diff options
Diffstat (limited to 'drivers/iommu/dma-iommu.c')
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 7195d46f8233..6c6e70c56d88 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -203,6 +203,7 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, struct iommu_dma_cookie *cookie = domain->iova_cookie; struct iova_domain *iovad = &cookie->iovad; unsigned long order, base_pfn, end_pfn; + bool pci = dev && dev_is_pci(dev); if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE) return -EINVAL; @@ -225,19 +226,31 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, end_pfn = min_t(unsigned long, end_pfn, domain->geometry.aperture_end >> order); } + /* + * PCI devices may have larger DMA masks, but still prefer allocating + * within a 32-bit mask to avoid DAC addressing. Such limitations don't + * apply to the typical platform device, so for those we may as well + * leave the cache limit at the top of their range to save an rb_last() + * traversal on every allocation. + */ + if (pci) + end_pfn &= DMA_BIT_MASK(32) >> order; - /* All we can safely do with an existing domain is enlarge it */ + /* start_pfn is always nonzero for an already-initialised domain */ if (iovad->start_pfn) { if (1UL << order != iovad->granule || - base_pfn != iovad->start_pfn || - end_pfn < iovad->dma_32bit_pfn) { + base_pfn != iovad->start_pfn) { pr_warn("Incompatible range for DMA domain\n"); return -EFAULT; } - iovad->dma_32bit_pfn = end_pfn; + /* + * If we have devices with different DMA masks, move the free + * area cache limit down for the benefit of the smaller one. + */ + iovad->dma_32bit_pfn = min(end_pfn, iovad->dma_32bit_pfn); } else { init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn); - if (dev && dev_is_pci(dev)) + if (pci) iova_reserve_pci_windows(to_pci_dev(dev), iovad); } return 0; |