v4.19.13 snapshot.
diff --git a/drivers/irqchip/irq-xilinx-intc.c b/drivers/irqchip/irq-xilinx-intc.c
new file mode 100644
index 0000000..e3043de
--- /dev/null
+++ b/drivers/irqchip/irq-xilinx-intc.c
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2012-2013 Xilinx, Inc.
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/jump_label.h>
+#include <linux/bug.h>
+#include <linux/of_irq.h>
+
+/* No one else should require these constants, so define them locally here. */
+#define ISR 0x00			/* Interrupt Status Register */
+#define IPR 0x04			/* Interrupt Pending Register */
+#define IER 0x08			/* Interrupt Enable Register */
+#define IAR 0x0c			/* Interrupt Acknowledge Register */
+#define SIE 0x10			/* Set Interrupt Enable bits */
+#define CIE 0x14			/* Clear Interrupt Enable bits */
+#define IVR 0x18			/* Interrupt Vector Register */
+#define MER 0x1c			/* Master Enable Register */
+
+#define MER_ME (1<<0)
+#define MER_HIE (1<<1)
+
+static DEFINE_STATIC_KEY_FALSE(xintc_is_be);
+
+struct xintc_irq_chip {
+	void		__iomem *base;
+	struct		irq_domain *root_domain;
+	u32		intr_mask;
+};
+
+static struct xintc_irq_chip *xintc_irqc;
+
+static void xintc_write(int reg, u32 data)
+{
+	if (static_branch_unlikely(&xintc_is_be))
+		iowrite32be(data, xintc_irqc->base + reg);
+	else
+		iowrite32(data, xintc_irqc->base + reg);
+}
+
+static unsigned int xintc_read(int reg)
+{
+	if (static_branch_unlikely(&xintc_is_be))
+		return ioread32be(xintc_irqc->base + reg);
+	else
+		return ioread32(xintc_irqc->base + reg);
+}
+
+static void intc_enable_or_unmask(struct irq_data *d)
+{
+	unsigned long mask = 1 << d->hwirq;
+
+	pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq);
+
+	/* ack level irqs because they can't be acked during
+	 * ack function since the handle_level_irq function
+	 * acks the irq before calling the interrupt handler
+	 */
+	if (irqd_is_level_type(d))
+		xintc_write(IAR, mask);
+
+	xintc_write(SIE, mask);
+}
+
+static void intc_disable_or_mask(struct irq_data *d)
+{
+	pr_debug("irq-xilinx: disable: %ld\n", d->hwirq);
+	xintc_write(CIE, 1 << d->hwirq);
+}
+
+static void intc_ack(struct irq_data *d)
+{
+	pr_debug("irq-xilinx: ack: %ld\n", d->hwirq);
+	xintc_write(IAR, 1 << d->hwirq);
+}
+
+static void intc_mask_ack(struct irq_data *d)
+{
+	unsigned long mask = 1 << d->hwirq;
+
+	pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq);
+	xintc_write(CIE, mask);
+	xintc_write(IAR, mask);
+}
+
+static struct irq_chip intc_dev = {
+	.name = "Xilinx INTC",
+	.irq_unmask = intc_enable_or_unmask,
+	.irq_mask = intc_disable_or_mask,
+	.irq_ack = intc_ack,
+	.irq_mask_ack = intc_mask_ack,
+};
+
+unsigned int xintc_get_irq(void)
+{
+	unsigned int hwirq, irq = -1;
+
+	hwirq = xintc_read(IVR);
+	if (hwirq != -1U)
+		irq = irq_find_mapping(xintc_irqc->root_domain, hwirq);
+
+	pr_debug("irq-xilinx: hwirq=%d, irq=%d\n", hwirq, irq);
+
+	return irq;
+}
+
+static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+	if (xintc_irqc->intr_mask & (1 << hw)) {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_edge_irq, "edge");
+		irq_clear_status_flags(irq, IRQ_LEVEL);
+	} else {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_level_irq, "level");
+		irq_set_status_flags(irq, IRQ_LEVEL);
+	}
+	return 0;
+}
+
+static const struct irq_domain_ops xintc_irq_domain_ops = {
+	.xlate = irq_domain_xlate_onetwocell,
+	.map = xintc_map,
+};
+
+static void xil_intc_irq_handler(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 pending;
+
+	chained_irq_enter(chip, desc);
+	do {
+		pending = xintc_get_irq();
+		if (pending == -1U)
+			break;
+		generic_handle_irq(pending);
+	} while (true);
+	chained_irq_exit(chip, desc);
+}
+
+static int __init xilinx_intc_of_init(struct device_node *intc,
+					     struct device_node *parent)
+{
+	u32 nr_irq;
+	int ret, irq;
+	struct xintc_irq_chip *irqc;
+
+	if (xintc_irqc) {
+		pr_err("irq-xilinx: Multiple instances aren't supported\n");
+		return -EINVAL;
+	}
+
+	irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
+	if (!irqc)
+		return -ENOMEM;
+
+	xintc_irqc = irqc;
+
+	irqc->base = of_iomap(intc, 0);
+	BUG_ON(!irqc->base);
+
+	ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
+	if (ret < 0) {
+		pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n");
+		goto err_alloc;
+	}
+
+	ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
+	if (ret < 0) {
+		pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n");
+		irqc->intr_mask = 0;
+	}
+
+	if (irqc->intr_mask >> nr_irq)
+		pr_warn("irq-xilinx: mismatch in kind-of-intr param\n");
+
+	pr_info("irq-xilinx: %pOF: num_irq=%d, edge=0x%x\n",
+		intc, nr_irq, irqc->intr_mask);
+
+
+	/*
+	 * Disable all external interrupts until they are
+	 * explicity requested.
+	 */
+	xintc_write(IER, 0);
+
+	/* Acknowledge any pending interrupts just in case. */
+	xintc_write(IAR, 0xffffffff);
+
+	/* Turn on the Master Enable. */
+	xintc_write(MER, MER_HIE | MER_ME);
+	if (!(xintc_read(MER) & (MER_HIE | MER_ME))) {
+		static_branch_enable(&xintc_is_be);
+		xintc_write(MER, MER_HIE | MER_ME);
+	}
+
+	irqc->root_domain = irq_domain_add_linear(intc, nr_irq,
+						  &xintc_irq_domain_ops, irqc);
+	if (!irqc->root_domain) {
+		pr_err("irq-xilinx: Unable to create IRQ domain\n");
+		goto err_alloc;
+	}
+
+	if (parent) {
+		irq = irq_of_parse_and_map(intc, 0);
+		if (irq) {
+			irq_set_chained_handler_and_data(irq,
+							 xil_intc_irq_handler,
+							 irqc);
+		} else {
+			pr_err("irq-xilinx: interrupts property not in DT\n");
+			ret = -EINVAL;
+			goto err_alloc;
+		}
+	} else {
+		irq_set_default_host(irqc->root_domain);
+	}
+
+	return 0;
+
+err_alloc:
+	xintc_irqc = NULL;
+	kfree(irqc);
+	return ret;
+
+}
+
+IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
+IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init);