Messages in this thread | | | Subject | Re: [PATCH 2/2 v2] iommu: use the __iommu_attach_device() directly for deferred attach | From | Robin Murphy <> | Date | Tue, 19 Jan 2021 13:40:10 +0000 |
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On 2021-01-19 11:16, Lianbo Jiang wrote: > Currently, because domain attach allows to be deferred from iommu > driver to device driver, and when iommu initializes, the devices > on the bus will be scanned and the default groups will be allocated. > > Due to the above changes, some devices could be added to the same > group as below: > > [ 3.859417] pci 0000:01:00.0: Adding to iommu group 16 > [ 3.864572] pci 0000:01:00.1: Adding to iommu group 16 > [ 3.869738] pci 0000:02:00.0: Adding to iommu group 17 > [ 3.874892] pci 0000:02:00.1: Adding to iommu group 17 > > But when attaching these devices, it doesn't allow that a group has > more than one device, otherwise it will return an error. This conflicts > with the deferred attaching. Unfortunately, it has two devices in the > same group for my side, for example: > > [ 9.627014] iommu_group_device_count(): device name[0]:0000:01:00.0 > [ 9.633545] iommu_group_device_count(): device name[1]:0000:01:00.1 > ... > [ 10.255609] iommu_group_device_count(): device name[0]:0000:02:00.0 > [ 10.262144] iommu_group_device_count(): device name[1]:0000:02:00.1 > > Finally, which caused the failure of tg3 driver when tg3 driver calls > the dma_alloc_coherent() to allocate coherent memory in the tg3_test_dma(). > > [ 9.660310] tg3 0000:01:00.0: DMA engine test failed, aborting > [ 9.754085] tg3: probe of 0000:01:00.0 failed with error -12 > [ 9.997512] tg3 0000:01:00.1: DMA engine test failed, aborting > [ 10.043053] tg3: probe of 0000:01:00.1 failed with error -12 > [ 10.288905] tg3 0000:02:00.0: DMA engine test failed, aborting > [ 10.334070] tg3: probe of 0000:02:00.0 failed with error -12 > [ 10.578303] tg3 0000:02:00.1: DMA engine test failed, aborting > [ 10.622629] tg3: probe of 0000:02:00.1 failed with error -12 > > In addition, the similar situations also occur in other drivers such > as the bnxt_en driver. That can be reproduced easily in kdump kernel > when SME is active > > Let's move the handling currently in iommu_dma_deferred_attach() into > the iommu core code so that it can call the __iommu_attach_device() > directly instead of the iommu_attach_device(). The external interface > iommu_attach_device() is not suitable for handling this situation.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: Lianbo Jiang <lijiang@redhat.com> > --- > drivers/iommu/dma-iommu.c | 18 +++--------------- > drivers/iommu/iommu.c | 12 ++++++++++++ > include/linux/iommu.h | 2 ++ > 3 files changed, 17 insertions(+), 15 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 3711b4a6e4f9..fa6f9098e77d 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -380,18 +380,6 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, > return iova_reserve_iommu_regions(dev, domain); > } > > -static int iommu_dma_deferred_attach(struct device *dev, > - struct iommu_domain *domain) > -{ > - const struct iommu_ops *ops = domain->ops; > - > - if (unlikely(ops->is_attach_deferred && > - ops->is_attach_deferred(domain, dev))) > - return iommu_attach_device(domain, dev); > - > - return 0; > -} > - > /** > * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API > * page flags. > @@ -535,7 +523,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, > dma_addr_t iova; > > if (static_branch_unlikely(&__deferred_attach) && > - iommu_dma_deferred_attach(dev, domain)) > + iommu_do_deferred_attach(dev, domain)) > return DMA_MAPPING_ERROR; > > size = iova_align(iovad, size + iova_off); > @@ -694,7 +682,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size, > *dma_handle = DMA_MAPPING_ERROR; > > if (static_branch_unlikely(&__deferred_attach) && > - iommu_dma_deferred_attach(dev, domain)) > + iommu_do_deferred_attach(dev, domain)) > return NULL; > > min_size = alloc_sizes & -alloc_sizes; > @@ -1005,7 +993,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, > int i; > > if (static_branch_unlikely(&__deferred_attach) && > - iommu_dma_deferred_attach(dev, domain)) > + iommu_do_deferred_attach(dev, domain)) > return 0; > > if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index ffeebda8d6de..32164d355d2e 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -1980,6 +1980,18 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) > } > EXPORT_SYMBOL_GPL(iommu_attach_device); > > +int iommu_do_deferred_attach(struct device *dev, > + struct iommu_domain *domain) > +{ > + const struct iommu_ops *ops = domain->ops; > + > + if (unlikely(ops->is_attach_deferred && > + ops->is_attach_deferred(domain, dev))) > + return __iommu_attach_device(domain, dev); > + > + return 0; > +} > + > /* > * Check flags and other user provided data for valid combinations. We also > * make sure no reserved fields or unused flags are set. This is to ensure > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index b3f0e2018c62..c04bbd30aa1d 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -424,6 +424,8 @@ extern struct iommu_group *iommu_group_get_by_id(int id); > extern void iommu_domain_free(struct iommu_domain *domain); > extern int iommu_attach_device(struct iommu_domain *domain, > struct device *dev); > +extern int iommu_do_deferred_attach(struct device *dev, > + struct iommu_domain *domain); > extern void iommu_detach_device(struct iommu_domain *domain, > struct device *dev); > extern int iommu_uapi_cache_invalidate(struct iommu_domain *domain, >
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