From patchwork Wed Jul 14 02:21:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 12375623 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 23271C07E95 for ; Wed, 14 Jul 2021 02:21:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CD3E3611C0 for ; Wed, 14 Jul 2021 02:21:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD3E3611C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2062C6B009C; Tue, 13 Jul 2021 22:21:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DD226B009D; Tue, 13 Jul 2021 22:21:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0A4B36B009E; Tue, 13 Jul 2021 22:21:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0131.hostedemail.com [216.40.44.131]) by kanga.kvack.org (Postfix) with ESMTP id D9A5C6B009C for ; Tue, 13 Jul 2021 22:21:37 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D64FF18578FEA for ; Wed, 14 Jul 2021 02:21:36 +0000 (UTC) X-FDA: 78359592192.02.45BAEB8 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf26.hostedemail.com (Postfix) with ESMTP id 7273920019E7 for ; Wed, 14 Jul 2021 02:21:36 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DAA3ED6E; Tue, 13 Jul 2021 19:21:35 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.65.222]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 76D863F7D8; Tue, 13 Jul 2021 19:21:32 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: akpm@linux-foundation.org, suzuki.poulose@arm.com, mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com, maz@kernel.org, james.morse@arm.com, steven.price@arm.com, Anshuman Khandual Subject: [RFC 08/10] arm64/mm: Add FEAT_LPA2 specific PTE_SHARED and PMD_SECT_S Date: Wed, 14 Jul 2021 07:51:29 +0530 Message-Id: <1626229291-6569-9-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1626229291-6569-1-git-send-email-anshuman.khandual@arm.com> References: <1626229291-6569-1-git-send-email-anshuman.khandual@arm.com> Authentication-Results: imf26.hostedemail.com; dkim=none; spf=pass (imf26.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com; dmarc=pass (policy=none) header.from=arm.com X-Rspamd-Server: rspam05 X-Stat-Signature: 81dkdeyh1xnmp3u3t9mri11gyhu5atd7 X-Rspamd-Queue-Id: 7273920019E7 X-HE-Tag: 1626229296-587814 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: PTE[9:8] which holds the sharability attribute bits SH[1:0] could collide with PA[51:50] when CONFIG_ARM64_PA_BITS_52 is enabled but then FEAT_LPA2 is not detected during boot. Dropping PTE_SHARED and PMD_SECT_S attributes completely in this scenario will create non-shared page table entries which would cause regression. Instead just define PTE_SHARED and PMD_SECT_S after accounting for runtime 'arm64_lpa2_enable', thus maintaining required sharability attributes for both kernel and user space page table entries. This updates ptdump handling for page table entry shared attributes accommodating FEAT_LPA2 scenarios. Signed-off-by: Anshuman Khandual --- arch/arm64/include/asm/kernel-pgtable.h | 4 ++-- arch/arm64/include/asm/pgtable-hwdef.h | 12 ++++++++++-- arch/arm64/kernel/head.S | 15 +++++++++++++++ arch/arm64/mm/ptdump.c | 26 ++++++++++++++++++++++++-- 4 files changed, 51 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 3512184..db682b5 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -103,8 +103,8 @@ /* * Initial memory map attributes. */ -#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) -#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) +#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF) +#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF) #if ARM64_KERNEL_USES_PMD_MAPS #define SWAPPER_MM_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS) diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index c815a85..8a3b75e 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -116,13 +116,21 @@ #define PMD_TYPE_SECT (_AT(pmdval_t, 1) << 0) #define PMD_TABLE_BIT (_AT(pmdval_t, 1) << 1) +#ifdef CONFIG_ARM64_PA_BITS_52_LPA2 +#define PTE_SHARED (arm64_lpa2_enabled ? 