Re: [PATCH V2 1/2] Add new flush_iotlb_range and handle freelists when using iommu_unmap_fast

[Tom Murphy]

On Tue, 18 Aug 2020 at 16:17, Robin Murphy <robin.murphy@xxxxxxx> wrote:
>
> On 2020-08-18 07:04, Tom Murphy wrote:
> > Add a flush_iotlb_range to allow flushing of an iova range instead of a
> > full flush in the dma-iommu path.
> >
> > Allow the iommu_unmap_fast to return newly freed page table pages and
> > pass the freelist to queue_iova in the dma-iommu ops path.
> >
> > This patch is useful for iommu drivers (in this case the intel iommu
> > driver) which need to wait for the ioTLB to be flushed before newly
> > free/unmapped page table pages can be freed. This way we can still batch
> > ioTLB free operations and handle the freelists.
>
> It sounds like the freelist is something that logically belongs in the
> iommu_iotlb_gather structure. And even if it's not a perfect fit I'd be
> inclined to jam it in there anyway just to avoid this giant argument
> explosion ;)

Good point, I'll do that.

>
> Why exactly do we need to introduce a new flush_iotlb_range() op? Can't
> the AMD driver simply use the gather mechanism like everyone else?

No, there's no reason it can't simply use the gather mechanism. I will
use the gather mechanism.
I think I wrote this patch way back before the gather mechanism was
introduced and I've been rebasing/slightly updating it since then
without paying proper attention to the code.

>
> Robin.
>
> > Change-log:
> > V2:
> > -fix missing parameter in mtk_iommu_v1.c
> >
> > Signed-off-by: Tom Murphy <murphyt7@xxxxxx>
> > ---
> >   drivers/iommu/amd/iommu.c       | 14 ++++++++-
> >   drivers/iommu/arm-smmu-v3.c     |  3 +-
> >   drivers/iommu/arm-smmu.c        |  3 +-
> >   drivers/iommu/dma-iommu.c       | 45 ++++++++++++++++++++-------
> >   drivers/iommu/exynos-iommu.c    |  3 +-
> >   drivers/iommu/intel/iommu.c     | 54 +++++++++++++++++++++------------
> >   drivers/iommu/iommu.c           | 25 +++++++++++----
> >   drivers/iommu/ipmmu-vmsa.c      |  3 +-
> >   drivers/iommu/msm_iommu.c       |  3 +-
> >   drivers/iommu/mtk_iommu.c       |  3 +-
> >   drivers/iommu/mtk_iommu_v1.c    |  3 +-
> >   drivers/iommu/omap-iommu.c      |  3 +-
> >   drivers/iommu/qcom_iommu.c      |  3 +-
> >   drivers/iommu/rockchip-iommu.c  |  3 +-
> >   drivers/iommu/s390-iommu.c      |  3 +-
> >   drivers/iommu/sun50i-iommu.c    |  3 +-
> >   drivers/iommu/tegra-gart.c      |  3 +-
> >   drivers/iommu/tegra-smmu.c      |  3 +-
> >   drivers/iommu/virtio-iommu.c    |  3 +-
> >   drivers/vfio/vfio_iommu_type1.c |  2 +-
> >   include/linux/iommu.h           | 21 +++++++++++--
> >   21 files changed, 150 insertions(+), 56 deletions(-)
> >
> > diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> > index 2f22326ee4df..25fbacab23c3 100644
> > --- a/drivers/iommu/amd/iommu.c
> > +++ b/drivers/iommu/amd/iommu.c
> > @@ -2513,7 +2513,8 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
> >
> >   static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
> >                             size_t page_size,
> > -                           struct iommu_iotlb_gather *gather)
> > +                           struct iommu_iotlb_gather *gather,
> > +                           struct page **freelist)
> >   {
> >       struct protection_domain *domain = to_pdomain(dom);
> >       struct domain_pgtable pgtable;
> > @@ -2636,6 +2637,16 @@ static void amd_iommu_flush_iotlb_all(struct iommu_domain *domain)
> >       spin_unlock_irqrestore(&dom->lock, flags);
> >   }
> >
> > +static void amd_iommu_flush_iotlb_range(struct iommu_domain *domain,
> > +                                     unsigned long iova, size_t size,
> > +                                     struct page *freelist)
> > +{
> > +     struct protection_domain *dom = to_pdomain(domain);
> > +
> > +     domain_flush_pages(dom, iova, size);
> > +     domain_flush_complete(dom);
> > +}
> > +
> >   static void amd_iommu_iotlb_sync(struct iommu_domain *domain,
> >                                struct iommu_iotlb_gather *gather)
