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,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 56F31C7618F for ; Tue, 16 Jul 2019 16:58:28 +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 2AF56205ED for ; Tue, 16 Jul 2019 16:58:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LNu/p+tL"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=soleen.com header.i=@soleen.com header.b="GGIQw/kg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AF56205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=soleen.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: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:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Q3+e80Y/FyztU0yuOHA2jYYdDFbcf8M2P5OqwkZ4yig=; b=LNu/p+tL0jcqol trWKGKJXJPy8AEHr7PxJ0fbcDDG9ZTtcZW66ecrtKq7MK6UQofDHfvPAHMi86KC2osvtFUjDXvuHb enxeoPGpqmlDhCH4UKRBGEl4+HVPOArw4T2CsGaNyLkierPYe1UGPBqNOfXUJL8Qq+eMCnqqxLIrd 9J9SdvpjZ4b4XEfzrAwvLm4kdAKjnhu77lPJzQWHX48dIbUCsyQNN8IWKaj3IZutBOMp5Ci71z1uN JHEqcDJW/6KR5d/onbrHwoBhKhmSzUE/WOBdD/DRSG7Tq8HGgrOHa3YGjTWY1HHbe+NV8SJD8Aw7O FfXOfma3nlhGseG08+2A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hnQmZ-0006Jx-BO; Tue, 16 Jul 2019 16:58:27 +0000 Received: from mail-qt1-x844.google.com ([2607:f8b0:4864:20::844]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hnQkz-00055H-J1 for linux-arm-kernel@lists.infradead.org; Tue, 16 Jul 2019 16:56:51 +0000 Received: by mail-qt1-x844.google.com with SMTP id 44so20246024qtg.11 for ; Tue, 16 Jul 2019 09:56:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=OHreDCpotkEUucxoE5EiEKrcc9yzecv+duVH9vOORKc=; b=GGIQw/kgAUl/eG3d2NKYO7rrigP3xCd6L3ITkDfbZyMEUnoEj0yVHLsV2LlbgRYbC+ wxGDoUKvbsOD49xDxxVjVMA/cVW24Ta7j9hj3+wxoFsCV7bE/6zX1BcHliTfmRJa2HL6 t1GMulrmuUdkYdtWJR3tWcDBbewttH11SYty1lYTYPi9/xqOKf63ADEYQ5vRWxW8OT6H VHjxbQVnM+5FFok1c8bap5vm+E40C8t2yYrwiy22m4L+k24TpV5SxJbfpoBHfRpCqzb2 H6dm0a1hIjm8g/mZThetxdugoRf8Pcyv6ZduRuCZRIwQmu9srFbLpacSM3DPtY1OABO9 4vlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=OHreDCpotkEUucxoE5EiEKrcc9yzecv+duVH9vOORKc=; b=dhhBgqPBYCTciL99jeda9JHgecemgsvsYyCuOs0KLrYs/s95CJziNZI0GshMc7DK6H Ck1yibY6OK/ZacIHAIKjZrEOXjPd4H5jNW7wntCvTSdLYSZAwFvvd7Xpc7Q4DvzJeNUV 2Pu/sK+vwBxl1RpXFeLmJS5L7zWIeCJDraRJRINT7RTdoOjhY5IhoC2k6KI+kkYs5kOX VVXWpX3ecJQ8aJrVz5EOZM8aej0Xle9x5xwkyPoNLtnYz45NSzAJocyfESO/hmko1Ul5 LsGbApUXXxaDC0O62LaU2PMGRIw4CiLQQaPcy+pdZgpZQ+zaPBmcr71slYbpRwjlTWDd Z8iw== X-Gm-Message-State: APjAAAUuYFffq6/aU2vw3msegcyT7djpCwFYGou9vjud4dsNQH91zS2W gphnRtmzi16CDpTZjNEUQbA= X-Google-Smtp-Source: APXvYqwxJ0A/FHhU5OVW66jrPFnnHKm79duNOHFiKTe25GUCXmo7/DTY10UCE+L1XIgV2bRdwMnQ6w== X-Received: by 2002:ac8:41d1:: with SMTP id o17mr23857397qtm.17.1563296207876; Tue, 16 Jul 2019 09:56:47 -0700 (PDT) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id f20sm8519538qkh.15.2019.07.16.09.56.46 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 16 Jul 2019 