File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mips/pci/fixup-rbtx4938.c b/arch/mips/pci/fixup-rbtx4938.c
new file mode 100644
index 0000000..a80579a
--- /dev/null
+++ b/arch/mips/pci/fixup-rbtx4938.c
@@ -0,0 +1,53 @@
+/*
+ * Toshiba rbtx4938 pci routines
+ * Copyright (C) 2000-2001 Toshiba Corporation
+ *
+ * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
+ * terms of the GNU General Public License version 2. This program is
+ * licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
+ */
+#include <linux/types.h>
+#include <asm/txx9/pci.h>
+#include <asm/txx9/rbtx4938.h>
+
+int __init rbtx4938_pci_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	int irq = tx4938_pcic1_map_irq(dev, slot);
+
+	if (irq >= 0)
+		return irq;
+	irq = pin;
+	/* IRQ rotation */
+	irq--;	/* 0-3 */
+	if (slot == TX4927_PCIC_IDSEL_AD_TO_SLOT(23)) {
+		/* PCI CardSlot (IDSEL=A23) */
+		/* PCIA => PCIA (IDSEL=A23) */
+		irq = (irq + 0 + slot) % 4;
+	} else {
+		/* PCI Backplane */
+		if (txx9_pci_option & TXX9_PCI_OPT_PICMG)
+			irq = (irq + 33 - slot) % 4;
+		else
+			irq = (irq + 3 + slot) % 4;
+	}
+	irq++;	/* 1-4 */
+
+	switch (irq) {
+	case 1:
+		irq = RBTX4938_IRQ_IOC_PCIA;
+		break;
+	case 2:
+		irq = RBTX4938_IRQ_IOC_PCIB;
+		break;
+	case 3:
+		irq = RBTX4938_IRQ_IOC_PCIC;
+		break;
+	case 4:
+		irq = RBTX4938_IRQ_IOC_PCID;
+		break;
+	}
+	return irq;
+}