On 25/01/17 12:53, Yoshihiro Shimoda wrote: > From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> > > To track mapped iova for a workaround code in the future. > > Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > --- > drivers/iommu/dma-iommu.c | 29 +++++++++++++++++++++++------ > include/linux/iommu.h | 2 ++ So what's being added here is a counter of allocations within the iova_domain held by an iommu_dma_cookie? Then why is it all the way down in the iommu_domain and not in the cookie? That's needlessly invasive - it would be almost understandable (but still horrible) if you needed to refer to it directly from the IOMMU driver, but as far as I can see you don't. Robin. > 2 files changed, 25 insertions(+), 6 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 2db0d64..a0b8c0f 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -19,6 +19,7 @@ > * along with this program. If not, see <http://www.gnu.org/licenses/>. > */ > > +#include <linux/atomic.h> > #include <linux/device.h> > #include <linux/dma-iommu.h> > #include <linux/gfp.h> > @@ -147,6 +148,7 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, > order = __ffs(domain->pgsize_bitmap); > base_pfn = max_t(unsigned long, 1, base >> order); > end_pfn = (base + size - 1) >> order; > + atomic_set(&domain->iova_pfns_mapped, 0); > > /* Check the domain allows at least some access to the device... */ > if (domain->geometry.force_aperture) { > @@ -209,6 +211,7 @@ static struct iova *__alloc_iova(struct iommu_domain *domain, size_t size, > struct iova_domain *iovad = cookie_iovad(domain); > unsigned long shift = iova_shift(iovad); > unsigned long length = iova_align(iovad, size) >> shift; > + struct iova *iova; > > if (domain->geometry.force_aperture) > dma_limit = min(dma_limit, domain->geometry.aperture_end); > @@ -216,9 +219,23 @@ static struct iova *__alloc_iova(struct iommu_domain *domain, size_t size, > * Enforce size-alignment to be safe - there could perhaps be an > * attribute to control this per-device, or at least per-domain... > */ > - return alloc_iova(iovad, length, dma_limit >> shift, true); > + iova = alloc_iova(iovad, length, dma_limit >> shift, true); > + if (iova) > + atomic_add(iova_size(iova), &domain->iova_pfns_mapped); > + > + return iova; > } > > +void > +__free_iova_domain(struct iommu_domain *domain, struct iova *iova) > +{ > + struct iova_domain *iovad = cookie_iovad(domain); > + > + atomic_sub(iova_size(iova), &domain->iova_pfns_mapped); > + __free_iova(iovad, iova); > +} > + > + > /* The IOVA allocator knows what we mapped, so just unmap whatever that was */ > static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr) > { > @@ -235,7 +252,7 @@ static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr) > size -= iommu_unmap(domain, pfn << shift, size); > /* ...and if we can't, then something is horribly, horribly wrong */ > WARN_ON(size > 0); > - __free_iova(iovad, iova); > + __free_iova_domain(domain, iova); > } > > static void __iommu_dma_free_pages(struct page **pages, int count) > @@ -401,7 +418,7 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp, > out_free_sg: > sg_free_table(&sgt); > out_free_iova: > - __free_iova(iovad, iova); > + __free_iova_domain(domain, iova); > out_free_pages: > __iommu_dma_free_pages(pages, count); > return NULL; > @@ -447,7 +464,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, > > dma_addr = iova_dma_addr(iovad, iova); > if (iommu_map(domain, dma_addr, phys - iova_off, len, prot)) { > - __free_iova(iovad, iova); > + __free_iova_domain(domain, iova); > return DMA_ERROR_CODE; > } > return dma_addr + iova_off; > @@ -613,7 +630,7 @@ int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, > return __finalise_sg(dev, sg, nents, dma_addr); > > out_free_iova: > - __free_iova(iovad, iova); > + __free_iova_domain(domain, iova); > out_restore_sg: > __invalidate_sg(sg, nents); > return 0; > @@ -689,7 +706,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev, > return msi_page; > > out_free_iova: > - __free_iova(iovad, iova); > + __free_iova_domain(domain, iova); > out_free_page: > kfree(msi_page); > return NULL; > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 0ff5111..91d0159 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -19,6 +19,7 @@ > #ifndef __LINUX_IOMMU_H > #define __LINUX_IOMMU_H > > +#include <linux/atomic.h> > #include <linux/errno.h> > #include <linux/err.h> > #include <linux/of.h> > @@ -84,6 +85,7 @@ struct iommu_domain { > void *handler_token; > struct iommu_domain_geometry geometry; > void *iova_cookie; > + atomic_t iova_pfns_mapped; > }; > > enum iommu_cap { >
