bbc3dfe880
Commit 2def86a720 ("hvc: Convert to using interrupts instead of opal
events") enabled the use of interrupts in the hvc_driver for OPAL
platforms. However on machines with more than one hvc console, any
console after the first will fail to register an interrupt handler in
notifier_add_irq() since all consoles share the same IRQ number but do
not set the IRQF_SHARED flag:
genirq: Flags mismatch irq 31. 00000000 (hvc_console) vs. 00000000 (hvc_console)
hvc_open: request_irq failed with rc -16.
This error propagates up to hvc_open() and the console is closed, but
OPAL will still generate interrupts that are not handled, leading to
rcu_sched stall warnings.
Set IRQF_SHARED when calling request_irq(), allowing additional consoles
to start properly. This is only set for consoles handled by
hvc_opal_probe(), leaving other types unaffected.
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
55 lines
1013 B
C
55 lines
1013 B
C
/*
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* Copyright IBM Corp. 2001,2008
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*
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* This file contains the IRQ specific code for hvc_console
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*
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*/
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#include <linux/interrupt.h>
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#include "hvc_console.h"
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static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
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{
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/* if hvc_poll request a repoll, then kick the hvcd thread */
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if (hvc_poll(dev_instance))
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hvc_kick();
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/*
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* We're safe to always return IRQ_HANDLED as the hvcd thread will
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* iterate through each hvc_struct.
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*/
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return IRQ_HANDLED;
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}
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/*
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* For IRQ based systems these callbacks can be used
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*/
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int notifier_add_irq(struct hvc_struct *hp, int irq)
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{
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int rc;
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if (!irq) {
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hp->irq_requested = 0;
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return 0;
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}
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rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
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"hvc_console", hp);
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if (!rc)
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hp->irq_requested = 1;
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return rc;
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}
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void notifier_del_irq(struct hvc_struct *hp, int irq)
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{
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if (!hp->irq_requested)
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return;
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free_irq(irq, hp);
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hp->irq_requested = 0;
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}
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void notifier_hangup_irq(struct hvc_struct *hp, int irq)
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{
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notifier_del_irq(hp, irq);
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}
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