> >   {
> > @@ -2675,6 +2686,7 @@ const struct iommu_ops amd_iommu_ops = {
> >       .is_attach_deferred = amd_iommu_is_attach_deferred,
> >       .pgsize_bitmap  = AMD_IOMMU_PGSIZES,
> >       .flush_iotlb_all = amd_iommu_flush_iotlb_all,
> > +     .flush_iotlb_range = amd_iommu_flush_iotlb_range,
> >       .iotlb_sync = amd_iommu_iotlb_sync,
> >       .def_domain_type = amd_iommu_def_domain_type,
> >   };
> > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> > index f578677a5c41..8d328dc25326 100644
> > --- a/drivers/iommu/arm-smmu-v3.c
> > +++ b/drivers/iommu/arm-smmu-v3.c
> > @@ -2854,7 +2854,8 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                          size_t size, struct iommu_iotlb_gather *gather)
> > +                          size_t size, struct iommu_iotlb_gather *gather,
> > +                          struct page **freelist)
> >   {
> >       struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
> >       struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
> > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> > index 243bc4cb2705..0cd0dfc89875 100644
> > --- a/drivers/iommu/arm-smmu.c
> > +++ b/drivers/iommu/arm-smmu.c
> > @@ -1234,7 +1234,8 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                          size_t size, struct iommu_iotlb_gather *gather)
> > +                          size_t size, struct iommu_iotlb_gather *gather,
> > +                          struct page **freelist)
> >   {
> >       struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
> >       struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu;
> > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > index 4959f5df21bd..7433f74d921a 100644
> > --- a/drivers/iommu/dma-iommu.c
> > +++ b/drivers/iommu/dma-iommu.c
> > @@ -50,6 +50,19 @@ struct iommu_dma_cookie {
> >       struct iommu_domain             *fq_domain;
> >   };
> >
> > +
> > +static void iommu_dma_entry_dtor(unsigned long data)
> > +{
> > +     struct page *freelist = (struct page *)data;
> > +
> > +     while (freelist != NULL) {
> > +             unsigned long p = (unsigned long)page_address(freelist);
> > +
> > +             freelist = freelist->freelist;
> > +             free_page(p);
> > +     }
> > +}
> > +
> >   static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
> >   {
> >       if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
> > @@ -344,7 +357,8 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
> >       if (!cookie->fq_domain && !iommu_domain_get_attr(domain,
> >                       DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr) && attr) {
> >               cookie->fq_domain = domain;
> > -             init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, NULL);
> > +             init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
> > +                             iommu_dma_entry_dtor);
> >       }
> >
> >       if (!dev)
> > @@ -438,7 +452,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
> >   }
> >
> >   static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
> > -             dma_addr_t iova, size_t size)
> > +             dma_addr_t iova, size_t size, struct page *freelist)
> >   {
> >       struct iova_domain *iovad = &cookie->iovad;
> >
> > @@ -447,7 +461,8 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
> >               cookie->msi_iova -= size;
> >       else if (cookie->fq_domain)     /* non-strict mode */
> >               queue_iova(iovad, iova_pfn(iovad, iova),
> > -                             size >> iova_shift(iovad), 0);
> > +                             size >> iova_shift(iovad),
> > +                             (unsigned long) freelist);
> >       else
> >               free_iova_fast(iovad, iova_pfn(iovad, iova),
> >                               size >> iova_shift(iovad));
> > @@ -461,18 +476,26 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr,
> >       struct iova_domain *iovad = &cookie->iovad;
