x86: Refactor PIRQ routing support

PIRQ routing is pretty much common in Intel chipset. It has several
PIRQ links (normally 8) and corresponding registers (either in PCI
configuration space or memory-mapped IBASE) to configure the legacy
8259 IRQ vector mapping. Refactor current Queensbay PIRQ routing
support using device tree and move it to a common place, so that we
can easily add PIRQ routing support on a new platform.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

11 files changed, 416 insertions, 300 deletions

diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
index 307545a..7ff05e6 100644
--- a/arch/x86/cpu/Makefile
+++ b/arch/x86/cpu/Makefile
@@ -19,7 +19,7 @@ obj-$(CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE) += ivybridge/
 obj-$(CONFIG_NORTHBRIDGE_INTEL_IVYBRIDGE) += ivybridge/
 obj-$(CONFIG_INTEL_QUARK) += quark/
 obj-$(CONFIG_INTEL_QUEENSBAY) += queensbay/
-obj-y += lapic.o
+obj-y += irq.o lapic.o
 obj-$(CONFIG_SMP) += mp_init.o
 obj-y += mtrr.o
 obj-$(CONFIG_PCI) += pci.o
diff --git a/arch/x86/cpu/irq.c b/arch/x86/cpu/irq.c
new file mode 100644
index 0000000..d1711af
--- /dev/null
+++ b/arch/x86/cpu/irq.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/pci.h>
+#include <asm/pirq_routing.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static struct irq_router irq_router;
+static struct irq_routing_table *pirq_routing_table;
+
+bool pirq_check_irq_routed(int link, u8 irq)
+{
+	u8 pirq;
+	int base = irq_router.link_base;
+
+	if (irq_router.config == PIRQ_VIA_PCI)
+		pirq = x86_pci_read_config8(irq_router.bdf,
+					    LINK_N2V(link, base));
+	else
+		pirq = readb(irq_router.ibase + LINK_N2V(link, base));
+
+	pirq &= 0xf;
+
+	/* IRQ# 0/1/2/8/13 are reserved */
+	if (pirq < 3 || pirq == 8 || pirq == 13)
+		return false;
+
+	return pirq == irq ? true : false;
+}
+
+int pirq_translate_link(int link)
+{
+	return LINK_V2N(link, irq_router.link_base);
+}
+
+void pirq_assign_irq(int link, u8 irq)
+{
+	int base = irq_router.link_base;
+
+	/* IRQ# 0/1/2/8/13 are reserved */
+	if (irq < 3 || irq == 8 || irq == 13)
+		return;
+
+	if (irq_router.config == PIRQ_VIA_PCI)
+		x86_pci_write_config8(irq_router.bdf,
+				      LINK_N2V(link, base), irq);
+	else
+		writeb(irq, irq_router.ibase + LINK_N2V(link, base));
+}
+
+static inline void fill_irq_info(struct irq_info **slotp, int *entries, u8 bus,
+				 u8 device, u8 func, u8 pin, u8 pirq)
+{
+	struct irq_info *slot = *slotp;
+
+	slot->bus = bus;
+	slot->devfn = (device << 3) | func;
+	slot->irq[pin - 1].link = LINK_N2V(pirq, irq_router.link_base);
+	slot->irq[pin - 1].bitmap = irq_router.irq_mask;
+	(*entries)++;
+	(*slotp)++;
+}
+
+__weak void cpu_irq_init(void)
+{
+	return;
+}
+
+static int create_pirq_routing_table(void)
+{
+	const void *blob = gd->fdt_blob;
+	struct fdt_pci_addr addr;
+	int node;
+	int len, count;
+	const u32 *cell;
+	struct irq_routing_table *rt;
+	struct irq_info *slot;
+	int irq_entries = 0;
+	int i;
+	int ret;
+
+	node = fdtdec_next_compatible(blob, 0, COMPAT_INTEL_IRQ_ROUTER);
+	if (node < 0) {
+		debug("%s: Cannot find irq router node\n", __func__);
+		return -EINVAL;
+	}
+
+	ret = fdtdec_get_pci_addr(blob, node, FDT_PCI_SPACE_CONFIG,
+				  "reg", &addr);
+	if (ret)
