linux-hardened/kernel/irq/chip.c
Steven Rostedt 971e5b35fb genirq: revert lazy irq disable for simple irqs
In commit 76d2160147 lazy irq disabling
was implemented, and the simple irq handler had a masking set to it.

Remy Bohmer discovered that some devices in the ARM architecture
would trigger the mask, but never unmask it. His patch to do the
unmasking was questioned by Russell King about masking simple irqs
to begin with. Looking further, it was discovered that the problems
Remy was seeing was due to improper use of the simple handler by
devices, and he later submitted patches to fix those. But the issue
that was uncovered was that the simple handler should never mask.

This patch reverts the masking in the simple handler.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-12-18 18:05:58 +01:00

591 lines
14 KiB
C

/*
* linux/kernel/irq/chip.c
*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006, Thomas Gleixner, Russell King
*
* This file contains the core interrupt handling code, for irq-chip
* based architectures.
*
* Detailed information is available in Documentation/DocBook/genericirq
*/
#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include "internals.h"
/**
* dynamic_irq_init - initialize a dynamically allocated irq
* @irq: irq number to initialize
*/
void dynamic_irq_init(unsigned int irq)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
WARN_ON(1);
return;
}
/* Ensure we don't have left over values from a previous use of this irq */
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
desc->status = IRQ_DISABLED;
desc->chip = &no_irq_chip;
desc->handle_irq = handle_bad_irq;
desc->depth = 1;
desc->msi_desc = NULL;
desc->handler_data = NULL;
desc->chip_data = NULL;
desc->action = NULL;
desc->irq_count = 0;
desc->irqs_unhandled = 0;
#ifdef CONFIG_SMP
desc->affinity = CPU_MASK_ALL;
#endif
spin_unlock_irqrestore(&desc->lock, flags);
}
/**
* dynamic_irq_cleanup - cleanup a dynamically allocated irq
* @irq: irq number to initialize
*/
void dynamic_irq_cleanup(unsigned int irq)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
WARN_ON(1);
return;
}
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
if (desc->action) {
spin_unlock_irqrestore(&desc->lock, flags);
printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n",
irq);
WARN_ON(1);
return;
}
desc->msi_desc = NULL;
desc->handler_data = NULL;
desc->chip_data = NULL;
desc->handle_irq = handle_bad_irq;
desc->chip = &no_irq_chip;
spin_unlock_irqrestore(&desc->lock, flags);
}
/**
* set_irq_chip - set the irq chip for an irq
* @irq: irq number
* @chip: pointer to irq chip description structure
*/
int set_irq_chip(unsigned int irq, struct irq_chip *chip)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
WARN_ON(1);
return -EINVAL;
}
if (!chip)
chip = &no_irq_chip;
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
irq_chip_set_defaults(chip);
desc->chip = chip;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_chip);
/**
* set_irq_type - set the irq type for an irq
* @irq: irq number
* @type: interrupt type - see include/linux/interrupt.h
*/
int set_irq_type(unsigned int irq, unsigned int type)
{
struct irq_desc *desc;
unsigned long flags;
int ret = -ENXIO;
if (irq >= NR_IRQS) {
printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
return -ENODEV;
}
desc = irq_desc + irq;
if (desc->chip->set_type) {
spin_lock_irqsave(&desc->lock, flags);
ret = desc->chip->set_type(irq, type);
spin_unlock_irqrestore(&desc->lock, flags);
}
return ret;
}
EXPORT_SYMBOL(set_irq_type);
/**
* set_irq_data - set irq type data for an irq
* @irq: Interrupt number
* @data: Pointer to interrupt specific data
*
* Set the hardware irq controller data for an irq
*/
int set_irq_data(unsigned int irq, void *data)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR
"Trying to install controller data for IRQ%d\n", irq);
return -EINVAL;
}
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
desc->handler_data = data;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_data);
/**
* set_irq_data - set irq type data for an irq
* @irq: Interrupt number
* @entry: Pointer to MSI descriptor data
*
* Set the hardware irq controller data for an irq
*/
int set_irq_msi(unsigned int irq, struct msi_desc *entry)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR
"Trying to install msi data for IRQ%d\n", irq);
return -EINVAL;
}
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
desc->msi_desc = entry;
if (entry)
entry->irq = irq;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
/**
* set_irq_chip_data - set irq chip data for an irq
* @irq: Interrupt number
* @data: Pointer to chip specific data
*
* Set the hardware irq chip data for an irq
*/
int set_irq_chip_data(unsigned int irq, void *data)
{
struct irq_desc *desc = irq_desc + irq;
unsigned long flags;
if (irq >= NR_IRQS || !desc->chip) {
printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
return -EINVAL;
}
spin_lock_irqsave(&desc->lock, flags);
desc->chip_data = data;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_chip_data);
/*
* default enable function
*/
static void default_enable(unsigned int irq)
{
struct irq_desc *desc = irq_desc + irq;
desc->chip->unmask(irq);
desc->status &= ~IRQ_MASKED;
}
/*
* default disable function
*/
static void default_disable(unsigned int irq)
{
}
/*
* default startup function
*/
static unsigned int default_startup(unsigned int irq)
{
irq_desc[irq].chip->enable(irq);
return 0;
}
/*
* Fixup enable/disable function pointers
*/
void irq_chip_set_defaults(struct irq_chip *chip)
{
if (!chip->enable)
chip->enable = default_enable;
if (!chip->disable)
chip->disable = default_disable;
if (!chip->startup)
chip->startup = default_startup;
if (!chip->shutdown)
chip->shutdown = chip->disable;
if (!chip->name)
chip->name = chip->typename;
if (!chip->end)
chip->end = dummy_irq_chip.end;
}
static inline void mask_ack_irq(struct irq_desc *desc, int irq)
{
if (desc->chip->mask_ack)
desc->chip->mask_ack(irq);
else {
desc->chip->mask(irq);
desc->chip->ack(irq);
}
}
/**
* handle_simple_irq - Simple and software-decoded IRQs.
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Simple interrupts are either sent from a demultiplexing interrupt
* handler or come from hardware, where no interrupt hardware control
* is necessary.
*
* Note: The caller is expected to handle the ack, clear, mask and
* unmask issues if necessary.
*/
void fastcall
handle_simple_irq(unsigned int irq, struct irq_desc *desc)
{
struct irqaction *action;
irqreturn_t action_ret;
const unsigned int cpu = smp_processor_id();
spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED)))
goto out_unlock;
desc->status |= IRQ_INPROGRESS;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
spin_unlock(&desc->lock);
}
/**
* handle_level_irq - Level type irq handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Level type interrupts are active as long as the hardware line has
* the active level. This may require to mask the interrupt and unmask
* it after the associated handler has acknowledged the device, so the
* interrupt line is back to inactive.
*/
void fastcall
handle_level_irq(unsigned int irq, struct irq_desc *desc)
{
unsigned int cpu = smp_processor_id();
struct irqaction *action;
irqreturn_t action_ret;
spin_lock(&desc->lock);
mask_ack_irq(desc, irq);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
/*
* If its disabled or no action available
* keep it masked and get out of here
*/
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED)))
goto out_unlock;
desc->status |= IRQ_INPROGRESS;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
desc->chip->unmask(irq);
out_unlock:
spin_unlock(&desc->lock);
}
/**
* handle_fasteoi_irq - irq handler for transparent controllers
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Only a single callback will be issued to the chip: an ->eoi()
* call when the interrupt has been serviced. This enables support
* for modern forms of interrupt handlers, which handle the flow
* details in hardware, transparently.
