From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id D64836B0005 for ; Wed, 14 Feb 2018 13:25:50 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id h10so2188308pgf.3 for ; Wed, 14 Feb 2018 10:25:50 -0800 (PST) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTPS id y26si327504pfm.63.2018.02.14.10.25.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 14 Feb 2018 10:25:49 -0800 (PST) From: "Kirill A. Shutemov" Subject: [PATCH 2/9] x86/mm: Initialize pgdir_shift and ptrs_per_p4d at boot-time Date: Wed, 14 Feb 2018 21:25:35 +0300 Message-Id: <20180214182542.69302-3-kirill.shutemov@linux.intel.com> In-Reply-To: <20180214182542.69302-1-kirill.shutemov@linux.intel.com> References: <20180214182542.69302-1-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" Cc: Linus Torvalds , Andy Lutomirski , Borislav Petkov , Andi Kleen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Switching between paging modes requires folding p4d page table level. It means we need to adjust pgdir_shift and ptrs_per_p4d during early boot according to paging mode. Signed-off-by: Kirill A. Shutemov --- arch/x86/boot/compressed/kaslr.c | 6 ++++-- arch/x86/kernel/head64.c | 6 ++++-- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index d02a838c0ce4..66e42a098d70 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -48,8 +48,8 @@ #ifdef CONFIG_X86_5LEVEL unsigned int pgtable_l5_enabled __ro_after_init; -unsigned int pgdir_shift __ro_after_init = 48; -unsigned int ptrs_per_p4d __ro_after_init = 512; +unsigned int pgdir_shift __ro_after_init = 39; +unsigned int ptrs_per_p4d __ro_after_init = 1; #endif extern unsigned long get_cmd_line_ptr(void); @@ -732,6 +732,8 @@ void choose_random_location(unsigned long input, #ifdef CONFIG_X86_5LEVEL if (__read_cr4() & X86_CR4_LA57) { pgtable_l5_enabled = 1; + pgdir_shift = 48; + ptrs_per_p4d = 512; } #endif diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index ffb31c50d515..8a0a485524da 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -42,9 +42,9 @@ pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); #ifdef CONFIG_X86_5LEVEL unsigned int pgtable_l5_enabled __ro_after_init; EXPORT_SYMBOL(pgtable_l5_enabled); -unsigned int pgdir_shift __ro_after_init = 48; +unsigned int pgdir_shift __ro_after_init = 39; EXPORT_SYMBOL(pgdir_shift); -unsigned int ptrs_per_p4d __ro_after_init = 512; +unsigned int ptrs_per_p4d __ro_after_init = 1; EXPORT_SYMBOL(ptrs_per_p4d); #endif @@ -79,6 +79,8 @@ static void __head check_la57_support(unsigned long physaddr) return; *fixup_int(&pgtable_l5_enabled, physaddr) = 1; + *fixup_int(&pgdir_shift, physaddr) = 48; + *fixup_int(&ptrs_per_p4d, physaddr) = 512; } #else static void __head check_la57_support(unsigned long physaddr) {} -- 2.15.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org