void MB_MarkPage(MemoryBitmap *Bitmap, physical Page, qword Flag) {
switch (Flag) {
case MB_PAGE_OCCUPIED:
{
address l_PageAddr = (address) Page;
l_PageAddr = PAGE_SHIFT(PAGE_ROUND_DOWN(l_PageAddr));
if (l_PageAddr / 32 < Bitmap->m_Length)
Bitmap->m_Bitmap[l_PageAddr / 32] &= ~(1 << (l_PageAddr % 32));
}
return;
case MB_PAGE_FREE:
{
address l_PageAddr = (address) Page;
qword t_Div32, t_Mod32;
l_PageAddr = PAGE_SHIFT(PAGE_ROUND_DOWN(l_PageAddr));
t_Div32 = l_PageAddr / 32;
t_Mod32 = l_PageAddr % 32;
if (t_Div32 < Bitmap->m_Length) Bitmap->m_Bitmap[t_Div32] |= 1 << t_Mod32;
if (t_Div32 < Bitmap->m_LastIndex) Bitmap->m_LastIndex = t_Div32;
}
return;
default:
return;
}
}
int sos_brk_move(sos_pcb *pcb, seL4_Word new_brk_vaddr) {
int err;
sos_region *region;
// First we need to find the brk region.
// This is guaranteed to be the region containing the heap bottom.
err = sos_resolve_region(&(pcb->regions), SOS_PROCESS_HEAP_START, ®ion);
if (err != SOS_REGION_SUCCESS) {
// This really should not happen - the heap is missing!
// Not much we can do, but it's possible the process can still do work.
dprintf(5, "ERROR: PID %d has no heap region.\n", pcb->pid);
return SOS_PAGE_TABLE_OOM;
}
// ... Then we try to resize it.
seL4_Word start_page = PAGE_SHIFT(region->base);
seL4_Word end_page = PAGE_SHIFT(new_brk_vaddr);
// XXX Check math - off by 1?
err = _resize_region(pcb, region, end_page - start_page);
return err;
}
/* Statically-sized initial heap, for now */
static int _create_heap(sos_pcb *pcb) {
int err;
err = sos_create_region(pcb, SOS_PROCESS_HEAP_START,
/* Number of pages in the initial heap region */
PAGE_SHIFT(SOS_PROCESS_BRK - SOS_PROCESS_HEAP_START),
SOS_PROCESS_HEAP_ATTRS);
if (err) return err;
// Allocate heap guard page
err = _create_guard_page(pcb, SOS_PROCESS_HEAP_GUARD);
return err;
}
/* Statically-sized stack frame, for now */
static int _create_stack_frame(sos_pcb *pcb) {
int err;
err = sos_create_region(pcb, SOS_PROCESS_STACK_BOTTOM,
/* Number of frames in the fixed-size stack */
PAGE_SHIFT(SOS_PROCESS_STACK_TOP - SOS_PROCESS_STACK_BOTTOM),
SOS_PROCESS_STACK_ATTRS);
if (err) return err;
// Allocate stack guard page
err = _create_guard_page(pcb, SOS_PROCESS_STACK_GUARD);
return err;
}
void MB_ReleasePages(MemoryBitmap *Bmp, linear BlockAddr, qword Pages) {
if (Pages == 0) return;
if (Pages == 1) {
MB_MarkPage(Bmp, LINEAR_TO_PHYSICAL(BlockAddr), MB_PAGE_FREE);
return;
}
address l_BlockAddr = (address) LINEAR_TO_PHYSICAL(BlockAddr);
qword t_Div32, t_Mod32;
l_BlockAddr = PAGE_SHIFT(PAGE_ROUND_DOWN(l_BlockAddr));
t_Div32 = l_BlockAddr / 32;
t_Mod32 = l_BlockAddr % 32;
if (t_Div32 < Bmp->m_LastIndex) Bmp->m_LastIndex = t_Div32;
while (t_Div32 < Bmp->m_Length && Pages != 0) {
Bmp->m_Bitmap[t_Div32] |= (1 << t_Mod32);
++t_Mod32;
if (t_Mod32 == 32) {
++t_Div32;
t_Mod32 = 0;
}
--Pages;
}
}
