Messages in this thread | | | Date | Fri, 18 May 2018 16:21:52 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH 2/6] swiotlb: do not panic on mapping failures |
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On Tue, May 15, 2018 at 08:05:19PM +0200, Christoph Hellwig wrote: > We now have error handling in map_single/map_page callers (most of them
Which ones are missing? Shouldn't we first fix those before we rip this out?
> anyway). As swiotlb_tbl_map_single already prints a useful warning > when running out of swiotlb pool swace we can also remove swiotlb_full
s/swace/so/
> entirely as it serves no purpose now. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > lib/swiotlb.c | 33 +-------------------------------- > 1 file changed, 1 insertion(+), 32 deletions(-) > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 721f93677eee..4d36340bc4f9 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -763,34 +763,6 @@ static bool swiotlb_free_buffer(struct device *dev, size_t size, > return true; > } > > -static void > -swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir, > - int do_panic) > -{ > - if (swiotlb_force == SWIOTLB_NO_FORCE) > - return; > - > - /* > - * Ran out of IOMMU space for this operation. This is very bad. > - * Unfortunately the drivers cannot handle this operation properly. > - * unless they check for dma_mapping_error (most don't) > - * When the mapping is small enough return a static buffer to limit > - * the damage, or panic when the transfer is too big. > - */ > - dev_err_ratelimited(dev, "DMA: Out of SW-IOMMU space for %zu bytes\n", > - size); > - > - if (size <= io_tlb_overflow || !do_panic) > - return; > - > - if (dir == DMA_BIDIRECTIONAL) > - panic("DMA: Random memory could be DMA accessed\n"); > - if (dir == DMA_FROM_DEVICE) > - panic("DMA: Random memory could be DMA written\n"); > - if (dir == DMA_TO_DEVICE) > - panic("DMA: Random memory could be DMA read\n"); > -} > - > /* > * Map a single buffer of the indicated size for DMA in streaming mode. The > * physical address to use is returned. > @@ -819,10 +791,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, > > /* Oh well, have to allocate and map a bounce buffer. */ > map = map_single(dev, phys, size, dir, attrs); > - if (map == SWIOTLB_MAP_ERROR) { > - swiotlb_full(dev, size, dir, 1); > + if (map == SWIOTLB_MAP_ERROR) > return __phys_to_dma(dev, io_tlb_overflow_buffer); > - } > > dev_addr = __phys_to_dma(dev, map); > > @@ -950,7 +920,6 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, > if (map == SWIOTLB_MAP_ERROR) { > /* Don't panic here, we expect map_sg users > to do proper error handling. */ > - swiotlb_full(hwdev, sg->length, dir, 0); > attrs |= DMA_ATTR_SKIP_CPU_SYNC; > swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, > attrs); > -- > 2.17.0 >
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