int
x86_pagedir_map_range (DWORD *pagedir, DWORD virt, DWORD phys, DWORD pages,
DWORD flags)
{
DWORD i;
DWORD this_virt, this_phys;
DWORD *pagetable;
RETURN_ON_FAILURE (x86_prepare_page_table (pagedir, virt));
pagetable = x86_get_page_table (pagedir, virt);
for (i = 0; i < pages; i++)
{
this_virt = virt + (i << 12);
this_phys = phys + (i << 12);
if (PAGE_ENTRY (this_virt) == 0)
{
if (x86_prepare_page_table (pagedir, this_virt) == -1)
return KERNEL_ERROR_VALUE;
pagetable = x86_get_page_table (pagedir, this_virt);
}
pagetable[PAGE_ENTRY (this_virt)] = this_phys | flags;
}
return KERNEL_SUCCESS_VALUE;
}
int
x86_pagedir_unset_flags (DWORD *pagedir, DWORD virt, DWORD pages, DWORD flags)
{
DWORD i;
DWORD this_virt;
DWORD *pagetable;
ASSERT (x86_page_table_present (pagedir, virt));
pagetable = x86_get_page_table (pagedir, virt);
for (i = 0; i < pages; i++)
{
this_virt = virt + (i << 12);
if (PAGE_ENTRY (this_virt) == 0)
{
ASSERT (x86_page_table_present (pagedir, this_virt));
pagetable = x86_get_page_table (pagedir, this_virt);
}
pagetable[PAGE_ENTRY (this_virt)] &= ~flags;
}
return KERNEL_SUCCESS_VALUE;
}
static pgentry_t pg_clone_tbl(pgentry_t tblent) {
uint32_t flags = (uint32_t)PTE_FLAGS(tblent);
paddr_t tblframe = (paddr_t)PTE_ADDR(tblent);
if ((flags & PAGE_LINK) != 0) {
return tblent;
}
if ((flags & PAGE_PRESENT) == 0) {
// Table not present, but some flags are set
return tblent;
}
paddr_t newtblframe = pg_dir_new();
pgentry_t *tbl = pg_tmp_map((pgaddr_t)tblframe);
pgentry_t *newtbl = pg_tmp_map((pgaddr_t)newtblframe);
for (int i = 0; i < 1024; i++) {
if (tbl[i] != NilPgEnt) {
newtbl[i] = pg_clone_page(tbl[i]);
}
}
pg_tmp_unmap(tbl);
pg_tmp_unmap(newtbl);
return PAGE_ENTRY(newtblframe, flags);
}
static pgentry_t pg_clone_page(pgentry_t page) {
uint32_t flags = (uint32_t)PTE_FLAGS(page);
paddr_t pgframe = (paddr_t)PTE_ADDR(page);
if ((flags & PAGE_PRESENT) == 0) {
// Page not present, but some flags are set
return page;
}
if ((flags & PAGE_LINK) != 0) {
return page;
}
paddr_t newpgframe = frame_alloc();
frame_set(newpgframe);
frame_copy(pgframe, newpgframe);
return PAGE_ENTRY(newpgframe, flags);
}
static pgentry_t pg_clone_page_4m(pgentry_t page) {
uint32_t flags = (uint32_t)PDE_FLAGS(page);
paddr_t pgframe = (paddr_t)PDE_ADDR(page);
if ((flags & PAGE_PRESENT) == 0) {
// Page not present, but some flags are set
return page;
}
if ((flags & PAGE_LINK) != 0) {
return page;
}
paddr_t newpgframe = frame_alloc_4m();
int num_pages = 1024;
paddr_t limit = newpgframe + (paddr_t)(num_pages * PAGE_SIZE);
frame_set_range(newpgframe, limit);
for (int i = 0; i < num_pages; i++) {
paddr_t offset = (paddr_t)i * PAGE_SIZE;
frame_copy(pgframe + offset, newpgframe + offset);
}
return PAGE_ENTRY(newpgframe, flags);
}
