WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/mm/as.c


/*
 * Copyright (C) 2001-2006 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
 * @brief   Address space related functions.
 *
 * This file contains address space manipulation functions.
 * Roughly speaking, this is a higher-level client of
 * Virtual Address Translation (VAT) subsystem.
 *
 * Functionality provided by this file allows one to
 * create address space and create, resize and share
 * address space areas.
 *
 * @see page.c
 *
 */
 
#include <mm/as.h>
#include <arch/mm/as.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <mm/slab.h>
#include <mm/tlb.h>
#include <arch/mm/page.h>
#include <genarch/mm/page_pt.h>
#include <genarch/mm/page_ht.h>
#include <mm/asid.h>
#include <arch/mm/asid.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <adt/list.h>
#include <adt/btree.h>
#include <proc/task.h>
#include <proc/thread.h>
#include <arch/asm.h>
#include <panic.h>
#include <debug.h>
#include <print.h>
#include <memstr.h>
#include <macros.h>
#include <arch.h>
#include <errno.h>
#include <config.h>
#include <align.h>
#include <arch/types.h>
#include <typedefs.h>
#include <syscall/copy.h>
#include <arch/interrupt.h>
 
as_operations_t *as_operations = NULL;
 
/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
 
/**
 * This list contains address spaces that are not active on any
 * processor and that have valid ASID.
 */
LIST_INITIALIZE(inactive_as_with_asid_head);
 
/** Kernel address space. */
as_t *AS_KERNEL = NULL;
 
static int area_flags_to_page_flags(int aflags);
static as_area_t *find_area_and_lock(as_t *as, __address va);
static bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area);
static void sh_info_remove_reference(share_info_t *sh_info);
 
/** Initialize address space subsystem. */
void as_init(void)
{
    as_arch_init();
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
    if (!AS_KERNEL)
        panic("can't create kernel address space\n");
   
}
 
/** Create address space.
 *
 * @param flags Flags that influence way in wich the address space is created.
 */
as_t *as_create(int flags)
{
    as_t *as;
 
    as = (as_t *) malloc(sizeof(as_t), 0);
    link_initialize(&as->inactive_as_with_asid_link);
    mutex_initialize(&as->lock);
    btree_create(&as->as_area_btree);
   
    if (flags & FLAG_AS_KERNEL)
        as->asid = ASID_KERNEL;
    else
        as->asid = ASID_INVALID;
   
    as->refcount = 0;
    as->cpu_refcount = 0;
    as->page_table = page_table_create(flags);
 
    return as;
}
 
/** Destroy adress space.
 *
 * When there are no tasks referencing this address space (i.e. its refcount is zero),
 * the address space can be destroyed.
 */
void as_destroy(as_t *as)
{
    ipl_t ipl;
    bool cond;
 
    ASSERT(as->refcount == 0);
   
    /*
     * Since there is no reference to this area,
     * it is safe not to lock its mutex.
     */
    ipl = interrupts_disable();
    spinlock_lock(&inactive_as_with_asid_lock);
    if (as->asid != ASID_INVALID && as != AS_KERNEL) {
        if (as != AS && as->cpu_refcount == 0)
            list_remove(&as->inactive_as_with_asid_link);
        asid_put(as->asid);
    }
    spinlock_unlock(&inactive_as_with_asid_lock);
 
    /*
     * Destroy address space areas of the address space.
     * The B+tee must be walked carefully because it is
     * also being destroyed.
     */
    for (cond = true; cond; ) {
        btree_node_t *node;
 
        ASSERT(!list_empty(&as->as_area_btree.leaf_head));
        node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
 
        if ((cond = node->keys)) {
            as_area_destroy(as, node->key[0]);
        }
    }
 
    btree_destroy(&as->as_area_btree);
    page_table_destroy(as->page_table);
 
    interrupts_restore(ipl);
   
    free(as);
}
 
/** Create address space area of common attributes.
 *
 * The created address space area is added to the target address space.
 *
 * @param as Target address space.
 * @param flags Flags of the area memory.
 * @param size Size of area.
 * @param base Base address of area.
 * @param attrs Attributes of the area.
 * @param backend Address space area backend. NULL if no backend is used.
 * @param backend_data NULL or a pointer to an array holding two void *.
 *
 * @return Address space area on success or NULL on failure.
 */
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)
{
    ipl_t ipl;
    as_area_t *a;
   
    if (base % PAGE_SIZE)
        return NULL;
 
    if (!size)
        return NULL;
 
    /* Writeable executable areas are not supported. */
    if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
        return NULL;
   
    ipl = interrupts_disable();
    mutex_lock(&as->lock);
   
    if (!check_area_conflicts(as, base, size, NULL)) {
        mutex_unlock(&as->lock);
        interrupts_restore(ipl);
        return NULL;
    }
   
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
 
    mutex_initialize(&a->lock);
   
    a->as = as;
    a->flags = flags;
    a->attributes = attrs;
    a->pages = SIZE2FRAMES(size);
    a->base = base;
    a->sh_info = NULL;
    a->backend = backend;
    if (backend_data)
        a->backend_data = *backend_data;
    else
        memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
 
    btree_create(&a->used_space);
   
    btree_insert(&as->as_area_btree, base, (void *) a, NULL);
 
    mutex_unlock(&as->lock);
    interrupts_restore(ipl);
 
    return a;
}
 
/** Find address space area and change it.
 *
 * @param as Address space.
 * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
 * @param size New size of the virtual memory block starting at address.
 * @param flags Flags influencing the remap operation. Currently unused.
 *
 * @return Zero on success or a value from @ref errno.h otherwise.
 */
int as_area_resize(as_t *as, __address address, size_t size, int flags)
{
    as_area_t *area;
    ipl_t ipl;
    size_t pages;
   
    ipl = interrupts_disable();
    mutex_lock(&as->lock);
   
    /*
     * Locate the area.
     */
    area = find_area_and_lock(as, address);
    if (!area) {
        mutex_unlock(&as->lock);
        interrupts_restore(ipl);
        return ENOENT;
    }
 
    if (area->backend == &phys_backend) {
        /*
         * Remapping of address space areas associated
         * with memory mapped devices is not supported.
         */
        mutex_unlock(&area->lock);
        mutex_unlock(&as->lock);
        interrupts_restore(ipl);
        return ENOTSUP;
    }
    if (area->sh_info) {
        /*
         * Remapping of shared address space areas
         * is not supported.
         */
        mutex_unlock(&area->lock);
        mutex_unlock(&as->lock);
        interrupts_restore(ipl);
        return ENOTSUP;
    }
 
    pages = SIZE2FRAMES((address - area->base) + size);
    if (!pages) {
        /*
         * Zero size address space areas are not allowed.
         */
        mutex_unlock(&area->lock);
        mutex_unlock(&as->lock);
        interrupts_restore(ipl);
        return EPERM;
    }
   
    if (pages < area->pages) {
        bool cond;
        __address start_free = area->base + pages*PAGE_SIZE;
 
        /*
         * Shrinking the area.
         * No need to check for overlaps.
         */
 
        /*
         * Start TLB shootdown sequence.
         */
        tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
 
        /*
         * Remove frames belonging to used space starting from
         * the highest addresses downwards until an overlap with
         * the resized address space area is found. Note that this
         * is also the right way to remove part of the used_space
         * B+tree leaf list.
         */    
        for (cond = true; cond;) {
            btree_node_t *node;
       
            ASSERT(!list_empty(&area->used_space.leaf_head));
            node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
            if ((cond = (bool) node->keys)) {
                __address b = node->key[node->keys - 1];
                count_t c = (count_t) node->value[node->keys - 1];
                int i = 0;
           
                if (overlaps(b, c*PAGE_SIZE, area->base, pages*PAGE_SIZE)) {
                   
                    if (b + c*PAGE_SIZE <= start_free) {
                        /*
                         * The whole interval fits completely
                         * in the resized address space area.
                         */
                        break;
                    }
       
