From patchwork Thu Jun 10 07:51:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Philippe Brucker X-Patchwork-Id: 457828 Delivered-To: patch@linaro.org Received: by 2002:a02:735a:0:0:0:0:0 with SMTP id a26csp165795jae; Thu, 10 Jun 2021 01:04:20 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzP7XuR/OHljnREhdtXe4GpdKybslgwwZAcWmES63lyceQOBwGJMpIQtfT63V+h5JtPH3g6 X-Received: by 2002:a17:906:974b:: with SMTP id o11mr2088ejy.363.1623312260536; Thu, 10 Jun 2021 01:04:20 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1623312260; cv=none; d=google.com; s=arc-20160816; b=YiFQWrHU4OR65yMFTkVqmtUlroXwCHvUMEd1oS4vM+Nu6HSakn+MOuY3Etwb67T2jF AMFzv+ts6S8d532BrBke3vznIx7Mvy9+rkyeJJF8oGBAiVdn24+ZilVt2Cty9F++OIF/ Px12MhGAAgRTdRZviyJf3RO7MwhkTWRsdOR3lOosVLmpZjgq/7GTJTmM0nZa0jBLA5NU U7WKNrB5T52M4xds2Ipe76iTFYlz5dl0l04EftCjZYqXWn2iWBb6o60DDTAPiecmnd9J 4u68fe9R/9cPBygBjtZr9HrrsCh3zKUP4bO4Ax7StgI7gv87zmPVl1t9PBz3tIX2MAk7 8NIQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=ejXnCAD2YkFfkqhzWWTWsXMNbN9hgkiFcpSDYxNlIvc=; b=pNvubktIDXyG+NjtJk3eIrHtD3l3olJoUry6OohlRO4x0txIiy/RrouwG5hcq8MMp0 +4huoyK1yLh5OOALtxJmmuOOOATVGa+t/IcMg3mwk8sd3BFb6azxCLs0UkunFq86n0jz wy60K7Rqvp6+qulyrrkAhgbA4OsGifmRJG+Kk1y4d+rX31/FMJvG1MjZNQ3IQzCo+r3e O1GVuFhYwiJtUk/zIjHuq/Tka640BwCgz3ZlU6gPgP2Nr8ckTpB+dKngCRuXc5SQJErn P3rZo7SXevp5OkFx0OzHpZsxJAd2ZuRmwKCVrsRbIvkSUwwUAi5KNigJi91j9ptQnC9s Za5g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=oORnf+gR; spf=pass (google.com: domain of linux-acpi-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-acpi-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id u11si1794275edx.42.2021.06.10.01.04.20; Thu, 10 Jun 2021 01:04:20 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-acpi-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=oORnf+gR; spf=pass (google.com: domain of linux-acpi-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-acpi-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230184AbhFJIFr (ORCPT + 4 others); Thu, 10 Jun 2021 04:05:47 -0400 Received: from mail-wr1-f41.google.com ([209.85.221.41]:42767 "EHLO mail-wr1-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229941AbhFJIFr (ORCPT ); Thu, 10 Jun 2021 04:05:47 -0400 Received: by mail-wr1-f41.google.com with SMTP id c5so1134311wrq.9 for ; Thu, 10 Jun 2021 01:03:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ejXnCAD2YkFfkqhzWWTWsXMNbN9hgkiFcpSDYxNlIvc=; b=oORnf+gR55H+H8KJ+6d+mKuNsMdugwSEiLspQ9CjGrD9fb0SHMmJP/Ih+nsiIGhvow X1ZPCb3ohknTr6vNJl/xHnJZXF/faRL9GRsgRFuvCmGjzA04PQypT6BPkdIwww6tVKLA 3kazkit8cl59z5NGnVhAso7Pbii/AMOzl1GthBV8DOLB1NroLN8PimYcAf/KlDOLfJRV 0kKprlACsuSbKlLduYseTQ4BRZ1keB3yk7/QYi6QtLZO9kuko40zfNFd1TqwzbL6aq7s SiDst4EmXZTmV0dKq3Pwvp0sexVnivcYYoExWEe/2+H0Q89lreEx70mdNNQpPfwTnKBV hZMw== 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=ejXnCAD2YkFfkqhzWWTWsXMNbN9hgkiFcpSDYxNlIvc=; b=OtdpYGtQAFV2PyzmMDkkJKmtDoZ5r7kXpnS5pFA26X0R7yFdysoFpejH5lvrUM+GU0 FV+tECQDK0iiDe4Gt0SWvG0TiNHbybTuA9ghiqphspfsIpHeh9aI86DTGITZe39ecM19 ejXjypr2sFd4qf3Sk6sFXjKqyqLnjYitOfn12M38BeeIvE6mQ2ucpSOyOCIFSLLrAqKO 3sIFTOEim91+1it4fRDTI1J3nWQOVOglsgYd/OBfP3ppelA4NP4uT95k8ZEd+FK9OUgF YqyjphutJc1/ZzoucbZtHYt3u6/qeOc1kfIGRweDbbZOVJXfHIhS2XPCAlXHaXD64F/1 n/uw== X-Gm-Message-State: AOAM530hNoqUjtpPUXfmePhLqtdrLrfUIwfo//aZG2w2RIUKuXIGOVUV PsK7WLVl1G9zorirQEiDPtRGjA== X-Received: by 2002:a05:6000:1148:: with SMTP id d8mr3956645wrx.266.1623312170481; Thu, 10 Jun 2021 01:02:50 -0700 (PDT) Received: from localhost.localdomain (adsl-84-226-111-173.adslplus.ch. [84.226.111.173]) by smtp.gmail.com with ESMTPSA id o3sm2715059wrm.78.2021.06.10.01.02.