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

From: [email-masked] (Timur Tabi)
Date: Tue, 27 Oct 2015 16:24:01 -0500

From: Shanker Donthineni <[email-masked]>

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 <[email-masked]>
Signed-off-by: Timur Tabi <[email-masked]>
---
 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,
-- 
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