Messages in this thread | | | Date | Thu, 23 Jun 2022 09:38:05 +0100 | Subject | Re: [PATCH v3 2/4] dma-iommu: Add iommu_dma_opt_mapping_size() | From | John Garry <> |
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On 14/06/2022 14:12, John Garry wrote: > On 06/06/2022 10:30, John Garry wrote: >> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which >> allows the drivers to know the optimal mapping limit and thus limit the >> requested IOVA lengths. >> >> This value is based on the IOVA rcache range limit, as IOVAs allocated >> above this limit must always be newly allocated, which may be quite slow. >> > > Can I please get some sort of ack from the IOMMU people on this one? >
Another request for an ack please.
Thanks, john
> >> Signed-off-by: John Garry <john.garry@huawei.com> >> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> >> --- >> drivers/iommu/dma-iommu.c | 6 ++++++ >> drivers/iommu/iova.c | 5 +++++ >> include/linux/iova.h | 2 ++ >> 3 files changed, 13 insertions(+) >> >> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c >> index f90251572a5d..9e1586447ee8 100644 >> --- a/drivers/iommu/dma-iommu.c >> +++ b/drivers/iommu/dma-iommu.c >> @@ -1459,6 +1459,11 @@ static unsigned long >> iommu_dma_get_merge_boundary(struct device *dev) >> return (1UL << __ffs(domain->pgsize_bitmap)) - 1; >> } >> +static size_t iommu_dma_opt_mapping_size(void) >> +{ >> + return iova_rcache_range(); >> +} >> + >> static const struct dma_map_ops iommu_dma_ops = { >> .alloc = iommu_dma_alloc, >> .free = iommu_dma_free, >> @@ -1479,6 +1484,7 @@ static const struct dma_map_ops iommu_dma_ops = { >> .map_resource = iommu_dma_map_resource, >> .unmap_resource = iommu_dma_unmap_resource, >> .get_merge_boundary = iommu_dma_get_merge_boundary, >> + .opt_mapping_size = iommu_dma_opt_mapping_size, >> }; >> /* >> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c >> index db77aa675145..9f00b58d546e 100644 >> --- a/drivers/iommu/iova.c >> +++ b/drivers/iommu/iova.c >> @@ -26,6 +26,11 @@ static unsigned long iova_rcache_get(struct >> iova_domain *iovad, >> static void free_cpu_cached_iovas(unsigned int cpu, struct >> iova_domain *iovad); >> static void free_iova_rcaches(struct iova_domain *iovad); >> +unsigned long iova_rcache_range(void) >> +{ >> + return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1); >> +} >> + >> static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node) >> { >> struct iova_domain *iovad; >> diff --git a/include/linux/iova.h b/include/linux/iova.h >> index 320a70e40233..c6ba6d95d79c 100644 >> --- a/include/linux/iova.h >> +++ b/include/linux/iova.h >> @@ -79,6 +79,8 @@ static inline unsigned long iova_pfn(struct >> iova_domain *iovad, dma_addr_t iova) >> int iova_cache_get(void); >> void iova_cache_put(void); >> +unsigned long iova_rcache_range(void); >> + >> void free_iova(struct iova_domain *iovad, unsigned long pfn); >> void __free_iova(struct iova_domain *iovad, struct iova *iova); >> struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size, >
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