From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49A62C2D0A8 for ; Mon, 28 Sep 2020 07:23:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E81D52080A for ; Mon, 28 Sep 2020 07:23:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ONoKqcfC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbgI1HXZ (ORCPT ); Mon, 28 Sep 2020 03:23:25 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47548 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726380AbgI1HXW (ORCPT ); Mon, 28 Sep 2020 03:23:22 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601277800; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=havTeoYgtA9GOaGDzgKjIxi/dmZGW3kqKm8c6KarYTo=; b=ONoKqcfCVPWB2DzQiCrHuYXldj7uqgN/7g+ue7/BdCmWiEYtNyEeVpS0zFU6ER37FNun5b 2sL9yXWxXiiqyPPFubYBMiNmCJ0s55nhnZozjKlBdyks3EIH5UMY6ebHUWiXC/+S2MOkCN qnUAdNxlG+QiYocrhQXloz5z3S2opaQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-74-4xxCT4aVNn6bNpBVcK882g-1; Mon, 28 Sep 2020 03:23:17 -0400 X-MC-Unique: 4xxCT4aVNn6bNpBVcK882g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 580551005504; Mon, 28 Sep 2020 07:23:16 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-128.bne.redhat.com [10.64.54.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4738E7848B; Mon, 28 Sep 2020 07:23:14 +0000 (UTC) From: Gavin Shan To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, mark.rutland@arm.com, anshuman.khandual@arm.com, robin.murphy@arm.com, catalin.marinas@arm.com, will@kernel.org, shan.gavin@gmail.com Subject: [PATCH v3 1/2] arm64/mm: Introduce zero PGD table Date: Mon, 28 Sep 2020 17:22:55 +1000 Message-Id: <20200928072256.13098-2-gshan@redhat.com> In-Reply-To: <20200928072256.13098-1-gshan@redhat.com> References: <20200928072256.13098-1-gshan@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The zero PGD table is used when TTBR_EL1 is changed. It's exactly the zero page. As the zero page(s) will be allocated dynamically when colored zero page feature is enabled in subsequent patch. the zero page(s) aren't usable during early boot stage. This introduces zero PGD table, which is decoupled from the zero page(s). Signed-off-by: Gavin Shan --- arch/arm64/include/asm/mmu_context.h | 6 +++--- arch/arm64/include/asm/pgtable.h | 2 ++ arch/arm64/kernel/setup.c | 2 +- arch/arm64/kernel/vmlinux.lds.S | 4 ++++ arch/arm64/mm/proc.S | 2 +- 5 files changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index f2d7537d6f83..6dbc5726fd56 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -36,11 +36,11 @@ static inline void contextidr_thread_switch(struct task_struct *next) } /* - * Set TTBR0 to empty_zero_page. No translations will be possible via TTBR0. + * Set TTBR0 to zero_pg_dir. No translations will be possible via TTBR0. */ static inline void cpu_set_reserved_ttbr0(void) { - unsigned long ttbr = phys_to_ttbr(__pa_symbol(empty_zero_page)); + unsigned long ttbr = phys_to_ttbr(__pa_symbol(zero_pg_dir)); write_sysreg(ttbr, ttbr0_el1); isb(); @@ -189,7 +189,7 @@ static inline void update_saved_ttbr0(struct task_struct *tsk, return; if (mm == &init_mm) - ttbr = __pa_symbol(empty_zero_page); + ttbr = __pa_symbol(zero_pg_dir); else ttbr = virt_to_phys(mm->pgd) | ASID(mm) << 48; diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index d5d3fbe73953..6953498f4d40 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -474,6 +474,8 @@ static inline bool pud_table(pud_t pud) { return true; } PUD_TYPE_TABLE) #endif +extern pgd_t zero_pg_dir[PTRS_PER_PGD]; +extern pgd_t zero_pg_end[]; extern pgd_t init_pg_dir[PTRS_PER_PGD]; extern pgd_t init_pg_end[]; extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 53acbeca4f57..7e83eaed641e 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -366,7 +366,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) * faults in case uaccess_enable() is inadvertently called by the init * thread. */ - init_task.thread_info.ttbr0 = __pa_symbol(empty_zero_page); + init_task.thread_info.ttbr0 = __pa_symbol(zero_pg_dir); #endif if (boot_args[1] || boot_args[2] || boot_args[3]) { diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 7cba7623fcec..3d3c155d10a4 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -137,6 +137,10 @@ SECTIONS /* everything from this point to __init_begin will be marked RO NX */ RO_DATA(PAGE_SIZE) + zero_pg_dir = .; + . += PAGE_SIZE; + zero_pg_end = .; + idmap_pg_dir = .; . += IDMAP_DIR_SIZE; idmap_pg_end = .; diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 796e47a571e6..90b135c366b3 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -163,7 +163,7 @@ SYM_FUNC_END(cpu_do_resume) .pushsection ".idmap.text", "awx" .macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 - adrp \tmp1, empty_zero_page + adrp \tmp1, zero_pg_dir phys_to_ttbr \tmp2, \tmp1 offset_ttbr1 \tmp2, \tmp1 msr ttbr1_el1, \tmp2 -- 2.23.0