                    /*
                     * Part of the interval corresponding to b and c
                     * overlaps with the resized address space area.
                     */
       
                    cond = false;   /* we are almost done */
                    i = (start_free - b) >> PAGE_WIDTH;
                    if (!used_space_remove(area, start_free, c - i))
                        panic("Could not remove used space.");
                } else {
                    /*
                     * The interval of used space can be completely removed.
                     */
                    if (!used_space_remove(area, b, c))
                        panic("Could not remove used space.\n");
                }
           
                for (; i < c; i++) {
                    pte_t *pte;
           
                    page_table_lock(as, false);
                    pte = page_mapping_find(as, b + i*PAGE_SIZE);
                    ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
                    if (area->backend && area->backend->frame_free) {
                        area->backend->frame_free(area,
                            b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
                    }
                    page_mapping_remove(as, b + i*PAGE_SIZE);
                    page_table_unlock(as, false);
                }
            }
        }
 
        /*
         * Finish TLB shootdown sequence.
         */
        tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
        tlb_shootdown_finalize();
    } else {
        /*
         * Growing the area.
         * Check for overlaps with other address space areas.
         */
        if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
            mutex_unlock(&area->lock);
            mutex_unlock(&as->lock);       
            interrupts_restore(ipl);
            return EADDRNOTAVAIL;
        }
    }
 
    area->pages = pages;
   
    mutex_unlock(&area->lock);
    mutex_unlock(&as->lock);
    interrupts_restore(ipl);
 
    return 0;
}
 
/** Destroy address space area.
 *
 * @param as Address space.
 * @param address Address withing the area to be deleted.
 *
 * @return Zero on success or a value from @ref errno.h on failure.
 */
int as_area_destroy(as_t *as, __address address)
{
    as_area_t *area;
    __address base;
    link_t *cur;
    ipl_t ipl;
 
    ipl = interrupts_disable();
    mutex_lock(&as->lock);
 
    area = find_area_and_lock(as, address);
    if (!area) {
        mutex_unlock(&as->lock);
        interrupts_restore(ipl);
        return ENOENT;
    }
 
    base = area->base;
 
    /*
     * Start TLB shootdown sequence.
     */
    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
 
    /*
     * Visit only the pages mapped by used_space B+tree.
     */
    for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
        btree_node_t *node;
        int i;
       
        node = list_get_instance(cur, btree_node_t, leaf_link);
        for (i = 0; i < node->keys; i++) {
            __address b = node->key[i];
            count_t j;
            pte_t *pte;
           
            for (j = 0; j < (count_t) node->value[i]; j++) {
                page_table_lock(as, false);
                pte = page_mapping_find(as, b + j*PAGE_SIZE);
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
                if (area->backend && area->backend->frame_free) {
                    area->backend->frame_free(area,
                        b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
                }
                page_mapping_remove(as, b + j*PAGE_SIZE);
                page_table_unlock(as, false);
            }
        }
    }
 
    /*
     * Finish TLB shootdown sequence.
     */
    tlb_invalidate_pages(AS->asid, area->base, area->pages);
    tlb_shootdown_finalize();
   
    btree_destroy(&area->used_space);
 
    area->attributes |= AS_AREA_ATTR_PARTIAL;
   
    if (area->sh_info)
        sh_info_remove_reference(area->sh_info);
       
    mutex_unlock(&area->lock);
 
    /*
     * Remove the empty area from address space.
     */
    btree_remove(&AS->as_area_btree, base, NULL);
   
    free(area);
   
    mutex_unlock(&AS->lock);
    interrupts_restore(ipl);
    return 0;
}
 
/** Share address space area with another or the same address space.
 *
 * Address space area mapping is shared with a new address space area.
 * If the source address space area has not been shared so far,
 * a new sh_info is created. The new address space area simply gets the
 * sh_info of the source area. The process of duplicating the
 * mapping is done through the backend share function.
 *
 * @param src_as Pointer to source address space.
 * @param src_base Base address of the source address space area.
 * @param acc_size Expected size of the source area.
 * @param dst_as Pointer to destination address space.
 * @param dst_base Target base address.
 * @param dst_flags_mask Destination address space area flags mask.
 *
 * @return Zero on success or ENOENT if there is no such task or
 *     if there is no such address space area,
 *     EPERM if there was a problem in accepting the area or
 *     ENOMEM if there was a problem in allocating destination
 *     address space area. ENOTSUP is returned if an attempt
 *     to share non-anonymous address space area is detected.
 */
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)
{
    ipl_t ipl;
    int src_flags;
    size_t src_size;
    as_area_t *src_area, *dst_area;
    share_info_t *sh_info;
    mem_backend_t *src_backend;
    mem_backend_data_t src_backend_data;
   
    ipl = interrupts_disable();
    mutex_lock(&src_as->lock);
    src_area = find_area_and_lock(src_as, src_base);
    if (!src_area) {
        /*
         * Could not find the source address space area.
         */
        mutex_unlock(&src_as->lock);
        interrupts_restore(ipl);
        return ENOENT;
    }
   
    if (!src_area->backend || !src_area->backend->share) {
        /*
         * There is now backend or the backend does not
         * know how to share the area.
         */
        mutex_unlock(&src_area->lock);
        mutex_unlock(&src_as->lock);
        interrupts_restore(ipl);
        return ENOTSUP;
    }
   
    src_size = src_area->pages * PAGE_SIZE;
    src_flags = src_area->flags;
    src_backend = src_area->backend;
    src_backend_data = src_area->backend_data;
 
    /* Share the cacheable flag from the original mapping */
    if (src_flags & AS_AREA_CACHEABLE)
        dst_flags_mask |= AS_AREA_CACHEABLE;
 
    if (src_size != acc_size || (src_flags & dst_flags_mask) != dst_flags_mask) {
        mutex_unlock(&src_area->lock);
        mutex_unlock(&src_as->lock);
        interrupts_restore(ipl);
        return EPERM;
    }
 
    /*
     * Now we are committed to sharing the area.
     * First prepare the area for sharing.
     * Then it will be safe to unlock it.
     */
    sh_info = src_area->sh_info;
    if (!sh_info) {
        sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
        mutex_initialize(&sh_info->lock);
        sh_info->refcount = 2;
        btree_create(&sh_info->pagemap);
        src_area->sh_info = sh_info;
    } else {
        mutex_lock(&sh_info->lock);
        sh_info->refcount++;
        mutex_unlock(&sh_info->lock);
    }
 
    src_area->backend->share(src_area);
 
    mutex_unlock(&src_area->lock);
    mutex_unlock(&src_as->lock);
 
    /*
     * Create copy of the source address space area.
     * The destination area is created with AS_AREA_ATTR_PARTIAL
     * attribute set which prevents race condition with
     * preliminary as_page_fault() calls.
     * The flags of the source area are masked against dst_flags_mask
     * to support sharing in less privileged mode.
     */
    dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
                  AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
    if (!dst_area) {
        /*
         * Destination address space area could not be created.
         */
        sh_info_remove_reference(sh_info);
       
        interrupts_restore(ipl);
        return ENOMEM;
    }
   
    /*
     * Now the destination address space area has been
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
     * attribute and set the sh_info.
     */
    mutex_lock(&dst_area->lock);
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
    dst_area->sh_info = sh_info;
    mutex_unlock(&dst_area->lock);
   
    interrupts_restore(ipl);
   
    return 0;
}
 
/** Check access mode for address space area.
 *
 * The address space area must be locked prior to this call.
 *
 * @param area Address space area.
 * @param access Access mode.
 *
 * @return False if access violates area's permissions, true otherwise.
 */
bool as_area_check_access(as_area_t *area, pf_access_t access)
{
    int flagmap[] = {
        [PF_ACCESS_READ] = AS_AREA_READ,
        [PF_ACCESS_WRITE] = AS_AREA_WRITE,
        [PF_ACCESS_EXEC] = AS_AREA_EXEC
    };
 
    if (!(area->flags & flagmap[access]))
        return false;
   
    return true;
}
 
/** Handle page fault within the current address space.
 *
 * This is the high-level page fault handler. It decides
 * whether the page fault can be resolved by any backend
 * and if so, it invokes the backend to resolve the page
 * fault.
 *
 * Interrupts are assumed disabled.
 *
 * @param page Faulting page.
 * @param access Access mode that caused the fault (i.e. read/write/exec).
 * @param istate Pointer to interrupted state.
 *
 * @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
 *     fault was caused by copy_to_uspace() or copy_from_uspace().
 */
int as_page_fault(__address page, pf_access_t access, istate_t *istate)
{
    pte_t *pte;
    as_area_t *area;
   
    if (!THREAD)
        return AS_PF_FAULT;
       
