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[2620:137:e000::1:20]) by mx.google.com with ESMTP id l4-20020a622504000000b0058dd0e03e08si4120027pfl.254.2023.01.27.06.37.27; Fri, 27 Jan 2023 06:37:43 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass (test mode) header.i=@axis.com header.s=axis-central1 header.b=MvvpGXs7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=axis.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232966AbjA0Oai (ORCPT + 99 others); Fri, 27 Jan 2023 09:30:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232257AbjA0Oah (ORCPT ); Fri, 27 Jan 2023 09:30:37 -0500 Received: from smtp1.axis.com (smtp1.axis.com [195.60.68.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24548FF0E for ; Fri, 27 Jan 2023 06:30:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1674829835; x=1706365835; h=from:date:subject:mime-version:content-transfer-encoding: message-id:to:cc; bh=RL1TVR8JpwDGXzhk2Xp/sjq8b+rwzvFYVEYMjlPcCWk=; b=MvvpGXs7wDRDCxf5t1CPJbD0jSxY3jdzdAZO9frq+TXILOn6yR1Mb3Dr ChsM+EMLPuB3a7HrDbmp/p+DOE6zwy7+ppOtpXyevgIuy3X817LjfHJvH b/Oc/zd/t/p8X60cZqGerf1SGVZBy/5IBVNO1y6nuNceRtcI4BX+9AUhc auSTsp8lwZ07yhJITRuPVM+ylFt1TH9QTv9AlHvW0HaIknwVZGGtD1rms AFQt7VqxlYdQ5zQrJ//C6PQSjr6ZgRKM9H2XoCOJ2y+WVVTIGlSfSsVIL 9WgSuHc8xi88TfqmtLB8XRwHlUMyhyGk1Q2t0BfbjzB2xVA6m5vPC39yx A==; From: Vincent Whitchurch Date: Fri, 27 Jan 2023 15:30:27 +0100 Subject: [PATCH] virt-pci: add platform bus support MIME-Version: 1.0 Message-ID: <20230127-uml-pci-platform-v1-1-ec6b45d2829f@axis.com> X-B4-Tracking: v=1; b=H4sIAALg02MC/x2NQQqDMBAAvyJ77kKSIkq/UnrYxE1dMDFsbCmIf zf2OAPD7FBZhSs8uh2Uv1JlzQ3srYMwU34zytQYnHF3Y92An7RgCYJloS2umpDj2FtPQx9HAy3 zVBm9Ug7zFW6pXLYoR/n9R8/XcZyN11SoeAAAAA== To: Richard Weinberger , Anton Ivanov , Johannes Berg CC: , , , , , Vincent Whitchurch X-Mailer: b4 0.12.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_PASS, SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756186818471828383?= X-GMAIL-MSGID: =?utf-8?q?1756186818471828383?= This driver registers PCI busses, but the underlying virtio protocol could just as easily be used to provide a platform bus instead. If the virtio device node in the devicetree indicates that it's compatible with simple-bus, register platform devices instead of handling it as a PCI bus. Only one platform bus is allowed and the logic MMIO region for the platform bus is placed at an arbitrarily-chosen address away from the PCI region. Signed-off-by: Vincent Whitchurch --- My first approach to getting platform drivers working on UML was by adding a minimal PCI-to-platform bridge driver, which worked without modifications to virt-pci, but that got shot down: https://lore.kernel.org/lkml/20230120-simple-mfd-pci-v1-1-c46b3d6601ef@axis.com/ --- arch/um/drivers/virt-pci.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) --- base-commit: 1b929c02afd37871d5afb9d498426f83432e71c2 change-id: 20230127-uml-pci-platform-ef851ba75f80 Best regards, diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c index 3ac220dafec4..0ff69d6ad253 100644 --- a/arch/um/drivers/virt-pci.c +++ b/arch/um/drivers/virt-pci.