Add UEFI locator for bus_get_device_path, pci acpi

Add a UEFI locator type. It prints the UEFI device names for a FreeBSD
device_t name. It works with PCI and ACPI device nodes. USB forthcoming.

Sponsored by:		Netflix
Reviewed by:		jhb
Differential Revision:	https://reviews.freebsd.org/D32749

sys/dev/acpica/acpi.c

@@ -958,6 +958,52 @@ acpi_get_device_path(device_t bus, device_t child, const char *locator, struct s
 	if (strcmp(locator, BUS_LOCATOR_ACPI) == 0)
 		return (acpi_get_acpi_device_path(bus, child, locator, sb));
 
+	if (strcmp(locator, BUS_LOCATOR_UEFI) == 0) {
+		ACPI_DEVICE_INFO *adinfo;
+		if (!ACPI_FAILURE(AcpiGetObjectInfo(dinfo->ad_handle, &adinfo)) &&
+		    dinfo->ad_handle != 0 && (adinfo->Valid & ACPI_VALID_HID)) {
+			const char *hid = adinfo->HardwareId.String;
+			u_long uid = (adinfo->Valid & ACPI_VALID_UID) ?
+			    strtoul(adinfo->UniqueId.String, NULL, 10) : 0UL;
+			u_long hidval;
+
+			/*
+			 * In UEFI Stanard Version 2.6, Section 9.6.1.6 Text
+			 * Device Node Reference, there's an insanely long table
+			 * 98. This implements the relevant bits from that
+			 * table. Newer versions appear to have not required
+			 * anything new. The EDK2 firmware presents both PciRoot
+			 * and PcieRoot as PciRoot. Follow the EDK2 standard.
+			 */
+			if (strncmp("PNP", hid, 3) != 0)
+				goto nomatch;
+			hidval = strtoul(hid + 3, NULL, 16);
+			switch (hidval) {
+			case 0x0301:
+				sbuf_printf(sb, "Keyboard(0x%lx)", uid);
+				break;
+			case 0x0401:
+				sbuf_printf(sb, "ParallelPort(0x%lx)", uid);
+				break;
+			case 0x0501:
+				sbuf_printf(sb, "Serial(0x%lx)", uid);
+				break;
+			case 0x0604:
+				sbuf_printf(sb, "Floppy(0x%lx)", uid);
+				break;
+			case 0x0a03:
+			case 0x0a08:
+				sbuf_printf(sb, "PciRoot(0x%lx)", uid);
+				break;
+			default: /* Everything else gets a generic encode */
+			nomatch:
+				sbuf_printf(sb, "Acpi(%s,0x%lx)", hid, uid);
+				break;
+			}
+		}
+		/* Not handled: AcpiAdr... unsure how to know it's one */
+	}
+
 	/* For the rest, punt to the default handler */
 	return (bus_generic_get_device_path(bus, child, locator, sb));
 }

sys/dev/acpica/acpi_pci.c

@@ -206,8 +206,8 @@ acpi_pci_get_device_path(device_t bus, device_t child, const char *locator, stru
 	if (strcmp(locator, BUS_LOCATOR_ACPI) == 0)
 		return (acpi_get_acpi_device_path(bus, child, locator, sb));
 
-	/* For the rest, punt to the default handler */
-	return (bus_generic_get_device_path(bus, child, locator, sb));
+	/* Otherwise follow base class' actions */
+	return 	(pci_get_device_path_method(bus, child, locator, sb));
 }
 
 /*

sys/dev/pci/pci.c

@@ -138,7 +138,6 @@ static int		pci_reset_child(device_t dev, device_t child,
 
 static int		pci_get_id_method(device_t dev, device_t child,
 			    enum pci_id_type type, uintptr_t *rid);
-
 static struct pci_devinfo * pci_fill_devinfo(device_t pcib, device_t bus, int d,
     int b, int s, int f, uint16_t vid, uint16_t did);
 
@@ -177,6 +176,7 @@ static device_method_t pci_methods[] = {
 	DEVMETHOD(bus_child_detached,	pci_child_detached),
 	DEVMETHOD(bus_child_pnpinfo,	pci_child_pnpinfo_method),
 	DEVMETHOD(bus_child_location,	pci_child_location_method),
+	DEVMETHOD(bus_get_device_path,	pci_get_device_path_method),
 	DEVMETHOD(bus_hint_device_unit,	pci_hint_device_unit),
 	DEVMETHOD(bus_remap_intr,	pci_remap_intr_method),
 	DEVMETHOD(bus_suspend_child,	pci_suspend_child),
@@ -5917,6 +5917,24 @@ pci_child_pnpinfo_method(device_t dev, device_t child, struct sbuf *sb)
 	return (0);
 }
 
+int
+pci_get_device_path_method(device_t bus, device_t child, const char *locator,
+    struct sbuf *sb)
+{
+	device_t parent = device_get_parent(bus);
+	int rv;
+
+	if (strcmp(locator, BUS_LOCATOR_UEFI) == 0) {
+		rv = bus_generic_get_device_path(parent, bus, locator, sb);
+		if (rv == 0) {
+			sbuf_printf(sb, "/Pci(0x%x,0x%x)", pci_get_slot(child),
+			    pci_get_function(child));
+		}
+		return (0);
+	}
+	return (bus_generic_get_device_path(bus, child, locator, sb));
+}
+
 int
 pci_assign_interrupt_method(device_t dev, device_t child)
 {

sys/dev/pci/pci_private.h

@@ -138,6 +138,8 @@ int		pci_child_location_method(device_t cbdev, device_t child,
 		    struct sbuf *sb);
 int		pci_child_pnpinfo_method(device_t cbdev, device_t child,
 		    struct sbuf *sb);
+int		pci_get_device_path_method(device_t dev, device_t child,
+		    const char *locator, struct sbuf *sb);
 int		pci_assign_interrupt_method(device_t dev, device_t child);
 int		pci_resume(device_t dev);
 int		pci_resume_child(device_t dev, device_t child);

sys/sys/bus.h

@@ -739,6 +739,7 @@ void	bus_data_generation_update(void);
 
 #define BUS_LOCATOR_ACPI	"ACPI"
 #define BUS_LOCATOR_FREEBSD	"FreeBSD"
+#define BUS_LOCATOR_UEFI	"UEFI"
 
 extern int bus_current_pass;