diff options
Diffstat (limited to 'drivers/iommu/dma-iommu.c')
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index af765c813cc8..fdd095e1fa52 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -52,6 +52,17 @@ struct iommu_dma_cookie { }; static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled); +bool iommu_dma_forcedac __read_mostly; + +static int __init iommu_dma_forcedac_setup(char *str) +{ + int ret = kstrtobool(str, &iommu_dma_forcedac); + + if (!ret && iommu_dma_forcedac) + pr_info("Forcing DAC for PCI devices\n"); + return ret; +} +early_param("iommu.forcedac", iommu_dma_forcedac_setup); void iommu_dma_free_cpu_cached_iovas(unsigned int cpu, struct iommu_domain *domain) @@ -444,7 +455,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain, dma_limit = min(dma_limit, (u64)domain->geometry.aperture_end); /* Try to get PCI devices a SAC address */ - if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev)) + if (dma_limit > DMA_BIT_MASK(32) && !iommu_dma_forcedac && dev_is_pci(dev)) iova = alloc_iova_fast(iovad, iova_len, DMA_BIT_MASK(32) >> shift, false); |