+		return ret;
+
+	/* extract the bdf from fdt_pci_addr */
+	irq_router.bdf = addr.phys_hi & 0xffff00;
+
+	ret = fdt_find_string(blob, node, "intel,pirq-config", "pci");
+	if (!ret) {
+		irq_router.config = PIRQ_VIA_PCI;
+	} else {
+		ret = fdt_find_string(blob, node, "intel,pirq-config", "ibase");
+		if (!ret)
+			irq_router.config = PIRQ_VIA_IBASE;
+		else
+			return -EINVAL;
+	}
+
+	ret = fdtdec_get_int_array(blob, node, "intel,pirq-link",
+				   &irq_router.link_base, 1);
+	if (ret)
+		return ret;
+
+	irq_router.irq_mask = fdtdec_get_int(blob, node,
+					     "intel,pirq-mask", PIRQ_BITMAP);
+
+	if (irq_router.config == PIRQ_VIA_IBASE) {
+		int ibase_off;
+
+		ibase_off = fdtdec_get_int(blob, node, "intel,ibase-offset", 0);
+		if (!ibase_off)
+			return -EINVAL;
+
+		/*
+		 * Here we assume that the IBASE register has already been
+		 * properly configured by U-Boot before.
+		 *
+		 * By 'valid' we mean:
+		 *   1) a valid memory space carved within system memory space
+		 *      assigned to IBASE register block.
+		 *   2) memory range decoding is enabled.
+		 * Hence we don't do any santify test here.
+		 */
+		irq_router.ibase = x86_pci_read_config32(irq_router.bdf,
+							 ibase_off);
+		irq_router.ibase &= ~0xf;
+	}
+
+	cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
+	if (!cell)
+		return -EINVAL;
+
+	if ((len % sizeof(struct pirq_routing)) == 0)
+		count = len / sizeof(struct pirq_routing);
+	else
+		return -EINVAL;
+
+	rt = malloc(sizeof(struct irq_routing_table));
+	if (!rt)
+		return -ENOMEM;
+	memset((char *)rt, 0, sizeof(struct irq_routing_table));
+
+	/* Populate the PIRQ table fields */
+	rt->signature = PIRQ_SIGNATURE;
+	rt->version = PIRQ_VERSION;
+	rt->rtr_bus = 0;
+	rt->rtr_devfn = (PCI_DEV(irq_router.bdf) << 3) |
+			PCI_FUNC(irq_router.bdf);
+	rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
+	rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;
+
+	slot = rt->slots;
+
+	/* Now fill in the irq_info entries in the PIRQ table */
+	for (i = 0; i < count; i++) {
+		struct pirq_routing pr;
+
+		pr.bdf = fdt_addr_to_cpu(cell[0]);
+		pr.pin = fdt_addr_to_cpu(cell[1]);
+		pr.pirq = fdt_addr_to_cpu(cell[2]);
+
+		debug("irq_info %d: b.d.f %x.%x.%x INT%c PIRQ%c\n",
+		      i, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
+		      PCI_FUNC(pr.bdf), 'A' + pr.pin - 1,
+		      'A' + pr.pirq);
+		fill_irq_info(&slot, &irq_entries, PCI_BUS(pr.bdf),
+			      PCI_DEV(pr.bdf), PCI_FUNC(pr.bdf),
+			      pr.pin, pr.pirq);
+		cell += sizeof(struct pirq_routing) / sizeof(u32);
+	}
+
+	rt->size = irq_entries * sizeof(struct irq_info) + 32;
+
+	pirq_routing_table = rt;
+
+	return 0;
+}
+
+void pirq_init(void)
+{
+	cpu_irq_init();
+
+	if (create_pirq_routing_table()) {
+		debug("Failed to create pirq routing table\n");
+	} else {
+		/* Route PIRQ */
+		pirq_route_irqs(pirq_routing_table->slots,
+				get_irq_slot_count(pirq_routing_table));
+	}
+}
+
+u32 write_pirq_routing_table(u32 addr)
+{
+	return copy_pirq_routing_table(addr, pirq_routing_table);
+}
diff --git a/arch/x86/cpu/queensbay/Makefile b/arch/x86/cpu/queensbay/Makefile
index 4599a48..d8761fd 100644
--- a/arch/x86/cpu/queensbay/Makefile
+++ b/arch/x86/cpu/queensbay/Makefile
@@ -5,5 +5,5 @@
 #
 
