From 649829157e9c034fd5eda0de87a39afa248bd4b2 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Fri, 4 Mar 2016 01:10:06 +0100
Subject: arm64: Allow EFI payload code to take exceptions

There are 2 ways an EFI payload could return into u-boot:

  - Callback function
  - Exception

While in EFI payload mode, x18 is owned by the payload and may not contain
a valid pointer to gd, so we need to fix it up. We do that properly for the
payload to callback path already.

This patch also adds gd pointer restoral for the exception path.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/arm/lib/interrupts_64.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/lib/interrupts_64.c b/arch/arm/lib/interrupts_64.c
index b476722556..7c9cfce69f 100644
--- a/arch/arm/lib/interrupts_64.c
+++ b/arch/arm/lib/interrupts_64.c
@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <linux/compiler.h>
+#include <efi_loader.h>
 
 
 int interrupt_init(void)
@@ -41,6 +42,7 @@ void show_regs(struct pt_regs *regs)
  */
 void do_bad_sync(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("Bad mode in \"Synchronous Abort\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -51,6 +53,7 @@ void do_bad_sync(struct pt_regs *pt_regs, unsigned int esr)
  */
 void do_bad_irq(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("Bad mode in \"Irq\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -61,6 +64,7 @@ void do_bad_irq(struct pt_regs *pt_regs, unsigned int esr)
  */
 void do_bad_fiq(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("Bad mode in \"Fiq\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -71,6 +75,7 @@ void do_bad_fiq(struct pt_regs *pt_regs, unsigned int esr)
  */
 void do_bad_error(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("Bad mode in \"Error\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -81,6 +86,7 @@ void do_bad_error(struct pt_regs *pt_regs, unsigned int esr)
  */
 void do_sync(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("\"Synchronous Abort\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -91,6 +97,7 @@ void do_sync(struct pt_regs *pt_regs, unsigned int esr)
  */
 void do_irq(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("\"Irq\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -101,6 +108,7 @@ void do_irq(struct pt_regs *pt_regs, unsigned int esr)
  */
 void do_fiq(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("\"Fiq\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
@@ -114,6 +122,7 @@ void do_fiq(struct pt_regs *pt_regs, unsigned int esr)
  */
 void __weak do_error(struct pt_regs *pt_regs, unsigned int esr)
 {
+	efi_restore_gd();
 	printf("\"Error\" handler, esr 0x%08x\n", esr);
 	show_regs(pt_regs);
 	panic("Resetting CPU ...\n");
-- 
cgit