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -39,6 +40,8 @@ struct um_pci_device { unsigned long status; int irq; + + bool platform; }; struct um_pci_device_reg { @@ -48,6 +51,7 @@ struct um_pci_device_reg { static struct pci_host_bridge *bridge; static DEFINE_MUTEX(um_pci_mtx); +static struct um_pci_device *um_pci_platform_device; static struct um_pci_device_reg um_pci_devices[MAX_DEVICES]; static struct fwnode_handle *um_pci_fwnode; static struct irq_domain *um_pci_inner_domain; @@ -480,6 +484,9 @@ static void um_pci_handle_irq_message(struct virtqueue *vq, struct virtio_device *vdev = vq->vdev; struct um_pci_device *dev = vdev->priv; + if (!dev->irq) + return; + /* we should properly chain interrupts, but on ARCH=um we don't care */ switch (msg->op) { @@ -561,6 +568,55 @@ static int um_pci_init_vqs(struct um_pci_device *dev) return 0; } +static void __um_pci_virtio_platform_remove(struct virtio_device *vdev, + struct um_pci_device *dev) +{ + virtio_reset_device(vdev); + vdev->config->del_vqs(vdev); + + mutex_lock(&um_pci_mtx); + um_pci_platform_device = NULL; + mutex_unlock(&um_pci_mtx); + + kfree(dev); +} + +static int um_pci_virtio_platform_probe(struct virtio_device *vdev, + struct um_pci_device *dev) +{ + int ret; + + dev->platform = true; + + mutex_lock(&um_pci_mtx); + + if (um_pci_platform_device) { + mutex_unlock(&um_pci_mtx); + ret = -EBUSY; + goto out_free; + } + + ret = um_pci_init_vqs(dev); + if (ret) { + mutex_unlock(&um_pci_mtx); + goto out_free; + } + + um_pci_platform_device = dev; + + mutex_unlock(&um_pci_mtx); + + ret = of_platform_default_populate(vdev->dev.of_node, NULL, &vdev->dev); + if (ret) + __um_pci_virtio_platform_remove(vdev, dev); + + return ret; + +out_free: + kfree(dev); + return ret; +} + static int um_pci_virtio_probe(struct virtio_device *vdev) { struct um_pci_device *dev; @@ -574,6 +630,9 @@ static int um_pci_virtio_probe(struct virtio_device *vdev) dev->vdev = vdev; vdev->priv = dev; + if (of_device_is_compatible(vdev->dev.of_node, "simple-bus")) + return um_pci_virtio_platform_probe(vdev, dev); + mutex_lock(&um_pci_mtx); for (i = 0; i < MAX_DEVICES; i++) { if (um_pci_devices[i].dev) @@ -623,6 +682,12 @@ static void um_pci_virtio_remove(struct virtio_device *vdev) struct um_pci_device *dev = vdev->priv; int i; + if (dev->platform) { + of_platform_depopulate(&vdev->dev); + __um_pci_virtio_platform_remove(vdev, dev); + return; + } + /* Stop all virtqueues */ virtio_reset_device(vdev); vdev->config->del_vqs(vdev); @@ -860,6 +925,30 @@ void *pci_root_bus_fwnode(struct pci_bus *bus) return um_pci_fwnode; } +static long um_pci_map_platform(unsigned long offset, size_t size, + const struct logic_iomem_ops **ops, + void **priv) +{ + if (!um_pci_platform_device) + return -ENOENT; + + *ops = &um_pci_device_bar_ops; + *priv = &um_pci_platform_device->resptr[0]; + + return 0; +} + +static const struct logic_iomem_region_ops um_pci_platform_ops = { + .map = um_pci_map_platform, +}; + +static struct resource virt_platform_resource = { + .name = "platform", + .start = 0x10000000, + .end = 0x1fffffff, + .flags = IORESOURCE_MEM, +}; + static int __init um_pci_init(void) { int err, i; @@ -868,6 +957,8 @@ static int __init um_pci_init(void) &um_pci_cfgspace_ops)); WARN_ON(logic_iomem_add_region(&virt_iomem_resource, &um_pci_iomem_ops)); + WARN_ON(logic_iomem_add_region(&virt_platform_resource, + &um_pci_platform_ops)); if (WARN(CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID < 0, "No virtio device ID configured for PCI - no PCI support\n"))