 obj-y += fsp_configs.o
-obj-y += irq.o tnc.o topcliff.o
+obj-y += tnc.o topcliff.o
 obj-$(CONFIG_PCI) += tnc_pci.o
diff --git a/arch/x86/cpu/queensbay/irq.c b/arch/x86/cpu/queensbay/irq.c
deleted file mode 100644
index faf9515..0000000
--- a/arch/x86/cpu/queensbay/irq.c
+++ /dev/null
@@ -1,242 +0,0 @@
-/*
- * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
- *
- * SPDX-License-Identifier:	GPL-2.0+
- */
-
-#include <common.h>
-#include <errno.h>
-#include <malloc.h>
-#include <asm/io.h>
-#include <asm/pci.h>
-#include <asm/post.h>
-#include <asm/processor.h>
-#include <asm/pirq_routing.h>
-#include <asm/arch/device.h>
-#include <asm/arch/tnc.h>
-#include <asm/arch/irq.h>
-
-static struct irq_routing_table *pirq_routing_table;
-
-bool pirq_check_irq_routed(int link, u8 irq)
-{
-	u8 pirq;
-
-	pirq = x86_pci_read_config8(TNC_LPC, LINK_N2V(link));
-	pirq &= 0xf;
-
-	/* IRQ# 0/1/2/8/13 are reserved */
-	if (pirq < 3 || pirq == 8 || pirq == 13)
-		return false;
-
-	return pirq == irq ? true : false;
-}
-
-int pirq_translate_link(int link)
-{
-	return LINK_V2N(link);
-}
-
-void pirq_assign_irq(int link, u8 irq)
-{
-	/* IRQ# 0/1/2/8/13 are reserved */
-	if (irq < 3 || irq == 8 || irq == 13)
-		return;
-
-	x86_pci_write_config8(TNC_LPC, LINK_N2V(link), irq);
-}
-
-static inline void fill_irq_info(struct irq_info **slotp, int *entries, u8 bus,
-				 u8 device, u8 func, u8 pin, u8 pirq)
-{
-	struct irq_info *slot = *slotp;
-
-	slot->bus = bus;
-	slot->devfn = (device << 3) | func;
-	slot->irq[pin - 1].link = LINK_N2V(pirq);
-	slot->irq[pin - 1].bitmap = PIRQ_BITMAP;
-	(*entries)++;
-	(*slotp)++;
-}
-
-/* PCIe port downstream INTx swizzle */
-static inline u8 pin_swizzle(u8 pin, int port)
-{
-	return (pin + port) % 4;
-}
-
-__weak int board_fill_irq_info(struct irq_info *slot)
-{
-	return 0;
-}
-
-static int create_pirq_routing_table(void)
-{
-	struct irq_routing_table *rt;
-	struct irq_info *slot;
-	int irq_entries = 0;
-	pci_dev_t tcf_bdf;
-	u8 tcf_bus, bus;
-	int i;
-
-	rt = malloc(sizeof(struct irq_routing_table));
-	if (!rt)
-		return -ENOMEM;
-	memset((char *)rt, 0, sizeof(struct irq_routing_table));
-
-	/* Populate the PIRQ table fields */
-	rt->signature = PIRQ_SIGNATURE;
-	rt->version = PIRQ_VERSION;
-	rt->rtr_bus = 0;
-	rt->rtr_devfn = (TNC_LPC_DEV << 3) | TNC_LPC_FUNC;
-	rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
-	rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;
-
-	slot = rt->slots;
-
-	/*
-	 * Now fill in the irq_info entries in the PIRQ table
-	 *
-	 * We start from internal TunnelCreek PCI devices first, then
-	 * followed by all the 4 PCIe ports downstream devices, including
-	 * the Queensbay platform Topcliff chipset devices.
-	 */
-	fill_irq_info(&slot, &irq_entries, 0, TNC_IGD_DEV,
-		      TNC_IGD_FUNC, INTA, PIRQE);
-	fill_irq_info(&slot, &irq_entries, 0, TNC_SDVO_DEV,
-		      TNC_SDVO_FUNC, INTA, PIRQF);
-	fill_irq_info(&slot, &irq_entries, 0, TNC_HDA_DEV,
-		      TNC_HDA_FUNC, INTA, PIRQG);
-	fill_irq_info(&slot, &irq_entries, 0, TNC_PCIE0_DEV,
-		      TNC_PCIE0_FUNC, INTA, PIRQE);
-	fill_irq_info(&slot, &irq_entries, 0, TNC_PCIE1_DEV,
-		      TNC_PCIE1_FUNC, INTA, PIRQF);
-	fill_irq_info(&slot, &irq_entries, 0, TNC_PCIE2_DEV,
-		      TNC_PCIE2_FUNC, INTA, PIRQG);
-	fill_irq_info(&slot, &irq_entries, 0, TNC_PCIE3_DEV,
-		      TNC_PCIE3_FUNC, INTA, PIRQH);
-
-	/* Check which PCIe port the Topcliff chipset is connected to */
-	tcf_bdf = pci_find_device(PCI_VENDOR_ID_INTEL, 0x8800, 0);
-	tcf_bus = PCI_BUS(tcf_bdf);
-	for (i = 0; i < 4; i++) {
-		bus = x86_pci_read_config8(PCI_BDF(0, TNC_PCIE0_DEV + i, 0),
-					   PCI_SECONDARY_BUS);
-		if (bus == tcf_bus)
-			break;
-	}
-
-	/* Fill in the Topcliff chipset devices' irq info */
-	if (i < 4) {
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_PCIE_PORT_DEV,
-			      TCF_PCIE_PORT_FUNC, INTA, pin_swizzle(PIRQA, i));
-
-		tcf_bus++;
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_0,
