1 files changed, 36 insertions, 112 deletions

diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index b4c2589d7c91..2c3869356147 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -1,139 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2013, 2014 Linaro Ltd;  <roy.franz@linaro.org>
  *
  * This file implements the EFI boot stub for the arm64 kernel.
  * Adapted from ARM version by Mark Salter <msalter@redhat.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
+
+
 #include <linux/efi.h>
 #include <asm/efi.h>
+#include <asm/memory.h>
 #include <asm/sections.h>
-#include <asm/sysreg.h>
 
 #include "efistub.h"
 
-efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
-{
-	u64 tg;
-
-	/* UEFI mandates support for 4 KB granularity, no need to check */
-	if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
-		return EFI_SUCCESS;
-
-	tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf;
-	if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) {
-		if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
-			pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n");
-		else
-			pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n");
-		return EFI_UNSUPPORTED;
-	}
-	return EFI_SUCCESS;
-}
-
-efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
-				 unsigned long *image_addr,
+efi_status_t handle_kernel_image(unsigned long *image_addr,
 				 unsigned long *image_size,
 				 unsigned long *reserve_addr,
 				 unsigned long *reserve_size,
-				 unsigned long dram_base,
-				 efi_loaded_image_t *image)
+				 efi_loaded_image_t *image,
+				 efi_handle_t image_handle)
 {
-	efi_status_t status;
-	unsigned long kernel_size, kernel_memsize = 0;
-	void *old_image_addr = (void *)*image_addr;
-	unsigned long preferred_offset;
-	u64 phys_seed = 0;
+	unsigned long kernel_size, kernel_codesize, kernel_memsize;
 
-	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
-		if (!nokaslr()) {
-			status = efi_get_random_bytes(sys_table_arg,
-						      sizeof(phys_seed),
-						      (u8 *)&phys_seed);
-			if (status == EFI_NOT_FOUND) {
-				pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n");
-			} else if (status != EFI_SUCCESS) {
-				pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n");
-				return status;
-			}
-		} else {
-			pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n");
-		}
+	if (image->image_base != _text) {
+		efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
+		image->image_base = _text;
 	}
 
-	/*
-	 * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond
-	 * a 2 MB aligned base, which itself may be lower than dram_base, as
-	 * long as the resulting offset equals or exceeds it.
-	 */
-	preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET;
-	if (preferred_offset < dram_base)
-		preferred_offset += MIN_KIMG_ALIGN;
+	if (!IS_ALIGNED((u64)_text, SEGMENT_ALIGN))
+		efi_err("FIRMWARE BUG: kernel image not aligned on %dk boundary\n",
+			SEGMENT_ALIGN >> 10);
 
 	kernel_size = _edata - _text;
+	kernel_codesize = __inittext_end - _text;
 	kernel_memsize = kernel_size + (_end - _edata);
+	*reserve_size = kernel_memsize;
+	*image_addr = (unsigned long)_text;
 
-	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
-		/*
-		 * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a
-		 * displacement in the interval [0, MIN_KIMG_ALIGN) that
-		 * is a multiple of the minimal segment alignment (SZ_64K)
-		 */
-		u32 mask = (MIN_KIMG_ALIGN - 1) & ~(SZ_64K - 1);
-		u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ?
-			     (phys_seed >> 32) & mask : TEXT_OFFSET;
-
-		/*
-		 * If KASLR is enabled, and we have some randomness available,
-		 * locate the kernel at a randomized offset in physical memory.
-		 */
-		*reserve_size = kernel_memsize + offset;
-		status = efi_random_alloc(sys_table_arg, *reserve_size,
-					  MIN_KIMG_ALIGN, reserve_addr,
-					  (u32)phys_seed);
-
-		*image_addr = *reserve_addr + offset;
-	} else {
-		/*
-		 * Else, try a straight allocation at the preferred offset.
-		 * This will work around the issue where, if dram_base == 0x0,
-		 * efi_low_alloc() refuses to allocate at 0x0 (to prevent the
-		 * address of the allocation to be mistaken for a FAIL return
-		 * 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'.
-		 */
-		if (*image_addr == preferred_offset)
-			return EFI_SUCCESS;
-
-		*image_addr = *reserve_addr = preferred_offset;
-		*reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN);
-
-		status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
-					EFI_LOADER_DATA,
-					*reserve_size / EFI_PAGE_SIZE,
-					(efi_physical_addr_t *)reserve_addr);
-	}
+	return efi_kaslr_relocate_kernel(image_addr, reserve_addr, reserve_size,
+					 kernel_size, kernel_codesize, kernel_memsize,
+					 efi_kaslr_get_phys_seed(image_handle));
+}
 
-	if (status != EFI_SUCCESS) {
-		*reserve_size = kernel_memsize + TEXT_OFFSET;
-		status = efi_low_alloc(sys_table_arg, *reserve_size,
-				       MIN_KIMG_ALIGN, reserve_addr);
+asmlinkage void primary_entry(void);
 
-		if (status != EFI_SUCCESS) {
-			pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
-			*reserve_size = 0;
-			return status;
-		}
-		*image_addr = *reserve_addr + TEXT_OFFSET;
-	}
-	memcpy((void *)*image_addr, old_image_addr, kernel_size);
+unsigned long primary_entry_offset(void)
+{
+	/*
+	 * When built as part of the kernel, the EFI stub cannot branch to the
+	 * kernel proper via the image header, as the PE/COFF header is
+	 * strictly not part of the in-memory presentation of the image, only
+	 * of the file representation. So instead, we need to jump to the
+	 * actual entrypoint in the .text region of the image.
+	 */
+	return (char *)primary_entry - _text;
+}
 
-	return EFI_SUCCESS;
+void efi_icache_sync(unsigned long start, unsigned long end)
+{
+	caches_clean_inval_pou(start, end);
 }