From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46371 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933154AbcHNUoL (ORCPT ); Sun, 14 Aug 2016 16:44:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Toshi Kani , Thomas Gleixner , Juergen Gross , Andrew Morton , Andy Lutomirski , Borislav Petkov , Borislav Petkov , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Konrad Rzeszutek Wilk , Linus Torvalds , "Luis R. Rodriguez" , Peter Zijlstra , Toshi Kani , elliott@hpe.com, paul.gortmaker@windriver.com, xen-devel@lists.xenproject.org, Ingo Molnar Subject: [PATCH 4.6 28/56] x86/xen, pat: Remove PAT table init code from Xen Date: Sun, 14 Aug 2016 22:37:32 +0200 Message-Id: <20160814202506.087770821@linuxfoundation.org> In-Reply-To: <20160814202504.908694181@linuxfoundation.org> References: <20160814202504.908694181@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Toshi Kani commit 88ba281108ed0c25c9d292b48bd3f272fcb90dd0 upstream. Xen supports PAT without MTRRs for its guests. In order to enable WC attribute, it was necessary for xen_start_kernel() to call pat_init_cache_modes() to update PAT table before starting guest kernel. Now that the kernel initializes PAT table to the BIOS handoff state when MTRR is disabled, this Xen-specific PAT init code is no longer necessary. Delete it from xen_start_kernel(). Also change __init_cache_modes() to a static function since PAT table should not be tweaked by other modules. Signed-off-by: Toshi Kani Reviewed-by: Thomas Gleixner Acked-by: Juergen Gross Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Konrad Rzeszutek Wilk Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Toshi Kani Cc: elliott@hpe.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-7-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/pat.h | 1 - arch/x86/mm/pat.c | 2 +- arch/x86/xen/enlighten.c | 9 --------- 3 files changed, 1 insertion(+), 11 deletions(-) --- a/arch/x86/include/asm/pat.h +++ b/arch/x86/include/asm/pat.h @@ -7,7 +7,6 @@ bool pat_enabled(void); void pat_disable(const char *reason); extern void pat_init(void); -void __init_cache_modes(u64); extern int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_pcm, enum page_cache_mode *ret_pcm); --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -192,7 +192,7 @@ static enum page_cache_mode pat_get_cach * configuration. * Using lower indices is preferred, so we start with highest index. */ -void __init_cache_modes(u64 pat) +static void __init_cache_modes(u64 pat) { enum page_cache_mode cache; char pat_msg[33]; --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -75,7 +75,6 @@ #include #include #include -#include #include #ifdef CONFIG_ACPI @@ -1511,7 +1510,6 @@ asmlinkage __visible void __init xen_sta { struct physdev_set_iopl set_iopl; unsigned long initrd_start = 0; - u64 pat; int rc; if (!xen_start_info) @@ -1618,13 +1616,6 @@ asmlinkage __visible void __init xen_sta xen_start_info->nr_pages); xen_reserve_special_pages(); - /* - * Modify the cache mode translation tables to match Xen's PAT - * configuration. - */ - rdmsrl(MSR_IA32_CR_PAT, pat); - __init_cache_modes(pat); - /* keep using Xen gdt for now; no urgent need to change it */ #ifdef CONFIG_X86_32