> >       size_t iova_off = iova_offset(iovad, dma_addr);
> >       struct iommu_iotlb_gather iotlb_gather;
> > +     struct page *freelist = NULL;
> >       size_t unmapped;
> >
> >       dma_addr -= iova_off;
> >       size = iova_align(iovad, size + iova_off);
> >       iommu_iotlb_gather_init(&iotlb_gather);
> >
> > -     unmapped = iommu_unmap_fast(domain, dma_addr, size, &iotlb_gather);
> > +     unmapped = iommu_unmap_fast(domain, dma_addr, size, &iotlb_gather,
> > +                     &freelist);
> >       WARN_ON(unmapped != size);
> >
> > -     if (!cookie->fq_domain)
> > -             iommu_tlb_sync(domain, &iotlb_gather);
> > -     iommu_dma_free_iova(cookie, dma_addr, size);
> > +     if (!cookie->fq_domain) {
> > +             if (domain->ops->flush_iotlb_range)
> > +                     domain->ops->flush_iotlb_range(domain, dma_addr, size,
> > +                                     freelist);
> > +             else
> > +                     iommu_tlb_sync(domain, &iotlb_gather);
> > +     }
> > +
> > +     iommu_dma_free_iova(cookie, dma_addr, size, freelist);
> >   }
> >
> >   static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
> > @@ -494,7 +517,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
> >               return DMA_MAPPING_ERROR;
> >
> >       if (iommu_map_atomic(domain, iova, phys - iova_off, size, prot)) {
> > -             iommu_dma_free_iova(cookie, iova, size);
> > +             iommu_dma_free_iova(cookie, iova, size, NULL);
> >               return DMA_MAPPING_ERROR;
> >       }
> >       return iova + iova_off;
> > @@ -649,7 +672,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
> >   out_free_sg:
> >       sg_free_table(&sgt);
> >   out_free_iova:
> > -     iommu_dma_free_iova(cookie, iova, size);
> > +     iommu_dma_free_iova(cookie, iova, size, NULL);
> >   out_free_pages:
> >       __iommu_dma_free_pages(pages, count);
> >       return NULL;
> > @@ -900,7 +923,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
> >       return __finalise_sg(dev, sg, nents, iova);
> >
> >   out_free_iova:
> > -     iommu_dma_free_iova(cookie, iova, iova_len);
> > +     iommu_dma_free_iova(cookie, iova, iova_len, NULL);
> >   out_restore_sg:
> >       __invalidate_sg(sg, nents);
> >       return 0;
> > @@ -1194,7 +1217,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
> >       return msi_page;
> >
> >   out_free_iova:
> > -     iommu_dma_free_iova(cookie, iova, size);
> > +     iommu_dma_free_iova(cookie, iova, size, NULL);
> >   out_free_page:
> >       kfree(msi_page);
> >       return NULL;
> > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> > index 60c8a56e4a3f..5d98985e60a2 100644
> > --- a/drivers/iommu/exynos-iommu.c
> > +++ b/drivers/iommu/exynos-iommu.c
> > @@ -1129,7 +1129,8 @@ static void exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain *domain
> >
> >   static size_t exynos_iommu_unmap(struct iommu_domain *iommu_domain,
> >                                unsigned long l_iova, size_t size,
> > -                              struct iommu_iotlb_gather *gather)
> > +                              struct iommu_iotlb_gather *gather,
> > +                              struct page **freelist)
> >   {
> >       struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
> >       sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index 237a470e1e9c..878178fe48f8 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -1160,17 +1160,17 @@ static struct page *dma_pte_clear_level(struct dmar_domain *domain, int level,
> >      pages can only be freed after the IOTLB flush has been done. */
> >   static struct page *domain_unmap(struct dmar_domain *domain,
> >                                unsigned long start_pfn,
> > -                              unsigned long last_pfn)
> > +                              unsigned long last_pfn,
> > +                              struct page *freelist)
> >   {
> > -     struct page *freelist;
> > -
> >       BUG_ON(!domain_pfn_supported(domain, start_pfn));
> >       BUG_ON(!domain_pfn_supported(domain, last_pfn));
