efi: stub: get rid of efi_get_max_fdt_addr()

Now that ARM started following the example of arm64 and RISC-V, and
no longer imposes any restrictions on the placement of the FDT in
memory at boot, we no longer need per-arch implementations of
efi_get_max_fdt_addr() to factor out the differences. So get rid of
it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20201029134901.9773-1-ardb@kernel.org

arch/arm/include/asm/efi.h

@@ -73,12 +73,6 @@ static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
  */
 #define EFI_PHYS_ALIGN		max(SZ_2M, roundup_pow_of_two(TEXT_OFFSET))
 
-/* on ARM, the FDT should be located in a lowmem region */
-static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr)
-{
-	return round_down(image_addr, EFI_PHYS_ALIGN) + SZ_512M;
-}
-
 /* on ARM, the initrd should be loaded in a lowmem region */
 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
 {

arch/arm64/include/asm/efi.h

@@ -64,12 +64,6 @@ efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
 #define EFI_KIMG_ALIGN	\
 	(SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
 
-/* on arm64, the FDT may be located anywhere in system RAM */
-static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr)
-{
-	return ULONG_MAX;
-}
-
 /*
  * On arm64, we have to ensure that the initrd ends up in the linear region,
  * which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is

arch/riscv/include/asm/efi.h

@@ -27,12 +27,6 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
 
 #define ARCH_EFI_IRQ_FLAGS_MASK (SR_IE | SR_SPIE)
 
-/* on RISC-V, the FDT may be located anywhere in system RAM */
-static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr)
-{
-	return ULONG_MAX;
-}
-
 /* Load initrd at enough distance from DRAM start */
 static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
 {

drivers/firmware/efi/libstub/efi-stub.c

@@ -273,7 +273,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	install_memreserve_table();
 
 	status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
-						efi_get_max_fdt_addr(image_addr),
 						initrd_addr, initrd_size,
 						cmdline_ptr, fdt_addr, fdt_size);
 	if (status != EFI_SUCCESS)

drivers/firmware/efi/libstub/efistub.h

@@ -750,7 +750,6 @@ efi_status_t efi_exit_boot_services(void *handle,
 
 efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 					    unsigned long *new_fdt_addr,
-					    unsigned long max_addr,
 					    u64 initrd_addr, u64 initrd_size,
 					    char *cmdline_ptr,
 					    unsigned long fdt_addr,

drivers/firmware/efi/libstub/fdt.c

@@ -238,7 +238,6 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
 
 efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 					    unsigned long *new_fdt_addr,
-					    unsigned long max_addr,
 					    u64 initrd_addr, u64 initrd_size,
 					    char *cmdline_ptr,
 					    unsigned long fdt_addr,
@@ -275,7 +274,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 	efi_info("Exiting boot services and installing virtual address map...\n");
 
 	map.map = &memory_map;
-	status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, max_addr);
+	status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
 	if (status != EFI_SUCCESS) {
 		efi_err("Unable to allocate memory for new device tree.\n");
 		goto fail;