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Regard whitespace Rev 1412 → Rev 1413

/kernel/trunk/generic/include/mm/as.h
148,7 → 148,7
extern int as_page_fault(__address page, pf_access_t access, istate_t *istate);
extern void as_switch(as_t *old, as_t *new);
extern void as_free(as_t *as);
extern int as_area_steal(task_t *src_task, __address src_base, size_t acc_size, __address dst_base);
extern int as_area_share(as_t *src_as, __address src_base, size_t acc_size, __address dst_base);
extern size_t as_get_size(__address base);
extern int used_space_insert(as_area_t *a, __address page, count_t count);
extern int used_space_remove(as_area_t *a, __address page, count_t count);
/kernel/trunk/generic/src/mm/as.c
450,15 → 450,15
return 0;
}
 
/** Steal address space area from another task.
/** Share address space area with another or the same address space.
*
* Address space area is stolen from another task
* Moreover, any existing mapping
* is copied as well, providing thus a mechanism
* for sharing group of pages. The source address
* space area and any associated mapping is preserved.
* Address space area of anonymous memory 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 and the original mapping is duplicated
* in its pagemap B+tree. The new address space are simply gets the
* sh_info of the source area.
*
* @param src_task Pointer of source task
* @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_base Target base address
467,22 → 467,20
* 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.
* address space area. ENOTSUP is returned if an attempt
* to share non-anonymous address space area is detected.
*/
int as_area_steal(task_t *src_task, __address src_base, size_t acc_size,
int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
__address dst_base)
{
ipl_t ipl;
count_t i;
as_t *src_as;
int src_flags;
size_t src_size;
as_area_t *src_area, *dst_area;
share_info_t *sh_info;
link_t *cur;
 
ipl = interrupts_disable();
spinlock_lock(&src_task->lock);
src_as = src_task->as;
mutex_lock(&src_as->lock);
src_area = find_area_and_lock(src_as, src_base);
if (!src_area) {
489,22 → 487,82
/*
* Could not find the source address space area.
*/
spinlock_unlock(&src_task->lock);
mutex_unlock(&src_as->lock);
interrupts_restore(ipl);
return ENOENT;
}
if (!src_area->backend || src_area->backend != &anon_backend) {
/*
* As of now, only anonymous address space areas can be shared.
*/
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;
if (src_size != acc_size) {
mutex_unlock(&src_area->lock);
mutex_unlock(&src_as->lock);
 
if (src_size != acc_size) {
spinlock_unlock(&src_task->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);
}
 
/*
* Copy used portions of the area to sh_info's page map.
*/
mutex_lock(&sh_info->lock);
for (cur = src_area->used_space.leaf_head.next; cur != &src_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 base = node->key[i];
count_t count = (count_t) node->value[i];
int j;
for (j = 0; j < count; j++) {
pte_t *pte;
page_table_lock(src_as, false);
pte = page_mapping_find(src_as, base + j*PAGE_SIZE);
ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
btree_insert(&sh_info->pagemap, (base + j*PAGE_SIZE) - src_area->base,
(void *) PTE_GET_FRAME(pte), NULL);
page_table_unlock(src_as, false);
}
}
}
mutex_unlock(&sh_info->lock);
 
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
515,57 → 573,22
/*
* Destination address space area could not be created.
*/
spinlock_unlock(&src_task->lock);
sh_info_remove_reference(sh_info);
interrupts_restore(ipl);
return ENOMEM;
}
spinlock_unlock(&src_task->lock);
/*
* Avoid deadlock by first locking the address space with lower address.
*/
if (AS < src_as) {
mutex_lock(&AS->lock);
mutex_lock(&src_as->lock);
} else {
mutex_lock(&AS->lock);
mutex_lock(&src_as->lock);
}
for (i = 0; i < SIZE2FRAMES(src_size); i++) {
pte_t *pte;
__address frame;
page_table_lock(src_as, false);
pte = page_mapping_find(src_as, src_base + i*PAGE_SIZE);
if (pte && PTE_VALID(pte)) {
ASSERT(PTE_PRESENT(pte));
frame = PTE_GET_FRAME(pte);
if (!(src_flags & AS_AREA_DEVICE))
frame_reference_add(ADDR2PFN(frame));
page_table_unlock(src_as, false);
} else {
page_table_unlock(src_as, false);
continue;
}
page_table_lock(AS, false);
page_mapping_insert(AS, dst_base + i*PAGE_SIZE, frame, area_flags_to_page_flags(src_flags));
page_table_unlock(AS, false);
}
 
/*
* Now the destination address space area has been
* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
* attribute.
* 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);
mutex_unlock(&AS->lock);
mutex_unlock(&src_as->lock);
interrupts_restore(ipl);
return 0;
1478,7 → 1501,8
* mapping, a new frame is allocated and the mapping is created.
*/
mutex_lock(&area->sh_info->lock);
frame = (__address) btree_search(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE), &leaf);
frame = (__address) btree_search(&area->sh_info->pagemap,
ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);
if (!frame) {
bool allocate = true;
int i;
1500,7 → 1524,7
/*
* Insert the address of the newly allocated frame to the pagemap.
*/
btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE), (void *) frame, leaf);
btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base, (void *) frame, leaf);
}
}
mutex_unlock(&area->sh_info->lock);
/kernel/trunk/generic/src/ipc/sysipc.c
129,8 → 129,16
}
} else if (IPC_GET_METHOD(*olddata) == IPC_M_AS_AREA_SEND) {
if (!IPC_GET_RETVAL(answer->data)) { /* Accepted, handle as_area receipt */
return as_area_steal(answer->sender,
IPC_GET_ARG2(*olddata),IPC_GET_ARG3(*olddata),
ipl_t ipl;
as_t *as;
ipl = interrupts_disable();
spinlock_lock(&answer->sender->lock);
as = answer->sender->as;
spinlock_unlock(&answer->sender->lock);
interrupts_restore(ipl);
return as_area_share(as, IPC_GET_ARG2(*olddata),IPC_GET_ARG3(*olddata),
IPC_GET_ARG1(answer->data));
}
}