Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755333AbcDNAI2 (ORCPT ); Wed, 13 Apr 2016 20:08:28 -0400 Received: from mail.kernel.org ([198.145.29.136]:36566 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932292AbcDNAFG (ORCPT ); Wed, 13 Apr 2016 20:05:06 -0400 From: "Luis R. Rodriguez" To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, rusty@rustcorp.com.au Cc: x86@kernel.org, linux-kernel@vger.kernel.org, luto@amacapital.net, boris.ostrovsky@oracle.com, jgross@suse.com, david.vrabel@citrix.com, konrad.wilk@oracle.com, xen-devel@lists.xensource.com, lguest@lists.ozlabs.org, andriy.shevchenko@linux.intel.com, jlee@suse.com, glin@suse.com, matt@codeblueprint.co.uk, andrew.cooper3@citrix.com, rjw@rjwysocki.net, lenb@kernel.org, robert.moore@intel.com, lv.zheng@intel.com, toshi.kani@hp.com, linux-acpi@vger.kernel.org, kozerkov@parallels.com, josh@joshtriplett.org, bigeasy@linutronix.de, ffainelli@freebox.fr, george.dunlap@citrix.com, julien.grall@linaro.org, mbizon@freebox.fr, tiwai@suse.de, "Luis R. Rodriguez" Subject: [PATCH v6 06/16] x86/init: use a platform legacy quirk for ebda Date: Wed, 13 Apr 2016 17:04:36 -0700 Message-Id: <1460592286-300-7-git-send-email-mcgrof@kernel.org> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1460592286-300-1-git-send-email-mcgrof@kernel.org> References: <1460592286-300-1-git-send-email-mcgrof@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2122 Lines: 70 This replaces the paravirt_enabled() check with a proper x86 legacy platform quirk. As per 0-day, this bumps the vmlinux size using i386-tinyconfig as follows: TOTAL TEXT init.text x86_early_init_platform_quirks() +39 +35 +35 +25 That's a 4 byte total overhead, the rest is all cleared out upon init as its all __init text. v2: document 0-day vmlinux size impact Signed-off-by: Luis R. Rodriguez --- arch/x86/include/asm/x86_init.h | 3 +++ arch/x86/kernel/head.c | 2 +- arch/x86/kernel/platform-quirks.c | 4 ++++ 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index 8bb8c1a4615a..89d9d57e145d 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -145,9 +145,12 @@ struct timespec; * struct x86_legacy_features - legacy x86 features * * @rtc: this device has a CMOS real-time clock present + * @ebda_search: it's safe to search for the EBDA signature in the hardware's + * low RAM */ struct x86_legacy_features { int rtc; + int ebda_search; }; /** diff --git a/arch/x86/kernel/head.c b/arch/x86/kernel/head.c index 992f442ca155..afe65dffee80 100644 --- a/arch/x86/kernel/head.c +++ b/arch/x86/kernel/head.c @@ -38,7 +38,7 @@ void __init reserve_ebda_region(void) * that the paravirt case can handle memory setup * correctly, without our help. */ - if (paravirt_enabled()) + if (!x86_platform.legacy.ebda_search) return; /* end of low (conventional) memory */ diff --git a/arch/x86/kernel/platform-quirks.c b/arch/x86/kernel/platform-quirks.c index 021a5f973ce3..01b159781d96 100644 --- a/arch/x86/kernel/platform-quirks.c +++ b/arch/x86/kernel/platform-quirks.c @@ -7,8 +7,12 @@ void __init x86_early_init_platform_quirks(void) { x86_platform.legacy.rtc = 1; + x86_platform.legacy.ebda_search = 0; switch (boot_params.hdr.hardware_subarch) { + case X86_SUBARCH_PC: + x86_platform.legacy.ebda_search = 1; + break; case X86_SUBARCH_XEN: case X86_SUBARCH_LGUEST: case X86_SUBARCH_INTEL_MID: -- 2.7.2