    ASSERT(AS);
 
    mutex_lock(&AS->lock);
    area = find_area_and_lock(AS, page);   
    if (!area) {
        /*
         * No area contained mapping for 'page'.
         * Signal page fault to low-level handler.
         */
        mutex_unlock(&AS->lock);
        goto page_fault;
    }
 
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
        /*
         * The address space area is not fully initialized.
         * Avoid possible race by returning error.
         */
        mutex_unlock(&area->lock);
        mutex_unlock(&AS->lock);
        goto page_fault;       
    }
 
    if (!area->backend || !area->backend->page_fault) {
        /*
         * The address space area is not backed by any backend
         * or the backend cannot handle page faults.
         */
        mutex_unlock(&area->lock);
        mutex_unlock(&AS->lock);
        goto page_fault;       
    }
 
    page_table_lock(AS, false);
   
    /*
     * To avoid race condition between two page faults
     * on the same address, we need to make sure
     * the mapping has not been already inserted.
     */
    if ((pte = page_mapping_find(AS, page))) {
        if (PTE_PRESENT(pte)) {
            if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) ||
                (access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) ||
                (access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
                page_table_unlock(AS, false);
                mutex_unlock(&area->lock);
                mutex_unlock(&AS->lock);
                return AS_PF_OK;
            }
        }
    }
   
    /*
     * Resort to the backend page fault handler.
     */
    if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
        page_table_unlock(AS, false);
        mutex_unlock(&area->lock);
        mutex_unlock(&AS->lock);
        goto page_fault;
    }
   
    page_table_unlock(AS, false);
    mutex_unlock(&area->lock);
    mutex_unlock(&AS->lock);
    return AS_PF_OK;
 
page_fault:
    if (THREAD->in_copy_from_uspace) {
        THREAD->in_copy_from_uspace = false;
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
    } else if (THREAD->in_copy_to_uspace) {
        THREAD->in_copy_to_uspace = false;
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
    } else {
        return AS_PF_FAULT;
    }
 
    return AS_PF_DEFER;
}
 
/** Switch address spaces.
 *
 * Note that this function cannot sleep as it is essentially a part of
 * scheduling. Sleeping here would lead to deadlock on wakeup.
 *
 * @param old Old address space or NULL.
 * @param new New address space.
 */
void as_switch(as_t *old, as_t *new)
{
    ipl_t ipl;
    bool needs_asid = false;
   
    ipl = interrupts_disable();
    spinlock_lock(&inactive_as_with_asid_lock);
 
    /*
     * First, take care of the old address space.
     */
    if (old) {
        mutex_lock_active(&old->lock);
        ASSERT(old->cpu_refcount);
        if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
            /*
             * The old address space is no longer active on
             * any processor. It can be appended to the
             * list of inactive address spaces with assigned
             * ASID.
             */
             ASSERT(old->asid != ASID_INVALID);
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
        }
        mutex_unlock(&old->lock);
    }
 
    /*
     * Second, prepare the new address space.
     */
    mutex_lock_active(&new->lock);
    if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
        if (new->asid != ASID_INVALID)
            list_remove(&new->inactive_as_with_asid_link);
        else
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
    }
    SET_PTL0_ADDRESS(new->page_table);
    mutex_unlock(&new->lock);
 
    if (needs_asid) {
        /*
         * Allocation of new ASID was deferred
         * until now in order to avoid deadlock.
         */
        asid_t asid;
       
        asid = asid_get();
        mutex_lock_active(&new->lock);
        new->asid = asid;
        mutex_unlock(&new->lock);
    }
    spinlock_unlock(&inactive_as_with_asid_lock);
    interrupts_restore(ipl);
   
    /*
     * Perform architecture-specific steps.
     * (e.g. write ASID to hardware register etc.)
     */
    as_install_arch(new);
   
    AS = new;
}
 
/** Convert address space area flags to page flags.
 *
 * @param aflags Flags of some address space area.
 *
 * @return Flags to be passed to page_mapping_insert().
 */
int area_flags_to_page_flags(int aflags)
{
    int flags;
 
    flags = PAGE_USER | PAGE_PRESENT;
   
    if (aflags & AS_AREA_READ)
        flags |= PAGE_READ;
       
    if (aflags & AS_AREA_WRITE)
        flags |= PAGE_WRITE;
   
    if (aflags & AS_AREA_EXEC)
        flags |= PAGE_EXEC;
   
    if (aflags & AS_AREA_CACHEABLE)
        flags |= PAGE_CACHEABLE;
       
    return flags;
}
 
/** Compute flags for virtual address translation subsytem.
 *
 * The address space area must be locked.
 * Interrupts must be disabled.
 *
 * @param a Address space area.
 *
 * @return Flags to be used in page_mapping_insert().
 */
int as_area_get_flags(as_area_t *a)
{
    return area_flags_to_page_flags(a->flags);
}
 
/** Create page table.
 *
 * Depending on architecture, create either address space
 * private or global page table.
 *
 * @param flags Flags saying whether the page table is for kernel address space.
 *
 * @return First entry of the page table.
 */
pte_t *page_table_create(int flags)
{
        ASSERT(as_operations);
        ASSERT(as_operations->page_table_create);
 
        return as_operations->page_table_create(flags);
}
 
/** Destroy page table.
 *
 * Destroy page table in architecture specific way.
 *
 * @param page_table Physical address of PTL0.
 */
void page_table_destroy(pte_t *page_table)
{
        ASSERT(as_operations);
        ASSERT(as_operations->page_table_destroy);
 
        as_operations->page_table_destroy(page_table);
}
 
/** Lock page table.
 *
 * This function should be called before any page_mapping_insert(),
 * page_mapping_remove() and page_mapping_find().
 *
 * Locking order is such that address space areas must be locked
 * prior to this call. Address space can be locked prior to this
 * call in which case the lock argument is false.
 *
 * @param as Address space.
 * @param lock If false, do not attempt to lock as->lock.
 */
void page_table_lock(as_t *as, bool lock)
{
    ASSERT(as_operations);
    ASSERT(as_operations->page_table_lock);
 
    as_operations->page_table_lock(as, lock);
}
 
/** Unlock page table.
 *
 * @param as Address space.
 * @param unlock If false, do not attempt to unlock as->lock.
 */
void page_table_unlock(as_t *as, bool unlock)
{
    ASSERT(as_operations);
    ASSERT(as_operations->page_table_unlock);
 
    as_operations->page_table_unlock(as, unlock);
}
 
 
/** Find address space area and lock it.
 *
 * The address space must be locked and interrupts must be disabled.
 *
 * @param as Address space.
 * @param va Virtual address.
 *
 * @return Locked address space area containing va on success or NULL on failure.
 */
as_area_t *find_area_and_lock(as_t *as, __address va)
{
    as_area_t *a;
    btree_node_t *leaf, *lnode;
    int i;
   
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
    if (a) {
        /* va is the base address of an address space area */
        mutex_lock(&a->lock);
        return a;
    }
   
    /*
     * Search the leaf node and the righmost record of its left neighbour
     * to find out whether this is a miss or va belongs to an address
     * space area found there.
     */
   
    /* First, search the leaf node itself. */
    for (i = 0; i < leaf->keys; i++) {
        a = (as_area_t *) leaf->value[i];
        mutex_lock(&a->lock);
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
            return a;
        }
        mutex_unlock(&a->lock);
    }
 
