source: mainline/src/mm/vm.c@ 623ba26c

/*
 * 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.
 */

#include <mm/vm.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <mm/tlb.h>
#include <mm/heap.h>
#include <arch/mm/page.h>
#include <arch/types.h>
#include <typedefs.h>
#include <synch/spinlock.h>
#include <config.h>
#include <list.h>
#include <panic.h>
#include <arch/asm.h>
#include <debug.h>
#include <memstr.h>
#include <arch.h>

#define KAS_START_INDEX         PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)
#define KAS_END_INDEX           PTL0_INDEX(KERNEL_ADDRESS_SPACE_END)
#define KAS_INDICES             (1+(KAS_END_INDEX-KAS_START_INDEX))

vm_t *vm_create(pte_t *ptl0)
{
        vm_t *m;

        m = (vm_t *) malloc(sizeof(vm_t));
        if (m) {
                spinlock_initialize(&m->lock);
                list_initialize(&m->vm_area_head);

                /*
                 * Each vm_t is supposed to have its own page table.
                 * It is either passed one or it has to allocate and set one up.
                 */
                m->ptl0 = ptl0;
                if (!m->ptl0) {
                        pte_t *src_ptl0, *dst_ptl0;
                
                        src_ptl0 = (pte_t *) PA2KA((__address) GET_PTL0_ADDRESS());
                        dst_ptl0 = (pte_t *) frame_alloc(FRAME_KA | FRAME_PANIC);

                        /* TODO: in theory, it should be only necessary to copy kernel address space... */
                        memcpy((void *)PA2KA((__address) dst_ptl0), (void *)GET_PTL0_ADDRESS() , PAGE_SIZE);

                        m->ptl0 = (pte_t *) KA2PA((__address) dst_ptl0);
                }
        }

        return m;
}

void vm_destroy(vm_t *m)
{
}

vm_area_t *vm_area_create(vm_t *m, vm_type_t type, size_t size, __address addr)
{
        pri_t pri;
        vm_area_t *a;
        
        if (addr % PAGE_SIZE)
                panic("addr not aligned to a page boundary");
        
        pri = cpu_priority_high();
        spinlock_lock(&m->lock);
        
        /*
         * TODO: test vm_area which is to be created doesn't overlap with an existing one.
         */
        
        a = (vm_area_t *) malloc(sizeof(vm_area_t));
        if (a) {
                int i;
        
                a->mapping = (__address *) malloc(size * sizeof(__address));
                if (!a->mapping) {
                        free(a);
                        spinlock_unlock(&m->lock);
                        cpu_priority_restore(pri);
                        return NULL;
                }
                
                for (i=0; i<size; i++)
                        a->mapping[i] = frame_alloc(0);
                
                spinlock_initialize(&a->lock);
                        
                link_initialize(&a->link);                      
                a->type = type;
                a->size = size;
                a->address = addr;
                
                list_append(&a->link, &m->vm_area_head);

        }

        spinlock_unlock(&m->lock);
        cpu_priority_restore(pri);
        
        return a;
}

void vm_area_destroy(vm_area_t *a)
{
}

void vm_area_map(vm_area_t *a, vm_t *m)
{
        int i, flags;
        pri_t pri;
        
        pri = cpu_priority_high();
        spinlock_lock(&m->lock);
        spinlock_lock(&a->lock);

        switch (a->type) {
                case VMA_TEXT:
                        flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
                        break;
                case VMA_DATA:
                case VMA_STACK:
                        flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
                        break;
                default:
                        panic("unexpected vm_type_t %d", a->type);
        }

        ASSERT(m->ptl0);
        for (i=0; i<a->size; i++)
                map_page_to_frame(a->address + i*PAGE_SIZE, a->mapping[i], flags, (__address) m->ptl0);
                
        spinlock_unlock(&a->lock);
        spinlock_unlock(&m->lock);
        cpu_priority_restore(pri);
}

void vm_area_unmap(vm_area_t *a, vm_t *m)
{
        int i;
        pri_t pri;
        
        pri = cpu_priority_high();
        spinlock_lock(&m->lock);
        spinlock_lock(&a->lock);

        ASSERT(m->ptl0);
        for (i=0; i<a->size; i++)               
                map_page_to_frame(a->address + i*PAGE_SIZE, 0, PAGE_NOT_PRESENT, (__address) m->ptl0);
        
        spinlock_unlock(&a->lock);
        spinlock_unlock(&m->lock);
        cpu_priority_restore(pri);
}

void vm_install(vm_t *m)
{
        link_t *l;
        pri_t pri;
        
        pri = cpu_priority_high();

        tlb_shootdown_start();
        spinlock_lock(&m->lock);

        ASSERT(m->ptl0);
        SET_PTL0_ADDRESS(m->ptl0);

        spinlock_unlock(&m->lock);
        tlb_shootdown_finalize();

        cpu_priority_restore(pri);
}