1 files changed, 351 insertions, 0 deletions

diff --git a/drivers/pci/pci-efi.c b/drivers/pci/pci-efi.c
new file mode 100644
index 0000000000..b8cd663161
--- /dev/null
+++ b/drivers/pci/pci-efi.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2019 Ahmad Fatoum <a.fatoum@pengutronix.de>
+ */
+#define pr_fmt(fmt) "pci-efi: " fmt
+
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <xfuncs.h>
+#include <efi.h>
+#include <efi/efi-payload.h>
+#include <efi/efi-device.h>
+#include <linux/pci.h>
+
+#include "pci-efi.h"
+
+struct efi_pci_priv {
+	struct efi_pci_root_bridge_io_protocol *protocol;
+	struct device *dev;
+	struct pci_controller pci;
+	struct resource mem;
+	struct resource mem_pref;
+	struct resource io;
+	struct list_head children;
+};
+
+struct pci_child_id {
+	size_t segmentno;
+	size_t busno;
+	size_t devno;
+	size_t funcno;
+};
+
+struct pci_child {
+	struct efi_pci_io_protocol *protocol;
+	struct device *dev;
+	struct list_head list;
+	struct pci_child_id id;
+};
+
+static inline bool pci_child_id_equal(struct pci_child_id *a, struct pci_child_id *b)
+{
+	return a->segmentno == b->segmentno
+		&& a->busno == b->busno
+		&& a->devno == b->devno
+		&& a->funcno == b->funcno;
+}
+
+#define host_to_efi_pci(host) container_of(host, struct efi_pci_priv, pci)
+
+static inline u64 efi_pci_addr(struct pci_bus *bus, u32 devfn, int where)
+{
+	return EFI_PCI_ADDRESS(bus->number,
+			       PCI_SLOT(devfn), PCI_FUNC(devfn),
+			       where);
+}
+
+static int efi_pci_rd_conf(struct pci_bus *bus, u32 devfn, int where,
+			   int size, u32 *val)
+{
+	struct efi_pci_priv *priv = host_to_efi_pci(bus->host);
+	efi_status_t efiret;
+	u32 value;
+	enum efi_pci_protocol_width width;
+
+	switch (size) {
+	case 4:
+		width = EFI_PCI_WIDTH_U32;
+		break;
+	case 2:
+		width = EFI_PCI_WIDTH_U16;
+		break;
+	case 1:
+		width = EFI_PCI_WIDTH_U8;
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	efiret = priv->protocol->pci.read(priv->protocol, width,
+		efi_pci_addr(bus, devfn, where),
+		1, &value);
+
+	*val = 0xFFFFFFFF;
+
+	if (EFI_ERROR(efiret))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	*val = value;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int efi_pci_wr_conf(struct pci_bus *bus, u32 devfn, int where,
+			   int size, u32 val)
+{
+	struct efi_pci_priv *priv = host_to_efi_pci(bus->host);
+	efi_status_t efiret;
+	enum efi_pci_protocol_width width;
+
+	switch (size) {
+	case 4:
+		width = EFI_PCI_WIDTH_U32;
+		break;
+	case 2:
+		width = EFI_PCI_WIDTH_U16;
+		break;
+	case 1:
+		width = EFI_PCI_WIDTH_U8;
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	efiret = priv->protocol->pci.write(priv->protocol, width,
+		efi_pci_addr(bus, devfn, where),
+		1, &val);
+	if (EFI_ERROR(efiret))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static inline struct resource build_resource(const char *name,
+					     resource_size_t start,
+					     resource_size_t len,
+					     unsigned long flags)
+{
+	struct resource res;
+
+	res.name = name;
+	res.start = start;
+	res.end = start + len - 1;
+	res.flags = flags;
+	res.parent = NULL;
+	INIT_LIST_HEAD(&res.children);
+	INIT_LIST_HEAD(&res.sibling);
+
+	return res;
+}
+
+static const struct pci_ops efi_pci_ops = {
+	.read = efi_pci_rd_conf,
+	.write = efi_pci_wr_conf,
+};
+
+static u8 *acpi_parse_resource(u8 *next, struct resource *out)
+{
+	struct efi_acpi_resource *res;
+	const char *name = NULL;
+	unsigned long flags = 0;
+
+	do {
+		if (*next == ACPI_RESOURCE_END_TAG)
+			return NULL;
+
+		if (*next != ACPI_RESOURCE_DESC_TAG)
+			return ERR_PTR(-EIO);
+
+		res = container_of(next, struct efi_acpi_resource, asd);
+
+		next = (u8 *)&res[1];
+	} while (res->addr_len == 0);
+
+	switch (res->restype) {
+	case ACPI_RESOURCE_TYPE_MEM:
+		if ((res->typflags & ACPI_RESOURCE_TYPFLAG_MTP_MASK)
+		    != ACPI_RESOURCE_TYPFLAG_MTP_MEM)
+			break;
+
+		name = "NP-MEM";
+		flags = IORESOURCE_MEM;
+
+		switch (res->typflags & ACPI_RESOURCE_TYPFLAG_MEM_MASK) {
+		case ACPI_RESOURCE_TYPFLAG_MEM_PREF:
+			name = "P-MEM";
+			flags |= IORESOURCE_PREFETCH;
+			/* fallthrough */
+		case ACPI_RESOURCE_TYPFLAG_MEM_WC:
+		case ACPI_RESOURCE_TYPFLAG_MEM_CACHEABLE:
+			flags |= IORESOURCE_CACHEABLE;