    /*
     * Second, locate the left neighbour and test its last record.
     * Because of its position in the B+tree, it must have base < va.
     */
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
        a = (as_area_t *) lnode->value[lnode->keys - 1];
        mutex_lock(&a->lock);
        if (va < a->base + a->pages * PAGE_SIZE) {
            return a;
        }
        mutex_unlock(&a->lock);
    }
 
    return NULL;
}
 
/** Check area conflicts with other areas.
 *
 * The address space must be locked and interrupts must be disabled.
 *
 * @param as Address space.
 * @param va Starting virtual address of the area being tested.
 * @param size Size of the area being tested.
 * @param avoid_area Do not touch this area.
 *
 * @return True if there is no conflict, false otherwise.
 */
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
{
    as_area_t *a;
    btree_node_t *leaf, *node;
    int i;
   
    /*
     * We don't want any area to have conflicts with NULL page.
     */
    if (overlaps(va, size, NULL, PAGE_SIZE))
        return false;
   
    /*
     * The leaf node is found in O(log n), where n is proportional to
     * the number of address space areas belonging to as.
     * The check for conflicts is then attempted on the rightmost
     * record in the left neighbour, the leftmost record in the right
     * neighbour and all records in the leaf node itself.
     */
   
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
        if (a != avoid_area)
            return false;
    }
   
    /* First, check the two border cases. */
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
        a = (as_area_t *) node->value[node->keys - 1];
        mutex_lock(&a->lock);
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
            mutex_unlock(&a->lock);
            return false;
        }
        mutex_unlock(&a->lock);
    }
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
        a = (as_area_t *) node->value[0];
        mutex_lock(&a->lock);
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
            mutex_unlock(&a->lock);
            return false;
        }
        mutex_unlock(&a->lock);
    }
   
    /* Second, check the leaf node. */
    for (i = 0; i < leaf->keys; i++) {
        a = (as_area_t *) leaf->value[i];
   
        if (a == avoid_area)
            continue;
   
        mutex_lock(&a->lock);
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
            mutex_unlock(&a->lock);
            return false;
        }
        mutex_unlock(&a->lock);
    }
 
    /*
     * So far, the area does not conflict with other areas.
     * Check if it doesn't conflict with kernel address space.
     */  
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
        return !overlaps(va, size,
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
    }
 
    return true;
}
 
/** Return size of the address space area with given base.  */
size_t as_get_size(__address base)
{
    ipl_t ipl;
    as_area_t *src_area;
    size_t size;
 
    ipl = interrupts_disable();
    src_area = find_area_and_lock(AS, base);
    if (src_area){
        size = src_area->pages * PAGE_SIZE;
        mutex_unlock(&src_area->lock);
    } else {
        size = 0;
    }
    interrupts_restore(ipl);
    return size;
}
 
/** Mark portion of address space area as used.
 *
 * The address space area must be already locked.
 *
 * @param a Address space area.
 * @param page First page to be marked.
 * @param count Number of page to be marked.
 *
 * @return 0 on failure and 1 on success.
 */
int used_space_insert(as_area_t *a, __address page, count_t count)
{
    btree_node_t *leaf, *node;
    count_t pages;
    int i;
 
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
    ASSERT(count);
 
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
    if (pages) {
        /*
         * We hit the beginning of some used space.
         */
        return 0;
    }
 
    if (!leaf->keys) {
        btree_insert(&a->used_space, page, (void *) count, leaf);
        return 1;
    }
 
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
    if (node) {
        __address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
        count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
       
        /*
         * Examine the possibility that the interval fits
         * somewhere between the rightmost interval of
         * the left neigbour and the first interval of the leaf.
         */
         
        if (page >= right_pg) {
            /* Do nothing. */
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
            /* The interval intersects with the left interval. */
            return 0;
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
            /* The interval intersects with the right interval. */
            return 0;          
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
            /* The interval can be added by merging the two already present intervals. */
            node->value[node->keys - 1] += count + right_cnt;
            btree_remove(&a->used_space, right_pg, leaf);
            return 1;
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
            /* The interval can be added by simply growing the left interval. */
            node->value[node->keys - 1] += count;
            return 1;
        } else if (page + count*PAGE_SIZE == right_pg) {
            /*
             * The interval can be addded by simply moving base of the right
             * interval down and increasing its size accordingly.
             */
            leaf->value[0] += count;
            leaf->key[0] = page;
            return 1;
        } else {
            /*
             * The interval is between both neigbouring intervals,
             * but cannot be merged with any of them.
             */
            btree_insert(&a->used_space, page, (void *) count, leaf);
            return 1;
        }
    } else if (page < leaf->key[0]) {
        __address right_pg = leaf->key[0];
        count_t right_cnt = (count_t) leaf->value[0];
   
        /*
         * Investigate the border case in which the left neighbour does not
         * exist but the interval fits from the left.
         */
         
        if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
            /* The interval intersects with the right interval. */
            return 0;
        } else if (page + count*PAGE_SIZE == right_pg) {
            /*
             * The interval can be added by moving the base of the right interval down
             * and increasing its size accordingly.
             */
            leaf->key[0] = page;
            leaf->value[0] += count;
            return 1;
        } else {
            /*
             * The interval doesn't adjoin with the right interval.
             * It must be added individually.
             */
            btree_insert(&a->used_space, page, (void *) count, leaf);
            return 1;
        }
    }
 
    node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
    if (node) {
        __address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
       
        /*
         * Examine the possibility that the interval fits
         * somewhere between the leftmost interval of
         * the right neigbour and the last interval of the leaf.
         */
 
        if (page < left_pg) {
            /* Do nothing. */
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
            /* The interval intersects with the left interval. */
            return 0;
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
            /* The interval intersects with the right interval. */
            return 0;          
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
            /* The interval can be added by merging the two already present intervals. */
            leaf->value[leaf->keys - 1] += count + right_cnt;
            btree_remove(&a->used_space, right_pg, node);
            return 1;
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
            /* The interval can be added by simply growing the left interval. */
            leaf->value[leaf->keys - 1] +=  count;
            return 1;
        } else if (page + count*PAGE_SIZE == right_pg) {
            /*
             * The interval can be addded by simply moving base of the right
             * interval down and increasing its size accordingly.
             */
            node->value[0] += count;
            node->key[0] = page;
            return 1;
        } else {
            /*
             * The interval is between both neigbouring intervals,
             * but cannot be merged with any of them.
             */
            btree_insert(&a->used_space, page, (void *) count, leaf);
            return 1;
        }
    } else if (page >= leaf->key[leaf->keys - 1]) {
        __address left_pg = leaf->key[leaf->keys - 1];
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
   
        /*
         * Investigate the border case in which the right neighbour does not
         * exist but the interval fits from the right.
         */
         
        if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
            /* The interval intersects with the left interval. */
            return 0;
        } else if (left_pg + left_cnt*PAGE_SIZE == page) {
            /* The interval can be added by growing the left interval. */
            leaf->value[leaf->keys - 1] += count;
            return 1;
        } else {
            /*
             * The interval doesn't adjoin with the left interval.
             * It must be added individually.
             */
            btree_insert(&a->used_space, page, (void *) count, leaf);
            return 1;
        }
    }
   
    /*
     * Note that if the algorithm made it thus far, the interval can fit only
     * between two other intervals of the leaf. The two border cases were already
     * resolved.
     */
    for (i = 1; i < leaf->keys; i++) {
        if (page < leaf->key[i]) {
            __address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
            count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
 
