tile PCI RC: support pci=off boot arg for tilepro

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/kernel/pci.c

@@ -51,6 +51,8 @@
  *
  */
 
+static int pci_probe = 1;
+
 /*
  * This flag tells if the platform is TILEmpower that needs
  * special configuration for the PLX switch chip.
@@ -143,6 +145,11 @@ int __init tile_pci_init(void)
 {
 	int i;
 
+	if (!pci_probe) {
+		pr_info("PCI: disabled by boot argument\n");
+		return 0;
+	}
+
 	pr_info("PCI: Searching for controllers...\n");
 
 	/* Re-init number of PCIe controllers to support hot-plug feature. */
@@ -378,6 +385,16 @@ void pcibios_set_master(struct pci_dev *dev)
 	/* No special bus mastering setup handling. */
 }
 
+/* Process any "pci=" kernel boot arguments. */
+char * __init pcibios_setup(char *str)
+{
+	if (!strcmp(str, "off")) {
+		pci_probe = 0;
+		return NULL;
+	}
+	return str;
+}
+
 /*
  * Enable memory and/or address decoding, as appropriate, for the
  * device described by the 'dev' struct.