linux/kernel/irq/internals.h
Thomas Gleixner 8d32a307e4 genirq: Provide forced interrupt threading
Add a commandline parameter "threadirqs" which forces all interrupts except
those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to
allow retrieving better debug data from crashing interrupt handlers. If
"threadirqs" is not enabled on the kernel command line, then there is no
impact in the interrupt hotpath.

Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after
marking the interrupts which cant be threaded IRQF_NO_THREAD. All
interrupts which have IRQF_TIMER set are implict marked
IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded.

Forced threading hard interrupts also forces all soft interrupt
handling into thread context.

When enabled it might slow down things a bit, but for debugging problems in
interrupt code it's a reasonable penalty as it does not immediately
crash and burn the machine when an interrupt handler is buggy.

Some test results on a Core2Duo machine:

Cache cold run of:
 # time git grep irq_desc

      non-threaded       threaded
 real 1m18.741s          1m19.061s
 user 0m1.874s           0m1.757s
 sys  0m5.843s           0m5.427s

 # iperf -c server
non-threaded
[  3]  0.0-10.0 sec  1.09 GBytes   933 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   934 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   933 Mbits/sec
threaded
[  3]  0.0-10.0 sec  1.09 GBytes   939 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   934 Mbits/sec
[  3]  0.0-10.0 sec  1.09 GBytes   937 Mbits/sec

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-26 11:57:18 +01:00

188 lines
5.6 KiB
C

/*
* IRQ subsystem internal functions and variables:
*
* Do not ever include this file from anything else than
* kernel/irq/. Do not even think about using any information outside
* of this file for your non core code.
*/
#include <linux/irqdesc.h>
#ifdef CONFIG_SPARSE_IRQ
# define IRQ_BITMAP_BITS (NR_IRQS + 8196)
#else
# define IRQ_BITMAP_BITS NR_IRQS
#endif
#define istate core_internal_state__do_not_mess_with_it
#ifdef CONFIG_GENERIC_HARDIRQS_NO_COMPAT
# define status status_use_accessors
#endif
extern int noirqdebug;
/*
* Bits used by threaded handlers:
* IRQTF_RUNTHREAD - signals that the interrupt handler thread should run
* IRQTF_DIED - handler thread died
* IRQTF_WARNED - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed
* IRQTF_AFFINITY - irq thread is requested to adjust affinity
* IRQTF_FORCED_THREAD - irq action is force threaded
*/
enum {
IRQTF_RUNTHREAD,
IRQTF_DIED,
IRQTF_WARNED,
IRQTF_AFFINITY,
IRQTF_FORCED_THREAD,
};
/*
* Bit masks for desc->state
*
* IRQS_AUTODETECT - autodetection in progress
* IRQS_SPURIOUS_DISABLED - was disabled due to spurious interrupt
* detection
* IRQS_POLL_INPROGRESS - polling in progress
* IRQS_INPROGRESS - Interrupt in progress
* IRQS_ONESHOT - irq is not unmasked in primary handler
* IRQS_REPLAY - irq is replayed
* IRQS_WAITING - irq is waiting
* IRQS_DISABLED - irq is disabled
* IRQS_PENDING - irq is pending and replayed later
* IRQS_MASKED - irq is masked
* IRQS_SUSPENDED - irq is suspended
*/
enum {
IRQS_AUTODETECT = 0x00000001,
IRQS_SPURIOUS_DISABLED = 0x00000002,
IRQS_POLL_INPROGRESS = 0x00000008,
IRQS_INPROGRESS = 0x00000010,
IRQS_ONESHOT = 0x00000020,
IRQS_REPLAY = 0x00000040,
IRQS_WAITING = 0x00000080,
IRQS_DISABLED = 0x00000100,
IRQS_PENDING = 0x00000200,
IRQS_MASKED = 0x00000400,
IRQS_SUSPENDED = 0x00000800,
};
#include "compat.h"
#include "debug.h"
#include "settings.h"
#define irq_data_to_desc(data) container_of(data, struct irq_desc, irq_data)
/* Set default functions for irq_chip structures: */
extern void irq_chip_set_defaults(struct irq_chip *chip);
extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
unsigned long flags);
extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
extern int irq_startup(struct irq_desc *desc);
extern void irq_shutdown(struct irq_desc *desc);
extern void irq_enable(struct irq_desc *desc);
extern void irq_disable(struct irq_desc *desc);
extern void mask_irq(struct irq_desc *desc);
extern void unmask_irq(struct irq_desc *desc);
extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
irqreturn_t handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action);
irqreturn_t handle_irq_event(struct irq_desc *desc);
/* Resending of interrupts :*/
void check_irq_resend(struct irq_desc *desc, unsigned int irq);
bool irq_wait_for_poll(struct irq_desc *desc);
#ifdef CONFIG_PROC_FS
extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void unregister_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void register_handler_proc(unsigned int irq, struct irqaction *action);
extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
#else
static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }
static inline void unregister_irq_proc(unsigned int irq, struct irq_desc *desc) { }
static inline void register_handler_proc(unsigned int irq,
struct irqaction *action) { }
static inline void unregister_handler_proc(unsigned int irq,
struct irqaction *action) { }
#endif
extern int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask);
extern void irq_set_thread_affinity(struct irq_desc *desc);
/* Inline functions for support of irq chips on slow busses */
static inline void chip_bus_lock(struct irq_desc *desc)
{
if (unlikely(desc->irq_data.chip->irq_bus_lock))
desc->irq_data.chip->irq_bus_lock(&desc->irq_data);
}
static inline void chip_bus_sync_unlock(struct irq_desc *desc)
{
if (unlikely(desc->irq_data.chip->irq_bus_sync_unlock))
desc->irq_data.chip->irq_bus_sync_unlock(&desc->irq_data);
}
struct irq_desc *
__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus);
void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus);
static inline struct irq_desc *
irq_get_desc_buslock(unsigned int irq, unsigned long *flags)
{
return __irq_get_desc_lock(irq, flags, true);
}
static inline void
irq_put_desc_busunlock(struct irq_desc *desc, unsigned long flags)
{
__irq_put_desc_unlock(desc, flags, true);
}
static inline struct irq_desc *
irq_get_desc_lock(unsigned int irq, unsigned long *flags)
{
return __irq_get_desc_lock(irq, flags, false);
}
static inline void
irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags)
{
__irq_put_desc_unlock(desc, flags, false);
}
/*
* Manipulation functions for irq_data.state
*/
static inline void irqd_set_move_pending(struct irq_data *d)
{
d->state_use_accessors |= IRQD_SETAFFINITY_PENDING;
irq_compat_set_move_pending(irq_data_to_desc(d));
}
static inline void irqd_clr_move_pending(struct irq_data *d)
{
d->state_use_accessors &= ~IRQD_SETAFFINITY_PENDING;
irq_compat_clr_move_pending(irq_data_to_desc(d));
}
static inline void irqd_clear(struct irq_data *d, unsigned int mask)
{
d->state_use_accessors &= ~mask;
}
static inline void irqd_set(struct irq_data *d, unsigned int mask)
{
d->state_use_accessors |= mask;
}
static inline bool irqd_has_set(struct irq_data *d, unsigned int mask)
{
return d->state_use_accessors & mask;
}