> >       BUG_ON(start_pfn > last_pfn);
> >
> >       /* we don't need lock here; nobody else touches the iova range */
> >       freelist = dma_pte_clear_level(domain, agaw_to_level(domain->agaw),
> > -                                    domain->pgd, 0, start_pfn, last_pfn, NULL);
> > +                                    domain->pgd, 0, start_pfn, last_pfn,
> > +                                    freelist);
> >
> >       /* free pgd */
> >       if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
> > @@ -1924,7 +1924,8 @@ static void domain_exit(struct dmar_domain *domain)
> >       if (domain->pgd) {
> >               struct page *freelist;
> >
> > -             freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
> > +             freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw),
> > +                             NULL);
> >               dma_free_pagelist(freelist);
> >       }
> >
> > @@ -3480,7 +3481,7 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
> >       if (dev_is_pci(dev))
> >               pdev = to_pci_dev(dev);
> >
> > -     freelist = domain_unmap(domain, start_pfn, last_pfn);
> > +     freelist = domain_unmap(domain, start_pfn, last_pfn, NULL);
> >       if (intel_iommu_strict || (pdev && pdev->untrusted) ||
> >                       !has_iova_flush_queue(&domain->iovad)) {
> >               iommu_flush_iotlb_psi(iommu, domain, start_pfn,
> > @@ -4575,7 +4576,8 @@ static int intel_iommu_memory_notifier(struct notifier_block *nb,
> >                       struct page *freelist;
> >
> >                       freelist = domain_unmap(si_domain,
> > -                                             start_vpfn, last_vpfn);
> > +                                             start_vpfn, last_vpfn,
> > +                                             NULL);
> >
> >                       rcu_read_lock();
> >                       for_each_active_iommu(iommu, drhd)
> > @@ -5540,13 +5542,12 @@ static int intel_iommu_map(struct iommu_domain *domain,
> >
> >   static size_t intel_iommu_unmap(struct iommu_domain *domain,
> >                               unsigned long iova, size_t size,
> > -                             struct iommu_iotlb_gather *gather)
> > +                             struct iommu_iotlb_gather *gather,
> > +                             struct page **freelist)
> >   {
> >       struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> > -     struct page *freelist = NULL;
> >       unsigned long start_pfn, last_pfn;
> > -     unsigned int npages;
> > -     int iommu_id, level = 0;
> > +     int level = 0;
> >
> >       /* Cope with horrid API which requires us to unmap more than the
> >          size argument if it happens to be a large-page mapping. */
> > @@ -5558,22 +5559,36 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
> >       start_pfn = iova >> VTD_PAGE_SHIFT;
> >       last_pfn = (iova + size - 1) >> VTD_PAGE_SHIFT;
> >
> > -     freelist = domain_unmap(dmar_domain, start_pfn, last_pfn);
> > +     *freelist = domain_unmap(dmar_domain, start_pfn, last_pfn, *freelist);
> > +
> > +     if (dmar_domain->max_addr == iova + size)
> > +             dmar_domain->max_addr = iova;
> >
> > -     npages = last_pfn - start_pfn + 1;
> > +     return size;
> > +}
> > +
> > +static void intel_iommu_flush_iotlb_range(struct iommu_domain *domain, unsigned
> > +             long iova, size_t size,
> > +             struct page *freelist)
> > +{
> > +     struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> > +     unsigned long start_pfn, last_pfn;
> > +     unsigned long iova_pfn = IOVA_PFN(iova);
> > +     unsigned long nrpages;
> > +     int iommu_id;
> > +
> > +     nrpages = aligned_nrpages(iova, size);
> > +     start_pfn = mm_to_dma_pfn(iova_pfn);
> > +     last_pfn = start_pfn + nrpages - 1;
> >
> >       for_each_domain_iommu(iommu_id, dmar_domain)
> >               iommu_flush_iotlb_psi(g_iommus[iommu_id], dmar_domain,
> > -                                   start_pfn, npages, !freelist, 0);