            /*
             * The interval fits between left_pg and right_pg.
             */
 
            if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
                /* The interval intersects with the left interval. */
                return 0;
            } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
                /* The interval intersects with the right interval. */
                return 0;          
            } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
                /* The interval can be added by merging the two already present intervals. */
                leaf->value[i - 1] += count + right_cnt;
                btree_remove(&a->used_space, right_pg, leaf);
                return 1;
            } else if (page == left_pg + left_cnt*PAGE_SIZE) {
                /* The interval can be added by simply growing the left interval. */
                leaf->value[i - 1] += count;
                return 1;
            } else if (page + count*PAGE_SIZE == right_pg) {
                /*
                     * The interval can be addded by simply moving base of the right
                 * interval down and increasing its size accordingly.
                 */
                leaf->value[i] += count;
                leaf->key[i] = page;
                return 1;
            } else {
                /*
                 * The interval is between both neigbouring intervals,
                 * but cannot be merged with any of them.
                 */
                btree_insert(&a->used_space, page, (void *) count, leaf);
                return 1;
            }
        }
    }
 
    panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page);
}
 
/** Mark portion of address space area as unused.
 *
 * The address space area must be already locked.
 *
 * @param a Address space area.
 * @param page First page to be marked.
 * @param count Number of page to be marked.
 *
 * @return 0 on failure and 1 on success.
 */
int used_space_remove(as_area_t *a, __address page, count_t count)
{
    btree_node_t *leaf, *node;
    count_t pages;
    int i;
 
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
    ASSERT(count);
 
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
    if (pages) {
        /*
         * We are lucky, page is the beginning of some interval.
         */
        if (count > pages) {
            return 0;
        } else if (count == pages) {
            btree_remove(&a->used_space, page, leaf);
            return 1;
        } else {
            /*
             * Find the respective interval.
             * Decrease its size and relocate its start address.
             */
            for (i = 0; i < leaf->keys; i++) {
                if (leaf->key[i] == page) {
                    leaf->key[i] += count*PAGE_SIZE;
                    leaf->value[i] -= count;
                    return 1;
                }
            }
            goto error;
        }
    }
 
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
    if (node && page < leaf->key[0]) {
        __address left_pg = node->key[node->keys - 1];
        count_t left_cnt = (count_t) node->value[node->keys - 1];
 
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
                /*
                 * The interval is contained in the rightmost interval
                 * of the left neighbour and can be removed by
                 * updating the size of the bigger interval.
                 */
                node->value[node->keys - 1] -= count;
                return 1;
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
                count_t new_cnt;
               
                /*
                 * The interval is contained in the rightmost interval
                 * of the left neighbour but its removal requires
                 * both updating the size of the original interval and
                 * also inserting a new interval.
                 */
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
                node->value[node->keys - 1] -= count + new_cnt;
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
                return 1;
            }
        }
        return 0;
    } else if (page < leaf->key[0]) {
        return 0;
    }
   
    if (page > leaf->key[leaf->keys - 1]) {
        __address left_pg = leaf->key[leaf->keys - 1];
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
 
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
                /*
                 * The interval is contained in the rightmost interval
                 * of the leaf and can be removed by updating the size
                 * of the bigger interval.
                 */
                leaf->value[leaf->keys - 1] -= count;
                return 1;
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
                count_t new_cnt;
               
                /*
                 * The interval is contained in the rightmost interval
                 * of the leaf but its removal requires both updating
                 * the size of the original interval and
                 * also inserting a new interval.
                 */
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
                leaf->value[leaf->keys - 1] -= count + new_cnt;
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
                return 1;
            }
        }
        return 0;
    }  
   
    /*
     * The border cases have been already resolved.
     * Now the interval can be only between intervals of the leaf.
     */
    for (i = 1; i < leaf->keys - 1; i++) {
        if (page < leaf->key[i]) {
            __address left_pg = leaf->key[i - 1];
            count_t left_cnt = (count_t) leaf->value[i - 1];
 
            /*
             * Now the interval is between intervals corresponding to (i - 1) and i.
             */
            if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
                if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
                    /*
                    * The interval is contained in the interval (i - 1)
                     * of the leaf and can be removed by updating the size
                     * of the bigger interval.
                     */
                    leaf->value[i - 1] -= count;
                    return 1;
                } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
                    count_t new_cnt;
               
                    /*
                     * The interval is contained in the interval (i - 1)
                     * of the leaf but its removal requires both updating
                     * the size of the original interval and
                     * also inserting a new interval.
                     */
                    new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
                    leaf->value[i - 1] -= count + new_cnt;
                    btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
                    return 1;
                }
            }
            return 0;
        }
    }
 
error:
    panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page);
}
 
/** Remove reference to address space area share info.
 *
 * If the reference count drops to 0, the sh_info is deallocated.
 *
 * @param sh_info Pointer to address space area share info.
 */
void sh_info_remove_reference(share_info_t *sh_info)
{
    bool dealloc = false;
 
    mutex_lock(&sh_info->lock);
    ASSERT(sh_info->refcount);
    if (--sh_info->refcount == 0) {
        dealloc = true;
        link_t *cur;
       
        /*
         * Now walk carefully the pagemap B+tree and free/remove
         * reference from all frames found there.
         */
        for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
            btree_node_t *node;
            int i;
           
            node = list_get_instance(cur, btree_node_t, leaf_link);
            for (i = 0; i < node->keys; i++)
                frame_free(ADDR2PFN((__address) node->value[i]));
        }
       
    }
    mutex_unlock(&sh_info->lock);
   
    if (dealloc) {
        btree_destroy(&sh_info->pagemap);
        free(sh_info);
    }
}
 
/*
 * Address space related syscalls.
 */
 
/** Wrapper for as_area_create(). */
__native sys_as_area_create(__address address, size_t size, int flags)
{
    if (as_area_create(AS, flags | AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
        return (__native) address;
    else
        return (__native) -1;
}
 
/** Wrapper for as_area_resize. */
__native sys_as_area_resize(__address address, size_t size, int flags)
{
    return (__native) as_area_resize(AS, address, size, 0);
}
 
/** Wrapper for as_area_destroy. */
__native sys_as_area_destroy(__address address)
{
    return (__native) as_area_destroy(AS, address);
}
 
 /** @}
 */
 
 

