On Tue, Sep 24, 2013 at 04:06:58PM +0100, Andreas Herrmann wrote: > With the right (or wrong;-) definition of v1 SMMU node in DTB it is > possible to trigger a division by zero in arm_smmu_init_domain_context > (if number of context irqs is 0): > > if (smmu->version == 1) { > root_cfg->irptndx = atomic_inc_return(&smmu->irptndx); > → root_cfg->irptndx %= smmu->num_context_irqs; > } else { > > Avoid this by checking for num_context_irqs > 0 before trying to > assign interrupts to contexts. > > Signed-off-by: Andreas Herrmann <andreas.herrm...@calxeda.com> > --- > drivers/iommu/arm-smmu.c | 31 +++++++++++++++++-------------- > 1 file changed, 17 insertions(+), 14 deletions(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index f5a856e..0dfd255 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -828,21 +828,24 @@ static int arm_smmu_init_domain_context(struct > iommu_domain *domain, > return ret; > > root_cfg->cbndx = ret; > - if (smmu->version == 1) { > - root_cfg->irptndx = atomic_inc_return(&smmu->irptndx); > - root_cfg->irptndx %= smmu->num_context_irqs; > - } else { > - root_cfg->irptndx = root_cfg->cbndx; > - } > > - irq = smmu->irqs[smmu->num_global_irqs + root_cfg->irptndx]; > - ret = request_irq(irq, arm_smmu_context_fault, IRQF_SHARED, > - "arm-smmu-context-fault", domain); > - if (IS_ERR_VALUE(ret)) { > - dev_err(smmu->dev, "failed to request context IRQ %d (%u)\n", > - root_cfg->irptndx, irq); > - root_cfg->irptndx = -1; > - goto out_free_context; > + if (smmu->num_context_irqs) {
Can we move this check to probe time, to avoid re-evaluating it every time we initialise a new domain? Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu