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6829310548
handle_prio_irq is almost identical with handle_fasteoi_irq. The subtle differences are 1) The handler checks for IRQ_DISABLED after the device handler has been called. In case it's set it masks the interrupt. 2) When the handler sees IRQ_DISABLED on entry it masks the interupt in the same way as handle_fastoei_irq, but does not set the IRQ_PENDING flag. 3) Instead of gracefully handling a recursive interrupt it crashes the kernel. #1 is just relevant when a device handler calls disable_irq_nosync() and it does not matter whether we mask the interrupt right away or not. We handle lazy masking for disable_irq anyway, so there is no real reason to have this extra mask in place. #2 will prevent the resend of a pending interrupt, which can result in lost interrupts for edge type interrupts. For level type interrupts the resend is a noop in the generic code. According to the datasheet all interrupts are level type, so marking them as such will result in the exact same behaviour as the private handle_prio_irq implementation. #3 is just stupid. Crashing the kernel instead of handling a problem gracefully is just wrong. With the current semantics- all handlers run with interrupts disabled - this is even more wrong. Rename ack to eoi, remove the unused mask_ack, switch to handle_fasteoi_irq and remove the private function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Cc: linux-arm-kernel@lists.infradead.org LKML-Reference: <20110202212552.299898447@linutronix.de>
76 lines
1.8 KiB
C
76 lines
1.8 KiB
C
/*
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* arch/arm/mach-ns9xxx/irq.c
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*
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* Copyright (C) 2006,2007 by Digi International Inc.
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/io.h>
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#include <asm/mach/irq.h>
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#include <mach/regs-sys-common.h>
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#include <mach/irqs.h>
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#include <mach/board.h>
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#include "generic.h"
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/* simple interrupt prio table: prio(x) < prio(y) <=> x < y */
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#define irq2prio(i) (i)
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#define prio2irq(p) (p)
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static void ns9xxx_mask_irq(struct irq_data *d)
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{
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/* XXX: better use cpp symbols */
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int prio = irq2prio(d->irq);
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u32 ic = __raw_readl(SYS_IC(prio / 4));
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ic &= ~(1 << (7 + 8 * (3 - (prio & 3))));
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__raw_writel(ic, SYS_IC(prio / 4));
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}
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static void ns9xxx_eoi_irq(struct irq_data *d)
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{
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__raw_writel(0, SYS_ISRADDR);
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}
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static void ns9xxx_unmask_irq(struct irq_data *d)
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{
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/* XXX: better use cpp symbols */
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int prio = irq2prio(d->irq);
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u32 ic = __raw_readl(SYS_IC(prio / 4));
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ic |= 1 << (7 + 8 * (3 - (prio & 3)));
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__raw_writel(ic, SYS_IC(prio / 4));
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}
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static struct irq_chip ns9xxx_chip = {
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.irq_eoi = ns9xxx_eoi_irq,
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.irq_mask = ns9xxx_mask_irq,
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.irq_unmask = ns9xxx_unmask_irq,
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};
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void __init ns9xxx_init_irq(void)
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{
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int i;
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/* disable all IRQs */
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for (i = 0; i < 8; ++i)
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__raw_writel(prio2irq(4 * i) << 24 |
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prio2irq(4 * i + 1) << 16 |
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prio2irq(4 * i + 2) << 8 |
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prio2irq(4 * i + 3),
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SYS_IC(i));
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for (i = 0; i < 32; ++i)
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__raw_writel(prio2irq(i), SYS_IVA(i));
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for (i = 0; i <= 31; ++i) {
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set_irq_chip(i, &ns9xxx_chip);
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set_irq_handler(i, handle_fasteoi_irq);
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set_irq_flags(i, IRQF_VALID);
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irq_set_status_flags(i, IRQ_LEVEL);
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}
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}
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