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Jun 2021 01:02:49 -0700 (PDT) From: Jean-Philippe Brucker To: rjw@rjwysocki.net, lenb@kernel.org, joro@8bytes.org, mst@redhat.com Cc: will@kernel.org, catalin.marinas@arm.com, baolu.lu@linux.intel.com, dwmw2@infradead.org, linux-acpi@vger.kernel.org, iommu@lists.linux-foundation.org, virtualization@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, eric.auger@redhat.com, sebastien.boeuf@intel.com, robin.murphy@arm.com, kevin.tian@intel.com, lorenzo.pieralisi@arm.com, guohanjun@huawei.com, sudeep.holla@arm.com, jean-philippe@linaro.org Subject: [PATCH v4 3/6] ACPI: Add driver for the VIOT table Date: Thu, 10 Jun 2021 09:51:30 +0200 Message-Id: <20210610075130.67517-4-jean-philippe@linaro.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210610075130.67517-1-jean-philippe@linaro.org> References: <20210610075130.67517-1-jean-philippe@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org The ACPI Virtual I/O Translation Table describes topology of para-virtual platforms, similarly to vendor tables DMAR, IVRS and IORT. For now it describes the relation between virtio-iommu and the endpoints it manages. Three steps are needed to configure DMA of endpoints: (1) acpi_viot_init(): parse the VIOT table, find or create the fwnode associated to each vIOMMU device. (2) When probing the vIOMMU device, the driver registers its IOMMU ops within the IOMMU subsystem. This step doesn't require any intervention from the VIOT driver. (3) viot_iommu_configure(): before binding the endpoint to a driver, find the associated IOMMU ops. Register them, along with the endpoint ID, into the device's iommu_fwspec. If step (3) happens before step (2), it is deferred until the IOMMU is initialized, then retried. Signed-off-by: Jean-Philippe Brucker --- drivers/acpi/Kconfig | 3 + drivers/iommu/Kconfig | 1 + drivers/acpi/Makefile | 2 + include/linux/acpi_viot.h | 19 ++ drivers/acpi/bus.c | 2 + drivers/acpi/scan.c | 3 + drivers/acpi/viot.c | 364 ++++++++++++++++++++++++++++++++++++++ MAINTAINERS | 8 + 8 files changed, 402 insertions(+) create mode 100644 include/linux/acpi_viot.h create mode 100644 drivers/acpi/viot.c -- 2.31.1 Reviewed-by: Eric Auger diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index eedec61e3476..3758c6940ed7 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -526,6 +526,9 @@ endif source "drivers/acpi/pmic/Kconfig" +config ACPI_VIOT + bool + endif # ACPI config X86_PM_TIMER diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 1f111b399bca..aff8a4830dd1 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -403,6 +403,7 @@ config VIRTIO_IOMMU depends on ARM64 select IOMMU_API select INTERVAL_TREE + select ACPI_VIOT if ACPI help Para-virtualised IOMMU driver with virtio. diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 700b41adf2db..a6e644c48987 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -118,3 +118,5 @@ video-objs += acpi_video.o video_detect.o obj-y += dptf/ obj-$(CONFIG_ARM64) += arm64/ + +obj-$(CONFIG_ACPI_VIOT) += viot.o diff --git a/include/linux/acpi_viot.h b/include/linux/acpi_viot.h new file mode 100644 index 000000000000..1eb8ee5b0e5f --- /dev/null +++ b/include/linux/acpi_viot.