1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/pnp/system.c b/drivers/pnp/system.c
new file mode 100644
index 000000000..835113b2c
--- /dev/null
+++ b/drivers/pnp/system.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * system.c - a driver for reserving pnp system resources
+ *
+ * Some code is based on pnpbios_core.c
+ * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ */
+
+#include <linux/pnp.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/ioport.h>
+
+static const struct pnp_device_id pnp_dev_table[] = {
+	/* General ID for reserving resources */
+	{"PNP0c02", 0},
+	/* memory controller */
+	{"PNP0c01", 0},
+	{"", 0}
+};
+
+static void reserve_range(struct pnp_dev *dev, struct resource *r, int port)
+{
+	char *regionid;
+	const char *pnpid = dev_name(&dev->dev);
+	resource_size_t start = r->start, end = r->end;
+	struct resource *res;
+
+	regionid = kmalloc(16, GFP_KERNEL);
+	if (!regionid)
+		return;
+
+	snprintf(regionid, 16, "pnp %s", pnpid);
+	if (port)
+		res = request_region(start, end - start + 1, regionid);
+	else
+		res = request_mem_region(start, end - start + 1, regionid);
+	if (res)
+		res->flags &= ~IORESOURCE_BUSY;
+	else
+		kfree(regionid);
+
+	/*
+	 * Failures at this point are usually harmless. pci quirks for
+	 * example do reserve stuff they know about too, so we may well
+	 * have double reservations.
+	 */
+	dev_info(&dev->dev, "%pR %s reserved\n", r,
+		 res ? "has been" : "could not be");
+}
+
+static void reserve_resources_of_dev(struct pnp_dev *dev)
+{
+	struct resource *res;
+	int i;
+
+	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
+		if (res->flags & IORESOURCE_DISABLED)
+			continue;
+		if (res->start == 0)
+			continue;	/* disabled */
+		if (res->start < 0x100)
+			/*
+			 * Below 0x100 is only standard PC hardware
+			 * (pics, kbd, timer, dma, ...)
+			 * We should not get resource conflicts there,
+			 * and the kernel reserves these anyway
+			 * (see arch/i386/kernel/setup.c).
+			 * So, do nothing
+			 */
+			continue;
+		if (res->end < res->start)
+			continue;	/* invalid */
+
+		reserve_range(dev, res, 1);
+	}
+
+	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
+		if (res->flags & IORESOURCE_DISABLED)
+			continue;
+
+		reserve_range(dev, res, 0);
+	}
+}
+
+static int system_pnp_probe(struct pnp_dev *dev,
+			    const struct pnp_device_id *dev_id)
+{
+	reserve_resources_of_dev(dev);
+	return 0;
+}
+
+static struct pnp_driver system_pnp_driver = {
+	.name     = "system",
+	.id_table = pnp_dev_table,
+	.flags    = PNP_DRIVER_RES_DO_NOT_CHANGE,
+	.probe    = system_pnp_probe,
+};
+
+static int __init pnp_system_init(void)
+{
+	return pnp_register_driver(&system_pnp_driver);
+}
+
+/*
+ * Reserve motherboard resources after PCI claim BARs,
+ * but before PCI assign resources for uninitialized PCI devices
+ */
+fs_initcall(pnp_system_init);