lx_emul: provide more pci functions

- pci_dev_present() based on devices on bus
- pci_request_regions() as dummy
- pci_release_regions() as dummy

repos/dde_linux/src/lib/lx_emul/shadow/drivers/pci/pci.c

@@ -1,3 +1,17 @@
+/*
+ * \brief  Replaces drivers/pci/pci.c
+ * \author Stefan Kalkowski
+ * \author Christian Helmuth
+ * \date   2021-03-16
+ */
+
+/*
+ * Copyright (C) 2021 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
 #include <linux/pci.h>
 #include <lx_emul/pci.h>
 
@@ -40,3 +54,12 @@ u8 pci_find_capability(struct pci_dev * dev,int cap)
 {
 	return 0;
 }
+
+
+void pci_release_regions(struct pci_dev *pdev) { }
+
+
+int pci_request_regions(struct pci_dev *pdev, const char *res_name)
+{
+	return 0;
+}

repos/dde_linux/src/lib/lx_emul/shadow/drivers/pci/search.c

@@ -1,6 +1,22 @@
+/*
+ * \brief  Replaces drivers/pci/search.c
+ * \author Stefan Kalkowski
+ * \author Christian Helmuth
+ * \date   2021-03-16
+ */
+
+/*
+ * Copyright (C) 2021 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
 #include <lx_emul/pci.h>
 #include <linux/pci.h>
 
+#include "../drivers/pci/pci.h"
+
 struct pci_dev * pci_get_class(unsigned int class, struct pci_dev *from)
 {
 	struct pci_dev *dev;
@@ -42,3 +58,20 @@ struct pci_dev * pci_get_device(unsigned int vendor,unsigned int device,struct p
 {
 	return NULL;
 }
+
+
+int pci_dev_present(const struct pci_device_id *ids)
+{
+	struct pci_dev *dev;
+	struct pci_bus *bus = (struct pci_bus *) lx_emul_pci_root_bus();
+
+	while (ids->vendor || ids->subvendor || ids->class_mask) {
+		list_for_each_entry(dev, &bus->devices, bus_list) {
+			if (pci_match_one_device(ids, dev))
+				return 1;
+		}
+		ids++;
+	}
+
+	return 0;
+}

repos/pc/src/drivers/framebuffer/intel/pc/generated_dummies.c

@@ -1596,14 +1596,6 @@ int pagecache_write_end(struct file * file,struct address_space * mapping,loff_t
 enum reboot_mode panic_reboot_mode;
 
 
-#include <linux/pci.h>
-
-int pci_dev_present(const struct pci_device_id * ids)
-{
-	lx_emul_trace_and_stop(__func__);
-}
-
-
 #include <linux/pci.h>
 
 void pci_disable_device(struct pci_dev * dev)