From patchwork Thu Oct 29 17:25:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 1390289 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.de Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CMXR139j4z9sTf for ; Fri, 30 Oct 2020 04:26:05 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727733AbgJ2R0D (ORCPT ); Thu, 29 Oct 2020 13:26:03 -0400 Received: from mx2.suse.de ([195.135.220.15]:56226 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727697AbgJ2R0D (ORCPT ); Thu, 29 Oct 2020 13:26:03 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B5A37B1D7; Thu, 29 Oct 2020 17:26:01 +0000 (UTC) From: Nicolas Saenz Julienne To: robh+dt@kernel.org, catalin.marinas@arm.com, hch@lst.de, ardb@kernel.org, linux-kernel@vger.kernel.org, Frank Rowand Cc: robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, jeremy.linton@arm.com, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, will@kernel.org, lorenzo.pieralisi@arm.com, guohanjun@huawei.com, Nicolas Saenz Julienne Subject: [PATCH v5 3/7] of/address: Introduce of_dma_get_max_cpu_address() Date: Thu, 29 Oct 2020 18:25:46 +0100 Message-Id: <20201029172550.3523-4-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.29.0 In-Reply-To: <20201029172550.3523-1-nsaenzjulienne@suse.de> References: <20201029172550.3523-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Introduce of_dma_get_max_cpu_address(), which provides the highest CPU physical address addressable by all DMA masters in the system. It's specially useful for setting memory zones sizes at early boot time. Signed-off-by: Nicolas Saenz Julienne Reviewed-by: Rob Herring --- Changes since v4: - Return max address, not address limit (one-off difference) Changes since v3: - use u64 with cpu_end Changes since v2: - Use PHYS_ADDR_MAX - return phys_dma_t - Rename function - Correct subject - Add support to start parsing from an arbitrary device node in order for the function to work with unit tests drivers/of/address.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 7 +++++++ 2 files changed, 49 insertions(+) diff --git a/drivers/of/address.c b/drivers/of/address.c index eb9ab4f1e80b..09c0af7fd1c4 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -1024,6 +1024,48 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map) } #endif /* CONFIG_HAS_DMA */ +/** + * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA + * @np: The node to start searching from or NULL to start from the root + * + * Gets the highest CPU physical address that is addressable by all DMA masters + * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no + * DMA constrained device is found, it returns PHYS_ADDR_MAX. + */ +phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np) +{ + phys_addr_t max_cpu_addr = PHYS_ADDR_MAX; + struct of_range_parser parser; + phys_addr_t subtree_max_addr; + struct device_node *child; + struct of_range range; + const __be32 *ranges; + u64 cpu_end = 0; + int len; + + if (!np) + np = of_root; + + ranges = of_get_property(np, "dma-ranges", &len); + if (ranges && len) { + of_dma_range_parser_init(&parser, np); + for_each_of_range(&parser, &range) + if (range.cpu_addr + range.size > cpu_end) + cpu_end = range.cpu_addr + range.size - 1; + + if (max_cpu_addr > cpu_end) + max_cpu_addr = cpu_end; + } + + for_each_available_child_of_node(np, child) { + subtree_max_addr = of_dma_get_max_cpu_address(child); + if (max_cpu_addr > subtree_max_addr) + max_cpu_addr = subtree_max_addr; + } + + return max_cpu_addr; +} + /** * of_dma_is_coherent - Check if device is coherent * @np: device node diff --git a/include/linux/of.h b/include/linux/of.h index 5d51891cbf1a..9ed5b8532c30 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u32 id, const char *map_name, const char *map_mask_name, struct device_node **target, u32 *id_out); +phys_addr_t of_dma_get_max_cpu_address(struct device_node *np); + #else /* CONFIG_OF */ static inline void of_core_init(void) @@ -995,6 +997,11 @@ static inline int of_map_id(struct device_node *np, u32 id, return -EINVAL; } +static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np) +{ + return PHYS_ADDR_MAX; +} + #define of_match_ptr(_ptr) NULL #define of_match_node(_matches, _node) NULL #endif /* CONFIG_OF */