/*
* The UEFI specification makes it clear that the operating system is free to do
* whatever it wants with boot services code after ExitBootServices() has been
* called. Ignoring this recommendation a significant bunch of EFI implementations
* continue calling into boot services code (SetVirtualAddressMap). In order to
* work around such buggy implementations we reserve boot services region during
* EFI init and make sure it stays executable. Then, after SetVirtualAddressMap(), it
* is discarded.
*/
void __init efi_reserve_boot_services(void)
{
void *p;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
efi_memory_desc_t *md = p;
u64 start = md->phys_addr;
u64 size = md->num_pages << EFI_PAGE_SHIFT;
if (md->type != EFI_BOOT_SERVICES_CODE &&
md->type != EFI_BOOT_SERVICES_DATA)
continue;
/* Only reserve where possible:
* - Not within any already allocated areas
* - Not over any memory area (really needed, if above?)
* - Not within any part of the kernel
* - Not the bios reserved area
*/
if ((start + size > __pa_symbol(_text)
&& start <= __pa_symbol(_end)) ||
!e820_all_mapped(start, start+size, E820_RAM) ||
memblock_is_region_reserved(start, size)) {
/* Could not reserve, skip it */
md->num_pages = 0;
memblock_dbg("Could not reserve boot range [0x%010llx-0x%010llx]\n",
start, start+size-1);
} else
memblock_reserve(start, size);
}
}
int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
{
memblock_dbg(" memblock_free: [%#016llx-%#016llx] %pF\n",
(unsigned long long)base,
(unsigned long long)base + size,
(void *)_RET_IP_);
return __memblock_remove(&memblock.reserved, base, size);
}
int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
{
struct memblock_type *_rgn = &memblock.reserved;
memblock_dbg("memblock_reserve: [%#016llx-%#016llx] %pF\n",
(unsigned long long)base,
(unsigned long long)base + size,
(void *)_RET_IP_);
BUG_ON(0 == size);
return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
}
static int __init_memblock memblock_double_array(struct memblock_type *type)
{
struct memblock_region *new_array, *old_array;
phys_addr_t old_size, new_size, addr;
int use_slab = slab_is_available();
/* We don't allow resizing until we know about the reserved regions
* of memory that aren't suitable for allocation
*/
if (!memblock_can_resize)
return -1;
/* Calculate new doubled size */
old_size = type->max * sizeof(struct memblock_region);
new_size = old_size << 1;
/* Try to find some space for it.
*
* WARNING: We assume that either slab_is_available() and we use it or
* we use MEMBLOCK for allocations. That means that this is unsafe to use
* when bootmem is currently active (unless bootmem itself is implemented
* on top of MEMBLOCK which isn't the case yet)
*
* This should however not be an issue for now, as we currently only
* call into MEMBLOCK while it's still active, or much later when slab is
* active for memory hotplug operations
*/
if (use_slab) {
new_array = kmalloc(new_size, GFP_KERNEL);
addr = new_array == NULL ? MEMBLOCK_ERROR : __pa(new_array);
} else
addr = memblock_find_base(new_size, sizeof(phys_addr_t), 0, MEMBLOCK_ALLOC_ACCESSIBLE);
if (addr == MEMBLOCK_ERROR) {
pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
memblock_type_name(type), type->max, type->max * 2);
return -1;
}
new_array = __va(addr);
memblock_dbg("memblock: %s array is doubled to %ld at [%#010llx-%#010llx]",
memblock_type_name(type), type->max * 2, (u64)addr, (u64)addr + new_size - 1);
/* Found space, we now need to move the array over before
* we add the reserved region since it may be our reserved
* array itself that is full.
*/
memcpy(new_array, type->regions, old_size);
memset(new_array + type->max, 0, old_size);
old_array = type->regions;
type->regions = new_array;
type->max <<= 1;
/* If we use SLAB that's it, we are done */
if (use_slab)
return 0;
/* Add the new reserved region now. Should not fail ! */
BUG_ON(memblock_add_region(&memblock.reserved, addr, new_size));
/* If the array wasn't our static init one, then free it. We only do
* that before SLAB is available as later on, we don't know whether
* to use kfree or free_bootmem_pages(). Shouldn't be a big deal
* anyways
*/
if (old_array != memblock_memory_init_regions &&
old_array != memblock_reserved_init_regions)
memblock_free(__pa(old_array), old_size);
return 0;
}
