[tip:x86/platform] x86/virt, x86/acpi: Add test for ACPI_FADT_NO_VGA

[tip-bot for Juergen Gross]

Commit-ID:  6d7305254ea947d575a066711c3349fafbebaffa
Gitweb:     https://git.kernel.org/tip/6d7305254ea947d575a066711c3349fafbebaffa
Author:     Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Thu, 9 Nov 2017 14:27:37 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 10 Nov 2017 10:03:13 +0100

x86/virt, x86/acpi: Add test for ACPI_FADT_NO_VGA

Add a test for ACPI_FADT_NO_VGA when scanning the FADT and set the new
flag x86_platform.legacy.no_vga accordingly.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: len.brown@xxxxxxxxx
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: pavel@xxxxxx
Cc: rjw@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20171109132739.23465-4-jgross@xxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/include/asm/x86_init.h | 1 +
 arch/x86/kernel/acpi/boot.c     | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index ad15a0f..260e9a8 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -208,6 +208,7 @@ enum x86_legacy_i8042_state {
 struct x86_legacy_features {
 	enum x86_legacy_i8042_state i8042;
 	int rtc;
+	int no_vga;
 	int reserve_bios_regions;
 	struct x86_legacy_devices devices;
 };
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 079535e..ef9e02e 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -961,6 +961,11 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table)
 		x86_platform.legacy.rtc = 0;
 	}
 
+	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_VGA) {
+		pr_debug("ACPI: probing for VGA not safe\n");
+		x86_platform.legacy.no_vga = 1;
+	}
+
 #ifdef CONFIG_X86_PM_TIMER
 	/* detect the location of the ACPI PM Timer */
 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {