267 lines
6.6 KiB
C
267 lines
6.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ip27-irq.c: Highlevel interrupt handling for IP27 architecture.
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*
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* Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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* Copyright (C) 1999 - 2001 Kanoj Sarcar
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*/
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#undef DEBUG
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#include <linux/irq.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/types.h>
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#include <linux/interrupt.h>
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#include <linux/ioport.h>
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#include <linux/timex.h>
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#include <linux/smp.h>
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#include <linux/random.h>
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#include <linux/kernel.h>
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#include <linux/kernel_stat.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
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#include <asm/bootinfo.h>
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#include <asm/io.h>
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#include <asm/mipsregs.h>
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#include <asm/processor.h>
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#include <asm/pci/bridge.h>
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#include <asm/sn/addrs.h>
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#include <asm/sn/agent.h>
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#include <asm/sn/arch.h>
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#include <asm/sn/hub.h>
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#include <asm/sn/intr.h>
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/*
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* Linux has a controller-independent x86 interrupt architecture.
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* every controller has a 'controller-template', that is used
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* by the main code to do the right thing. Each driver-visible
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* interrupt source is transparently wired to the appropriate
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* controller. Thus drivers need not be aware of the
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* interrupt-controller.
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*
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* Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
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* PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
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* (IO-APICs assumed to be messaging to Pentium local-APICs)
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*
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* the code is designed to be easily extended with new/different
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* interrupt controllers, without having to do assembly magic.
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*/
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extern struct bridge_controller *irq_to_bridge[];
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extern int irq_to_slot[];
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/*
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* use these macros to get the encoded nasid and widget id
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* from the irq value
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*/
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#define IRQ_TO_BRIDGE(i) irq_to_bridge[(i)]
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#define SLOT_FROM_PCI_IRQ(i) irq_to_slot[i]
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static inline int alloc_level(int cpu, int irq)
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{
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struct hub_data *hub = hub_data(cpu_to_node(cpu));
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struct slice_data *si = cpu_data[cpu].data;
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int level;
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level = find_first_zero_bit(hub->irq_alloc_mask, LEVELS_PER_SLICE);
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if (level >= LEVELS_PER_SLICE)
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panic("Cpu %d flooded with devices", cpu);
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__set_bit(level, hub->irq_alloc_mask);
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si->level_to_irq[level] = irq;
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return level;
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}
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static inline int find_level(cpuid_t *cpunum, int irq)
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{
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int cpu, i;
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for_each_online_cpu(cpu) {
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struct slice_data *si = cpu_data[cpu].data;
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for (i = BASE_PCI_IRQ; i < LEVELS_PER_SLICE; i++)
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if (si->level_to_irq[i] == irq) {
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*cpunum = cpu;
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return i;
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}
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}
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panic("Could not identify cpu/level for irq %d", irq);
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}
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static int intr_connect_level(int cpu, int bit)
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{
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nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
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struct slice_data *si = cpu_data[cpu].data;
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set_bit(bit, si->irq_enable_mask);
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if (!cputoslice(cpu)) {
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REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]);
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REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]);
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} else {
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REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]);
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REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]);
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}
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return 0;
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}
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static int intr_disconnect_level(int cpu, int bit)
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{
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nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
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struct slice_data *si = cpu_data[cpu].data;
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clear_bit(bit, si->irq_enable_mask);
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if (!cputoslice(cpu)) {
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REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]);
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REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]);
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} else {
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REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]);
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REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]);
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}
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return 0;
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}
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/* Startup one of the (PCI ...) IRQs routes over a bridge. */
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static unsigned int startup_bridge_irq(struct irq_data *d)
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{
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struct bridge_controller *bc;
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bridgereg_t device;
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bridge_t *bridge;
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int pin, swlevel;
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cpuid_t cpu;
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pin = SLOT_FROM_PCI_IRQ(d->irq);
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bc = IRQ_TO_BRIDGE(d->irq);
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bridge = bc->base;
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pr_debug("bridge_startup(): irq= 0x%x pin=%d\n", d->irq, pin);
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/*
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* "map" irq to a swlevel greater than 6 since the first 6 bits
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* of INT_PEND0 are taken
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*/
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swlevel = find_level(&cpu, d->irq);
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bridge->b_int_addr[pin].addr = (0x20000 | swlevel | (bc->nasid << 8));
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bridge->b_int_enable |= (1 << pin);
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bridge->b_int_enable |= 0x7ffffe00; /* more stuff in int_enable */
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/*
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* Enable sending of an interrupt clear packt to the hub on a high to
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* low transition of the interrupt pin.
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*
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* IRIX sets additional bits in the address which are documented as
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* reserved in the bridge docs.
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*/
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bridge->b_int_mode |= (1UL << pin);
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/*
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* We assume the bridge to have a 1:1 mapping between devices
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* (slots) and intr pins.
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*/
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device = bridge->b_int_device;
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device &= ~(7 << (pin*3));
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device |= (pin << (pin*3));
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bridge->b_int_device = device;
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bridge->b_wid_tflush;
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intr_connect_level(cpu, swlevel);
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return 0; /* Never anything pending. */
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}
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/* Shutdown one of the (PCI ...) IRQs routes over a bridge. */
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static void shutdown_bridge_irq(struct irq_data *d)
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{
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struct bridge_controller *bc = IRQ_TO_BRIDGE(d->irq);
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bridge_t *bridge = bc->base;
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int pin, swlevel;
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cpuid_t cpu;
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pr_debug("bridge_shutdown: irq 0x%x\n", d->irq);
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pin = SLOT_FROM_PCI_IRQ(d->irq);
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/*
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* map irq to a swlevel greater than 6 since the first 6 bits
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* of INT_PEND0 are taken
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*/
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swlevel = find_level(&cpu, d->irq);
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intr_disconnect_level(cpu, swlevel);
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bridge->b_int_enable &= ~(1 << pin);
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bridge->b_wid_tflush;
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}
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static inline void enable_bridge_irq(struct irq_data *d)
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{
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cpuid_t cpu;
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int swlevel;
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swlevel = find_level(&cpu, d->irq); /* Criminal offence */
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intr_connect_level(cpu, swlevel);
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}
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static inline void disable_bridge_irq(struct irq_data *d)
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{
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cpuid_t cpu;
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int swlevel;
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swlevel = find_level(&cpu, d->irq); /* Criminal offence */
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intr_disconnect_level(cpu, swlevel);
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}
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static struct irq_chip bridge_irq_type = {
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.name = "bridge",
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.irq_startup = startup_bridge_irq,
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.irq_shutdown = shutdown_bridge_irq,
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.irq_mask = disable_bridge_irq,
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.irq_unmask = enable_bridge_irq,
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};
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void register_bridge_irq(unsigned int irq)
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{
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irq_set_chip_and_handler(irq, &bridge_irq_type, handle_level_irq);
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}
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int request_bridge_irq(struct bridge_controller *bc)
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{
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int irq = allocate_irqno();
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int swlevel, cpu;
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nasid_t nasid;
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if (irq < 0)
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return irq;
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/*
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* "map" irq to a swlevel greater than 6 since the first 6 bits
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* of INT_PEND0 are taken
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*/
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cpu = bc->irq_cpu;
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swlevel = alloc_level(cpu, irq);
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if (unlikely(swlevel < 0)) {
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free_irqno(irq);
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return -EAGAIN;
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}
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/* Make sure it's not already pending when we connect it. */
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nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
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REMOTE_HUB_CLR_INTR(nasid, swlevel);
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intr_connect_level(cpu, swlevel);
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register_bridge_irq(irq);
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return irq;
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}
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