From 08a543ad33fc188650801bd36eed4ffe272643e1 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Tue, 26 Jul 2011 03:19:06 -0600 Subject: irq: add irq_domain translation infrastructure This patch adds irq_domain infrastructure for translating from hardware irq numbers to linux irqs. This is particularly important for architectures adding device tree support because the current implementation (excluding PowerPC and SPARC) cannot handle translation for more than a single interrupt controller. irq_domain supports device tree translation for any number of interrupt controllers. This patch converts x86, Microblaze, ARM and MIPS to use irq_domain for device tree irq translation. x86 is untested beyond compiling it, irq_domain is enabled for MIPS and Microblaze, but the old behaviour is preserved until the core code is modified to actually register an irq_domain yet. On ARM it works and is required for much of the new ARM device tree board support. PowerPC has /not/ been converted to use this new infrastructure. It is still missing some features before it can replace the virq infrastructure already in powerpc (see documentation on irq_domain_map/unmap for details). Followup patches will add the missing pieces and migrate PowerPC to use irq_domain. SPARC has its own method of managing interrupts from the device tree and is unaffected by this change. Acked-by: Ralf Baechle Signed-off-by: Grant Likely --- include/linux/irq.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/irq.h') diff --git a/include/linux/irq.h b/include/linux/irq.h index 5f695041090c..87a06f345bd2 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -108,14 +108,18 @@ enum { }; struct msi_desc; +struct irq_domain; /** * struct irq_data - per irq and irq chip data passed down to chip functions * @irq: interrupt number + * @hwirq: hardware interrupt number, local to the interrupt domain * @node: node index useful for balancing * @state_use_accessors: status information for irq chip functions. * Use accessor functions to deal with it * @chip: low level interrupt hardware access + * @domain: Interrupt translation domain; responsible for mapping + * between hwirq number and linux irq number. * @handler_data: per-IRQ data for the irq_chip methods * @chip_data: platform-specific per-chip private data for the chip * methods, to allow shared chip implementations @@ -128,9 +132,11 @@ struct msi_desc; */ struct irq_data { unsigned int irq; + unsigned long hwirq; unsigned int node; unsigned int state_use_accessors; struct irq_chip *chip; + struct irq_domain *domain; void *handler_data; void *chip_data; struct msi_desc *msi_desc; -- cgit v1.2.3 From b6873807a7143b7d6d8b06809295e559d07d7deb Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 11 Jul 2011 12:17:31 +0200 Subject: irq: Track the owner of irq descriptor Interrupt descriptors can be allocated from modules. The interrupts are used by other modules, but we have no refcount on the module which provides the interrupts and there is no way to establish one on the device level as the interrupt using module is agnostic to the fact that the interrupt is provided by a module rather than by some builtin interrupt controller. To prevent removal of the interrupt providing module, we can track the owner of the interrupt descriptor, which also provides the relevant irq chip functions in the irq descriptor. request/setup_irq() can now acquire a refcount on the owner module to prevent unloading. free_irq() drops the refcount. Signed-off-by: Sebastian Andrzej Siewior Link: http://lkml.kernel.org/r/20110711101731.GA13804@Chamillionaire.breakpoint.cc Signed-off-by: Thomas Gleixner --- include/linux/irq.h | 11 ++++++++++- include/linux/irqdesc.h | 1 + kernel/irq/irqdesc.c | 36 ++++++++++++++++++++++++------------ kernel/irq/manage.c | 17 +++++++++++++---- 4 files changed, 48 insertions(+), 17 deletions(-) (limited to 'include/linux/irq.h') diff --git a/include/linux/irq.h b/include/linux/irq.h index baa397eb9c33..16d6f54ef1dd 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -546,7 +547,15 @@ static inline struct msi_desc *irq_data_get_msi(struct irq_data *d) return d->msi_desc; } -int irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node); +int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, + struct module *owner); + +static inline int irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, + int node) +{ + return __irq_alloc_descs(irq, from, cnt, node, THIS_MODULE); +} + void irq_free_descs(unsigned int irq, unsigned int cnt); int irq_reserve_irqs(unsigned int from, unsigned int cnt); diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 2d921b35212c..150134ac709a 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -66,6 +66,7 @@ struct irq_desc { #ifdef CONFIG_PROC_FS struct proc_dir_entry *dir; #endif + struct module *owner; const char *name; } ____cacheline_internodealigned_in_smp; diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 4c60a50e66b2..cb65d0360e31 