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=-9.7 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 24A54ECE588 for ; Tue, 15 Oct 2019 16:30:20 +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 EC80F2086A for ; Tue, 15 Oct 2019 16:30:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="mRyEZyzf"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TR4JS+xJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC80F2086A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.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=RyMzM36x7+ErWf3sf5ACiEsI5CnEfJRlhix3pLbXBj4=; b=mRyEZyzf+zL9Vt INVXyyiC7JDNq+ZLZtRxb0zIAZcCVaR92XdS36qG9wDpgu4sy9r2or5YMGEgIBrs616p2KMXDK0yY oz1JWBoyN9inDEIZvuZgbp42IlUwGRrM1A8Yl1w1AdH9z/Qn8LtpBxXAt+GpcPuIy/qw05ME2biX3 NonCVAROFeUeSsAiohn0UFOgiGGXgPUxPE26JYVhaIvChAFPjIeExf1d29YxyOL7+gtmdnUWX8Ykh zOGD9z4/QLWERQviyyKtMjo9qKKYN50jOAgeQ9t4gj1iMkO70oqlShX1l67ggIifS4PqaDYDQ8FL7 vFGLgxBMNUu0YCNsoXPQ==; 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 1iKPi8-0006oY-33; Tue, 15 Oct 2019 16:30:12 +0000 Received: from mail-wr1-x444.google.com ([2a00:1450:4864:20::444]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iKPho-0006Y5-J5 for linux-arm-kernel@lists.infradead.org; Tue, 15 Oct 2019 16:29:54 +0000 Received: by mail-wr1-x444.google.com with SMTP id o28so2025173wro.7 for ; Tue, 15 Oct 2019 09:29:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=TpzOutponfPCE66kYKUzbnWZf9wUFokgB1aEqqzJRN4=; b=TR4JS+xJjiL5PpcHHo1bHsLqgAf+I5G1almKK9qnnQzdIlAxJQSuZ/rWVUob/0MFkq SV/xJ5oLSpNwuKp5jHNjYJ7YhQc2GuhMxpZT8MMiCiTTy+LJmhTKm/L5wjxRPTyDTp6k zHTFBSzk35o0PbIRGO1Wz6W6eP5IYIoOiwEX/BIZQmaAFfiGMRPff1rsbx9NfXLGOFoz je2ycnzqgxzx7DjSkM4YUeO64k44Tybyx6Tyz8XaRCS1Bq2H5ekyXM85v7Z7wQZVm7ad pMyH23XPihr4kOjhbL7Y5z11Q3FBYxp4SPlpjBwDwsozBheOOq8ppytZclKbuRRVyQxj yCkA== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=TpzOutponfPCE66kYKUzbnWZf9wUFokgB1aEqqzJRN4=; b=qMEFhoJkun1oJFmdnM2s4d5yykzuO8/ZGsUSVVJzIxuxDxJjx2lAMG6c01dT9AmL2e rNc51kMcy6jSX045WNGym9fo1xjVXjinBrziMr2iuhbi40Y3Uc+JU1ZsiuiW4TTSsTFc Z53ludY1yrOVMf812TnJQQhRgXBcUebtrQ7aSVXzlulxHepG/c1rtCKjg6w9wxV1RXkh zjyq5RtOekUpFzLs5ebtbhHRyC/WxYOrywIga5Q2lsLeoZU4zuSut7ePkC64lPNsaaIU hrNnhpvT+ChqRGZI3JhYPyALGZEbHIwAg3gkyfAH7UOQ1l5V2d3SlL2ejnGSnXwUP3Sp AGaQ== X-Gm-Message-State: APjAAAWHqObU8k2WYxSNVTEfNAVsJjQBUZTqTCTOVr94hY2bGvxtfXRM EAt7pgQsSXtCtXwOvcK0OfY= X-Google-Smtp-Source: APXvYqxWF5drIRUxDhcv3ypIwvXmMeeoDfbseM/6FwwVczfTNOW4OPmxA+jqeGDYOiXzFwUS8zQ88Q== X-Received: by 2002:adf:ebd1:: with SMTP id v17mr23996540wrn.204.1571156990937; Tue, 15 Oct 2019 09:29:50 -0700 (PDT) Received: from localhost (p2E5BE2CE.dip0.t-ipconnect.de. [46.91.226.206]) by smtp.gmail.com with ESMTPSA id z13sm16541534wrm.64.2019.10.15.09.29.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Oct 2019 09:29:49 -0700 (PDT) From: Thierry Reding To: Arnd Bergmann Subject: [RFC 1/3] memory: Introduce memory controller mini-framework Date: Tue, 15 Oct 2019 18:29:43 +0200 Message-Id: <20191015162945.1203736-2-thierry.reding@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191015162945.1203736-1-thierry.reding@gmail.com> References: <20191015162945.1203736-1-thierry.reding@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191015_092952_627034_69815F8E X-CRM114-Status: GOOD ( 20.19 ) 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: Will Deacon , Jonathan Hunter , iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org, Robin Murphy , 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 From: Thierry Reding This new framework is currently nothing more than a registry of memory controllers, with the goal being to order device probing. One use-case where this is useful, for example, is a memory controller device which needs to program some registers before the system MMU can be enabled. Associating the memory controller with the SMMU allows the SMMU driver to defer the probe until the memory controller has been registered. One such example is Tegra186 where the memory controller contains some registers that are used to program stream IDs for the various memory clients (display, USB, PCI, ...) in the system. Programming these SIDs is required for the memory clients to emit the proper SIDs as part of their memory