-			      TCF_GBE_FUNC, INTA, pin_swizzle(PIRQA, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_0,
-			      TCF_GPIO_FUNC, INTA, pin_swizzle(PIRQA, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_2,
-			      TCF_USB1_OHCI0_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_2,
-			      TCF_USB1_OHCI1_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_2,
-			      TCF_USB1_OHCI2_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_2,
-			      TCF_USB1_EHCI_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_2,
-			      TCF_USB_DEVICE_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_4,
-			      TCF_SDIO0_FUNC, INTC, pin_swizzle(PIRQC, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_4,
-			      TCF_SDIO1_FUNC, INTC, pin_swizzle(PIRQC, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_6,
-			      TCF_SATA_FUNC, INTD, pin_swizzle(PIRQD, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_8,
-			      TCF_USB2_OHCI0_FUNC, INTA, pin_swizzle(PIRQA, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_8,
-			      TCF_USB2_OHCI1_FUNC, INTA, pin_swizzle(PIRQA, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_8,
-			      TCF_USB2_OHCI2_FUNC, INTA, pin_swizzle(PIRQA, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_8,
-			      TCF_USB2_EHCI_FUNC, INTA, pin_swizzle(PIRQA, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_10,
-			      TCF_DMA1_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_10,
-			      TCF_UART0_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_10,
-			      TCF_UART1_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_10,
-			      TCF_UART2_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_10,
-			      TCF_UART3_FUNC, INTB, pin_swizzle(PIRQB, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_12,
-			      TCF_DMA2_FUNC, INTC, pin_swizzle(PIRQC, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_12,
-			      TCF_SPI_FUNC, INTC, pin_swizzle(PIRQC, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_12,
-			      TCF_I2C_FUNC, INTC, pin_swizzle(PIRQC, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_12,
-			      TCF_CAN_FUNC, INTC, pin_swizzle(PIRQC, i));
-		fill_irq_info(&slot, &irq_entries, tcf_bus, TCF_DEV_12,
-			      TCF_1588_FUNC, INTC, pin_swizzle(PIRQC, i));
-	}
-
-	/* Call board-specific routine to fill in add-in card's irq info */
-	irq_entries += board_fill_irq_info(slot);
-
-	rt->size = irq_entries * sizeof(struct irq_info) + 32;
-
-	pirq_routing_table = rt;
-
-	return 0;
-}
-
-void pirq_init(void)
-{
-	struct tnc_rcba *rcba;
-	u32 base;
-
-	base = x86_pci_read_config32(TNC_LPC, LPC_RCBA);
-	base &= ~MEM_BAR_EN;
-	rcba = (struct tnc_rcba *)base;
-
-	/* Make sure all internal PCI devices are using INTA */
-	writel(INTA, &rcba->d02ip);
-	writel(INTA, &rcba->d03ip);
-	writel(INTA, &rcba->d27ip);
-	writel(INTA, &rcba->d31ip);
-	writel(INTA, &rcba->d23ip);
-	writel(INTA, &rcba->d24ip);
-	writel(INTA, &rcba->d25ip);
-	writel(INTA, &rcba->d26ip);
-
-	/*
-	 * Route TunnelCreek PCI device interrupt pin to PIRQ
-	 *
-	 * Since PCIe downstream ports received INTx are routed to PIRQ
-	 * A/B/C/D directly and not configurable, we route internal PCI
-	 * device's INTx to PIRQ E/F/G/H.
-	 */
-	writew(PIRQE, &rcba->d02ir);
-	writew(PIRQF, &rcba->d03ir);
-	writew(PIRQG, &rcba->d27ir);
-	writew(PIRQH, &rcba->d31ir);
-	writew(PIRQE, &rcba->d23ir);
-	writew(PIRQF, &rcba->d24ir);
-	writew(PIRQG, &rcba->d25ir);
-	writew(PIRQH, &rcba->d26ir);
-
-	if (create_pirq_routing_table()) {
-		debug("Failed to create pirq routing table\n");
-	} else {
-		/* Route PIRQ */
-		pirq_route_irqs(pirq_routing_table->slots,
-				get_irq_slot_count(pirq_routing_table));
-	}
-}
-
-u32 write_pirq_routing_table(u32 addr)
-{
-	return copy_pirq_routing_table(addr, pirq_routing_table);
-}
diff --git a/arch/x86/cpu/queensbay/tnc.c b/arch/x86/cpu/queensbay/tnc.c
index b46a7e9..873de7b 100644
--- a/arch/x86/cpu/queensbay/tnc.c
+++ b/arch/x86/cpu/queensbay/tnc.c
@@ -6,10 +6,11 @@
 