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ACPI_VIOT_H__ +#define __ACPI_VIOT_H__ + +#include + +#ifdef CONFIG_ACPI_VIOT +void __init acpi_viot_init(void); +int viot_iommu_configure(struct device *dev); +#else +static inline void acpi_viot_init(void) {} +static inline int viot_iommu_configure(struct device *dev) +{ + return -ENODEV; +} +#endif + +#endif /* __ACPI_VIOT_H__ */ diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index be7da23fad76..b835ca702ff0 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -27,6 +27,7 @@ #include #endif #include +#include #include #include #include @@ -1339,6 +1340,7 @@ static int __init acpi_init(void) pci_mmcfg_late_init(); acpi_iort_init(); acpi_scan_init(); + acpi_viot_init(); acpi_ec_init(); acpi_debugfs_init(); acpi_sleep_proc_init(); diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 0c53c8533300..4fa684fdfda8 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -1556,6 +1557,8 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev, return ops; err = iort_iommu_configure_id(dev, id_in); + if (err && err != -EPROBE_DEFER) + err = viot_iommu_configure(dev); /* * If we have reason to believe the IOMMU driver missed the initial diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c new file mode 100644 index 000000000000..892cd9fa7b6d --- /dev/null +++ b/drivers/acpi/viot.c @@ -0,0 +1,364 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Virtual I/O topology + * + * The Virtual I/O Translation Table (VIOT) describes the topology of + * para-virtual IOMMUs and the endpoints they manage. The OS uses it to + * initialize devices in the right order, preventing endpoints from issuing DMA + * before their IOMMU is ready. + * + * When binding a driver to a device, before calling the device driver's probe() + * method, the driver infrastructure calls dma_configure(). At that point the + * VIOT driver looks for an IOMMU associated to the device in the VIOT table. + * If an IOMMU exists and has been initialized, the VIOT driver initializes the + * device's IOMMU fwspec, allowing the DMA infrastructure to invoke the IOMMU + * ops when the device driver configures DMA mappings. If an IOMMU exists and + * hasn't yet been initialized, VIOT returns -EPROBE_DEFER to postpone probing + * the device until the IOMMU is available. + */ +#define pr_fmt(fmt) "ACPI: VIOT: " fmt + +#include +#include +#include +#include +#include +#include +#include + +struct viot_iommu { + /* Node offset within the table */ + unsigned int offset; + struct fwnode_handle *fwnode; + struct list_head list; +}; + +struct viot_endpoint { + union { + /* PCI range */ + struct { + u16 segment_start; + u16 segment_end; + u16 bdf_start; + u16 bdf_end; + }; + /* MMIO */ + u64 address; + }; + u32 endpoint_id; + struct viot_iommu *viommu; + struct list_head list; +}; + +static struct acpi_table_viot *viot; +static LIST_HEAD(viot_iommus); +static LIST_HEAD(viot_pci_ranges); +static LIST_HEAD(viot_mmio_endpoints); + +static int __init viot_check_bounds(const struct acpi_viot_header *hdr) +{ + struct acpi_viot_header *start, *end, *hdr_end; + + start = ACPI_ADD_PTR(struct acpi_viot_header, viot, + max_t(size_t, sizeof(*viot), viot->node_offset)); + end = ACPI_ADD_PTR(struct acpi_viot_header, viot, viot->header.length); + hdr_end = ACPI_ADD_PTR(struct acpi_viot_header, hdr, sizeof(*hdr)); + + if (hdr < start || hdr_end > end) { + pr_err(FW_BUG "Node pointer overflows\n"); + return -EOVERFLOW; + } + if (hdr->length < sizeof(*hdr)) { + pr_err(FW_BUG "Empty node\n"); + return -EINVAL; + } + return 0; +} + +static int __init viot_get_pci_iommu_fwnode(struct viot_iommu *viommu, + u16 segment, u16 bdf) +{ + struct pci_dev *pdev; + struct fwnode_handle *fwnode; + + pdev = pci_get_domain_bus_and_slot(segment, PCI_BUS_NUM(bdf), + bdf & 0xff); + if (!pdev) { + pr_err("Could not find PCI IOMMU\n"); + return -ENODEV; + } + + fwnode = pdev->dev.fwnode; + if (!fwnode) { + /* + * PCI devices aren't necessarily described by ACPI. Create a + * fwnode so the IOMMU subsystem can identify this device. + */ + fwnode = acpi_alloc_fwnode_static(); + if (!fwnode) { + pci_dev_put(pdev); + return -ENOMEM; + } + set_primary_fwnode(&pdev->dev, fwnode); + } + viommu->fwnode = pdev->dev.fwnode; + pci_dev_put(pdev); + return 0; +} + +static int __init viot_get_mmio_iommu_fwnode(struct viot_iommu *viommu, + u64 address) +{ + struct acpi_device *adev; + struct resource res = { + .start = address, + .end = address, + .flags = IORESOURCE_MEM, + }; + + adev = acpi_resource_consumer(&res); + if (!adev) { + pr_err("Could not find MMIO IOMMU\n"); + return -EINVAL; + } + viommu->fwnode = &adev->fwnode; + return 0; +} + +static struct viot_iommu * __init viot_get_iommu(unsigned int offset) +{ + int ret; + struct viot_iommu *viommu; + struct acpi_viot_header *hdr = ACPI_ADD_PTR(struct acpi_viot_header, + viot, offset); + union { + struct acpi_viot_virtio_iommu_pci pci; + struct acpi_viot_virtio_iommu_mmio mmio; + } *node = (void *)hdr; + + list_for_each_entry(viommu, &viot_iommus, list) + if (viommu->offset == offset) + return viommu; + + if (viot_check_bounds(hdr)) + return NULL; + + viommu = kzalloc(sizeof(*viommu), GFP_KERNEL); + if (!viommu) + return NULL; + + viommu->offset = offset; + switch (hdr->type) { + case ACPI_VIOT_NODE_VIRTIO_IOMMU_PCI: + if (hdr->length < sizeof(node->pci)) + goto err_free; + + ret = viot_get_pci_iommu_fwnode(viommu, node->pci.segment, + node->pci.bdf); + break; + case ACPI_VIOT_NODE_VIRTIO_IOMMU_MMIO: + if (hdr->length < sizeof(node->mmio)) + goto err_free; + + ret = viot_get_mmio_iommu_fwnode(viommu, + node->mmio.base_address); + break; + default: + ret = -EINVAL; + } + if (ret) + goto err_free; + + list_add(&viommu->list, &viot_iommus); + return viommu; + +err_free: + kfree(viommu); + return NULL; +} + +static int __init viot_parse_node(const struct acpi_viot_header *hdr) +{ + int ret = -EINVAL; + struct list_head *list; + struct viot_endpoint *ep; + union { + struct acpi_viot_mmio mmio; + struct acpi_viot_pci_range pci; + } *node = (void *)hdr; + + if (viot_check_bounds(hdr)) + return -EINVAL; + + if (hdr->type == ACPI_VIOT_NODE_VIRTIO_IOMMU_PCI || + hdr->type == ACPI_VIOT_NODE_VIRTIO_IOMMU_MMIO) + return 0; + + ep = kzalloc(sizeof(*ep), GFP_KERNEL); + if (!ep) + return -ENOMEM; + + switch (hdr->type) { + case ACPI_VIOT_NODE_PCI_RANGE: + if (hdr->length < sizeof(node->pci)) { + pr_err(FW_BUG "Invalid PCI node size\n"); + goto err_free; + } + + ep->segment_start = node->pci.segment_start; + ep->segment_end = node->pci.segment_end; + ep->bdf_start = node->pci.bdf_start; + ep->bdf_end = node->pci.bdf_end; + ep->endpoint_id = node->pci.endpoint_start; + ep->viommu = viot_get_iommu(node->pci.output_node); + list = &viot_pci_ranges; + break; + case ACPI_VIOT_NODE_MMIO: + if (hdr->length < sizeof(node->mmio)) { + pr_err(FW_BUG "Invalid MMIO node size\n"); + goto err_free; + } + + ep->address = node->mmio.base_address; + ep->endpoint_id = node->mmio.endpoint; + ep->viommu = viot_get_iommu(node->mmio.output_node); + list = &viot_mmio_endpoints; + break; + default: + pr_warn("Unsupported node %x\n", hdr->type); + ret = 0; + goto