From 6a03e25a705c8d59bb9a849b9eee13f04b0a7b1d Mon Sep 17 00:00:00 2001
From: Matt Fleming <matt@codeblueprint.co.uk>
Date: Mon, 25 Apr 2016 21:07:00 +0100
Subject: [PATCH 12/27] x86/efi: Force EFI reboot to process pending capsules

Commit 87615a34d561ef59bd0cffc73256a21220dfdffd upstream.

If an EFI capsule has been sent to the firmware we must match the type
of EFI reset against that required by the capsule to ensure it is
processed correctly.

Force an EFI reboot if a capsule is pending for the next reset.

Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kweh Hock Leong <hock.leong.kweh@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: joeyli <jlee@suse.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-29-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kernel/reboot.c | 9 +++++++++
 include/linux/efi.h      | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index f660d63f40fe..01d9e1edda07 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -535,6 +535,15 @@ static void native_machine_emergency_restart(void)
 	mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 	*((unsigned short *)__va(0x472)) = mode;
 
+	/*
+	 * If an EFI capsule has been registered with the firmware then
+	 * override the reboot= parameter.
+	 */
+	if (efi_capsule_pending(NULL)) {
+		pr_info("EFI capsule is pending, forcing EFI reboot.\n");
+		reboot_type = BOOT_EFI;
+	}
+
 	for (;;) {
 		/* Could also try the reset bit in the Hammer NB */
 		switch (reboot_type) {
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 848678a1cace..a1a41d027b93 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1004,6 +1004,12 @@ static inline bool efi_enabled(int feature)
 }
 static inline void
 efi_reboot(enum reboot_mode reboot_mode, const char *__unused) {}
+
+static inline bool
+efi_capsule_pending(int *reset_type)
+{
+	return false;
+}
 #endif
 
 extern int efi_status_to_err(efi_status_t status);
-- 
2.12.0

