Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 380 insertions, 0 deletions

diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
new file mode 100644
index 0000000000..c8025921c1
--- /dev/null
+++ b/drivers/acpi/viot.c
@@ -0,0 +1,380 @@
+// 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 <linux/acpi_viot.h>
+#include <linux/fwnode.h>
+#include <linux/iommu.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+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 = dev_fwnode(&pdev->dev);
+	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 = dev_fwnode(&pdev->dev);
+	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;
+	}
+
+	if (!ep->viommu) {
+		pr_warn("No IOMMU node found\n");
+		/*
+		 * A future version of the table may use the node for other
+		 * purposes. Keep parsing.
+		 */
+		ret = 0;
+		goto err_free;
+	}
+
+	list_add(&ep->list, list);
+	return 0;
+
+err_free:
+	kfree(ep);
+	return ret;
+}
+
+/**
+ * acpi_viot_early_init - Test the presence of VIOT and enable ACS
+ *
+ * If the VIOT does exist, ACS must be enabled. This cannot be
+ * done in acpi_viot_init() which is called after the bus scan
+ */
+void __init acpi_viot_early_init(void)
+{
+#ifdef CONFIG_PCI
+	acpi_status status;
+	struct acpi_table_header *hdr;
+
+	status = acpi_get_table(ACPI_SIG_VIOT, 0, &hdr);
+	if (ACPI_FAILURE(status))
+		return;
+	pci_request_acs();
+	acpi_put_table(hdr);
+#endif
+}
+
+/**
+ * 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);
+	}
+
+	acpi_put_table(hdr);
+}
+
+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 (device_match_fwnode(dev, viommu->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;
+	struct device *aliased_dev = data;
+	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;
+
+			return viot_dev_iommu_init(aliased_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, dev);
+	else if (dev_is_platform(dev))
+		return viot_mmio_dev_iommu_init(to_platform_device(dev));
+	return -ENODEV;
+}