[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v8 10/10] xen/arm: make accesses to desc->status flags atomic
Using *_bit manipulation functions on desc->status is safe on arm64: status is an unsigned int but is the first field of a struct that contains pointers, therefore the alignement of the struct is at least 8 bytes. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Changes in v2: - rebase on ab78724fc5628318b172b4344f7280621a151e1b. --- xen/arch/arm/gic-v2.c | 4 ++-- xen/arch/arm/gic.c | 6 +++--- xen/arch/arm/irq.c | 33 +++++++++++++++++---------------- 3 files changed, 22 insertions(+), 21 deletions(-) diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c index ae95178..30fd32c 100644 --- a/xen/arch/arm/gic-v2.c +++ b/xen/arch/arm/gic-v2.c @@ -519,7 +519,7 @@ static void gicv2_irq_enable(struct irq_desc *desc) ASSERT(spin_is_locked(&desc->lock)); spin_lock_irqsave(&gicv2.lock, flags); - desc->status &= ~IRQ_DISABLED; + clear_bit(_IRQ_DISABLED, &desc->status); dsb(sy); /* Enable routing */ writel_gicd((1u << (irq % 32)), GICD_ISENABLER + (irq / 32) * 4); @@ -536,7 +536,7 @@ static void gicv2_irq_disable(struct irq_desc *desc) spin_lock_irqsave(&gicv2.lock, flags); /* Disable routing */ writel_gicd(1u << (irq % 32), GICD_ICENABLER + (irq / 32) * 4); - desc->status |= IRQ_DISABLED; + set_bit(_IRQ_DISABLED, &desc->status); spin_unlock_irqrestore(&gicv2.lock, flags); } diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index d7e1882..d7a120f 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -115,7 +115,7 @@ void gic_route_irq_to_xen(struct irq_desc *desc, const cpumask_t *cpu_mask, { ASSERT(priority <= 0xff); /* Only 8 bits of priority */ ASSERT(desc->irq < gic_number_lines());/* Can't route interrupts that don't exist */ - ASSERT(desc->status & IRQ_DISABLED); + ASSERT(test_bit(_IRQ_DISABLED, &desc->status)); ASSERT(spin_is_locked(&desc->lock)); desc->handler = gic_hw_ops->gic_host_irq_type; @@ -133,7 +133,7 @@ void gic_route_irq_to_guest(struct domain *d, struct irq_desc *desc, ASSERT(spin_is_locked(&desc->lock)); desc->handler = gic_hw_ops->gic_guest_irq_type; - desc->status |= IRQ_GUEST; + set_bit(_IRQ_GUEST, &desc->status); gic_set_irq_properties(desc, cpumask_of(smp_processor_id()), GIC_PRI_IRQ); @@ -369,7 +369,7 @@ static void gic_update_one_lr(struct vcpu *v, int i) if ( p->desc != NULL ) { - p->desc->status &= ~IRQ_INPROGRESS; + clear_bit(_IRQ_INPROGRESS, &p->desc->status); if ( platform_has_quirk(PLATFORM_QUIRK_GUEST_PIRQ_NEED_EOI) ) gic_hw_ops->deactivate_irq(p->desc); } diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c index 695c69f..0c6f653 100644 --- a/xen/arch/arm/irq.c +++ b/xen/arch/arm/irq.c @@ -126,7 +126,7 @@ static inline struct domain *irq_get_domain(struct irq_desc *desc) { ASSERT(spin_is_locked(&desc->lock)); - if ( !(desc->status & IRQ_GUEST) ) + if ( !test_bit(_IRQ_GUEST, &desc->status) ) return dom_xen; ASSERT(desc->action != NULL); @@ -195,13 +195,13 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq) goto out; } - if ( desc->status & IRQ_GUEST ) + if ( test_bit(_IRQ_GUEST, &desc->status) ) { struct domain *d = irq_get_domain(desc); desc->handler->end(desc); - desc->status |= IRQ_INPROGRESS; + set_bit(_IRQ_INPROGRESS, &desc->status); desc->arch.eoi_cpu = smp_processor_id(); /* the irq cannot be a PPI, we only support delivery of SPIs to @@ -210,22 +210,23 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq) goto out_no_end; } - desc->status |= IRQ_PENDING; + set_bit(_IRQ_PENDING, &desc->status); /* * Since we set PENDING, if another processor is handling a different * instance of this same irq, the other processor will take care of it. */ - if ( desc->status & (IRQ_DISABLED | IRQ_INPROGRESS) ) + if ( test_bit(_IRQ_DISABLED, &desc->status) || + test_bit(_IRQ_INPROGRESS, &desc->status) ) goto out; - desc->status |= IRQ_INPROGRESS; + set_bit(_IRQ_INPROGRESS, &desc->status); - while ( desc->status & IRQ_PENDING ) + while ( test_bit(_IRQ_PENDING, &desc->status) ) { struct irqaction *action; - desc->status &= ~IRQ_PENDING; + clear_bit(_IRQ_PENDING, &desc->status); action = desc->action; spin_unlock_irq(&desc->lock); @@ -239,7 +240,7 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq) spin_lock_irq(&desc->lock); } - desc->status &= ~IRQ_INPROGRESS; + clear_bit(_IRQ_INPROGRESS, &desc->status); out: desc->handler->end(desc); @@ -282,13 +283,13 @@ void release_irq(unsigned int irq, const void *dev_id) if ( !desc->action ) { desc->handler->shutdown(desc); - desc->status &= ~IRQ_GUEST; + clear_bit(_IRQ_GUEST, &desc->status); } 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 ); + do { smp_mb(); } while ( test_bit(_IRQ_INPROGRESS, &desc->status) ); if ( action->free_on_release ) xfree(action); @@ -305,13 +306,13 @@ static int __setup_irq(struct irq_desc *desc, unsigned int irqflags, * - if the IRQ is marked as shared * - dev_id is not NULL when IRQ_SHARED is set */ - if ( desc->action != NULL && (!(desc->status & IRQ_SHARED) || !shared) ) + if ( desc->action != NULL && (!test_bit(_IRQ_SHARED, &desc->status) || !shared) ) return -EINVAL; if ( shared && new->dev_id == NULL ) return -EINVAL; if ( shared ) - desc->status |= IRQ_SHARED; + set_bit(IRQ_SHARED, &desc->status); new->next = desc->action; dsb(ish); @@ -332,7 +333,7 @@ int setup_irq(unsigned int irq, unsigned int irqflags, struct irqaction *new) spin_lock_irqsave(&desc->lock, flags); - if ( desc->status & IRQ_GUEST ) + if ( test_bit(_IRQ_GUEST, &desc->status) ) { struct domain *d = irq_get_domain(desc); @@ -396,10 +397,10 @@ int route_irq_to_guest(struct domain *d, unsigned int irq, { struct domain *ad = irq_get_domain(desc); - if ( (desc->status & IRQ_GUEST) && d == ad ) + if ( test_bit(_IRQ_GUEST, &desc->status) && d == ad ) goto out; - if ( desc->status & IRQ_GUEST ) + if ( test_bit(_IRQ_GUEST, &desc->status) ) printk(XENLOG_ERR "ERROR: IRQ %u is already used by domain %u\n", irq, ad->domain_id); else -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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