 #include <common.h>
 #include <asm/io.h>
+#include <asm/irq.h>
 #include <asm/pci.h>
 #include <asm/post.h>
 #include <asm/arch/device.h>
-#include <asm/arch/irq.h>
+#include <asm/arch/tnc.h>
 #include <asm/fsp/fsp_support.h>
 #include <asm/processor.h>
 
@@ -45,6 +46,42 @@ int arch_cpu_init(void)
 	return 0;
 }
 
+void cpu_irq_init(void)
+{
+	struct tnc_rcba *rcba;
+	u32 base;
+
+	base = x86_pci_read_config32(TNC_LPC, LPC_RCBA);
+	base &= ~MEM_BAR_EN;
+	rcba = (struct tnc_rcba *)base;
+
+	/* Make sure all internal PCI devices are using INTA */
+	writel(INTA, &rcba->d02ip);
+	writel(INTA, &rcba->d03ip);
+	writel(INTA, &rcba->d27ip);
+	writel(INTA, &rcba->d31ip);
+	writel(INTA, &rcba->d23ip);
+	writel(INTA, &rcba->d24ip);
+	writel(INTA, &rcba->d25ip);
+	writel(INTA, &rcba->d26ip);
+
+	/*
+	 * Route TunnelCreek PCI device interrupt pin to PIRQ
+	 *
+	 * Since PCIe downstream ports received INTx are routed to PIRQ
+	 * A/B/C/D directly and not configurable, we route internal PCI
+	 * device's INTx to PIRQ E/F/G/H.
+	 */
+	writew(PIRQE, &rcba->d02ir);
+	writew(PIRQF, &rcba->d03ir);
+	writew(PIRQG, &rcba->d27ir);
+	writew(PIRQH, &rcba->d31ir);
+	writew(PIRQE, &rcba->d23ir);
+	writew(PIRQF, &rcba->d24ir);
+	writew(PIRQG, &rcba->d25ir);
+	writew(PIRQH, &rcba->d26ir);
+}
+
 int arch_misc_init(void)
 {
 	pirq_init();
diff --git a/arch/x86/dts/crownbay.dts b/arch/x86/dts/crownbay.dts
index fbdeade..d68efda 100644
--- a/arch/x86/dts/crownbay.dts
+++ b/arch/x86/dts/crownbay.dts
@@ -6,6 +6,8 @@
 
 /dts-v1/;
 
+#include <dt-bindings/interrupt-router/intel-irq.h>
+
 /include/ "skeleton.dtsi"
 /include/ "serial.dtsi"
 
