From patchwork Mon Feb 15 12:17:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 1440510 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=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DfNTT3ZQwz9sVV for ; Mon, 15 Feb 2021 23:19:57 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230231AbhBOMTg (ORCPT ); Mon, 15 Feb 2021 07:19:36 -0500 Received: from marcansoft.com ([212.63.210.85]:42798 "EHLO mail.marcansoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230190AbhBOMT0 (ORCPT ); Mon, 15 Feb 2021 07:19:26 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id B2FDA424BA; Mon, 15 Feb 2021 12:18:33 +0000 (UTC) From: Hector Martin To: linux-arm-kernel@lists.infradead.org Cc: Hector Martin , Marc Zyngier , Rob Herring , Arnd Bergmann , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 12/25] of/address: Add infrastructure to declare MMIO as non-posted Date: Mon, 15 Feb 2021 21:17:00 +0900 Message-Id: <20210215121713.57687-13-marcan@marcan.st> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210215121713.57687-1-marcan@marcan.st> References: <20210215121713.57687-1-marcan@marcan.st> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This implements the 'nonposted-mmio' and 'posted-mmio' boolean properties. Placing these properties in a bus marks all child devices as requiring non-posted or posted MMIO mappings. If no such properties are found, the default is posted MMIO. of_mmio_is_nonposted() performs the tree walking to determine if a given device has requested non-posted MMIO. of_address_to_resource() uses this to set the IORESOURCE_MEM_NONPOSTED flag on resources that require non-posted MMIO. of_iomap() and of_io_request_and_map() then use this flag to pick the correct ioremap() variant. This mechanism is currently restricted to Apple ARM platforms, as an optimization. Signed-off-by: Hector Martin --- drivers/of/address.c | 72 ++++++++++++++++++++++++++++++++++++-- include/linux/of_address.h | 1 + 2 files changed, 71 insertions(+), 2 deletions(-) diff --git a/drivers/of/address.c b/drivers/of/address.c index 73ddf2540f3f..6114dceb1ba6 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -847,6 +847,9 @@ static int __of_address_to_resource(struct device_node *dev, return -EINVAL; memset(r, 0, sizeof(struct resource)); + if (of_mmio_is_nonposted(dev)) + flags |= IORESOURCE_MEM_NONPOSTED; + r->start = taddr; r->end = taddr + size - 1; r->flags = flags; @@ -896,7 +899,10 @@ void __iomem *of_iomap(struct device_node *np, int index) if (of_address_to_resource(np, index, &res)) return NULL; - return ioremap(res.start, resource_size(&res)); + if (res.flags & IORESOURCE_MEM_NONPOSTED) + return ioremap_np(res.start, resource_size(&res)); + else + return ioremap(res.start, resource_size(&res)); } EXPORT_SYMBOL(of_iomap); @@ -928,7 +934,11 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index, if (!request_mem_region(res.start, resource_size(&res), name)) return IOMEM_ERR_PTR(-EBUSY); - mem = ioremap(res.start, resource_size(&res)); + if (res.flags & IORESOURCE_MEM_NONPOSTED) + mem = ioremap_np(res.start, resource_size(&res)); + else + mem = ioremap(res.start, resource_size(&res)); + if (!mem) { release_mem_region(res.start, resource_size(&res)); return IOMEM_ERR_PTR(-ENOMEM); @@ -1094,3 +1104,61 @@ bool of_dma_is_coherent(struct device_node *np) return false; } EXPORT_SYMBOL_GPL(of_dma_is_coherent); + +static bool of_nonposted_mmio_quirk(void) +{ + if (IS_ENABLED(CONFIG_ARCH_APPLE)) { + /* To save cycles, we cache the result for global "Apple ARM" setting */ + static int quirk_state = -1; + + /* Make quirk cached */ + if (quirk_state < 0) + quirk_state = of_machine_is_compatible("apple,arm-platform"); + return !!quirk_state; + } + return false; +} + +/** + * of_mmio_is_nonposted - Check if device uses non-posted MMIO + * @np: device node + * + * Returns true if the "nonposted-mmio" property was found for + * the device's bus or a parent. "posted-mmio" has the opposite + * effect, terminating recursion and overriding any + * "nonposted-mmio" properties in parent buses. + * + * Recursion terminates if reach a non-translatable boundary + * (a node without a 'ranges' property). + * + * This is currently only enabled on Apple ARM devices, as an + * optimization. + */ +bool of_mmio_is_nonposted(struct device_node *np) +{ + struct device_node *node; + struct device_node *parent; + + if (!of_nonposted_mmio_quirk()) + return false; + + node = of_get_parent(np); + + while (node) { + if (!of_property_read_bool(node, "ranges")) { + break; + } else if (of_property_read_bool(node, "nonposted-mmio")) { + of_node_put(node); + return true; + } else if (of_property_read_bool(node, "posted-mmio")) { + break; + } + parent = of_get_parent(node); + of_node_put(node); + node = parent; + } + + of_node_put(node); + return false; +} +EXPORT_SYMBOL_GPL(of_mmio_is_nonposted); diff --git a/include/linux/of_address.h b/include/linux/of_address.h index 88bc943405cd..88f6333fee6c 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -62,6 +62,7 @@ extern struct of_pci_range *of_pci_range_parser_one( struct of_pci_range_parser *parser, struct of_pci_range *range); extern bool of_dma_is_coherent(struct device_node *np); +extern bool of_mmio_is_nonposted(struct device_node *np); #else /* CONFIG_OF_ADDRESS */ static inline void __iomem *of_io_request_and_map(struct device_node *device, int index, const char *name)