/* Initialize an address space */
void addrspace_init(addrspace_t *addrspace, paddr_t address_space, vaddr_t free_start, vaddr_t free_length)
{
/* System address space */
if (addrspace == ADDRSPACE_SYSTEM)
{
/* Create the initial slab cache for VADs */
for (size_t i = free_start; i < free_start + SLAB_SIZE; i += PAGE_SIZE)
{
int color = vaddr_cache_color(i, NUMA_DOMAIN_BEST, 0);
vmm_map_page(address_space, i, pmm_alloc_page(0, NUMA_DOMAIN_BEST, color), PAGE_READ | PAGE_WRITE | PAGE_GLOBAL);
}
vad_cache = (slab_cache_t*) free_start;
slab_cache_init(vad_cache, sizeof(vad_t), PAGE_READ | PAGE_WRITE);
free_start += SLAB_SIZE;
free_length -= SLAB_SIZE;
/* Set up the pointer to the system address space */
addrspace = &system_addrspace;
}
/* Fill in the information */
addrspace->address_space = address_space;
addrspace->numa_domain = NUMA_DOMAIN_CURRENT;
spinlock_recursive_init(&addrspace->lock);
/* Initialize the free VAD */
addrspace->free.start = free_start;
addrspace->free.length = free_length;
addrspace->free.flags = 0;
addrspace->free.prev = addrspace->free.next = NULL;
/* Initialize the used VAD */
addrspace->used_root = &addrspace->used;
addrspace->used.height = 0;
if (addrspace == &system_addrspace)
{
addrspace->used.start = KERNEL_ADDRSPACE_START;
addrspace->used.length = free_start - KERNEL_ADDRSPACE_START;
addrspace->used.flags = PAGE_READ | PAGE_WRITE | PAGE_EXECUTE | PAGE_PRIVATE;
addrspace->used.left = addrspace->used.right = NULL;
}
else
{
addrspace->used.start = USER_ADDRSPACE_START;
addrspace->used.length = free_start - USER_ADDRSPACE_START;
addrspace->used.flags = PAGE_INVALID | PAGE_PRIVATE;
addrspace->used.left = addrspace->used.right = NULL;
}
}
void syscall_malloc_pages(uint32_t *ebx, uint32_t *ecx, uint32_t *edx) {
size_t pages = *ebx;
uintptr_t vaddr_start = (uintptr_t) vmm_find(current_context, pages, VADDR_USER_HEAP_START, VADDR_USER_HEAP_END);
int i;
for(i = 0; i < pages; i++) {
uintptr_t vaddr = vaddr_start + i*PAGE_SIZE;
uintptr_t paddr = (uintptr_t) pmm_alloc();
vmm_map_page(current_context, vaddr, paddr, VMM_USER_FLAGS);
}
*ecx = vaddr_start;
current_proc->used_mem_pages += pages;
}
/* Allocate regions of a virtual address space */
void *addrspace_alloc(addrspace_t *addrspace, size_t size_reserved, size_t size_committed, int flags)
{
/* Get the address space pointer */
addrspace = resolve_addrspace(addrspace);
/* Round up both the reserved and committed sizes to a page boundary */
size_reserved = PAGE_ALIGN_UP(size_reserved);
size_committed = PAGE_ALIGN_UP(size_committed);
/* Make sure we don't commit more than we reserve */
if (size_committed > size_reserved)
{
size_committed = size_reserved;
}
/* Search the address space for a free region of suitable size */
spinlock_recursive_acquire(&addrspace->lock);
vad_t *vad = &addrspace->free;
while (vad)
{
/* Move on if it doesn't fit our allocation */
if (vad->length < size_reserved)
{
vad = vad->next;
continue;
}
/* Store the starting address of the allocation */
vaddr_t address = vad->start;
/* Create the guard page if requested */
vaddr_t i = address;
if (flags & GUARD_BOTTOM)
{
vmm_map_page(addrspace->address_space, i, 0, PAGE_INVALID);
i += PAGE_SIZE;
}
/* Commit all the needed pages */
for (; i < address + size_committed; i += PAGE_SIZE)
{
int color = vaddr_cache_color(i, addrspace->numa_domain, 0);
vmm_map_page(addrspace->address_space, i, pmm_alloc_page(0, addrspace->numa_domain, color), flags);
}
/* Modify the free VAD or remove it entirely */
if (size_reserved < vad->length)
{
vad->start += size_reserved;
vad->length -= size_reserved;
}
else
{
/* Later VAD */
if (vad != &addrspace->free)
{
/* Readjust the linked list */
vad->prev->next = vad->next;
vad->next->prev = vad->prev;
/* Free the VAD */
slab_cache_free(vad_cache, vad);
}
/* Root VAD */
else
{
/* Copy the next VAD into the root one */
vad_t *vad_next = vad->next;
memcpy(vad, vad_next, sizeof(vad_t));
/* Free the dynamically-allocated VAD */
slab_cache_free(vad_cache, vad_next);
}
}
/* Record metadata, unless told not to */
if (!(flags & PAGE_PRIVATE))
{
/* Create a new VAD to represent the now-used region */
vad = slab_cache_alloc(vad_cache);
vad->start = address;
vad->length = size_reserved;
vad->flags = flags;
vad->left = vad->right = NULL;
vad->height = 0;
/* Insert it into the tree */
addrspace->used_root = vad_tree_insert(addrspace->used_root, vad);
}
/* Return the address of the allocated region */
spinlock_recursive_release(&addrspace->lock);
return (void*) address;
}
/* No free region of the address space available */
spinlock_recursive_release(&addrspace->lock);
return NULL;
}