@@ -135,6 +137,58 @@
 				};
 			};
 		};
+
+		irq-router@1f,0 {
+			reg = <0x0000f800 0 0 0 0>;
+			compatible = "intel,irq-router";
+			intel,pirq-config = "pci";
+			intel,pirq-link = <0x60 8>;
+			intel,pirq-mask = <0xdee0>;
+			intel,pirq-routing = <
+				/* TunnelCreek PCI devices */
+				PCI_BDF(0, 2, 0) INTA PIRQE
+				PCI_BDF(0, 3, 0) INTA PIRQF
+				PCI_BDF(0, 23, 0) INTA PIRQE
+				PCI_BDF(0, 24, 0) INTA PIRQF
+				PCI_BDF(0, 25, 0) INTA PIRQG
+				PCI_BDF(0, 26, 0) INTA PIRQH
+				PCI_BDF(0, 27, 0) INTA PIRQG
+				/*
+				 * Topcliff PCI devices
+				 *
+				 * Note on the Crown Bay board, Topcliff chipset
+				 * is connected to TunnelCreek PCIe port 0, so
+				 * its bus number is 1 for its PCIe port and 2
+				 * for its PCI devices per U-Boot currnet PCI
+				 * bus enumeration algorithm.
+				 */
+				PCI_BDF(1, 0, 0) INTA PIRQA
+				PCI_BDF(2, 0, 1) INTA PIRQA
+				PCI_BDF(2, 0, 2) INTA PIRQA
+				PCI_BDF(2, 2, 0) INTB PIRQB
+				PCI_BDF(2, 2, 1) INTB PIRQB
+				PCI_BDF(2, 2, 2) INTB PIRQB
+				PCI_BDF(2, 2, 3) INTB PIRQB
+				PCI_BDF(2, 2, 4) INTB PIRQB
+				PCI_BDF(2, 4, 0) INTC PIRQC
+				PCI_BDF(2, 4, 1) INTC PIRQC
+				PCI_BDF(2, 6, 0) INTD PIRQD
+				PCI_BDF(2, 8, 0) INTA PIRQA
+				PCI_BDF(2, 8, 1) INTA PIRQA
+				PCI_BDF(2, 8, 2) INTA PIRQA
+				PCI_BDF(2, 8, 3) INTA PIRQA
+				PCI_BDF(2, 10, 0) INTB PIRQB
+				PCI_BDF(2, 10, 1) INTB PIRQB
+				PCI_BDF(2, 10, 2) INTB PIRQB
+				PCI_BDF(2, 10, 3) INTB PIRQB
+				PCI_BDF(2, 10, 4) INTB PIRQB
+				PCI_BDF(2, 12, 0) INTC PIRQC
+				PCI_BDF(2, 12, 1) INTC PIRQC
+				PCI_BDF(2, 12, 2) INTC PIRQC
+				PCI_BDF(2, 12, 3) INTC PIRQC
+				PCI_BDF(2, 12, 4) INTC PIRQC
+			>;
+		};
 	};
 
