From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: [PATCH v3 18/18] xen/arm: IRQ: Handle multiple action per IRQ Date: Tue, 8 Apr 2014 15:44:07 +0100 Message-ID: <1396968247-8768-19-git-send-email-julien.grall@linaro.org> References: <1396968247-8768-1-git-send-email-julien.grall@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WXXGN-0000R8-Et for xen-devel@lists.xenproject.org; Tue, 08 Apr 2014 14:44:35 +0000 Received: by mail-ee0-f43.google.com with SMTP id e53so771777eek.30 for ; Tue, 08 Apr 2014 07:44:33 -0700 (PDT) In-Reply-To: <1396968247-8768-1-git-send-email-julien.grall@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: Keir Fraser , ian.campbell@citrix.com, Julien Grall , tim@xen.org, stefano.stabellini@citrix.com, Jan Beulich List-Id: xen-devel@lists.xenproject.org On ARM, it may happen (eg ARM SMMU) to setup multiple handler for the same interrupt. To be able to use multiple action, the driver has to explicitly call {setup,request}_irq with IRQF_SHARED as 2nd parameter. The behavior stays the same on x86, e.g only one action is handled. Signed-off-by: Julien Grall Cc: Keir Fraser Cc: Jan Beulich --- Changes in v3: - Drop {setup,request}_irq_flags, the current function has been extended on an earlier patch. - Rename IRQ_SHARED into IRQF_SHARED Changes in v2: - Explain design choice - Introduce CONFIG_IRQ_HAS_MULTIPLE_ACTION - Use list instead of custom pointer - release_irq should not shutdown the IRQ at the beginning - Add IRQ_SHARED flags - Introduce request_irq_flags and setup_irq_flags - Fix compilation on x86. Some code are creating the irqaction via = { ... } so the "next" field should be moved toward the end --- xen/arch/arm/irq.c | 83 +++++++++++++++++++++++++++++++----------- xen/common/irq.c | 3 ++ xen/include/asm-arm/config.h | 2 + xen/include/xen/irq.h | 8 ++++ 4 files changed, 74 insertions(+), 22 deletions(-) diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c index 18217e8..31edfc8 100644 --- a/xen/arch/arm/irq.c +++ b/xen/arch/arm/irq.c @@ -68,7 +68,6 @@ static int __init init_irq_data(void) struct irq_desc *desc = irq_to_desc(irq); init_one_irq_desc(desc); desc->irq = irq; - desc->action = NULL; } return 0; @@ -82,7 +81,6 @@ static int __cpuinit init_local_irq_data(void) struct irq_desc *desc = irq_to_desc(irq); init_one_irq_desc(desc); desc->irq = irq; - desc->action = NULL; /* PPIs are include in local_irqs, we have to copy the IRQ type from * CPU0 otherwise we may miss the type if the IRQ type has been @@ -107,11 +105,15 @@ void __cpuinit init_secondary_IRQ(void) static inline struct domain *irq_get_domain(struct irq_desc *desc) { + struct irqaction *action; + ASSERT(spin_is_locked(&desc->lock)); ASSERT(desc->status & IRQ_GUEST); - ASSERT(desc->action != NULL); + ASSERT(!list_empty(&desc->action)); + + action = list_entry(desc->action.next, struct irqaction, next); - return desc->action->dev_id; + return action->dev_id; } int request_irq(unsigned int irq, unsigned int irqflags, @@ -152,7 +154,6 @@ int request_irq(unsigned int irq, unsigned int irqflags, void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq) { struct irq_desc *desc = irq_to_desc(irq); - struct irqaction *action = desc->action; /* TODO: perfc_incr(irqs); */ @@ -163,7 +164,7 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq) spin_lock(&desc->lock); desc->handler->ack(desc); - if ( action == NULL ) + if ( list_empty(&desc->action) ) { printk("Unknown %s %#3.3x\n", is_fiq ? "FIQ" : "IRQ", irq); @@ -195,12 +196,14 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq) desc->status |= IRQ_INPROGRESS; - action = desc->action; while ( desc->status & IRQ_PENDING ) { + struct irqaction *action, *next; + desc->status &= ~IRQ_PENDING; spin_unlock_irq(&desc->lock); - action->handler(irq, action->dev_id, regs); + list_for_each_entry_safe(action, next, &desc->action, next) + action->handler(irq, action->dev_id, regs); spin_lock_irq(&desc->lock); } @@ -217,33 +220,69 @@ void release_irq(unsigned int irq, const void *dev_id) { struct irq_desc *desc; unsigned long flags; - struct irqaction *action; + struct irqaction *action; + bool_t found = 0; desc = irq_to_desc(irq); spin_lock_irqsave(&desc->lock,flags); - desc->handler->shutdown(desc); + list_for_each_entry(action, &desc->action, next) + { + if ( action->dev_id == dev_id ) + { + found = 1; + break; + } + } + + if ( !found ) + { + printk(XENLOG_WARNING "Trying to free already-free IRQ %u\n", irq); + return; + } - action = desc->action; - desc->action = NULL; - desc->status &= ~IRQ_GUEST; + /* Found it - remove it from the action list */ + list_del_init(&action->next); + + /* If this was the last action, shut down the IRQ */ + if ( list_empty(&desc->action) ) + { + desc->handler->shutdown(desc); + desc->status &= ~IRQ_GUEST; + } spin_unlock_irqrestore(&desc->lock,flags); /* Wait to make sure it's not being used on another CPU */ do { smp_mb(); } while ( desc->status & IRQ_INPROGRESS ); - if ( action && action->free_on_release ) + if ( action->free_on_release ) xfree(action); } -static int __setup_irq(struct irq_desc *desc, struct irqaction *new) +static int __setup_irq(struct irq_desc *desc, unsigned int irqflags, + struct irqaction *new) { - if ( desc->action != NULL ) - return -EBUSY; + bool_t shared = !!(irqflags & IRQF_SHARED); + + ASSERT(new != NULL); + + /* Sanity checks: + * - if the IRQ is marked as shared + * - dev_id is not NULL when IRQF_SHARED is set + */ + if ( !list_empty(&desc->action) && + (!(desc->status & IRQF_SHARED) || !shared) ) + return -EINVAL; + if ( shared && new->dev_id == NULL ) + return -EINVAL; + + if ( shared ) + desc->status |= IRQF_SHARED; - desc->action = new; + INIT_LIST_HEAD(&new->next); + list_add_tail(&new->next, &desc->action); dsb(sy); return 0; @@ -270,9 +309,9 @@ int setup_irq(unsigned int irq, unsigned int irqflags, struct irqaction *new) return -EBUSY; } - disabled = (desc->action == NULL); + disabled = list_empty(&desc->action); - rc = __setup_irq(desc, new); + rc = __setup_irq(desc, irqflags, new); if ( rc ) goto err; @@ -320,7 +359,7 @@ int route_dt_irq_to_guest(struct domain *d, const struct dt_irq *irq, * - Otherwise -> For now, don't allow the IRQ to be shared between * Xen and domains. */ - if ( desc->action != NULL ) + if ( !list_empty(&desc->action) ) { struct domain *ad = irq_get_domain(desc); @@ -337,7 +376,7 @@ int route_dt_irq_to_guest(struct domain *d, const struct dt_irq *irq, goto out; } - retval = __setup_irq(desc, action); + retval = __setup_irq(desc, 0, action); if ( retval ) { xfree(action); diff --git a/xen/common/irq.c b/xen/common/irq.c index 3e55dfa..688e48a 100644 --- a/xen/common/irq.c +++ b/xen/common/irq.c @@ -17,6 +17,9 @@ int init_one_irq_desc(struct irq_desc *desc) spin_lock_init(&desc->lock); cpumask_setall(desc->affinity); INIT_LIST_HEAD(&desc->rl_link); +#ifdef CONFIG_IRQ_HAS_MULTIPLE_ACTION + INIT_LIST_HEAD(&desc->action); +#endif err = arch_init_one_irq_desc(desc); if ( err ) diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h index 5b7b1a8..079e8b9 100644 --- a/xen/include/asm-arm/config.h +++ b/xen/include/asm-arm/config.h @@ -37,6 +37,8 @@ #define CONFIG_VIDEO 1 +#define CONFIG_IRQ_HAS_MULTIPLE_ACTION 1 + #define OPT_CONSOLE_STR "dtuart" #ifdef MAX_PHYS_CPUS diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h index f9a18d8..c42b022 100644 --- a/xen/include/xen/irq.h +++ b/xen/include/xen/irq.h @@ -14,6 +14,9 @@ struct irqaction { const char *name; void *dev_id; bool_t free_on_release; +#ifdef CONFIG_IRQ_HAS_MULTIPLE_ACTION + struct list_head next; +#endif }; /* @@ -27,6 +30,7 @@ struct irqaction { #define IRQ_MOVE_PENDING (1u<<5) /* IRQ is migrating to another CPUs */ #define IRQ_PER_CPU (1u<<6) /* IRQ is per CPU */ #define IRQ_GUEST_EOI_PENDING (1u<<7) /* IRQ was disabled, pending a guest EOI */ +#define IRQF_SHARED (1<<8) /* IRQ is shared */ /* Special IRQ numbers. */ #define AUTO_ASSIGN_IRQ (-1) @@ -68,7 +72,11 @@ typedef struct irq_desc { unsigned int status; /* IRQ status */ hw_irq_controller *handler; struct msi_desc *msi_desc; +#ifdef CONFIG_IRQ_HAS_MULTIPLE_ACTION + struct list_head action; /* IRQ action list */ +#else struct irqaction *action; /* IRQ action list */ +#endif int irq; spinlock_t lock; struct arch_irq_desc arch; -- 1.7.10.4