Rev 1705	Rev 1735
1	/*	1	/*
2	* Copyright (C) 2001-2006 Jakub Jermar	2	* Copyright (C) 2001-2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup genericmm	29	/** @addtogroup genericmm
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Address space related functions.	35	* @brief Address space related functions.
36	*	36	*
37	* This file contains address space manipulation functions.	37	* This file contains address space manipulation functions.
38	* Roughly speaking, this is a higher-level client of	38	* Roughly speaking, this is a higher-level client of
39	* Virtual Address Translation (VAT) subsystem.	39	* Virtual Address Translation (VAT) subsystem.
40	*	40	*
41	* Functionality provided by this file allows one to	41	* Functionality provided by this file allows one to
42	* create address space and create, resize and share	42	* create address space and create, resize and share
43	* address space areas.	43	* address space areas.
44	*	44	*
45	* @see page.c	45	* @see page.c
46	*	46	*
47	*/	47	*/
48		48
49	#include <mm/as.h>	49	#include <mm/as.h>
50	#include <arch/mm/as.h>	50	#include <arch/mm/as.h>
51	#include <mm/page.h>	51	#include <mm/page.h>
52	#include <mm/frame.h>	52	#include <mm/frame.h>
53	#include <mm/slab.h>	53	#include <mm/slab.h>
54	#include <mm/tlb.h>	54	#include <mm/tlb.h>
55	#include <arch/mm/page.h>	55	#include <arch/mm/page.h>
56	#include <genarch/mm/page_pt.h>	56	#include <genarch/mm/page_pt.h>
57	#include <genarch/mm/page_ht.h>	57	#include <genarch/mm/page_ht.h>
58	#include <mm/asid.h>	58	#include <mm/asid.h>
59	#include <arch/mm/asid.h>	59	#include <arch/mm/asid.h>
60	#include <synch/spinlock.h>	60	#include <synch/spinlock.h>
61	#include <synch/mutex.h>	61	#include <synch/mutex.h>
62	#include <adt/list.h>	62	#include <adt/list.h>
63	#include <adt/btree.h>	63	#include <adt/btree.h>
64	#include <proc/task.h>	64	#include <proc/task.h>
65	#include <proc/thread.h>	65	#include <proc/thread.h>
66	#include <arch/asm.h>	66	#include <arch/asm.h>
67	#include <panic.h>	67	#include <panic.h>
68	#include <debug.h>	68	#include <debug.h>
69	#include <print.h>	69	#include <print.h>
70	#include <memstr.h>	70	#include <memstr.h>
71	#include <macros.h>	71	#include <macros.h>
72	#include <arch.h>	72	#include <arch.h>
73	#include <errno.h>	73	#include <errno.h>
74	#include <config.h>	74	#include <config.h>
75	#include <align.h>	75	#include <align.h>
76	#include <arch/types.h>	76	#include <arch/types.h>
77	#include <typedefs.h>	77	#include <typedefs.h>
78	#include <syscall/copy.h>	78	#include <syscall/copy.h>
79	#include <arch/interrupt.h>	79	#include <arch/interrupt.h>
80		80
81	as_operations_t *as_operations = NULL;	81	as_operations_t *as_operations = NULL;
82		82
83	/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */	83	/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
84	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);	84	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
85		85
86	/**	86	/**
87	* This list contains address spaces that are not active on any	87	* This list contains address spaces that are not active on any
88	* processor and that have valid ASID.	88	* processor and that have valid ASID.
89	*/	89	*/
90	LIST_INITIALIZE(inactive_as_with_asid_head);	90	LIST_INITIALIZE(inactive_as_with_asid_head);
91		91
92	/** Kernel address space. */	92	/** Kernel address space. */
93	as_t *AS_KERNEL = NULL;	93	as_t *AS_KERNEL = NULL;
94		94
95	static int area_flags_to_page_flags(int aflags);	95	static int area_flags_to_page_flags(int aflags);
96	static as_area_t find_area_and_lock(as_t as, __address va);	96	static as_area_t find_area_and_lock(as_t as, __address va);
97	static bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area);	97	static bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area);
98	static void sh_info_remove_reference(share_info_t *sh_info);	98	static void sh_info_remove_reference(share_info_t *sh_info);
99		99
100	/** Initialize address space subsystem. */	100	/** Initialize address space subsystem. */
101	void as_init(void)	101	void as_init(void)
102	{	102	{
103	as_arch_init();	103	as_arch_init();
104	AS_KERNEL = as_create(FLAG_AS_KERNEL);	104	AS_KERNEL = as_create(FLAG_AS_KERNEL);
105	if (!AS_KERNEL)	105	if (!AS_KERNEL)
106	panic("can't create kernel address space\n");	106	panic("can't create kernel address space\n");
107		107
108	}	108	}
109		109
110	/** Create address space.	110	/** Create address space.
111	*	111	*
112	* @param flags Flags that influence way in wich the address space is created.	112	* @param flags Flags that influence way in wich the address space is created.
113	*/	113	*/
114	as_t *as_create(int flags)	114	as_t *as_create(int flags)
115	{	115	{
116	as_t *as;	116	as_t *as;
117		117
118	as = (as_t *) malloc(sizeof(as_t), 0);	118	as = (as_t *) malloc(sizeof(as_t), 0);
119	link_initialize(&as->inactive_as_with_asid_link);	119	link_initialize(&as->inactive_as_with_asid_link);
120	mutex_initialize(&as->lock);	120	mutex_initialize(&as->lock);
121	btree_create(&as->as_area_btree);	121	btree_create(&as->as_area_btree);
122		122
123	if (flags & FLAG_AS_KERNEL)	123	if (flags & FLAG_AS_KERNEL)
124	as->asid = ASID_KERNEL;	124	as->asid = ASID_KERNEL;
125	else	125	else
126	as->asid = ASID_INVALID;	126	as->asid = ASID_INVALID;
127		127
128	as->refcount = 0;	128	as->refcount = 0;
129	as->cpu_refcount = 0;	129	as->cpu_refcount = 0;
130	as->page_table = page_table_create(flags);	130	as->page_table = page_table_create(flags);
131		131
132	return as;	132	return as;
133	}	133	}
134		134
135	/** Destroy adress space.	135	/** Destroy adress space.
136	*	136	*
137	* When there are no tasks referencing this address space (i.e. its refcount is zero),	137	* When there are no tasks referencing this address space (i.e. its refcount is zero),
138	* the address space can be destroyed.	138	* the address space can be destroyed.
139	*/	139	*/
140	void as_destroy(as_t *as)	140	void as_destroy(as_t *as)
141	{	141	{
142	ipl_t ipl;	142	ipl_t ipl;
143	bool cond;	143	bool cond;
144		144
145	ASSERT(as->refcount == 0);	145	ASSERT(as->refcount == 0);
146		146
147	/*	147	/*
148	* Since there is no reference to this area,	148	* Since there is no reference to this area,
149	* it is safe not to lock its mutex.	149	* it is safe not to lock its mutex.
150	*/	150	*/
151	ipl = interrupts_disable();	151	ipl = interrupts_disable();
152	spinlock_lock(&inactive_as_with_asid_lock);	152	spinlock_lock(&inactive_as_with_asid_lock);
153	if (as->asid != ASID_INVALID && as != AS_KERNEL) {	153	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
154	if (as != AS && as->cpu_refcount == 0)	154	if (as != AS && as->cpu_refcount == 0)
155	list_remove(&as->inactive_as_with_asid_link);	155	list_remove(&as->inactive_as_with_asid_link);
156	asid_put(as->asid);	156	asid_put(as->asid);
157	}	157	}
158	spinlock_unlock(&inactive_as_with_asid_lock);	158	spinlock_unlock(&inactive_as_with_asid_lock);
159		159
160	/*	160	/*
161	* Destroy address space areas of the address space.	161	* Destroy address space areas of the address space.
162	* The B+tee must be walked carefully because it is	162	* The B+tee must be walked carefully because it is
163	* also being destroyed.	163	* also being destroyed.
164	*/	164	*/
165	for (cond = true; cond; ) {	165	for (cond = true; cond; ) {
166	btree_node_t *node;	166	btree_node_t *node;
167		167
168	ASSERT(!list_empty(&as->as_area_btree.leaf_head));	168	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
169	node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);	169	node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
170		170
171	if ((cond = node->keys)) {	171	if ((cond = node->keys)) {
172	as_area_destroy(as, node->key[0]);	172	as_area_destroy(as, node->key[0]);
173	}	173	}
174	}	174	}
175		175
176	btree_destroy(&as->as_area_btree);	176	btree_destroy(&as->as_area_btree);
177	page_table_destroy(as->page_table);	177	page_table_destroy(as->page_table);
178		178
179	interrupts_restore(ipl);	179	interrupts_restore(ipl);
180		180
181	free(as);	181	free(as);
182	}	182	}
183		183
184	/** Create address space area of common attributes.	184	/** Create address space area of common attributes.
185	*	185	*
186	* The created address space area is added to the target address space.	186	* The created address space area is added to the target address space.
