[PATCH] arm64: efi: make sure vmlinux load address aligned on 2MBytes

From: Shanker Donthineni <redacted>

The vmlinux image load address must be aligned to 2MB, as documented
in Documentation/arm64/booting.txt. Otherwise, __create_page_tables
in head.S will create incorrect page table entries.

Signed-off-by: Shanker Donthineni <redacted>
Signed-off-by: Timur Tabi <redacted>
---
 arch/arm64/kernel/efi-stub.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
index 816120e..df1433d 100644
--- a/arch/arm64/kernel/efi-stub.c
+++ b/arch/arm64/kernel/efi-stub.c

@@ -21,7 +21,7 @@ efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
                                        unsigned long dram_base,
                                        efi_loaded_image_t *image)
 {
-       efi_status_t status;
+       efi_status_t status = EFI_LOAD_ERROR;
        unsigned long kernel_size, kernel_memsize = 0;
        unsigned long nr_pages;
        void *old_image_addr = (void *)*image_addr;

@@ -39,15 +39,18 @@ efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
                 * value or a NULL pointer). It will also ensure that, on
                 * platforms where the [dram_base, dram_base + TEXT_OFFSET)
                 * interval is partially occupied by the firmware (like on APM
-                * Mustang), we can still place the kernel at the address
-                * 'dram_base + TEXT_OFFSET'.
+                * Mustang) and dram_base is aligned on 2Mbytes, we can still
+                * place the kernel at the address 'dram_base + TEXT_OFFSET'.
                 */
-               *image_addr = *reserve_addr = dram_base + TEXT_OFFSET;
-               nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
+               if (IS_ALIGNED(dram_base, SZ_2M)) {
+                       *image_addr = *reserve_addr = dram_base + TEXT_OFFSET;
+                       nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
                           EFI_PAGE_SIZE;
-               status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
+                       status = efi_call_early(allocate_pages,
+                                       EFI_ALLOCATE_ADDRESS,
                                        EFI_LOADER_DATA, nr_pages,
                                        (efi_physical_addr_t *)reserve_addr);
+               }
                if (status != EFI_SUCCESS) {
                        kernel_memsize += TEXT_OFFSET;
                        status = efi_low_alloc(sys_table_arg, kernel_memsize,