1 files changed, 10 insertions, 86 deletions

diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c
index b450ebf95977..145c9f0ba217 100644
--- a/drivers/firmware/efi/libstub/riscv-stub.c
+++ b/drivers/firmware/efi/libstub/riscv-stub.c
@@ -4,7 +4,6 @@
  */
 
 #include <linux/efi.h>
-#include <linux/libfdt.h>
 
 #include <asm/efi.h>
 #include <asm/sections.h>
@@ -12,92 +11,16 @@
 
 #include "efistub.h"
 
-/*
- * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and
- * 4MB for 32 bit.
- */
-#ifdef CONFIG_64BIT
-#define MIN_KIMG_ALIGN		SZ_2M
-#else
-#define MIN_KIMG_ALIGN		SZ_4M
-#endif
-
-typedef void __noreturn (*jump_kernel_func)(unsigned long, unsigned long);
-
-static unsigned long hartid;
-
-static int get_boot_hartid_from_fdt(void)
-{
-	const void *fdt;
-	int chosen_node, len;
-	const void *prop;
-
-	fdt = get_efi_config_table(DEVICE_TREE_GUID);
-	if (!fdt)
-		return -EINVAL;
-
-	chosen_node = fdt_path_offset(fdt, "/chosen");
-	if (chosen_node < 0)
-		return -EINVAL;
-
-	prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len);
-	if (!prop)
-		return -EINVAL;
-
-	if (len == sizeof(u32))
-		hartid = (unsigned long) fdt32_to_cpu(*(fdt32_t *)prop);
-	else if (len == sizeof(u64))
-		hartid = (unsigned long) fdt64_to_cpu(__get_unaligned_t(fdt64_t, prop));
-	else
-		return -EINVAL;
-
-	return 0;
-}
-
-static efi_status_t get_boot_hartid_from_efi(void)
+unsigned long stext_offset(void)
 {
-	efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
-	struct riscv_efi_boot_protocol *boot_protocol;
-	efi_status_t status;
-
-	status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
-			     (void **)&boot_protocol);
-	if (status != EFI_SUCCESS)
-		return status;
-	return efi_call_proto(boot_protocol, get_boot_hartid, &hartid);
-}
-
-efi_status_t check_platform_features(void)
-{
-	efi_status_t status;
-	int ret;
-
-	status = get_boot_hartid_from_efi();
-	if (status != EFI_SUCCESS) {
-		ret = get_boot_hartid_from_fdt();
-		if (ret) {
-			efi_err("Failed to get boot hartid!\n");
-			return EFI_UNSUPPORTED;
-		}
-	}
-	return EFI_SUCCESS;
-}
-
-void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt,
-				 unsigned long fdt_size)
-{
-	unsigned long stext_offset = _start_kernel - _start;
-	unsigned long kernel_entry = entrypoint + stext_offset;
-	jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry;
-
 	/*
-	 * Jump to real kernel here with following constraints.
-	 * 1. MMU should be disabled.
-	 * 2. a0 should contain hartid
-	 * 3. a1 should DT address
+	 * 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.
 	 */
-	csr_write(CSR_SATP, 0);
-	jump_kernel(hartid, fdt);
+	return _start_kernel - _start;
 }
 
 efi_status_t handle_kernel_image(unsigned long *image_addr,
@@ -125,9 +48,10 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
 	 * lowest possible memory region as long as the address and size meets
 	 * the alignment constraints.
 	 */
-	preferred_addr = MIN_KIMG_ALIGN;
+	preferred_addr = EFI_KIMG_PREFERRED_ADDRESS;
 	status = efi_relocate_kernel(image_addr, kernel_size, *image_size,
-				     preferred_addr, MIN_KIMG_ALIGN, 0x0);
+				     preferred_addr, efi_get_kimg_min_align(),
+				     0x0);
 
 	if (status != EFI_SUCCESS) {
 		efi_err("Failed to relocate kernel\n");