From 921b1f52c942ad2da971c38f54a2045ec7cfe9cb Mon Sep 17 00:00:00 2001 From: Robin Murphy <robin.murphy@arm.com> Date: Tue, 19 Apr 2016 17:01:32 +0100 Subject: [PATCH] arm64/dma-mapping: Remove default domain workaround With the IOMMU core now taking care of default domains for groups regardless of bus type, we can gleefully rip out this stop-gap, as slight recompense for having to expand the other one. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/mm/dma-mapping.c | 52 ++++++------------------------------- 1 file changed, 8 insertions(+), 44 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 607e70911173..fd8b9426f140 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -804,57 +804,24 @@ struct iommu_dma_notifier_data { static LIST_HEAD(iommu_dma_masters); static DEFINE_MUTEX(iommu_dma_notifier_lock); -/* - * Temporarily "borrow" a domain feature flag to to tell if we had to resort - * to creating our own domain here, in case we need to clean it up again. - */ -#define __IOMMU_DOMAIN_FAKE_DEFAULT (1U << 31) - static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops, u64 dma_base, u64 size) { struct iommu_domain *domain = iommu_get_domain_for_dev(dev); /* - * Best case: The device is either part of a group which was - * already attached to a domain in a previous call, or it's - * been put in a default DMA domain by the IOMMU core. + * If the IOMMU driver has the DMA domain support that we require, + * then the IOMMU core will have already configured a group for this + * device, and allocated the default domain for that group. */ - if (!domain) { - /* - * Urgh. The IOMMU core isn't going to do default domains - * for non-PCI devices anyway, until it has some means of - * abstracting the entirely implementation-specific - * sideband data/SoC topology/unicorn dust that may or - * may not differentiate upstream masters. - * So until then, HORRIBLE HACKS! - */ - domain = ops->domain_alloc(IOMMU_DOMAIN_DMA); - if (!domain) - goto out_no_domain; - - domain->ops = ops; - domain->type = IOMMU_DOMAIN_DMA | __IOMMU_DOMAIN_FAKE_DEFAULT; - - if (iommu_attach_device(domain, dev)) - goto out_put_domain; + if (!domain || iommu_dma_init_domain(domain, dma_base, size)) { + pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n", + dev_name(dev)); + return false; } - if (iommu_dma_init_domain(domain, dma_base, size)) - goto out_detach; - dev->archdata.dma_ops = &iommu_dma_ops; return true; - -out_detach: - iommu_detach_device(domain, dev); -out_put_domain: - if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT) - iommu_domain_free(domain); -out_no_domain: - pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n", - dev_name(dev)); - return false; } static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops, @@ -971,11 +938,8 @@ void arch_teardown_dma_ops(struct device *dev) { struct iommu_domain *domain = iommu_get_domain_for_dev(dev); - if (domain) { + if (WARN_ON(domain)) iommu_detach_device(domain, dev); - if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT) - iommu_domain_free(domain); - } dev->archdata.dma_ops = NULL; }