With efi_fake_memmap() and efi_arch_mem_reserve() the efi table may be
updated and replaced multiple times. When that happens a previous
dynamically allocated efi memory map can be garbage collected. Use the
new EFI_MEMMAP_{SLAB,MEMBLOCK} flags to detect when a dynamically
allocated memory map is being replaced.Debug statements in efi_memmap_free() reveal: efi: __efi_memmap_free:37: phys: 0x23ffdd580 size: 2688 flags: 0x2 efi: __efi_memmap_free:37: phys: 0x9db00 size: 2640 flags: 0x2 efi: __efi_memmap_free:37: phys: 0x9e580 size: 2640 flags: 0x2 ...a savings of 7968 bytes on a qemu boot with 2 entries specified to efi_fake_mem=. Cc: Taku Izumi <[email protected]> Cc: Ard Biesheuvel <[email protected]> Signed-off-by: Dan Williams <[email protected]> --- drivers/firmware/efi/memmap.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index 04dfa56b994b..bffa320d2f9a 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -29,6 +29,28 @@ static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size) return PFN_PHYS(page_to_pfn(p)); } +static void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags) +{ + if (flags & EFI_MEMMAP_MEMBLOCK) { + if (slab_is_available()) + memblock_free_late(phys, size); + else + memblock_free(phys, size); + } else if (flags & EFI_MEMMAP_SLAB) { + struct page *p = pfn_to_page(PHYS_PFN(phys)); + unsigned int order = get_order(size); + + free_pages((unsigned long) page_address(p), order); + } +} + +static void __init efi_memmap_free(void) +{ + __efi_memmap_free(efi.memmap.phys_map, + efi.memmap.desc_size * efi.memmap.nr_map, + efi.memmap.flags); +} + /** * efi_memmap_alloc - Allocate memory for the EFI memory map * @num_entries: Number of entries in the allocated map. @@ -100,6 +122,8 @@ static int __init __efi_memmap_init(struct efi_memory_map_data *data) return -ENOMEM; } + efi_memmap_free(); + map.phys_map = data->phys_map; map.nr_map = data->size / data->desc_size; map.map_end = map.map + data->size; _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
