pci: Add a framework for quirks

In future we may want to be able to do fixups for specific PCI devices in
skiboot, so add a small framework for doing this.

This is not intended for the same purposes as quirks in the Linux kernel,
as the PCI devices that quirks can match for in skiboot are not properly
configured.  This is intended to enable having a custom path to make
changes that don't directly interact with the PCI device, for example
adding device tree entries.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
[stewart@linux.vnet.ibm.com: fix 0 vs NULL sparse warning, (C) date]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

core/Makefile.inc

@@ -8,7 +8,7 @@ CORE_OBJS += pci-opal.o fast-reboot.o device.o exceptions.o trace.o affinity.o
 CORE_OBJS += vpd.o hostservices.o platform.o nvram.o nvram-format.o hmi.o
 CORE_OBJS += console-log.o ipmi.o time-utils.o pel.o pool.o errorlog.o
 CORE_OBJS += timer.o i2c.o rtc.o flash.o sensor.o ipmi-opal.o
-CORE_OBJS += flash-subpartition.o bitmap.o buddy.o
+CORE_OBJS += flash-subpartition.o bitmap.o buddy.o pci-quirk.o
 
 ifeq ($(SKIBOOT_GCOV),1)
 CORE_OBJS += gcov-profiling.o

core/pci-quirk.c

@@ -0,0 +1,41 @@
+/* Copyright 2017 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <skiboot.h>
+#include <pci.h>
+#include <pci-quirk.h>
+#include <ast.h>
+
+/* Quirks are: {fixup function, vendor ID, (device ID or PCI_ANY_ID)} */
+static const struct pci_quirk quirk_table[] = {
+	{NULL}
+};
+
+void pci_handle_quirk(struct phb *phb,
+		      struct pci_device *pd,
+		      uint16_t vendor_id,
+		      uint16_t device_id)
+{
+	const struct pci_quirk *quirks = quirk_table;
+
+	while (quirks->vendor_id) {
+		if (vendor_id == quirks->vendor_id &&
+		    (quirks->device_id == PCI_ANY_ID ||
+		     device_id == quirks->device_id))
+			quirks->fixup(phb, pd);
+		quirks++;
+	}
+}

core/pci.c

@@ -20,6 +20,7 @@
 #include <pci-cfg.h>
 #include <pci-iov.h>
 #include <pci-slot.h>
+#include <pci-quirk.h>
 #include <timebase.h>
 #include <device.h>
 #include <fsp.h>
@@ -1430,6 +1431,8 @@ static void pci_add_one_device_node(struct phb *phb,
 	if (intpin)
 		dt_add_property_cells(np, "interrupts", intpin);
 
+	pci_handle_quirk(phb, pd, vdid & 0xffff, vdid >> 16);
+
 	/* XXX FIXME: Add a few missing ones such as
 	 *
 	 *  - devsel-speed (!express)

include/pci-quirk.h

@@ -0,0 +1,35 @@
+/* Copyright 2016 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __PCI_QUIRK_H
+#define __PCI_QUIRK_H
+
+#include <pci.h>
+
+#define PCI_ANY_ID 0xFFFF
+
+struct pci_quirk {
+	void (*fixup)(struct phb *, struct pci_device *);
+	uint16_t vendor_id;
+	uint16_t device_id;
+};
+
+void pci_handle_quirk(struct phb *phb,
+		      struct pci_device *pd,
+		      uint16_t vendor_id,
+		      uint16_t device_id);
+
+#endif /* __PCI_QUIRK_H */