0 : PTE_SHARED_STATIC) +#define PMD_SECT_S (arm64_lpa2_enabled ? 0 : PMD_SECT_S_STATIC) +#else /* !CONFIG_ARM64_PA_BITS_52_LPA2 */ +#define PTE_SHARED PTE_SHARED_STATIC +#define PMD_SECT_S PMD_SECT_S_STATIC +#endif /* CONFIG_ARM64_PA_BITS_52_LPA2 */ + /* * Section */ #define PMD_SECT_VALID (_AT(pmdval_t, 1) << 0) #define PMD_SECT_USER (_AT(pmdval_t, 1) << 6) /* AP[1] */ #define PMD_SECT_RDONLY (_AT(pmdval_t, 1) << 7) /* AP[2] */ -#define PMD_SECT_S (_AT(pmdval_t, 3) << 8) +#define PMD_SECT_S_STATIC (_AT(pmdval_t, 3) << 8) #define PMD_SECT_AF (_AT(pmdval_t, 1) << 10) #define PMD_SECT_NG (_AT(pmdval_t, 1) << 11) #define PMD_SECT_CONT (_AT(pmdval_t, 1) << 52) @@ -146,7 +154,7 @@ #define PTE_TABLE_BIT (_AT(pteval_t, 1) << 1) #define PTE_USER (_AT(pteval_t, 1) << 6) /* AP[1] */ #define PTE_RDONLY (_AT(pteval_t, 1) << 7) /* AP[2] */ -#define PTE_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */ +#define PTE_SHARED_STATIC (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */ #define PTE_AF (_AT(pteval_t, 1) << 10) /* Access Flag */ #define PTE_NG (_AT(pteval_t, 1) << 11) /* nG */ #define PTE_GP (_AT(pteval_t, 1) << 50) /* BTI guarded */ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 9cf79ea..5732da0 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -302,6 +302,21 @@ SYM_FUNC_START_LOCAL(__create_page_tables) mov x7, SWAPPER_MM_MMUFLAGS +#ifdef CONFIG_ARM64_PA_BITS_52_LPA2 + ldr_l x2, arm64_lpa2_enabled + cmp x2, #1 + b.eq 1f +#endif /* CONFIG_ARM64_PA_BITS_52_LPA2 */ + + /* + * FEAT_LPA2 has not been detected during boot. + * Hence SWAPPER_MM_MMUFLAGS needs to have the + * regular sharability attributes in PTE[9:8]. + * Same is also applicable when FEAT_LPA2 has + * not been requested in the first place. + */ + orr x7, x7, PTE_SHARED_STATIC +1: /* * Create the identity mapping. */ diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c index 1c40353..be171cf 100644 --- a/arch/arm64/mm/ptdump.c +++ b/arch/arm64/mm/ptdump.c @@ -115,8 +115,8 @@ static const struct prot_bits pte_bits[] = { .set = "NX", .clear = "x ", }, { - .mask = PTE_SHARED, - .val = PTE_SHARED, + .mask = PTE_SHARED_STATIC, + .val = PTE_SHARED_STATIC, .set = "SHD", .clear = " ", }, { @@ -211,6 +211,28 @@ static void dump_prot(struct pg_state *st, const struct prot_bits *bits, for (i = 0; i < num; i++, bits++) { const char *s; + if (IS_ENABLED(CONFIG_ARM64_PA_BITS_52_LPA2) && + (bits->mask == PTE_SHARED_STATIC)) { + /* + * If FEAT_LPA2 has been detected and enabled + * sharing attributes for page table entries + * are inherited from TCR_EL1.SH1 as init_mm + * based mappings are enabled from TTBR1_EL1. + */ + if (arm64_lpa2_enabled) { + if ((read_sysreg(tcr_el1) & TCR_SH1_INNER) == TCR_SH1_INNER) + pt_dump_seq_printf(st->seq, " SHD "); + else + pt_dump_seq_printf(st->seq, " "); + continue; + } + /* + * In case FEAT_LPA2 has not been detected and + * enabled sharing attributes should be found + * in the regular PTE positions. It just falls + * through regular PTE attribute handling. + */ + } if ((st->current_prot & bits->mask) == bits->val) s = bits->set; else