linux-kernel - [tip:x86/boot] x86/boot: Clarify what x86_legacy_features.reserve_bios

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Message-ID: <tip-30f027398b329c75c8f23a3c13be240b50866fdc@git.kernel.org>
Date:	Fri, 22 Jul 2016 03:25:36 -0700
From:	tip-bot for Andy Lutomirski <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	tglx@...utronix.de, toshi.kani@...com, jpoimboe@...hat.com,
	keescook@...omium.org, mingo@...nel.org, peterz@...radead.org,
	brgerst@...il.com, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, luto@...nel.org, bp@...en8.de,
	mario_limonciello@...l.com, dvlasenk@...hat.com, mcgrof@...e.com,
	linux-kernel@...r.kernel.org, hpa@...or.com, mjg59@...f.ucam.org
Subject: [tip:x86/boot] x86/boot: Clarify what
 x86_legacy_features.reserve_bios_regions does

Commit-ID:  30f027398b329c75c8f23a3c13be240b50866fdc
Gitweb:     http://git.kernel.org/tip/30f027398b329c75c8f23a3c13be240b50866fdc
Author:     Andy Lutomirski <luto@...nel.org>
AuthorDate: Thu, 21 Jul 2016 14:16:51 -0700
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Fri, 22 Jul 2016 11:46:01 +0200

x86/boot: Clarify what x86_legacy_features.reserve_bios_regions does

It doesn't just control probing for the EBDA -- it controls whether we
detect and reserve the <1MB BIOS regions in general.

Signed-off-by: Andy Lutomirski <luto@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Kees Cook <keescook@...omium.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@...e.com>
Cc: Mario Limonciello <mario_limonciello@...l.com>
Cc: Matthew Garrett <mjg59@...f.ucam.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Toshi Kani <toshi.kani@...com>
Link: http://lkml.kernel.org/r/55bd591115498440d461857a7b64f349a5d911f3.1469135598.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/include/asm/x86_init.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index c519c05..66c15a0 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -168,8 +168,9 @@ struct x86_legacy_devices {
  * struct x86_legacy_features - legacy x86 features
  *
  * @rtc: this device has a CMOS real-time clock present
- * @reserve_bios_regions: it's safe to search for the EBDA signature in the hardware's
- * 	low RAM
+ * @reserve_bios_regions: boot code will search for the EBDA address and the
+ * 	start of the 640k - 1M BIOS region.  If false, the platform must
+ * 	ensure that its memory map correctly reserves sub-1MB regions as needed.
  * @devices: legacy x86 devices, refer to struct x86_legacy_devices
  * 	documentation for further details.
  */