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=-11.1 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 BDA56C4363D for ; Wed, 23 Sep 2020 05:38:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E72521D43 for ; Wed, 23 Sep 2020 05:38:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TE+wmUB8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727054AbgIWFiJ (ORCPT ); Wed, 23 Sep 2020 01:38:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:49923 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726557AbgIWFiF (ORCPT ); Wed, 23 Sep 2020 01:38:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600839484; 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=TE+wmUB8+XjtT1JBia2LC/VOBHjT1PcxEjN3WvwKEl6T3bybETC9MXp46IEbdeVilNN7cy 2KbWbhuRhkJAqO/V1j2iYMRlEYhyQSzmuX1A7V2W6aNQFma03KOzgInGPBmjgt7QfmCNAp LOIL9BYS7RQypUigy2i4Jvu7V6Qmpvc= 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-596-Au2kdizPN4qDlg-Ig2h7AQ-1; Wed, 23 Sep 2020 01:38:00 -0400 X-MC-Unique: Au2kdizPN4qDlg-Ig2h7AQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3432F1868410; Wed, 23 Sep 2020 05:37:59 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-30.bne.redhat.com [10.64.54.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id 21FBE19C4F; Wed, 23 Sep 2020 05:37:56 +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, will@kernel.org, catalin.marinas@arm.com, shan.gavin@gmail.com Subject: [PATCH v2 1/2] arm64/mm: Introduce zero PGD table Date: Wed, 23 Sep 2020 15:37:20 +1000 Message-Id: <20200923053721.28873-2-gshan@redhat.com> In-Reply-To: <20200923053721.28873-1-gshan@redhat.com> References: <20200923053721.28873-1-gshan@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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