 };
diff --git a/arch/x86/include/asm/arch-queensbay/irq.h b/arch/x86/include/asm/arch-queensbay/irq.h
deleted file mode 100644
index e7f8616..0000000
--- a/arch/x86/include/asm/arch-queensbay/irq.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
- *
- * SPDX-License-Identifier:	GPL-2.0+
- */
-
-#ifndef _ARCH_IRQ_H_
-#define _ARCH_IRQ_H_
-
-enum pci_int_pin {
-	INTX,
-	INTA,
-	INTB,
-	INTC,
-	INTD
-};
-
-enum pirq_pin {
-	PIRQA,
-	PIRQB,
-	PIRQC,
-	PIRQD,
-	PIRQE,
-	PIRQF,
-	PIRQG,
-	PIRQH
-};
-
-/* PIRQ link number and value conversion */
-#define LINK_V2N(link)	(link - 0x60)
-#define LINK_N2V(link)	(link + 0x60)
-
-#define PIRQ_BITMAP	0xdee0
-
-struct irq_info;
-
-/**
- * board_fill_irq_info() - Board-specific irq_info fill routine
- *
- * This fills the irq_info table for any board-specific add-in cards.
- *
- * @slot:	pointer to the struct irq_info that is to be filled in
- * @return:	number of entries were written to the struct irq_info
- */
-int board_fill_irq_info(struct irq_info *slot);
-
-/**
- * pirq_init() - Initialize platform PIRQ routing
- *
- * This initializes the PIRQ routing on the platform and configures all PCI
- * devices' interrupt line register to a working IRQ number on the 8259 PIC.
- */
-void pirq_init(void);
-
-#endif /* _ARCH_IRQ_H_ */
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
new file mode 100644
index 0000000..4de5512
--- /dev/null
+++ b/arch/x86/include/asm/irq.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _ARCH_IRQ_H_
+#define _ARCH_IRQ_H_
+
+#include <dt-bindings/interrupt-router/intel-irq.h>
+
+/**
+ * Intel interrupt router configuration mechanism
+ *
+ * There are two known ways of Intel interrupt router configuration mechanism
+ * so far. On most cases, the IRQ routing configuraiton is controlled by PCI
+ * configuraiton registers on the legacy bridge, normally PCI BDF(0, 31, 0).
+ * On some newer platforms like BayTrail and Braswell, the IRQ routing is now
+ * in the IBASE register block where IBASE is memory-mapped.
+ */
+enum pirq_config {
+	PIRQ_VIA_PCI,
+	PIRQ_VIA_IBASE
+};
+
+/**
+ * Intel interrupt router control block
+ *
+ * Its members' value will be filled in based on device tree's input.
+ *
+ * @config:	PIRQ_VIA_PCI or PIRQ_VIA_IBASE
+ * @link_base:	link value base number
+ * @irq_mask:	IRQ mask reprenting the 16 IRQs in 8259, bit N is 1 means
+ *		IRQ N is available to be routed
+ * @lb_bdf:	irq router's PCI bus/device/function number encoding
+ * @ibase:	IBASE register block base address
+ */
+struct irq_router {
+	int config;
+	u32 link_base;
+	u16 irq_mask;
+	u32 bdf;
+	u32 ibase;
+};
+
+struct pirq_routing {
+	int bdf;
+	int pin;
+	int pirq;
+};
+
+/* PIRQ link number and value conversion */
+#define LINK_V2N(link, base)	(link - base)
+#define LINK_N2V(link, base)	(link + base)
+
+#define PIRQ_BITMAP		0xdef8
+
+/**
+ * cpu_irq_init() - Initialize CPU IRQ routing
+ *
+ * This initializes some platform-specific registers related to IRQ routing,
+ * like configuring internal PCI devices to use which PCI interrupt pin,
+ * and which PCI interrupt pin is mapped to which PIRQ line. Note on some
+ * platforms, such IRQ routing might be hard-coded thus cannot configure.
+ */
+void cpu_irq_init(void);
+
+/**
+ * pirq_init() - Initialize platform PIRQ routing
+ *
+ * This initializes the PIRQ routing on the platform and configures all PCI
+ * devices' interrupt line register to a working IRQ number on the 8259 PIC.
+ */
+void pirq_init(void);
+
+#endif /* _ARCH_IRQ_H_ */
diff --git a/include/dt-bindings/interrupt-router/intel-irq.h b/include/dt-bindings/interrupt-router/intel-irq.h
new file mode 100644
index 0000000..5092f33
--- /dev/null
+++ b/include/dt-bindings/interrupt-router/intel-irq.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _DT_BINDINGS_INTEL_IRQ_H_
+#define _DT_BINDINGS_INTEL_IRQ_H_
+
+/* PCI interrupt pin */
+#define INTA			1
+#define INTB			2
+#define INTC			3
+#define INTD			4
+
+/* PIRQs */
+#define PIRQA			0
+#define PIRQB			1
+#define PIRQC			2
+#define PIRQD			3
+#define PIRQE			4
+#define PIRQF			5
+#define PIRQG			6
+#define PIRQH			7
+
+/* PCI bdf encoding */
+#ifndef PCI_BDF
+#define PCI_BDF(b, d, f)	((b) << 16 | (d) << 11 | (f) << 8)
+#endif
+
+#endif /* _DT_BINDINGS_INTEL_IRQ_H_ */
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 6bf5f61..64c7fa1 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -178,6 +178,7 @@ enum fdt_compat_id {
 	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
 	COMPAT_SOCIONEXT_XHCI,		/* Socionext UniPhier xHCI */
 	COMPAT_INTEL_PCH,		/* Intel PCH */
+	COMPAT_INTEL_IRQ_ROUTER,	/* Intel Interrupt Router */
 
 	COMPAT_COUNT,
 };
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index b586da2..1808350 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -77,6 +77,7 @@ static const char * const compat_names[COMPAT_COUNT] = {
 	COMPAT(INTEL_QRK_MRC, "intel,quark-mrc"),
 	COMPAT(SOCIONEXT_XHCI, "socionext,uniphier-xhci"),
 	COMPAT(COMPAT_INTEL_PCH, "intel,bd82x6x"),
+	COMPAT(COMPAT_INTEL_IRQ_ROUTER, "intel,irq-router"),
 };
 
 const char *fdtdec_get_compatible(enum fdt_compat_id id)