[PATCH v7 2/6] iommu/dma: Add support for non-strict mode
From: Will Deacon <hidden>
Date: 2018-09-18 17:09:51
Also in:
linux-iommu, lkml
Hi Robin, On Fri, Sep 14, 2018 at 03:30:20PM +0100, Robin Murphy wrote:
From: Zhen Lei <redacted> 1. Save the related domain pointer in struct iommu_dma_cookie, make iovad capable call domain->ops->flush_iotlb_all to flush TLB. 2. During the iommu domain initialization phase, base on domain->non_strict field to check whether non-strict mode is supported or not. If so, call init_iova_flush_queue to register iovad->flush_cb callback. 3. All unmap(contains iova-free) APIs will finally invoke __iommu_dma_unmap -->iommu_dma_free_iova. If the domain is non-strict, call queue_iova to put off iova freeing, and omit iommu_tlb_sync operation.
Hmm, this is basically just a commentary on the code. Please could you write it more in terms of the problem that's being solved?
quoted hunk ↗ jump to hunk
Signed-off-by: Zhen Lei <redacted> [rm: convert raw boolean to domain attribute] Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/dma-iommu.c | 29 ++++++++++++++++++++++++++++- include/linux/iommu.h | 1 + 2 files changed, 29 insertions(+), 1 deletion(-)diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 511ff9a1d6d9..092e6926dc3c 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c@@ -55,6 +55,9 @@ struct iommu_dma_cookie { }; struct list_head msi_page_list; spinlock_t msi_lock; + + /* Only be assigned in non-strict mode, otherwise it's NULL */ + struct iommu_domain *domain; }; static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)@@ -257,6 +260,17 @@ static int iova_reserve_iommu_regions(struct device *dev, return ret; } +static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad) +{ + struct iommu_dma_cookie *cookie; + struct iommu_domain *domain; + + cookie = container_of(iovad, struct iommu_dma_cookie, iovad); + domain = cookie->domain; + + domain->ops->flush_iotlb_all(domain);
Can we rely on this function pointer being non-NULL? I think it would be better to call iommu_flush_tlb_all(cookie->domain) instead.
quoted hunk ↗ jump to hunk
+} + /** * iommu_dma_init_domain - Initialise a DMA mapping domain * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()@@ -275,6 +289,7 @@ 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; + int attr = 1;
Do we actually need to initialise this? Will