/** Initializes page tables.
*
* 1:1 virtual-physical mapping is created in kernel address space. Mapping
* for table with exception vectors is also created.
*/
void page_arch_init(void)
{
int flags = PAGE_CACHEABLE;
page_mapping_operations = &pt_mapping_operations;
page_table_lock(AS_KERNEL, true);
uintptr_t cur;
/* Kernel identity mapping */
for (cur = PHYSMEM_START_ADDR;
cur < min(config.identity_size, config.physmem_end);
cur += FRAME_SIZE)
page_mapping_insert(AS_KERNEL, PA2KA(cur), cur, flags);
#ifdef HIGH_EXCEPTION_VECTORS
/* Create mapping for exception table at high offset */
uintptr_t ev_frame = (uintptr_t) frame_alloc(ONE_FRAME, FRAME_NONE);
page_mapping_insert(AS_KERNEL, EXC_BASE_ADDRESS, ev_frame, flags);
#else
#error "Only high exception vector supported now"
#endif
page_table_unlock(AS_KERNEL, true);
as_switch(NULL, AS_KERNEL);
boot_page_table_free();
}
void page_arch_init(void)
{
if (config.cpu_active > 1) {
write_cr3((uintptr_t) AS_KERNEL->genarch.page_table);
return;
}
uintptr_t cur;
unsigned int identity_flags =
PAGE_GLOBAL | PAGE_CACHEABLE | PAGE_EXEC | PAGE_WRITE | PAGE_READ;
page_mapping_operations = &pt_mapping_operations;
page_table_lock(AS_KERNEL, true);
/*
* PA2KA(identity) mapping for all low-memory frames.
*/
for (cur = 0; cur < min(config.identity_size, config.physmem_end);
cur += FRAME_SIZE)
page_mapping_insert(AS_KERNEL, PA2KA(cur), cur, identity_flags);
page_table_unlock(AS_KERNEL, true);
exc_register(14, "page_fault", true, (iroutine_t) page_fault);
write_cr3((uintptr_t) AS_KERNEL->genarch.page_table);
}
static uintptr_t
km_map_aligned(uintptr_t paddr, size_t size, unsigned int flags)
{
uintptr_t vaddr;
size_t align;
uintptr_t offs;
ASSERT(ALIGN_DOWN(paddr, FRAME_SIZE) == paddr);
ASSERT(ALIGN_UP(size, FRAME_SIZE) == size);
/* Enforce natural or at least PAGE_SIZE alignment. */
align = ispwr2(size) ? size : (1U << (fnzb(size) + 1));
vaddr = km_page_alloc(size, max(PAGE_SIZE, align));
page_table_lock(AS_KERNEL, true);
for (offs = 0; offs < size; offs += PAGE_SIZE) {
page_mapping_insert(AS_KERNEL, vaddr + offs, paddr + offs,
flags);
}
page_table_unlock(AS_KERNEL, true);
return vaddr;
}
void page_arch_init(void)
{
int flags = PAGE_CACHEABLE | PAGE_EXEC;
page_mapping_operations = &pt_mapping_operations;
page_table_lock(AS_KERNEL, true);
/* Kernel identity mapping */
// FIXME:
// We need to consider the possibility that
// identity_base > identity_size and physmem_end.
// This might lead to overflow if identity_size is too big.
for (uintptr_t cur = PHYSMEM_START_ADDR;
cur < min(KA2PA(config.identity_base) +
config.identity_size, config.physmem_end);
cur += FRAME_SIZE)
page_mapping_insert(AS_KERNEL, PA2KA(cur), cur, flags);
page_table_unlock(AS_KERNEL, true);
as_switch(NULL, AS_KERNEL);
/* Switch MMU to new context table */
asi_u32_write(ASI_MMUREGS, MMU_CONTEXT_TABLE, KA2PA(as_context_table) >> 4);
}
