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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=no 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 95E50C49ED7 for ; Tue, 10 Sep 2019 16:09:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BBA121479 for ; Tue, 10 Sep 2019 16:09:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="YJDh2YLe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394142AbfIJQJF (ORCPT ); Tue, 10 Sep 2019 12:09:05 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:43749 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394140AbfIJQJF (ORCPT ); Tue, 10 Sep 2019 12:09:05 -0400 Received: by mail-pg1-f196.google.com with SMTP id u72so9969321pgb.10 for ; Tue, 10 Sep 2019 09:09:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=TUvxJ7wlmXdEjdS8Ji+2ki9BT3REdqo3NpskuD2RAZE=; b=YJDh2YLeoTKo99EIHf/GbAcGlRVVjeHebFXD80CmOEXk6TDGBbj/Uh5lPLn3Z2Y21x gTixE7rHSZVLLXSJ6GbQCyzq9QYepRhuOnus3wPSwsY1vxwywof4CRlDE9o5bB6kFdRh L0aDQx9uJi6dcUYgOueyyIdi7vxhQ8v6gGLkc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=TUvxJ7wlmXdEjdS8Ji+2ki9BT3REdqo3NpskuD2RAZE=; b=NUMuzVDrXB8S0s3LofDVCFFox5pYJv21trrR5rlqDvH/1q7aXjlT7VAecB2v6TuDij s0b6/+OEP3KIZl1A2Ji9hUh+DrKyLDP0DPa8D7zYRGLTVHkPp6zFabzaeHxBJXqeqx7x KtWUEc8/l7BPlcRVZiTuQiFCjakTewED4nrRA1CeewZfewN496vdhdc3xqlr9dEastMk pMEoeBb0oRq/lDx9QL4fwTC1E0HiwmJc1u/5HSU33ahlX+4pVSTxzF/kYaYYRmg96ES8 7R99MacUU00qgMbXk4ATR8zN+32ItIpVId/J7VM0Er1oaqDDd7JLmEfOSLBmCT2LgADV wLqg== X-Gm-Message-State: APjAAAW6Wbk9HuBZiaFYCgWWZf4DBJ5RVU9Y2Cm427SK+FbHHlIBPEwg bZO55CCb2jw6ozVoM7A2QcgUng== X-Google-Smtp-Source: APXvYqwv8qruQZ4KH/LAzFeFB5Fw6fLmcphoP8mGiPT4myBOZsUnw+zQpjwu6W6Ar30JnBYs9mBOxQ== X-Received: by 2002:a62:64c9:: with SMTP id y192mr37931196pfb.6.1568131744630; Tue, 10 Sep 2019 09:09:04 -0700 (PDT) Received: from smtp.gmail.com ([2620:15c:202:1:fa53:7765:582b:82b9]) by smtp.gmail.com with ESMTPSA id em21sm106088pjb.31.2019.09.10.09.09.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Sep 2019 09:09:04 -0700 (PDT) From: Stephen Boyd To: Dan Williams Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Evan Green , Rob Herring , Bjorn Andersson , Andy Gross , Will Deacon , Catalin Marinas Subject: [PATCH v3 0/5] Read-only memremap() Date: Tue, 10 Sep 2019 09:08:58 -0700 Message-Id: <20190910160903.65694-1-swboyd@chromium.org> X-Mailer: git-send-email 2.23.0.162.g0b9fbb3734-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org This patch series implements a read-only version of memremap() via a new MEMREMAP_RO flag. If this is passed in the mapping call, we'll try to map the memory region as read-only if it doesn't intersect with an existing mapping. Otherwise, we'll try to fallback to other flags to try to map the memory that way. The main use case I have is to map the command-db memory region on Qualcomm devices with a read-only mapping. It's already a const marked pointer and the API returns const pointers as well, so this series makes sure that even stray writes can't modify the memory. To get there we introduce a devm version of memremap() for a reserved memory region, add a memremap() flag, and implement support for that flag on arm64. Changes from v2 (https://lkml.kernel.org/r/20190614203717.75479-1-swboyd@chromium.org): * Added a comment to kerneldoc for the new MEMREMAP_RO flag * Rebased to v5.3-rc1 Changes from v1: * Picked up tags and rebased to v5.2-rc3 Stephen Boyd (5): reserved_mem: Add a devm_memremap_reserved_mem() API soc: qcom: cmd-db: Migrate to devm_memremap_reserved_mem() memremap: Add support for read-only memory mappings arm64: Add support for arch_memremap_ro() soc: qcom: cmd-db: Map with read-only mappings Cc: Evan Green Cc: Rob Herring Cc: Bjorn Andersson Cc: Andy Gross Cc: Will Deacon Cc: Catalin Marinas arch/arm64/include/asm/io.h | 1 + drivers/of/of_reserved_mem.c | 45 +++++++++++++++++++++++++++++++++ drivers/soc/qcom/cmd-db.c | 14 +++------- include/linux/io.h | 1 + include/linux/of_reserved_mem.h | 6 +++++ kernel/iomem.c | 20 ++++++++++++--- 6 files changed, 74 insertions(+), 13 deletions(-) base-commit: 5f9e832c137075045d15cd6899ab0505cfb2ca4b -- Sent by a computer through tubes