09:56:47 -0700 (PDT) From: Pavel Tatashin To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC v1 4/4] arm64: Keep MMU on while kernel is being relocated Date: Tue, 16 Jul 2019 12:56:41 -0400 Message-Id: <20190716165641.6990-5-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190716165641.6990-1-pasha.tatashin@soleen.com> References: <20190716165641.6990-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190716_095649_697406_C379A0FC X-CRM114-Status: UNSURE ( 9.57 ) X-CRM114-Notice: Please train this message. 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: , 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 It is inefficient to do kernel relocation with MMU disabled. This is because if MMU is disabled, dcache must also be disabled. Now, that we have identity page table we can disable MMU after relocation is completed. Signed-off-by: Pavel Tatashin --- arch/arm64/kernel/cpu-reset.S | 8 ------- arch/arm64/kernel/relocate_kernel.S | 36 ++++++++++++++++++----------- 2 files changed, 22 insertions(+), 22 deletions(-) diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S index 6ea337d464c4..d5cfc17b8e1f 100644 --- a/arch/arm64/kernel/cpu-reset.S +++ b/arch/arm64/kernel/cpu-reset.S @@ -30,14 +30,6 @@ * flat identity mapping. */ ENTRY(__cpu_soft_restart) - /* Clear sctlr_el1 flags. */ - mrs x12, sctlr_el1 - ldr x13, =SCTLR_ELx_FLAGS - bic x12, x12, x13 - pre_disable_mmu_workaround - msr sctlr_el1, x12 - isb - cbz x0, 1f // el2_switch? mov x0, #HVC_SOFT_RESTART hvc #0 // no return diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S index c1d7db71a726..e2724fedd082 100644 --- a/arch/arm64/kernel/relocate_kernel.S +++ b/arch/arm64/kernel/relocate_kernel.S @@ -36,18 +36,6 @@ ENTRY(arm64_relocate_new_kernel) mov x14, xzr /* x14 = entry ptr */ mov x13, xzr /* x13 = copy dest */ - /* Clear the sctlr_el2 flags. */ - mrs x0, CurrentEL - cmp x0, #CurrentEL_EL2 - b.ne 1f - mrs x0, sctlr_el2 - ldr x1, =SCTLR_ELx_FLAGS - bic x0, x0, x1 - pre_disable_mmu_workaround - msr sctlr_el2, x0 - isb -1: - /* Check if the new image needs relocation. */ tbnz x16, IND_DONE_BIT, .Ldone @@ -63,10 +51,10 @@ ENTRY(arm64_relocate_new_kernel) add x20, x0, #PAGE_SIZE sub x1, x15, #1 bic x0, x0, x1 -2: dc ivac, x0 +1: dc ivac, x0 add x0, x0, x15 cmp x0, x20 - b.lo 2b + b.lo 1b dsb sy mov x20, x13 @@ -104,6 +92,26 @@ ENTRY(arm64_relocate_new_kernel) dsb nsh isb + /* Clear sctlr_el1 flags. */ + mrs x12, sctlr_el1 + ldr x13, =SCTLR_ELx_FLAGS + bic x12, x12, x13 + pre_disable_mmu_workaround + msr sctlr_el1, x12 + isb + + /* Clear the sctlr_el2 flags. */ + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL2 + b.ne 2f + mrs x0, sctlr_el2 + ldr x1, =SCTLR_ELx_FLAGS + bic x0, x0, x1 + pre_disable_mmu_workaround + msr sctlr_el2, x0 + isb +2: + /* Start new image. */ mov x0, x18 mov x1, xzr -- 2.22.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel