Adding Robin. On Tue, May 05, 2020 at 12:07:59AM +0530, Ajay Kumar wrote: > The current IOVA allocation code stores a cached copy of the > first allocated IOVA address node, and all the subsequent allocations > have no way to get past(higher than) the first allocated IOVA range. > > This causes issue when dma_mask for the master device is changed. > Though the DMA window is increased, the allocation code unaware of > the change, goes ahead allocating IOVA address lower than the > first allocated IOVA address. > > This patch adds a check for dma_mask change in the IOVA allocation > function and resets the cached IOVA node to anchor node everytime > the dma_mask change is observed. > > NOTE: > This patch is needed to address the issue discussed in below thread: > https://www.spinics.net/lists/iommu/msg43586.html > > Signed-off-by: Ajay Kumar <ajaykumar.rs@xxxxxxxxxxx> > Signed-off-by: Sathyam Panda <sathya.panda@xxxxxxxxxxx> > --- > drivers/iommu/iova.c | 17 ++++++++++++++++- > include/linux/iova.h | 1 + > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c > index 41c605b0058f..0e99975036ae 100644 > --- a/drivers/iommu/iova.c > +++ b/drivers/iommu/iova.c > @@ -44,6 +44,7 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule, > iovad->granule = granule; > iovad->start_pfn = start_pfn; > iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad)); > + iovad->curr_limit_pfn = iovad->dma_32bit_pfn; > iovad->max32_alloc_size = iovad->dma_32bit_pfn; > iovad->flush_cb = NULL; > iovad->fq = NULL; > @@ -116,9 +117,20 @@ EXPORT_SYMBOL_GPL(init_iova_flush_queue); > static struct rb_node * > __get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn) > { > - if (limit_pfn <= iovad->dma_32bit_pfn) > + if (limit_pfn <= iovad->dma_32bit_pfn) { > + /* re-init cached node if DMA limit has changed */ > + if (limit_pfn != iovad->curr_limit_pfn) { > + iovad->cached32_node = &iovad->anchor.node; > + iovad->curr_limit_pfn = limit_pfn; > + } > return iovad->cached32_node; > + } > > + /* re-init cached node if DMA limit has changed */ > + if (limit_pfn != iovad->curr_limit_pfn) { > + iovad->cached_node = &iovad->anchor.node; > + iovad->curr_limit_pfn = limit_pfn; > + } > return iovad->cached_node; > } > > @@ -190,6 +202,9 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad, > if (size_aligned) > align_mask <<= fls_long(size - 1); > > + if (limit_pfn != iovad->curr_limit_pfn) > + iovad->max32_alloc_size = iovad->dma_32bit_pfn; > + > /* Walk the tree backwards */ > spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); > if (limit_pfn <= iovad->dma_32bit_pfn && > diff --git a/include/linux/iova.h b/include/linux/iova.h > index a0637abffee8..be2220c096ef 100644 > --- a/include/linux/iova.h > +++ b/include/linux/iova.h > @@ -73,6 +73,7 @@ struct iova_domain { > unsigned long granule; /* pfn granularity for this domain */ > unsigned long start_pfn; /* Lower limit for this domain */ > unsigned long dma_32bit_pfn; > + unsigned long curr_limit_pfn; /* Current max limit for this domain */ > unsigned long max32_alloc_size; /* Size of last failed allocation */ > struct iova_fq __percpu *fq; /* Flush Queue */ > > -- > 2.17.1