187	*	187	*
188	* @param as Target address space.	188	* @param as Target address space.
189	* @param flags Flags of the area memory.	189	* @param flags Flags of the area memory.
190	* @param size Size of area.	190	* @param size Size of area.
191	* @param base Base address of area.	191	* @param base Base address of area.
192	* @param attrs Attributes of the area.	192	* @param attrs Attributes of the area.
193	* @param backend Address space area backend. NULL if no backend is used.	193	* @param backend Address space area backend. NULL if no backend is used.
194	* @param backend_data NULL or a pointer to an array holding two void *.	194	* @param backend_data NULL or a pointer to an array holding two void *.
195	*	195	*
196	* @return Address space area on success or NULL on failure.	196	* @return Address space area on success or NULL on failure.
197	*/	197	*/
198	as_area_t as_area_create(as_t as, int flags, size_t size, __address base, int attrs,	198	as_area_t as_area_create(as_t as, int flags, size_t size, __address base, int attrs,
199	mem_backend_t backend, mem_backend_data_t backend_data)	199	mem_backend_t backend, mem_backend_data_t backend_data)
200	{	200	{
201	ipl_t ipl;	201	ipl_t ipl;
202	as_area_t *a;	202	as_area_t *a;
203		203
204	if (base % PAGE_SIZE)	204	if (base % PAGE_SIZE)
205	return NULL;	205	return NULL;
206		206
207	if (!size)	207	if (!size)
208	return NULL;	208	return NULL;
209		209
210	/* Writeable executable areas are not supported. */	210	/* Writeable executable areas are not supported. */
211	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))	211	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
212	return NULL;	212	return NULL;
213		213
214	ipl = interrupts_disable();	214	ipl = interrupts_disable();
215	mutex_lock(&as->lock);	215	mutex_lock(&as->lock);
216		216
217	if (!check_area_conflicts(as, base, size, NULL)) {	217	if (!check_area_conflicts(as, base, size, NULL)) {
218	mutex_unlock(&as->lock);	218	mutex_unlock(&as->lock);
219	interrupts_restore(ipl);	219	interrupts_restore(ipl);
220	return NULL;	220	return NULL;
221	}	221	}
222		222
223	a = (as_area_t *) malloc(sizeof(as_area_t), 0);	223	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
224		224
225	mutex_initialize(&a->lock);	225	mutex_initialize(&a->lock);
226		226
227	a->as = as;	227	a->as = as;
228	a->flags = flags;	228	a->flags = flags;
229	a->attributes = attrs;	229	a->attributes = attrs;
230	a->pages = SIZE2FRAMES(size);	230	a->pages = SIZE2FRAMES(size);
231	a->base = base;	231	a->base = base;
232	a->sh_info = NULL;	232	a->sh_info = NULL;
233	a->backend = backend;	233	a->backend = backend;
234	if (backend_data)	234	if (backend_data)
235	a->backend_data = *backend_data;	235	a->backend_data = *backend_data;
236	else	236	else
237	memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);	237	memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
238		238
239	btree_create(&a->used_space);	239	btree_create(&a->used_space);
240		240
241	btree_insert(&as->as_area_btree, base, (void *) a, NULL);	241	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
242		242
243	mutex_unlock(&as->lock);	243	mutex_unlock(&as->lock);
244	interrupts_restore(ipl);	244	interrupts_restore(ipl);
245		245
246	return a;	246	return a;
247	}	247	}
248		248
249	/** Find address space area and change it.	249	/** Find address space area and change it.
250	*	250	*
251	* @param as Address space.	251	* @param as Address space.
252	* @param address Virtual address belonging to the area to be changed. Must be page-aligned.	252	* @param address Virtual address belonging to the area to be changed. Must be page-aligned.
253	* @param size New size of the virtual memory block starting at address.	253	* @param size New size of the virtual memory block starting at address.
254	* @param flags Flags influencing the remap operation. Currently unused.	254	* @param flags Flags influencing the remap operation. Currently unused.
255	*	255	*
256	* @return Zero on success or a value from @ref errno.h otherwise.	256	* @return Zero on success or a value from @ref errno.h otherwise.
257	*/	257	*/
258	int as_area_resize(as_t *as, __address address, size_t size, int flags)	258	int as_area_resize(as_t *as, __address address, size_t size, int flags)
259	{	259	{
260	as_area_t *area;	260	as_area_t *area;
261	ipl_t ipl;	261	ipl_t ipl;
262	size_t pages;	262	size_t pages;
263		263
264	ipl = interrupts_disable();	264	ipl = interrupts_disable();
265	mutex_lock(&as->lock);	265	mutex_lock(&as->lock);
266		266
267	/*	267	/*
268	* Locate the area.	268	* Locate the area.
269	*/	269	*/
270	area = find_area_and_lock(as, address);	270	area = find_area_and_lock(as, address);
271	if (!area) {	271	if (!area) {
272	mutex_unlock(&as->lock);	272	mutex_unlock(&as->lock);
273	interrupts_restore(ipl);	273	interrupts_restore(ipl);
274	return ENOENT;	274	return ENOENT;
275	}	275	}
276		276
277	if (area->backend == &phys_backend) {	277	if (area->backend == &phys_backend) {
278	/*	278	/*
279	* Remapping of address space areas associated	279	* Remapping of address space areas associated
280	* with memory mapped devices is not supported.	280	* with memory mapped devices is not supported.
281	*/	281	*/
282	mutex_unlock(&area->lock);	282	mutex_unlock(&area->lock);
283	mutex_unlock(&as->lock);	283	mutex_unlock(&as->lock);
284	interrupts_restore(ipl);	284	interrupts_restore(ipl);
285	return ENOTSUP;	285	return ENOTSUP;
286	}	286	}
287	if (area->sh_info) {	287	if (area->sh_info) {
288	/*	288	/*
289	* Remapping of shared address space areas	289	* Remapping of shared address space areas
290	* is not supported.	290	* is not supported.
291	*/	291	*/
292	mutex_unlock(&area->lock);	292	mutex_unlock(&area->lock);
293	mutex_unlock(&as->lock);	293	mutex_unlock(&as->lock);
294	interrupts_restore(ipl);	294	interrupts_restore(ipl);
295	return ENOTSUP;	295	return ENOTSUP;
296	}	296	}
297		297
298	pages = SIZE2FRAMES((address - area->base) + size);	298	pages = SIZE2FRAMES((address - area->base) + size);
299	if (!pages) {	299	if (!pages) {
300	/*	300	/*
301	* Zero size address space areas are not allowed.	301	* Zero size address space areas are not allowed.
302	*/	302	*/
303	mutex_unlock(&area->lock);	303	mutex_unlock(&area->lock);
304	mutex_unlock(&as->lock);	304	mutex_unlock(&as->lock);
305	interrupts_restore(ipl);	305	interrupts_restore(ipl);
306	return EPERM;	306	return EPERM;
307	}	307	}
308		308
309	if (pages < area->pages) {	309	if (pages < area->pages) {
310	bool cond;	310	bool cond;
311	__address start_free = area->base + pages*PAGE_SIZE;	311	__address start_free = area->base + pages*PAGE_SIZE;
312		312
313	/*	313	/*
314	* Shrinking the area.	314	* Shrinking the area.
315	* No need to check for overlaps.	315	* No need to check for overlaps.
316	*/	316	*/
317		317
318	/*	318	/*
319	* Start TLB shootdown sequence.	319	* Start TLB shootdown sequence.
320	*/	320	*/
321	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);	321	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
322		322
323	/*	323	/*
324	* Remove frames belonging to used space starting from	324	* Remove frames belonging to used space starting from
325	* the highest addresses downwards until an overlap with	325	* the highest addresses downwards until an overlap with
326	* the resized address space area is found. Note that this	326	* the resized address space area is found. Note that this
327	* is also the right way to remove part of the used_space	327	* is also the right way to remove part of the used_space
328	* B+tree leaf list.	328	* B+tree leaf list.
329	*/	329	*/
330	for (cond = true; cond;) {	330	for (cond = true; cond;) {
331	btree_node_t *node;	331	btree_node_t *node;
332		332
333	ASSERT(!list_empty(&area->used_space.leaf_head));	333	ASSERT(!list_empty(&area->used_space.leaf_head));
334	node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);	334	node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
335	if ((cond = (bool) node->keys)) {	335	if ((cond = (bool) node->keys)) {
336	__address b = node->key[node->keys - 1];	336	__address b = node->key[node->keys - 1];
337	count_t c = (count_t) node->value[node->keys - 1];	337	count_t c = (count_t) node->value[node->keys - 1];
338	int i = 0;	338	int i = 0;
339		339
340	if (overlaps(b, cPAGE_SIZE, area->base, pagesPAGE_SIZE)) {	340	if (overlaps(b, cPAGE_SIZE, area->base, pagesPAGE_SIZE)) {