+		}
+
+		if (res->typflags & ACPI_RESOURCE_TYPFLAG_RW_MASK)
+			flags |= IORESOURCE_MEM_WRITEABLE;
+
+		break;
+	case ACPI_RESOURCE_TYPE_IO:
+		name = "IO";
+		flags = IORESOURCE_IO;
+		break;
+	case ACPI_RESOURCE_TYPE_BUSNO:
+		name = "BUS";
+		flags = IORESOURCE_BUS;
+		break;
+	default:
+		return ERR_PTR(-ENXIO);
+	}
+
+	*out = build_resource(name, res->addr_min, res->addr_len, flags);
+
+	pr_debug("%s: %llx-%llx (len=%llx, gr=%lld, xlate_off=%llx, resflags=%08lx)\n",
+		 out->name,
+		 res->addr_min, res->addr_max, res->addr_len,
+		 res->addr_granularity, res->addr_xlate_off,
+		 flags);
+
+	return next;
+}
+
+static struct efi_driver efi_pci_driver;
+
+/* EFI already enumerated the bus for us, match our new pci devices with the efi
+ * handles
+ */
+static void efi_pci_fixup_dev_parent(struct pci_dev *dev)
+{
+	struct efi_pci_priv *priv;
+	struct pci_child *child;
+	struct pci_child_id id;
+
+	if (dev->dev.driver != &efi_pci_driver.driver)
+		return;
+
+	priv = host_to_efi_pci(dev->bus->host);
+
+	id.segmentno = priv->protocol->segmentno;
+	id.busno = dev->bus->number;
+	id.devno = PCI_SLOT(dev->devfn);
+	id.funcno = PCI_FUNC(dev->devfn);
+
+	list_for_each_entry(child, &priv->children, list) {
+		if (IS_ERR(child->protocol))
+			continue;
+
+		if (!child->protocol) {
+			struct efi_device *efichild = to_efi_device(child->dev);
+			efi_status_t efiret;
+
+			BS->handle_protocol(efichild->handle, &EFI_PCI_IO_PROTOCOL_GUID,
+					    (void **)&child->protocol);
+			if (!child->protocol) {
+				child->protocol = ERR_PTR(-ENODEV);
+				continue;
+			}
+
+			efiret = child->protocol->get_location(child->protocol,
+						       &child->id.segmentno,
+						       &child->id.busno,
+						       &child->id.devno,
+						       &child->id.funcno);
+
+			if (EFI_ERROR(efiret)) {
+				child->protocol = ERR_PTR(-efi_errno(efiret));
+				continue;
+			}
+		}
+
+		if (pci_child_id_equal(&child->id, &id)) {
+			dev->dev.priv = child->protocol;
+			dev->dev.parent = child->dev;
+			return;
+		}
+	}
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, efi_pci_fixup_dev_parent);
+
+static int efi_pci_probe(struct efi_device *efidev)
+{
+	struct device *child;
+	struct efi_pci_priv *priv;
+	efi_status_t efiret;
+	void *resources;
+	struct resource resource;
+	u8 *res;
+
+	priv = xzalloc(sizeof(*priv));
+
+	priv->pci.parent = &efidev->dev;
+	pci_controller_init(&priv->pci);
+
+	BS->handle_protocol(efidev->handle, &EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_GUID,
+			(void **)&priv->protocol);
+	if (!priv->protocol)
+		return -ENODEV;
+
+	efiret = priv->protocol->configuration(priv->protocol, &resources);
+	if (EFI_ERROR(efiret))
+		return -efi_errno(efiret);
+
+	res = resources;
+
+	while (1) {
+		res = acpi_parse_resource(res, &resource);
+
+		if (IS_ERR(res))
+			return PTR_ERR(res);
+
+		if (!res)
+			break;
+
+		if ((resource.flags & (IORESOURCE_MEM | IORESOURCE_PREFETCH))
+		    == (IORESOURCE_MEM | IORESOURCE_PREFETCH)) {
+			priv->pci.mem_pref_resource = &priv->mem_pref;
+			priv->mem_pref = resource;
+		} else if (resource.flags & IORESOURCE_MEM) {
+			priv->pci.mem_resource = &priv->mem;
+			priv->mem = resource;
+		} else if (resource.flags & IORESOURCE_IO) {
+			priv->pci.io_resource = &priv->io;
+			priv->io = resource;
+		}
+	}
+
+	priv->pci.pci_ops = &efi_pci_ops;
+
+	INIT_LIST_HEAD(&priv->children);
+
+	device_for_each_child(&efidev->dev, child) {
+		struct pci_child *pci_child;
+		struct efi_device *efichild = to_efi_device(child);
+
+		if (!efi_device_has_guid(efichild, EFI_PCI_IO_PROTOCOL_GUID))
+			continue;
+
+		pci_child = xzalloc(sizeof(*pci_child));
+
+		pci_child->dev = &efichild->dev;
+
+		/*
+		 * regiser_pci_controller can reconfigure bridge bus numbers,
+		 * thus we only collect the child node handles here, but
+		 * don't yet call GetLocation on them
+		 */
+		list_add_tail(&pci_child->list, &priv->children);
+	};
+
+	register_pci_controller(&priv->pci);
+
+	return 0;
+}
+
+static struct efi_driver efi_pci_driver = {
+        .driver = {
+		.name  = "efi-pci",
+	},
+        .probe = efi_pci_probe,
+	.guid = EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_GUID,
+};
+device_efi_driver(efi_pci_driver);