err_free; + } + + /* + * To be compatible with future versions of the table which may include + * other node types, keep parsing. + */ + if (!ep->viommu) { + pr_warn("No IOMMU node found\n"); + ret = 0; + goto err_free; + } + + list_add(&ep->list, list); + return 0; + +err_free: + kfree(ep); + return ret; +} + +/** + * acpi_viot_init - Parse the VIOT table + * + * Parse the VIOT table, prepare the list of endpoints to be used during DMA + * setup of devices. + */ +void __init acpi_viot_init(void) +{ + int i; + acpi_status status; + struct acpi_table_header *hdr; + struct acpi_viot_header *node; + + status = acpi_get_table(ACPI_SIG_VIOT, 0, &hdr); + if (ACPI_FAILURE(status)) { + if (status != AE_NOT_FOUND) { + const char *msg = acpi_format_exception(status); + + pr_err("Failed to get table, %s\n", msg); + } + return; + } + + viot = (void *)hdr; + + node = ACPI_ADD_PTR(struct acpi_viot_header, viot, viot->node_offset); + for (i = 0; i < viot->node_count; i++) { + if (viot_parse_node(node)) + return; + + node = ACPI_ADD_PTR(struct acpi_viot_header, node, + node->length); + } +} + +static int viot_dev_iommu_init(struct device *dev, struct viot_iommu *viommu, + u32 epid) +{ + const struct iommu_ops *ops; + + if (!viommu) + return -ENODEV; + + /* We're not translating ourself */ + if (viommu->fwnode == dev->fwnode) + return -EINVAL; + + ops = iommu_ops_from_fwnode(viommu->fwnode); + if (!ops) + return IS_ENABLED(CONFIG_VIRTIO_IOMMU) ? + -EPROBE_DEFER : -ENODEV; + + return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode, ops); +} + +static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data) +{ + u32 epid; + struct viot_endpoint *ep; + u32 domain_nr = pci_domain_nr(pdev->bus); + + list_for_each_entry(ep, &viot_pci_ranges, list) { + if (domain_nr >= ep->segment_start && + domain_nr <= ep->segment_end && + dev_id >= ep->bdf_start && + dev_id <= ep->bdf_end) { + epid = ((domain_nr - ep->segment_start) << 16) + + dev_id - ep->bdf_start + ep->endpoint_id; + + /* + * If we found a PCI range managed by the viommu, we're + * the one that has to request ACS. + */ + pci_request_acs(); + + return viot_dev_iommu_init(&pdev->dev, ep->viommu, + epid); + } + } + return -ENODEV; +} + +static int viot_mmio_dev_iommu_init(struct platform_device *pdev) +{ + struct resource *mem; + struct viot_endpoint *ep; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) + return -ENODEV; + + list_for_each_entry(ep, &viot_mmio_endpoints, list) { + if (ep->address == mem->start) + return viot_dev_iommu_init(&pdev->dev, ep->viommu, + ep->endpoint_id); + } + return -ENODEV; +} + +/** + * viot_iommu_configure - Setup IOMMU ops for an endpoint described by VIOT + * @dev: the endpoint + * + * Return: 0 on success, <0 on failure + */ +int viot_iommu_configure(struct device *dev) +{ + if (dev_is_pci(dev)) + return pci_for_each_dma_alias(to_pci_dev(dev), + viot_pci_dev_iommu_init, NULL); + else if (dev_is_platform(dev)) + return viot_mmio_dev_iommu_init(to_platform_device(dev)); + return -ENODEV; +} diff --git a/MAINTAINERS b/MAINTAINERS index b706dd20ff2b..8d71591f979a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -431,6 +431,14 @@ W: https://01.org/linux-acpi B: https://bugzilla.kernel.org F: drivers/acpi/acpi_video.c +ACPI VIOT DRIVER +M: Jean-Philippe Brucker +L: linux-acpi@vger.kernel.org +L: iommu@lists.linux-foundation.org +S: Maintained +F: drivers/acpi/viot.c +F: include/linux/acpi_viot.h + ACPI WMI DRIVER L: platform-driver-x86@vger.kernel.org S: Orphan