Robin Murphy
2021-Dec-07 11:44 UTC
[PATCH v2] iova: Move fast alloc size roundup into alloc_iova_fast()
On 2021-12-07 11:17, John Garry wrote:> It really is a property of the IOVA rcache code that we need to alloc a > power-of-2 size, so relocate the functionality to resize into > alloc_iova_fast(), rather than the callsites.I'd still much prefer to resolve the issue that there shouldn't *be* more than one caller in the first place, but hey. Acked-by: Robin Murphy <robin.murphy at arm.com>> Signed-off-by: John Garry <john.garry at huawei.com> > Acked-by: Will Deacon <will at kernel.org> > Reviewed-by: Xie Yongji <xieyongji at bytedance.com> > Acked-by: Jason Wang <jasowang at redhat.com> > Acked-by: Michael S. Tsirkin <mst at redhat.com> > --- > Differences to v1: > - Separate out from original series which conflicts with Robin's IOVA FQ work: > https://lore.kernel.org/linux-iommu/1632477717-5254-1-git-send-email-john.garry at huawei.com/ > - Add tags - thanks! > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index b42e38a0dbe2..84dee53fe892 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -442,14 +442,6 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain, > > shift = iova_shift(iovad); > iova_len = size >> shift; > - /* > - * Freeing non-power-of-two-sized allocations back into the IOVA caches > - * will come back to bite us badly, so we have to waste a bit of space > - * rounding up anything cacheable to make sure that can't happen. The > - * order of the unadjusted size will still match upon freeing. > - */ > - if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1))) > - iova_len = roundup_pow_of_two(iova_len); > > dma_limit = min_not_zero(dma_limit, dev->bus_dma_limit); > > diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c > index 9e8bc802ac05..ff567cbc42f7 100644 > --- a/drivers/iommu/iova.c > +++ b/drivers/iommu/iova.c > @@ -497,6 +497,15 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size, > unsigned long iova_pfn; > struct iova *new_iova; > > + /* > + * Freeing non-power-of-two-sized allocations back into the IOVA caches > + * will come back to bite us badly, so we have to waste a bit of space > + * rounding up anything cacheable to make sure that can't happen. The > + * order of the unadjusted size will still match upon freeing. > + */ > + if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1))) > + size = roundup_pow_of_two(size); > + > iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1); > if (iova_pfn) > return iova_pfn; > diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c > index 1daae2608860..2b1143f11d8f 100644 > --- a/drivers/vdpa/vdpa_user/iova_domain.c > +++ b/drivers/vdpa/vdpa_user/iova_domain.c > @@ -292,14 +292,6 @@ vduse_domain_alloc_iova(struct iova_domain *iovad, > unsigned long iova_len = iova_align(iovad, size) >> shift; > unsigned long iova_pfn; > > - /* > - * Freeing non-power-of-two-sized allocations back into the IOVA caches > - * will come back to bite us badly, so we have to waste a bit of space > - * rounding up anything cacheable to make sure that can't happen. The > - * order of the unadjusted size will still match upon freeing. > - */ > - if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1))) > - iova_len = roundup_pow_of_two(iova_len); > iova_pfn = alloc_iova_fast(iovad, iova_len, limit >> shift, true); > > return iova_pfn << shift; >