uint64_t heap_sbrk(intptr_t increase)
{
// Acquire lock
spinlock_acquire(&heap_lock);
// Increase?
if (increase > 0) {
// Align
increase = mem_align((uintptr_t) increase, 0x1000);
// Determine amount of pages
size_t pages = increase / 0x1000;
size_t i;
for (i = 0; i < pages; ++i) {
// Allocate frame
uintptr_t phys = frame_alloc();
// Map frame
page_map(
heap_begin + heap_length,
phys,
PG_PRESENT | PG_GLOBAL | PG_WRITABLE);
// Increase length
heap_length += 0x1000;
}
// Decrease
} else if (increase < 0) {
// Align decrease
uintptr_t decrease = mem_align((uintptr_t) (-increase), 0x1000);
// Determine amount of pages
size_t pages = decrease / 0x1000;
size_t i;
for (i = 0; i < pages; ++i) {
// Get (virtual) begin address of last page
uintptr_t virt = heap_begin + heap_length;
// Get physical address
uintptr_t phys = page_get_physical(virt);
// Unmap page
page_unmap(virt);
// Decrease length
heap_length -= 0x1000;
}
}
// Release lock
spinlock_release(&heap_lock);
// Beginning of the heap
return heap_begin;
}
int
ipc_port_send(const struct ipc_header *ipch, void *vpage)
{
struct vm_page *page;
struct task *task;
struct vm *vm;
int error;
task = current_task();
ASSERT(task != NULL, "Must have a running task.");
ASSERT(ipch != NULL, "Must have a header.");
/*
* Extract the vm_page for this page.
*/
if (vpage == NULL) {
page = NULL;
} else {
if ((task->t_flags & TASK_KERNEL) == 0)
vm = task->t_vm;
else
vm = &kernel_vm;
error = page_extract(vm, (vaddr_t)vpage, &page);
if (error != 0)
return (error);
if (vm == &kernel_vm) {
error = page_unmap_direct(vm, page, (vaddr_t)vpage);
if (error != 0)
panic("%s: could not unmap direct page: %m", __func__, error);
} else {
error = page_unmap(vm, (vaddr_t)vpage, page);
if (error != 0)
panic("%s: could not unmap source page: %m", __func__, error);
error = vm_free_address(vm, (vaddr_t)vpage);
if (error != 0)
panic("%s: could not free source page address: %m", __func__, error);
}
}
error = ipc_port_send_page(ipch, page);
if (error != 0) {
if (page != NULL)
page_release(page);
return (error);
}
return (0);
}
void *
Vmem_alloc::page_unmap (void *page)
{
Address phys = Kmem::virt_to_phys(page);
if (phys == (Address) -1)
return 0;
Address va = reinterpret_cast<Address>(page);
void *res = (void*)Mem_layout::phys_to_pmem(phys);
if (va < Mem_layout::Vmem_end)
{
// clean out page-table entry
*(Kmem::kdir->walk(Virt_addr(va)).e) = 0;
page_unmap (page, 0);
Mem_unit::tlb_flush(va);
}
return res;
}
void
Vmem_alloc::page_free (void *page)
{
Address phys = Kmem::virt_to_phys(page);
if (phys == (Address) -1)
return;
// convert back to virt (do not use "page") to get canonic mapping
Mapped_allocator::allocator()->free(Config::PAGE_SHIFT, // 2^0=1 pages
Kmem::phys_to_virt(phys));
Address va = reinterpret_cast<Address>(page);
if (va < Mem_layout::Vmem_end)
{
// clean out page-table entry
Kmem::kdir->walk(Virt_addr(va)).e->clear();
page_unmap (page, 0);
Mem_unit::tlb_flush(va);
}
}