requests. The memory controller driver therefore needs to be programmed prior to the SMMU driver. To achieve that, the memory controller will be referenced via phandle from the SMMU device tree node, the SMMU driver can then use the memory controller framework to find it and defer probe until it has been registered. Signed-off-by: Thierry Reding --- drivers/memory/Makefile | 1 + drivers/memory/core.c | 99 +++++++++++++++++++++++++++++++ include/linux/memory-controller.h | 25 ++++++++ 3 files changed, 125 insertions(+) create mode 100644 drivers/memory/core.c create mode 100644 include/linux/memory-controller.h diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile index 27b493435e61..d16e7dca8ef9 100644 --- a/drivers/memory/Makefile +++ b/drivers/memory/Makefile @@ -3,6 +3,7 @@ # Makefile for memory devices # +obj-y += core.o obj-$(CONFIG_DDR) += jedec_ddr_data.o ifeq ($(CONFIG_DDR),y) obj-$(CONFIG_OF) += of_memory.o diff --git a/drivers/memory/core.c b/drivers/memory/core.c new file mode 100644 index 000000000000..1772e839305a --- /dev/null +++ b/drivers/memory/core.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 NVIDIA Corporation. + */ + +#include +#include + +static DEFINE_MUTEX(controllers_lock); +static LIST_HEAD(controllers); + +static void memory_controller_release(struct kref *ref) +{ + struct memory_controller *mc = container_of(ref, struct memory_controller, ref); + + WARN_ON(!list_empty(&mc->list)); +} + +int memory_controller_register(struct memory_controller *mc) +{ + kref_init(&mc->ref); + + mutex_lock(&controllers_lock); + list_add_tail(&mc->list, &controllers); + mutex_unlock(&controllers_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(memory_controller_register); + +void memory_controller_unregister(struct memory_controller *mc) +{ + mutex_lock(&controllers_lock); + list_del_init(&mc->list); + mutex_unlock(&controllers_lock); + + kref_put(&mc->ref, memory_controller_release); +} +EXPORT_SYMBOL_GPL(memory_controller_unregister); + +static struct memory_controller * +of_memory_controller_get(struct device *dev, struct device_node *np, + const char *con_id) +{ + const char *cells = "#memory-controller-cells"; + const char *names = "memory-controller-names"; + const char *prop = "memory-controllers"; + struct memory_controller *mc; + struct of_phandle_args args; + int index = 0, err; + + if (con_id) { + index = of_property_match_string(np, names, con_id); + if (index < 0) + return ERR_PTR(index); + } + + err = of_parse_phandle_with_args(np, prop, cells, index, &args); + if (err) { + if (err == -ENOENT) + err = -ENODEV; + + return ERR_PTR(err); + } + + mutex_lock(&controllers_lock); + + list_for_each_entry(mc, &controllers, list) { + if (mc->dev && mc->dev->of_node == args.np) { + kref_get(&mc->ref); + mutex_unlock(&controllers_lock); + goto unlock; + } + } + + mc = ERR_PTR(-EPROBE_DEFER); + +unlock: + mutex_unlock(&controllers_lock); + of_node_put(args.np); + return mc; +} + +struct memory_controller * +memory_controller_get(struct device *dev, const char *con_id) +{ + if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) + return of_memory_controller_get(dev, dev->of_node, con_id); + + return ERR_PTR(-ENODEV); +} +EXPORT_SYMBOL_GPL(memory_controller_get); + +void memory_controller_put(struct memory_controller *mc) +{ + if (mc) + kref_put(&mc->ref, memory_controller_release); +} +EXPORT_SYMBOL_GPL(memory_controller_put); diff --git a/include/linux/memory-controller.h b/include/linux/memory-controller.h new file mode 100644 index 000000000000..4b06b2ea1d14 --- /dev/null +++ b/include/linux/memory-controller.h @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 NVIDIA Corporation. + */ + +#ifndef _LINUX_MEMORY_CONTROLLER_H +#define _LINUX_MEMORY_CONTROLLER_H + +#include +#include + +struct memory_controller { + struct device *dev; + struct kref ref; + struct list_head list; +}; + +int memory_controller_register(struct memory_controller *mc); +void memory_controller_unregister(struct memory_controller *mc); + +struct memory_controller *memory_controller_get(struct device *dev, + const char *con_id); +void memory_controller_put(struct memory_controller *mc); + +#endif -- 2.23.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel