/*
* 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 __AS_H__
#define __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 <typedefs.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <adt/list.h>
#include <adt/btree.h>
#include <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
#define FLAG_AS_KERNEL (1 << 0) /**< Kernel address space. */
/** 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.
*/
struct as {
/** Protected by asidlock. */
link_t inactive_as_with_asid_link;
mutex_t lock;
/** Number of references (i.e tasks that reference this as). */
count_t refcount;
/** Number of processors on wich is this address space active. */
count_t cpu_refcount;
/** B+tree of address space areas. */
btree_t as_area_btree;
/** Page table pointer. Constant on architectures that use global page hash table. */
pte_t *page_table;
/** Address space identifier. Constant on architectures that do not support ASIDs.*/
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;
/** Address space area attributes. */
#define AS_AREA_ATTR_NONE 0
#define AS_AREA_ATTR_PARTIAL 1 /**< Not fully initialized area. */
#define AS_PF_FAULT 0 /**< The page fault was not resolved by as_page_fault(). */
#define AS_PF_OK 1 /**< The page fault was resolved by as_page_fault(). */
#define AS_PF_DEFER 2 /**< The page fault was caused by memcpy_from_uspace()
or memcpy_to_uspace(). */
/** This structure contains information associated with the shared address space area. */
typedef struct {
mutex_t lock; /**< This lock must be acquired only when the as_area lock is held. */
count_t refcount; /**< This structure can be deallocated if refcount drops to 0. */
btree_t pagemap; /**< B+tree containing complete map of anonymous pages of the shared area. */
} share_info_t;
/** Address space area backend structure. */
typedef struct {
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;
/** Backend data stored in address space area. */
typedef union {
struct { /**< elf_backend members */
elf_header_t *elf;
elf_segment_header_t *segment;
};
struct { /**< phys_backend members */
uintptr_t base;
count_t frames;
};
} mem_backend_data_t;
/** Address space area structure.
*
* Each as_area_t structure describes one contiguous area of virtual memory.
* In the future, it should not be difficult to support shared areas.
*/
struct as_area {
mutex_t lock;
as_t *as; /**< Containing address space. */
int flags; /**< Flags related to the memory represented by the address space area. */
int attributes; /**< Attributes related to the address space area itself. */
count_t pages; /**< Size of this area in multiples of PAGE_SIZE. */
uintptr_t base; /**< Base address of this area. */
btree_t used_space; /**< Map of used space. */
share_info_t *sh_info; /**< If the address space area has been shared, this pointer will
reference the share info structure. */
mem_backend_t *backend; /**< Memory backend backing this address space area. */
/** Data to be used by the 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(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_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(uintptr_t base);
extern int used_space_insert(as_area_t *a, uintptr_t page, count_t count);
extern int used_space_remove(as_area_t *a, uintptr_t 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 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_destroy(uintptr_t address);
#endif /* KERNEL */
#endif
/** @}
*/