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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 165AFC54FD0 for ; Fri, 24 Apr 2020 16:38:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D2B1C206D7 for ; Fri, 24 Apr 2020 16:38:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="onSUyD1K" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2B1C206D7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qvINqZv+jhVKH+HxPWQCuYvCQxMFbnu7Sa/+Zatrs5I=; b=onSUyD1K2HVxcK aiKXsJJRwGL2l0UBLfTOJkKfIiZsGft/w4dD6FXqX4+ZiB6G1mt59Sb/+XDdkbXAH31ksb3m6/7UP hsk+HFAjjG01tzV0V7KUCfVfUpmpjVBNhw661ryT8Tqz1dTcmCh9YwtdatSUwLjFAyttnkHmPBeBx gQrKWJjw/bITktzz+DbRg6R5Wp9mr1xdFsiFOlWdoDufTxcV+EWZawZKEcug7LRrYajyZ+tkPWmXT 43jj97MtX31pdbOwNl2rEjDnN+9Cg7PRFRLXbtM++4qOF208cHjkydz1HzutP+phUgSu5ylERIeNB UdW165NyxnYiyI+FR1JA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jS1Lo-0008Ad-0e; Fri, 24 Apr 2020 16:38:52 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jS1LS-0007ui-No for linux-arm-kernel@lists.infradead.org; Fri, 24 Apr 2020 16:38:32 +0000 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 308E4C14; Fri, 24 Apr 2020 09:38:30 -0700 (PDT) Received: from melchizedek.cambridge.arm.com (melchizedek.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B41333F68F; Fri, 24 Apr 2020 09:38:29 -0700 (PDT) From: James Morse To: stable@vger.kernel.org Subject: [stable:PATCH 2/4 v5.4] arm64: Fake the IminLine size on systems affected by Neoverse-N1 #1542419 Date: Fri, 24 Apr 2020 17:38:03 +0100 Message-Id: <20200424163805.4087-3-james.morse@arm.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20200424163805.4087-1-james.morse@arm.com> References: <20200424163805.4087-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200424_093830_822985_AE069080 X-CRM114-Status: GOOD ( 12.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org [ Upstream commit ee9d90be9ddace01b7fb126567e4b539fbe1f82f ] Systems affected by Neoverse-N1 #1542419 support DIC so do not need to perform icache maintenance once new instructions are cleaned to the PoU. For the errata workaround, the kernel hides DIC from user-space, so that the unnecessary cache maintenance can be trapped by firmware. To reduce the number of traps, produce a fake IminLine value based on PAGE_SIZE. Signed-off-by: James Morse Reviewed-by: Suzuki K Poulose Signed-off-by: Catalin Marinas Signed-off-by: James Morse --- arch/arm64/include/asm/cache.h | 3 ++- arch/arm64/kernel/traps.c | 8 +++++++- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h index 43da6dd29592..806e9dc2a852 100644 --- a/arch/arm64/include/asm/cache.h +++ b/arch/arm64/include/asm/cache.h @@ -11,6 +11,7 @@ #define CTR_L1IP_MASK 3 #define CTR_DMINLINE_SHIFT 16 #define CTR_IMINLINE_SHIFT 0 +#define CTR_IMINLINE_MASK 0xf #define CTR_ERG_SHIFT 20 #define CTR_CWG_SHIFT 24 #define CTR_CWG_MASK 15 @@ -18,7 +19,7 @@ #define CTR_DIC_SHIFT 29 #define CTR_CACHE_MINLINE_MASK \ - (0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT) + (0xf << CTR_DMINLINE_SHIFT | CTR_IMINLINE_MASK << CTR_IMINLINE_SHIFT) #define CTR_L1IP(ctr) (((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 465f0a0f8f0a..4e3e9d9c8151 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -470,9 +470,15 @@ static void ctr_read_handler(unsigned int esr, struct pt_regs *regs) int rt = ESR_ELx_SYS64_ISS_RT(esr); unsigned long val = arm64_ftr_reg_user_value(&arm64_ftr_reg_ctrel0); - if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) + if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) { + /* Hide DIC so that we can trap the unnecessary maintenance...*/ val &= ~BIT(CTR_DIC_SHIFT); + /* ... and fake IminLine to reduce the number of traps. */ + val &= ~CTR_IMINLINE_MASK; + val |= (PAGE_SHIFT - 2) & CTR_IMINLINE_MASK; + } + pt_regs_write_reg(regs, rt, val); arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); -- 2.19.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel