Break out the code to create an aligned page allocation from mem.c and move it into a function efi_allocate_pages_aligned() in alignedmem.c. Update efi_allocate_pages() to invoke it unless the minimum alignment equals the EFI page size (4 KB), in which case the ordinary page allocator is sufficient. This way, efi_allocate_pages_aligned() will only be pulled into the build if it is actually being used (which will be on arm64 only in the immediate future) Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- drivers/firmware/efi/libstub/Makefile | 3 +- drivers/firmware/efi/libstub/alignedmem.c | 57 +++++++++++++++++++++++ drivers/firmware/efi/libstub/efistub.h | 3 ++ drivers/firmware/efi/libstub/mem.c | 25 ++++------ 4 files changed, 71 insertions(+), 17 deletions(-) create mode 100644 drivers/firmware/efi/libstub/alignedmem.c diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75cb2c3a1519..bb8af2b16c49 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -42,7 +42,8 @@ KCOV_INSTRUMENT := n lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \ file.o mem.o random.o randomalloc.o pci.o \ - skip_spaces.o lib-cmdline.o lib-ctype.o + skip_spaces.o lib-cmdline.o lib-ctype.o \ + alignedmem.o # include the stub's generic dependencies from lib/ when building for ARM/arm64 efi-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c diff --git a/drivers/firmware/efi/libstub/alignedmem.c b/drivers/firmware/efi/libstub/alignedmem.c new file mode 100644 index 000000000000..cc89c4d6196f --- /dev/null +++ b/drivers/firmware/efi/libstub/alignedmem.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/efi.h> +#include <asm/efi.h> + +#include "efistub.h" + +/** + * efi_allocate_pages_aligned() - Allocate memory pages + * @size: minimum number of bytes to allocate + * @addr: On return the address of the first allocated page. The first + * allocated page has alignment EFI_ALLOC_ALIGN which is an + * architecture dependent multiple of the page size. + * @max: the address that the last allocated memory page shall not + * exceed + * @align: minimum alignment of the base of the allocation + * + * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according + * to @align, which should be >= EFI_ALLOC_ALIGN. The last allocated page will + * not exceed the address given by @max. + * + * Return: status code + */ +efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr, + unsigned long max, unsigned long align) +{ + efi_physical_addr_t alloc_addr; + efi_status_t status; + int slack; + + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; + + alloc_addr = ALIGN_DOWN(max + 1, align) - 1; + size = round_up(size, EFI_ALLOC_ALIGN); + slack = align / EFI_PAGE_SIZE - 1; + + status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, + EFI_LOADER_DATA, size / EFI_PAGE_SIZE + slack, + &alloc_addr); + if (status != EFI_SUCCESS) + return status; + + *addr = ALIGN((unsigned long)alloc_addr, align); + + if (slack > 0) { + int l = (alloc_addr % align) / EFI_PAGE_SIZE; + + if (l) { + efi_bs_call(free_pages, alloc_addr, slack - l + 1); + slack = l - 1; + } + if (slack) + efi_bs_call(free_pages, *addr + size, slack); + } + return EFI_SUCCESS; +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 9af65be3b278..baa0bc166074 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -657,6 +657,9 @@ efi_status_t efi_low_alloc(unsigned long size, unsigned long align, efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr, unsigned long max); +efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr, + unsigned long max, unsigned long align); + efi_status_t efi_relocate_kernel(unsigned long *image_addr, unsigned long image_size, unsigned long alloc_size, diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c index 869a79c8946f..0020b0fa9587 100644 --- a/drivers/firmware/efi/libstub/mem.c +++ b/drivers/firmware/efi/libstub/mem.c @@ -93,31 +93,24 @@ efi_status_t efi_get_memory_map(struct efi_boot_memmap *map) efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr, unsigned long max) { - efi_physical_addr_t alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1; - int slack = EFI_ALLOC_ALIGN / EFI_PAGE_SIZE - 1; + efi_physical_addr_t alloc_addr; efi_status_t status; - size = round_up(size, EFI_ALLOC_ALIGN); + if (EFI_ALLOC_ALIGN > EFI_PAGE_SIZE) + return efi_allocate_pages_aligned(size, addr, max, + EFI_ALLOC_ALIGN); + + alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1; status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, - EFI_LOADER_DATA, size / EFI_PAGE_SIZE + slack, + EFI_LOADER_DATA, DIV_ROUND_UP(size, EFI_PAGE_SIZE), &alloc_addr); if (status != EFI_SUCCESS) return status; - *addr = ALIGN((unsigned long)alloc_addr, EFI_ALLOC_ALIGN); - - if (slack > 0) { - int l = (alloc_addr % EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; - - if (l) { - efi_bs_call(free_pages, alloc_addr, slack - l + 1); - slack = l - 1; - } - if (slack) - efi_bs_call(free_pages, *addr + size, slack); - } + *addr = alloc_addr; return EFI_SUCCESS; } + /** * efi_low_alloc_above() - allocate pages at or above given address * @size: size of the memory area to allocate -- 2.17.1