forked from Minki/linux
33517881ed
Using the irq_gc_lock/irq_gc_unlock functions in the suspend and
resume functions creates the opportunity for a deadlock during
suspend, resume, and shutdown. Using the irq_gc_lock_irqsave/
irq_gc_unlock_irqrestore variants prevents this possible deadlock.
Cc: stable@vger.kernel.org
Fixes: 7f646e9276
("irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 interrupt controller")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
[maz: tidied up $SUBJECT]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
292 lines
8.0 KiB
C
292 lines
8.0 KiB
C
/*
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* Generic Broadcom Set Top Box Level 2 Interrupt controller driver
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*
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* Copyright (C) 2014-2017 Broadcom
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/spinlock.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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#include <linux/of_address.h>
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#include <linux/of_platform.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/io.h>
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#include <linux/irqdomain.h>
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#include <linux/irqchip.h>
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#include <linux/irqchip/chained_irq.h>
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struct brcmstb_intc_init_params {
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irq_flow_handler_t handler;
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int cpu_status;
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int cpu_clear;
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int cpu_mask_status;
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int cpu_mask_set;
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int cpu_mask_clear;
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};
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/* Register offsets in the L2 latched interrupt controller */
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static const struct brcmstb_intc_init_params l2_edge_intc_init = {
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.handler = handle_edge_irq,
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.cpu_status = 0x00,
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.cpu_clear = 0x08,
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.cpu_mask_status = 0x0c,
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.cpu_mask_set = 0x10,
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.cpu_mask_clear = 0x14
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};
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/* Register offsets in the L2 level interrupt controller */
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static const struct brcmstb_intc_init_params l2_lvl_intc_init = {
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.handler = handle_level_irq,
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.cpu_status = 0x00,
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.cpu_clear = -1, /* Register not present */
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.cpu_mask_status = 0x04,
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.cpu_mask_set = 0x08,
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.cpu_mask_clear = 0x0C
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};
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/* L2 intc private data structure */
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struct brcmstb_l2_intc_data {
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struct irq_domain *domain;
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struct irq_chip_generic *gc;
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int status_offset;
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int mask_offset;
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bool can_wake;
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u32 saved_mask; /* for suspend/resume */
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};
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/**
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* brcmstb_l2_mask_and_ack - Mask and ack pending interrupt
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* @d: irq_data
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*
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* Chip has separate enable/disable registers instead of a single mask
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* register and pending interrupt is acknowledged by setting a bit.
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*
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* Note: This function is generic and could easily be added to the
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* generic irqchip implementation if there ever becomes a will to do so.
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* Perhaps with a name like irq_gc_mask_disable_and_ack_set().
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*
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* e.g.: https://patchwork.kernel.org/patch/9831047/
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*/
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static void brcmstb_l2_mask_and_ack(struct irq_data *d)
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{
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struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
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struct irq_chip_type *ct = irq_data_get_chip_type(d);
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u32 mask = d->mask;
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irq_gc_lock(gc);
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irq_reg_writel(gc, mask, ct->regs.disable);
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*ct->mask_cache &= ~mask;
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irq_reg_writel(gc, mask, ct->regs.ack);
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irq_gc_unlock(gc);
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}
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static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
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{
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struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
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struct irq_chip *chip = irq_desc_get_chip(desc);
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unsigned int irq;
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u32 status;
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chained_irq_enter(chip, desc);
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status = irq_reg_readl(b->gc, b->status_offset) &
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~(irq_reg_readl(b->gc, b->mask_offset));
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if (status == 0) {
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raw_spin_lock(&desc->lock);
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handle_bad_irq(desc);
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raw_spin_unlock(&desc->lock);
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goto out;
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}
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do {
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irq = ffs(status) - 1;
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status &= ~(1 << irq);
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generic_handle_irq(irq_linear_revmap(b->domain, irq));
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} while (status);
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out:
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chained_irq_exit(chip, desc);
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}
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static void brcmstb_l2_intc_suspend(struct irq_data *d)
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{
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struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
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struct irq_chip_type *ct = irq_data_get_chip_type(d);
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struct brcmstb_l2_intc_data *b = gc->private;
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unsigned long flags;
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irq_gc_lock_irqsave(gc, flags);
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/* Save the current mask */
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b->saved_mask = irq_reg_readl(gc, ct->regs.mask);
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if (b->can_wake) {
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/* Program the wakeup mask */
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irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable);
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irq_reg_writel(gc, gc->wake_active, ct->regs.enable);
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}
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irq_gc_unlock_irqrestore(gc, flags);
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}
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static void brcmstb_l2_intc_resume(struct irq_data *d)
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{
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struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
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struct irq_chip_type *ct = irq_data_get_chip_type(d);
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struct brcmstb_l2_intc_data *b = gc->private;
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unsigned long flags;
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irq_gc_lock_irqsave(gc, flags);
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if (ct->chip.irq_ack) {
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/* Clear unmasked non-wakeup interrupts */
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irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active,
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ct->regs.ack);
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}
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/* Restore the saved mask */
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irq_reg_writel(gc, b->saved_mask, ct->regs.disable);
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irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable);
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irq_gc_unlock_irqrestore(gc, flags);
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}
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static int __init brcmstb_l2_intc_of_init(struct device_node *np,
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struct device_node *parent,
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const struct brcmstb_intc_init_params
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*init_params)
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{
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unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
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struct brcmstb_l2_intc_data *data;
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struct irq_chip_type *ct;
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int ret;
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unsigned int flags;
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int parent_irq;
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void __iomem *base;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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base = of_iomap(np, 0);
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if (!base) {
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pr_err("failed to remap intc L2 registers\n");
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ret = -ENOMEM;
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goto out_free;
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}
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/* Disable all interrupts by default */
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writel(0xffffffff, base + init_params->cpu_mask_set);
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/* Wakeup interrupts may be retained from S5 (cold boot) */
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data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
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if (!data->can_wake && (init_params->cpu_clear >= 0))
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writel(0xffffffff, base + init_params->cpu_clear);
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parent_irq = irq_of_parse_and_map(np, 0);
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if (!parent_irq) {
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pr_err("failed to find parent interrupt\n");
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ret = -EINVAL;
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goto out_unmap;
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}
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data->domain = irq_domain_add_linear(np, 32,
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&irq_generic_chip_ops, NULL);
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if (!data->domain) {
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ret = -ENOMEM;
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goto out_unmap;
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}
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/* MIPS chips strapped for BE will automagically configure the
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* peripheral registers for CPU-native byte order.
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*/
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flags = 0;
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if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
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flags |= IRQ_GC_BE_IO;
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/* Allocate a single Generic IRQ chip for this node */
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ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
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np->full_name, init_params->handler, clr, 0, flags);
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if (ret) {
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pr_err("failed to allocate generic irq chip\n");
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goto out_free_domain;
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}
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/* Set the IRQ chaining logic */
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irq_set_chained_handler_and_data(parent_irq,
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brcmstb_l2_intc_irq_handle, data);
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data->gc = irq_get_domain_generic_chip(data->domain, 0);
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data->gc->reg_base = base;
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data->gc->private = data;
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data->status_offset = init_params->cpu_status;
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data->mask_offset = init_params->cpu_mask_status;
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ct = data->gc->chip_types;
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if (init_params->cpu_clear >= 0) {
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ct->regs.ack = init_params->cpu_clear;
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ct->chip.irq_ack = irq_gc_ack_set_bit;
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ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
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} else {
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/* No Ack - but still slightly more efficient to define this */
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ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
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}
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ct->chip.irq_mask = irq_gc_mask_disable_reg;
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ct->regs.disable = init_params->cpu_mask_set;
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ct->regs.mask = init_params->cpu_mask_status;
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ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
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ct->regs.enable = init_params->cpu_mask_clear;
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ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
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ct->chip.irq_resume = brcmstb_l2_intc_resume;
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ct->chip.irq_pm_shutdown = brcmstb_l2_intc_suspend;
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if (data->can_wake) {
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/* This IRQ chip can wake the system, set all child interrupts
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* in wake_enabled mask
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*/
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data->gc->wake_enabled = 0xffffffff;
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ct->chip.irq_set_wake = irq_gc_set_wake;
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}
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return 0;
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out_free_domain:
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irq_domain_remove(data->domain);
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out_unmap:
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iounmap(base);
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out_free:
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kfree(data);
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return ret;
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}
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int __init brcmstb_l2_edge_intc_of_init(struct device_node *np,
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struct device_node *parent)
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{
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return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init);
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}
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IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_edge_intc_of_init);
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int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np,
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struct device_node *parent)
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{
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return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init);
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}
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IRQCHIP_DECLARE(bcm7271_l2_intc, "brcm,bcm7271-l2-intc",
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brcmstb_l2_lvl_intc_of_init);
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