extern as_area_t *as_area_create(as_t *as, int flags, size_t size,
uintptr_t base, int attrs, mem_backend_t *backend,
mem_backend_data_t *backend_data);
extern int as_area_destroy(as_t *as, uintptr_t address);
extern int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags);
int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
as_t *dst_as, uintptr_t dst_base, int dst_flags_mask);
extern int as_area_change_flags(as_t *as, int flags, uintptr_t address);
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_area_get_size(uintptr_t base);
extern int used_space_insert(as_area_t *a, uintptr_t page, size_t count);
extern int used_space_remove(as_area_t *a, uintptr_t page, size_t count);
/* Interface to be implemented by architectures. */
#ifndef as_constructor_arch
extern int as_constructor_arch(as_t *as, int flags);
#endif /* !def as_constructor_arch */
#ifndef as_destructor_arch
extern int as_destructor_arch(as_t *as);
#endif /* !def as_destructor_arch */
#ifndef as_create_arch
extern int as_create_arch(as_t *as, int flags);
#endif /* !def as_create_arch */
#ifndef as_install_arch
extern void as_install_arch(as_t *as);
#endif /* !def as_install_arch */
#ifndef as_deinstall_arch
extern void as_deinstall_arch(as_t *as);
#endif /* !def as_deinstall_arch */
/* Backend declarations and functions. */
extern mem_backend_t anon_backend;
extern mem_backend_t elf_backend;
extern mem_backend_t phys_backend;
/**
* This flags is passed when running the loader, otherwise elf_load()
* would return with a EE_LOADER error code.
*/
#define ELD_F_NONE 0
#define ELD_F_LOADER 1
extern unsigned int elf_load(elf_header_t *header, as_t *as, int flags);
/* Address space area related syscalls. */
extern unative_t sys_as_area_create(uintptr_t address, size_t size, int flags);
extern unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags);
extern unative_t sys_as_area_change_flags(uintptr_t address, int flags);
extern unative_t sys_as_area_destroy(uintptr_t address);
/* Introspection functions. */
extern void as_print(as_t *as);
#endif /* KERNEL */
#endif
/** @}
*/