From 7f1b1244e159a8490d7fb13667c6cb7e1e75046b Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Thu, 7 Apr 2011 06:01:44 +0900 Subject: [PATCH] genirq: Support per-IRQ thread disabling. This adds support for disabling threading on a per-IRQ basis via the IRQ status instead of the IRQ flow, which is necessary for interrupts that don't follow the natural IRQ flow channels, such as those that are virtually created. The new APIs added are simply: irq_set_thread() irq_set_nothread() which follow the rest of the IRQ status routines. Chained handlers also have IRQ_NOTHREAD set on them automatically, making the lack of threading explicit rather than implicit. Subsequently, the nothread flag can be viewed through the standard genirq debugging facilities. [ tglx: Fixed cleanup fallout ] Signed-off-by: Paul Mundt Link: http://lkml.kernel.org/r/%3C20110406210135.GF18426%40linux-sh.org%3E Signed-off-by: Thomas Gleixner --- include/linux/irq.h | 14 +++++++++++++- kernel/irq/chip.c | 1 + kernel/irq/debug.h | 1 + kernel/irq/manage.c | 3 ++- kernel/irq/settings.h | 17 +++++++++++++++++ 5 files changed, 34 insertions(+), 2 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index a71dd18639fb..39c23786c1db 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -59,6 +59,7 @@ typedef void (*irq_preflow_handler_t)(struct irq_data *data); * IRQ_NOPROBE - Interrupt cannot be probed by autoprobing * IRQ_NOREQUEST - Interrupt cannot be requested via * request_irq() + * IRQ_NOTHREAD - Interrupt cannot be threaded * IRQ_NOAUTOEN - Interrupt is not automatically enabled in * request/setup_irq() * IRQ_NO_BALANCING - Interrupt cannot be balanced (affinity set) @@ -85,6 +86,7 @@ enum { IRQ_NO_BALANCING = (1 << 13), IRQ_MOVE_PCNTXT = (1 << 14), IRQ_NESTED_THREAD = (1 << 15), + IRQ_NOTHREAD = (1 << 16), }; #define IRQF_MODIFY_MASK \ @@ -422,7 +424,7 @@ irq_set_handler(unsigned int irq, irq_flow_handler_t handle) /* * Set a highlevel chained flow handler for a given IRQ. * (a chained handler is automatically enabled and set to - * IRQ_NOREQUEST and IRQ_NOPROBE) + * IRQ_NOREQUEST, IRQ_NOPROBE, and IRQ_NOTHREAD) */ static inline void irq_set_chained_handler(unsigned int irq, irq_flow_handler_t handle) @@ -452,6 +454,16 @@ static inline void irq_set_probe(unsigned int irq) irq_modify_status(irq, IRQ_NOPROBE, 0); } +static inline void irq_set_nothread(unsigned int irq) +{ + irq_modify_status(irq, 0, IRQ_NOTHREAD); +} + +static inline void irq_set_thread(unsigned int irq) +{ + irq_modify_status(irq, IRQ_NOTHREAD, 0); +} + static inline void irq_set_nested_thread(unsigned int irq, bool nest) { if (nest) diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 4af1e2b244cb..52d856d513ff 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -573,6 +573,7 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, if (handle != handle_bad_irq && is_chained) { irq_settings_set_noprobe(desc); irq_settings_set_norequest(desc); + irq_settings_set_nothread(desc); irq_startup(desc); } out: diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h index 306cba37e9a5..97a8bfadc88a 100644 --- a/kernel/irq/debug.h +++ b/kernel/irq/debug.h @@ -27,6 +27,7 @@ static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc) P(IRQ_PER_CPU); P(IRQ_NOPROBE); P(IRQ_NOREQUEST); + P(IRQ_NOTHREAD); P(IRQ_NOAUTOEN); PS(IRQS_AUTODETECT); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 07c1611f3899..f7ce0021e1c4 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -900,7 +900,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) */ new->handler = irq_nested_primary_handler; } else { - irq_setup_forced_threading(new); + if (irq_settings_can_thread(desc)) + irq_setup_forced_threading(new); } /* diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index 0d91730b6330..f1667833d444 100644 --- a/kernel/irq/settings.h +++ b/kernel/irq/settings.h @@ -8,6 +8,7 @@ enum { _IRQ_LEVEL = IRQ_LEVEL, _IRQ_NOPROBE = IRQ_NOPROBE, _IRQ_NOREQUEST = IRQ_NOREQUEST, + _IRQ_NOTHREAD = IRQ_NOTHREAD, _IRQ_NOAUTOEN = IRQ_NOAUTOEN, _IRQ_MOVE_PCNTXT = IRQ_MOVE_PCNTXT, _IRQ_NO_BALANCING = IRQ_NO_BALANCING, @@ -20,6 +21,7 @@ enum { #define IRQ_LEVEL GOT_YOU_MORON #define IRQ_NOPROBE GOT_YOU_MORON #define IRQ_NOREQUEST GOT_YOU_MORON +#define IRQ_NOTHREAD GOT_YOU_MORON #define IRQ_NOAUTOEN GOT_YOU_MORON #define IRQ_NESTED_THREAD GOT_YOU_MORON #undef IRQF_MODIFY_MASK @@ -94,6 +96,21 @@ static inline void irq_settings_set_norequest(struct irq_desc *desc) desc->status_use_accessors |= _IRQ_NOREQUEST; } +static inline bool irq_settings_can_thread(struct irq_desc *desc) +{ + return !(desc->status_use_accessors & _IRQ_NOTHREAD); +} + +static inline void irq_settings_clr_nothread(struct irq_desc *desc) +{ + desc->status_use_accessors &= ~_IRQ_NOTHREAD; +} + +static inline void irq_settings_set_nothread(struct irq_desc *desc) +{ + desc->status_use_accessors |= _IRQ_NOTHREAD; +} + static inline bool irq_settings_can_probe(struct irq_desc *desc) { return !(desc->status_use_accessors & _IRQ_NOPROBE);