Add a function to reconfigure the IOMMU group for a device, if necessary. IOVAs are cached in power-of-2 granules, so there is no point in allocating a new IOMMU domain if the current range is suitable.
Signed-off-by: John Garry <[email protected]> --- drivers/iommu/dma-iommu.c | 25 +++++++++++++++++++++++++ include/linux/dma-iommu.h | 4 ++++ 2 files changed, 29 insertions(+) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index f6d3302bb829..4fb82c554ede 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -315,6 +315,31 @@ static bool dev_is_untrusted(struct device *dev) return dev_is_pci(dev) && to_pci_dev(dev)->untrusted; } +void iommu_reconfig_dev_group_dma(struct device *dev) +{ + struct iommu_domain *domain = iommu_get_domain_for_dev(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + unsigned long shift, iova_len; + struct iova_domain *iovad; + size_t max_opt_dma_size; + + if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE) + return; + + max_opt_dma_size = iommu_group_get_max_opt_dma_size(dev->iommu_group); + if (!max_opt_dma_size) + return; + + iovad = &cookie->iovad; + shift = iova_shift(iovad); + iova_len = max_opt_dma_size >> shift; + + if (iova_domain_len_is_cached(iovad, iova_len)) + return; + + iommu_realloc_dev_group(dev); +} + /** * iommu_dma_init_domain - Initialise a DMA mapping domain * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 6e75a2d689b4..097398b76dcc 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -20,6 +20,7 @@ void iommu_put_dma_cookie(struct iommu_domain *domain); /* Setup call for arch DMA mapping code */ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size); +void iommu_reconfig_dev_group_dma(struct device *dev); /* The DMA API isn't _quite_ the whole story, though... */ /* @@ -53,6 +54,9 @@ static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size) { } +static inline void iommu_reconfig_dev_group_dma(struct device *dev) +{ +} static inline int iommu_get_dma_cookie(struct iommu_domain *domain) { -- 2.26.2 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
