11790 ACPI method _CRS should be used to identify bus numbers during initial probe

Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Randy Fishel <randyf@sibernet.com>
Approved by: Dan McDonald <danmcd@joyent.com>

3 files changed, 78 insertions, 15 deletions

diff --git a/usr/src/uts/intel/io/acpica/osl.c b/usr/src/uts/intel/io/acpica/osl.c
index a6e7f9788a..adb46eeae4 100644
--- a/usr/src/uts/intel/io/acpica/osl.c
+++ b/usr/src/uts/intel/io/acpica/osl.c
@@ -23,6 +23,7 @@
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  * Copyright 2018 Joyent, Inc.
+ * Copyright 2019 Western Digital Corporation
  */
 /*
  * Copyright (c) 2009-2010, Intel Corporation.
@@ -1259,6 +1260,73 @@ AcpiOsGetLine(char *Buffer, UINT32 len, UINT32 *BytesRead)
 	return (0);
 }
 
+static ACPI_STATUS
+acpica_crs_cb(ACPI_RESOURCE *rp, void *context)
+{
+	int	*busno = context;
+
+	if (rp->Data.Address.ProducerConsumer == 1)
+		return (AE_OK);
+
+	switch (rp->Type) {
+	case ACPI_RESOURCE_TYPE_ADDRESS16:
+		if (rp->Data.Address16.Address.AddressLength == 0)
+			break;
+		if (rp->Data.Address16.ResourceType != ACPI_BUS_NUMBER_RANGE)
+			break;
+
+		*busno = rp->Data.Address16.Address.Minimum;
+		break;
+
+	case ACPI_RESOURCE_TYPE_ADDRESS32:
+		if (rp->Data.Address32.Address.AddressLength == 0)
+			break;
+		if (rp->Data.Address32.ResourceType != ACPI_BUS_NUMBER_RANGE)
+			break;
+
+		*busno = rp->Data.Address32.Address.Minimum;
+		break;
+
+	case ACPI_RESOURCE_TYPE_ADDRESS64:
+		if (rp->Data.Address64.Address.AddressLength == 0)
+			break;
+		if (rp->Data.Address64.ResourceType != ACPI_BUS_NUMBER_RANGE)
+			break;
+
+		*busno = (int)rp->Data.Address64.Address.Minimum;
+		break;
+
+	default:
+		break;
+	}
+
+	return (AE_OK);
+}
+
+/*
+ * Retrieve the bus number for a root bus.
+ *
+ * _CRS (Current Resource Setting) holds the bus number as set in
+ * PCI configuration, this may differ from _BBN and is a more reliable
+ * indicator of what the bus number is.
+ */
+ACPI_STATUS
+acpica_get_busno(ACPI_HANDLE hdl, int *busno)
+{
+	ACPI_STATUS	rv;
+	int		bus = -1;
+	int		bbn;
+
+	if (ACPI_FAILURE(rv = acpica_eval_int(hdl, "_BBN", &bbn)))
+		return (rv);
+
+	(void) AcpiWalkResources(hdl, "_CRS", acpica_crs_cb, &bus);
+
+	*busno = bus == -1 ? bbn : bus;
+
+	return (AE_OK);
+}
+
 /*
  * Device tree binding
  */
@@ -1304,7 +1372,7 @@ acpica_find_pcibus_walker(ACPI_HANDLE hdl, UINT32 lvl, void *ctxp, void **rvpp)
 			*hdlp = hdl;
 			return (AE_CTRL_TERMINATE);
 		}
-	} else if (ACPI_SUCCESS(acpica_eval_int(hdl, "_BBN", &bbn))) {
+	} else if (ACPI_SUCCESS(acpica_get_busno(hdl, &bbn))) {
 		if (bbn == busno) {
 			*hdlp = hdl;
 			return (AE_CTRL_TERMINATE);
diff --git a/usr/src/uts/intel/io/pci/pci_boot.c b/usr/src/uts/intel/io/pci/pci_boot.c
index 55fa91915d..20bc1bdda8 100644
--- a/usr/src/uts/intel/io/pci/pci_boot.c
+++ b/usr/src/uts/intel/io/pci/pci_boot.c
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2019 Joyent, Inc.
+ * Copyright 2019 Western Digital Corporation
  */
 
 #include <sys/types.h>
@@ -189,8 +190,6 @@ int		pua_cache_valid = 0;
 static ACPI_STATUS
 pci_process_acpi_device(ACPI_HANDLE hdl, UINT32 level, void *ctx, void **rv)
 {
-	ACPI_BUFFER	rb;
-	ACPI_OBJECT	ro;
 	ACPI_DEVICE_INFO *adi;
 	int		busnum;
 
@@ -218,18 +217,12 @@ pci_process_acpi_device(ACPI_HANDLE hdl, UINT32 level, void *ctx, void **rv)
 	AcpiOsFree(adi);
 
 	/*
-	 * XXX: ancient Big Bear broken _BBN will result in two
-	 * bus 0 _BBNs being found, so we need to handle duplicate
-	 * bus 0 gracefully.  However, broken _BBN does not
-	 * hide a childless root-bridge so no need to work-around it
-	 * here
+	 * acpica_get_busno() will check the presence of _BBN and
+	 * fail if not present. It will then use the _CRS method to
+	 * retrieve the actual bus number assigned, it will fall back
+	 * to _BBN should the _CRS method fail.
 	 */
-	rb.Pointer = &ro;
-	rb.Length = sizeof (ro);
-	if (ACPI_SUCCESS(AcpiEvaluateObjectTyped(hdl, "_BBN",
-	    NULL, &rb, ACPI_TYPE_INTEGER))) {
-		busnum = ro.Integer.Value;
-
+	if (ACPI_SUCCESS(acpica_get_busno(hdl, &busnum))) {
 		/*
 		 * Ignore invalid _BBN return values here (rather
 		 * than panic) and emit a warning; something else
diff --git a/usr/src/uts/intel/sys/acpica.h b/usr/src/uts/intel/sys/acpica.h
index b60b4df114..e15ccc78a7 100644
--- a/usr/src/uts/intel/sys/acpica.h
+++ b/usr/src/uts/intel/sys/acpica.h
@@ -26,6 +26,7 @@
 /*
  * Copyright (c) 2009-2010, Intel Corporation.
  * All rights reserved.
+ * Copyright 2019 Western Digital Corporation.
  */
 
 #ifndef _SYS_ACPICA_H
@@ -141,7 +142,7 @@ typedef struct iflag {
  */
 typedef struct device_id {
 	struct device_id *next;
-	char 	*id;
+	char	*id;
 } device_id_t;
 
 typedef struct property {
@@ -192,6 +193,7 @@ extern ACPI_STATUS acpica_get_cpu_object_by_apicid(UINT32, ACPI_HANDLE *);
 extern ACPI_STATUS acpica_get_cpu_id_by_object(ACPI_HANDLE, processorid_t *);
 extern ACPI_STATUS acpica_get_apicid_by_object(ACPI_HANDLE, UINT32 *);
 extern ACPI_STATUS acpica_get_procid_by_object(ACPI_HANDLE, UINT32 *);
+extern ACPI_STATUS acpica_get_busno(ACPI_HANDLE, int *);
 
 extern uint64_t acpica_get_core_feature(uint64_t);
 extern void acpica_set_core_feature(uint64_t);