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -70,7 +70,8 @@ static inline void desc_smp_init(struct irq_desc *desc, int node) { } static inline int desc_node(struct irq_desc *desc) { return 0; } #endif -static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node) +static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node, + struct module *owner) { int cpu; @@ -86,6 +87,7 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node) desc->irq_count = 0; desc->irqs_unhandled = 0; desc->name = NULL; + desc->owner = owner; for_each_possible_cpu(cpu) *per_cpu_ptr(desc->kstat_irqs, cpu) = 0; desc_smp_init(desc, node); @@ -128,7 +130,7 @@ static void free_masks(struct irq_desc *desc) static inline void free_masks(struct irq_desc *desc) { } #endif -static struct irq_desc *alloc_desc(int irq, int node) +static struct irq_desc *alloc_desc(int irq, int node, struct module *owner) { struct irq_desc *desc; gfp_t gfp = GFP_KERNEL; @@ -147,7 +149,7 @@ static struct irq_desc *alloc_desc(int irq, int node) raw_spin_lock_init(&desc->lock); lockdep_set_class(&desc->lock, &irq_desc_lock_class); - desc_set_defaults(irq, desc, node); + desc_set_defaults(irq, desc, node, owner); return desc; @@ -173,13 +175,14 @@ static void free_desc(unsigned int irq) kfree(desc); } -static int alloc_descs(unsigned int start, unsigned int cnt, int node) +static int alloc_descs(unsigned int start, unsigned int cnt, int node, + struct module *owner) { struct irq_desc *desc; int i; for (i = 0; i < cnt; i++) { - desc = alloc_desc(start + i, node); + desc = alloc_desc(start + i, node, owner); if (!desc) goto err; mutex_lock(&sparse_irq_lock); @@ -227,7 +230,7 @@ int __init early_irq_init(void) nr_irqs = initcnt; for (i = 0; i < initcnt; i++) { - desc = alloc_desc(i, node); + desc = alloc_desc(i, node, NULL); set_bit(i, allocated_irqs); irq_insert_desc(i, desc); } @@ -261,7 +264,7 @@ int __init early_irq_init(void) alloc_masks(&desc[i], GFP_KERNEL, node); raw_spin_lock_init(&desc[i].lock); lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); - desc_set_defaults(i, &desc[i], node); + desc_set_defaults(i, &desc[i], node, NULL); } return arch_early_irq_init(); } @@ -276,8 +279,16 @@ static void free_desc(unsigned int irq) dynamic_irq_cleanup(irq); } -static inline int alloc_descs(unsigned int start, unsigned int cnt, int node) +static inline int alloc_descs(unsigned int start, unsigned int cnt, int node, + struct module *owner) { + u32 i; + + for (i = 0; i < cnt; i++) { + struct irq_desc *desc = irq_to_desc(start + i); + + desc->owner = owner; + } return start; } @@ -337,7 +348,8 @@ EXPORT_SYMBOL_GPL(irq_free_descs); * Returns the first irq number or error code */ int __ref -irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node) +__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, + struct module *owner) { int start, ret; @@ -366,13 +378,13 @@ irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node) bitmap_set(allocated_irqs, start, cnt); mutex_unlock(&sparse_irq_lock); - return alloc_descs(start, cnt, node); + return alloc_descs(start, cnt, node, owner); err: mutex_unlock(&sparse_irq_lock); return ret; } -EXPORT_SYMBOL_GPL(irq_alloc_descs); +EXPORT_SYMBOL_GPL(__irq_alloc_descs); /** * irq_reserve_irqs - mark irqs allocated @@ -440,7 +452,7 @@ void dynamic_irq_cleanup(unsigned int irq) unsigned long flags; raw_spin_lock_irqsave(&desc->lock, flags); - desc_set_defaults(irq, desc, desc_node(desc)); + desc_set_defaults(irq, desc, desc_node(desc), NULL); raw_spin_unlock_irqrestore(&desc->lock, flags); } diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 3f9cd4799da7..2e9425889fa8 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -883,6 +883,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) if (desc->irq_data.chip == &no_irq_chip) return -ENOSYS; + if (!try_module_get(desc->owner)) + return -ENODEV; /* * Some drivers like serial.c use request_irq() heavily, * so we have to be careful not to interfere with a @@ -906,8 +908,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) */ nested = irq_settings_is_nested_thread(desc); if (nested) { - if (!new->thread_fn) - return -EINVAL; + if (!new->thread_fn) { + ret = -EINVAL; + goto out_mput; + } /* * Replace the primary handler which was provided from * the driver for non nested interrupt handling by the @@ -929,8 +933,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) t = kthread_create(irq_thread, new, "irq/%d-%s", irq, new->name); - if (IS_ERR(t)) - return PTR_ERR(t); + if (IS_ERR(t)) { + ret = PTR_ERR(t); + goto out_mput; + } /* * We keep the reference to the task struct even if * the thread dies to avoid that the interrupt code @@ -1095,6 +1101,8 @@ out_thread: kthread_stop(t); put_task_struct(t); } +out_mput: + module_put(desc->owner); return ret; } @@ -1203,6 +1211,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) put_task_struct(action->thread); } + module_put(desc->owner); return action; } -- cgit v1.2.3