341		341
342	if (b + c*PAGE_SIZE <= start_free) {	342	if (b + c*PAGE_SIZE <= start_free) {
343	/*	343	/*
344	* The whole interval fits completely	344	* The whole interval fits completely
345	* in the resized address space area.	345	* in the resized address space area.
346	*/	346	*/
347	break;	347	break;
348	}	348	}
349		349
350	/*	350	/*
351	* Part of the interval corresponding to b and c	351	* Part of the interval corresponding to b and c
352	* overlaps with the resized address space area.	352	* overlaps with the resized address space area.
353	*/	353	*/
354		354
355	cond = false; /* we are almost done */	355	cond = false; /* we are almost done */
356	i = (start_free - b) >> PAGE_WIDTH;	356	i = (start_free - b) >> PAGE_WIDTH;
357	if (!used_space_remove(area, start_free, c - i))	357	if (!used_space_remove(area, start_free, c - i))
358	panic("Could not remove used space.");	358	panic("Could not remove used space.");
359	} else {	359	} else {
360	/*	360	/*
361	* The interval of used space can be completely removed.	361	* The interval of used space can be completely removed.
362	*/	362	*/
363	if (!used_space_remove(area, b, c))	363	if (!used_space_remove(area, b, c))
364	panic("Could not remove used space.\n");	364	panic("Could not remove used space.\n");
365	}	365	}
366		366
367	for (; i < c; i++) {	367	for (; i < c; i++) {
368	pte_t *pte;	368	pte_t *pte;
369		369
370	page_table_lock(as, false);	370	page_table_lock(as, false);
371	pte = page_mapping_find(as, b + i*PAGE_SIZE);	371	pte = page_mapping_find(as, b + i*PAGE_SIZE);
372	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));	372	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
373	if (area->backend && area->backend->frame_free) {	373	if (area->backend && area->backend->frame_free) {
374	area->backend->frame_free(area,	374	area->backend->frame_free(area,
375	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));	375	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
376	}	376	}
377	page_mapping_remove(as, b + i*PAGE_SIZE);	377	page_mapping_remove(as, b + i*PAGE_SIZE);
378	page_table_unlock(as, false);	378	page_table_unlock(as, false);
379	}	379	}
380	}	380	}
381	}	381	}
382		382
383	/*	383	/*
384	* Finish TLB shootdown sequence.	384	* Finish TLB shootdown sequence.
385	*/	385	*/
386	tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);	386	tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
387	tlb_shootdown_finalize();	387	tlb_shootdown_finalize();
388	} else {	388	} else {
389	/*	389	/*
390	* Growing the area.	390	* Growing the area.
391	* Check for overlaps with other address space areas.	391	* Check for overlaps with other address space areas.
392	*/	392	*/
393	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {	393	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
394	mutex_unlock(&area->lock);	394	mutex_unlock(&area->lock);
395	mutex_unlock(&as->lock);	395	mutex_unlock(&as->lock);
396	interrupts_restore(ipl);	396	interrupts_restore(ipl);
397	return EADDRNOTAVAIL;	397	return EADDRNOTAVAIL;
398	}	398	}
399	}	399	}
400		400
401	area->pages = pages;	401	area->pages = pages;
402		402
403	mutex_unlock(&area->lock);	403	mutex_unlock(&area->lock);
404	mutex_unlock(&as->lock);	404	mutex_unlock(&as->lock);
405	interrupts_restore(ipl);	405	interrupts_restore(ipl);
406		406
407	return 0;	407	return 0;
408	}	408	}
409		409
410	/** Destroy address space area.	410	/** Destroy address space area.
411	*	411	*
412	* @param as Address space.	412	* @param as Address space.
413	* @param address Address withing the area to be deleted.	413	* @param address Address withing the area to be deleted.
414	*	414	*
415	* @return Zero on success or a value from @ref errno.h on failure.	415	* @return Zero on success or a value from @ref errno.h on failure.
416	*/	416	*/
417	int as_area_destroy(as_t *as, __address address)	417	int as_area_destroy(as_t *as, __address address)
418	{	418	{
419	as_area_t *area;	419	as_area_t *area;
420	__address base;	420	__address base;
421	link_t *cur;	421	link_t *cur;
422	ipl_t ipl;	422	ipl_t ipl;
423		423
424	ipl = interrupts_disable();	424	ipl = interrupts_disable();
425	mutex_lock(&as->lock);	425	mutex_lock(&as->lock);
426		426
427	area = find_area_and_lock(as, address);	427	area = find_area_and_lock(as, address);
428	if (!area) {	428	if (!area) {
429	mutex_unlock(&as->lock);	429	mutex_unlock(&as->lock);
430	interrupts_restore(ipl);	430	interrupts_restore(ipl);
431	return ENOENT;	431	return ENOENT;
432	}	432	}
433		433
434	base = area->base;	434	base = area->base;
435		435
436	/*	436	/*
437	* Start TLB shootdown sequence.	437	* Start TLB shootdown sequence.
438	*/	438	*/
439	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);	439	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
440		440
441	/*	441	/*
442	* Visit only the pages mapped by used_space B+tree.	442	* Visit only the pages mapped by used_space B+tree.
443	*/	443	*/
444	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {	444	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
445	btree_node_t *node;	445	btree_node_t *node;
446	int i;	446	int i;
447		447
448	node = list_get_instance(cur, btree_node_t, leaf_link);	448	node = list_get_instance(cur, btree_node_t, leaf_link);
449	for (i = 0; i < node->keys; i++) {	449	for (i = 0; i < node->keys; i++) {
450	__address b = node->key[i];	450	__address b = node->key[i];
451	count_t j;	451	count_t j;
452	pte_t *pte;	452	pte_t *pte;
453		453
454	for (j = 0; j < (count_t) node->value[i]; j++) {	454	for (j = 0; j < (count_t) node->value[i]; j++) {
455	page_table_lock(as, false);	455	page_table_lock(as, false);
456	pte = page_mapping_find(as, b + j*PAGE_SIZE);	456	pte = page_mapping_find(as, b + j*PAGE_SIZE);
457	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));	457	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
458	if (area->backend && area->backend->frame_free) {	458	if (area->backend && area->backend->frame_free) {
459	area->backend->frame_free(area,	459	area->backend->frame_free(area,
460	b + j*PAGE_SIZE, PTE_GET_FRAME(pte));	460	b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
461	}	461	}
462	page_mapping_remove(as, b + j*PAGE_SIZE);	462	page_mapping_remove(as, b + j*PAGE_SIZE);
463	page_table_unlock(as, false);	463	page_table_unlock(as, false);
464	}	464	}
465	}	465	}
466	}	466	}
467		467
468	/*	468	/*
469	* Finish TLB shootdown sequence.	469	* Finish TLB shootdown sequence.
470	*/	470	*/
471	tlb_invalidate_pages(AS->asid, area->base, area->pages);	471	tlb_invalidate_pages(AS->asid, area->base, area->pages);
472	tlb_shootdown_finalize();	472	tlb_shootdown_finalize();
473		473
474	btree_destroy(&area->used_space);	474	btree_destroy(&area->used_space);
475		475
476	area->attributes \|= AS_AREA_ATTR_PARTIAL;	476	area->attributes \|= AS_AREA_ATTR_PARTIAL;
477		477
478	if (area->sh_info)	478	if (area->sh_info)
479	sh_info_remove_reference(area->sh_info);	479	sh_info_remove_reference(area->sh_info);
480		480
481	mutex_unlock(&area->lock);	481	mutex_unlock(&area->lock);
482		482
483	/*	483	/*
484	* Remove the empty area from address space.	484	* Remove the empty area from address space.
485	*/	485	*/
486	btree_remove(&AS->as_area_btree, base, NULL);	486	btree_remove(&AS->as_area_btree, base, NULL);
487		487
488	free(area);	488	free(area);
489		489
490	mutex_unlock(&AS->lock);	490	mutex_unlock(&AS->lock);
491	interrupts_restore(ipl);	491	interrupts_restore(ipl);
492	return 0;	492	return 0;
493	}	493	}
494		494
495	/** Share address space area with another or the same address space.	495	/** Share address space area with another or the same address space.
496	*	496	*
497	* Address space area mapping is shared with a new address space area.	497	* Address space area mapping is shared with a new address space area.
498	* If the source address space area has not been shared so far,	498	* If the source address space area has not been shared so far,
499	* a new sh_info is created. The new address space area simply gets the	499	* a new sh_info is created. The new address space area simply gets the
500	* sh_info of the source area. The process of duplicating the	500	* sh_info of the source area. The process of duplicating the

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(root)/kernel/trunk/generic/src/mm/as.c – Rev 1705 → 1735