From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162122AbeBNS3G (ORCPT ); Wed, 14 Feb 2018 13:29:06 -0500 Received: from mga18.intel.com ([134.134.136.126]:3615 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161887AbeBNSZu (ORCPT ); Wed, 14 Feb 2018 13:25:50 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,513,1511856000"; d="scan'208";a="17889190" From: "Kirill A. Shutemov" 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" 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> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180214182542.69302-1-kirill.shutemov@linux.intel.com> References: <20180214182542.69302-1-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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