*/
void fastcall
handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
{
unsigned int cpu = smp_processor_id();
struct irqaction *action;
irqreturn_t action_ret;
spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
/*
* If its disabled or no action available
* then mask it and get out of here:
*/
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
desc->status |= IRQ_PENDING;
if (desc->chip->mask)
desc->chip->mask(irq);
goto out;
}
desc->status |= IRQ_INPROGRESS;
desc->status &= ~IRQ_PENDING;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
out:
desc->chip->eoi(irq);
spin_unlock(&desc->lock);
}
/**
* handle_edge_irq - edge type IRQ handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Interrupt occures on the falling and/or rising edge of a hardware
* signal. The occurence is latched into the irq controller hardware
* and must be acked in order to be reenabled. After the ack another
* interrupt can happen on the same source even before the first one
* is handled by the assosiacted event handler. If this happens it
* might be necessary to disable (mask) the interrupt depending on the
* controller hardware. This requires to reenable the interrupt inside
* of the loop which handles the interrupts which have arrived while
* the handler was running. If all pending interrupts are handled, the
* loop is left.
*/
void fastcall
handle_edge_irq(unsigned int irq, struct irq_desc *desc)
{
const unsigned int cpu = smp_processor_id();
spin_lock(&desc->lock);
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
/*
* If we're currently running this IRQ, or its disabled,
* we shouldn't process the IRQ. Mark it pending, handle
* the necessary masking and go out
*/
if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
!desc->action)) {
desc->status |= (IRQ_PENDING | IRQ_MASKED);
mask_ack_irq(desc, irq);
goto out_unlock;
}
kstat_cpu(cpu).irqs[irq]++;
/* Start handling the irq */
desc->chip->ack(irq);
/* Mark the IRQ currently in progress.*/
desc->status |= IRQ_INPROGRESS;
do {
struct irqaction *action = desc->action;
irqreturn_t action_ret;
if (unlikely(!action)) {
desc->chip->mask(irq);
goto out_unlock;
}
/*
* When another irq arrived while we were handling
* one, we could have masked the irq.
* Renable it, if it was not disabled in meantime.
*/
if (unlikely((desc->status &
(IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
(IRQ_PENDING | IRQ_MASKED))) {
desc->chip->unmask(irq);
desc->status &= ~IRQ_MASKED;
}
desc->status &= ~IRQ_PENDING;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
spin_lock(&desc->lock);
} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
spin_unlock(&desc->lock);
}
/**
* handle_percpu_IRQ - Per CPU local irq handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Per CPU interrupts on SMP machines without locking requirements
*/
void fastcall
handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
{
irqreturn_t action_ret;
kstat_this_cpu.irqs[irq]++;
if (desc->chip->ack)
desc->chip->ack(irq);
action_ret = handle_IRQ_event(irq, desc->action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
if (desc->chip->eoi)
desc->chip->eoi(irq);
}
void
__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
const char *name)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR
"Trying to install type control for IRQ%d\n", irq);
return;
}
desc = irq_desc + irq;
if (!handle)
handle = handle_bad_irq;
else if (desc->chip == &no_irq_chip) {
printk(KERN_WARNING "Trying to install %sinterrupt handler "
"for IRQ%d\n", is_chained ? "chained " : "", irq);
/*
* Some ARM implementations install a handler for really dumb
* interrupt hardware without setting an irq_chip. This worked
* with the ARM no_irq_chip but the check in setup_irq would
* prevent us to setup the interrupt at all. Switch it to
* dummy_irq_chip for easy transition.
*/
desc->chip = &dummy_irq_chip;
}
spin_lock_irqsave(&desc->lock, flags);
/* Uninstall? */
if (handle == handle_bad_irq) {
if (desc->chip != &no_irq_chip)
mask_ack_irq(desc, irq);
desc->status |= IRQ_DISABLED;
desc->depth = 1;
}
desc->handle_irq = handle;
desc->name = name;
if (handle != handle_bad_irq && is_chained) {
desc->status &= ~IRQ_DISABLED;
desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
desc->depth = 0;
desc->chip->unmask(irq);
}
spin_unlock_irqrestore(&desc->lock, flags);
}
void
set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handle)
{
set_irq_chip(irq, chip);
__set_irq_handler(irq, handle, 0, NULL);
}
void
set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handle, const char *name)
{
set_irq_chip(irq, chip);
__set_irq_handler(irq, handle, 0, name);
}