void cbmem_initialize_empty(void)
{
uintptr_t pointer_addr;
uintptr_t root_addr;
unsigned long max_entries;
struct cbmem_root *root;
struct cbmem_root_pointer *pointer;
/* Place the root pointer and the root. The number of entries is
* dictated by difference between the root address and the pointer
* where the root address is aligned down to
* DYN_CBMEM_ALIGN_SIZE. The pointer falls just below the
* address returned by get_top_aligned(). */
pointer_addr = get_top_aligned();
if (pointer_addr == 0)
return;
root_addr = pointer_addr - ROOT_MIN_SIZE;
root_addr &= ~(DYN_CBMEM_ALIGN_SIZE - 1);
pointer_addr -= sizeof(struct cbmem_root_pointer);
max_entries = (pointer_addr - (root_addr + sizeof(*root))) /
sizeof(struct cbmem_entry);
pointer = (void *)pointer_addr;
pointer->magic = CBMEM_POINTER_MAGIC;
pointer->root = root_addr;
root = (void *)root_addr;
root->max_entries = max_entries;
root->num_entries = 0;
root->locked = 0;
root->size = pointer_addr - root_addr +
sizeof(struct cbmem_root_pointer);
/* Add an entry covering the root region. */
cbmem_entry_append(root, CBMEM_ID_ROOT, root_addr, root->size);
printk(BIOS_DEBUG, "CBMEM: root @ %p %d entries.\n",
root, root->max_entries);
/* Complete migration to CBMEM. */
cbmem_run_init_hooks();
}
const struct cbmem_entry *cbmem_entry_add(u32 id, u64 size64)
{
struct cbmem_root *root;
const struct cbmem_entry *entry;
unsigned long base;
u32 size;
u32 aligned_size;
entry = cbmem_entry_find(id);
if (entry != NULL)
return entry;
/* Only handle sizes <= UINT_MAX internally. */
if (size64 > (u64)UINT_MAX)
return NULL;
size = size64;
root = get_root();
if (root == NULL)
return NULL;
/* Nothing can be added once it is locked down. */
if (root->locked)
return NULL;
if (root->max_entries == root->num_entries)
return NULL;
aligned_size = ALIGN(size, DYN_CBMEM_ALIGN_SIZE);
base = (unsigned long)cbmem_base();
base -= aligned_size;
return cbmem_entry_append(root, id, base, aligned_size);
}