> > +                                   start_pfn, nrpages, !freelist, 0);
> >
> >       dma_free_pagelist(freelist);
> > -
> > -     if (dmar_domain->max_addr == iova + size)
> > -             dmar_domain->max_addr = iova;
> > -
> > -     return size;
> >   }
> >
> > +
> >   static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
> >                                           dma_addr_t iova)
> >   {
> > @@ -6058,6 +6073,7 @@ const struct iommu_ops intel_iommu_ops = {
> >       .aux_get_pasid          = intel_iommu_aux_get_pasid,
> >       .map                    = intel_iommu_map,
> >       .unmap                  = intel_iommu_unmap,
> > +     .flush_iotlb_range      = intel_iommu_flush_iotlb_range,
> >       .iova_to_phys           = intel_iommu_iova_to_phys,
> >       .probe_device           = intel_iommu_probe_device,
> >       .probe_finalize         = intel_iommu_probe_finalize,
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > index b6858adc4f17..9065127d7e9c 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -2245,11 +2245,13 @@ EXPORT_SYMBOL_GPL(iommu_map_atomic);
> >
> >   static size_t __iommu_unmap(struct iommu_domain *domain,
> >                           unsigned long iova, size_t size,
> > -                         struct iommu_iotlb_gather *iotlb_gather)
> > +                         struct iommu_iotlb_gather *iotlb_gather,
> > +                         struct page **freelist)
> >   {
> >       const struct iommu_ops *ops = domain->ops;
> >       size_t unmapped_page, unmapped = 0;
> >       unsigned long orig_iova = iova;
> > +     struct page *freelist_head = NULL;
> >       unsigned int min_pagesz;
> >
> >       if (unlikely(ops->unmap == NULL ||
> > @@ -2282,7 +2284,8 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
> >       while (unmapped < size) {
> >               size_t pgsize = iommu_pgsize(domain, iova, size - unmapped);
> >
> > -             unmapped_page = ops->unmap(domain, iova, pgsize, iotlb_gather);
> > +             unmapped_page = ops->unmap(domain, iova, pgsize, iotlb_gather,
> > +                             &freelist_head);
> >               if (!unmapped_page)
> >                       break;
> >
> > @@ -2293,6 +2296,9 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
> >               unmapped += unmapped_page;
> >       }
> >
> > +     if (freelist)
> > +             *freelist = freelist_head;
> > +
> >       trace_unmap(orig_iova, size, unmapped);
> >       return unmapped;
> >   }
> > @@ -2300,12 +2306,18 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
> >   size_t iommu_unmap(struct iommu_domain *domain,
> >                  unsigned long iova, size_t size)
> >   {
> > +     const struct iommu_ops *ops = domain->ops;
> >       struct iommu_iotlb_gather iotlb_gather;
> > +     struct page *freelist;
> >       size_t ret;
> >
> >       iommu_iotlb_gather_init(&iotlb_gather);
> > -     ret = __iommu_unmap(domain, iova, size, &iotlb_gather);
> > -     iommu_tlb_sync(domain, &iotlb_gather);
> > +     ret = __iommu_unmap(domain, iova, size, &iotlb_gather, &freelist);
> > +
> > +     if (ops->flush_iotlb_range)
> > +             ops->flush_iotlb_range(domain, iova, ret, freelist);
> > +     else
> > +             iommu_tlb_sync(domain, &iotlb_gather);
> >
> >       return ret;
> >   }
> > @@ -2313,9 +2325,10 @@ EXPORT_SYMBOL_GPL(iommu_unmap);
> >
> >   size_t iommu_unmap_fast(struct iommu_domain *domain,
> >                       unsigned long iova, size_t size,
> > -                     struct iommu_iotlb_gather *iotlb_gather)
> > +                     struct iommu_iotlb_gather *iotlb_gather,
> > +                     struct page **freelist)
> >   {
> > -     return __iommu_unmap(domain, iova, size, iotlb_gather);
> > +     return __iommu_unmap(domain, iova, size, iotlb_gather, freelist);
> >   }
> >   EXPORT_SYMBOL_GPL(iommu_unmap_fast);
> >
> > diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
> > index 6de86e73dfc3..08c39e95e387 100644
> > --- a/drivers/iommu/ipmmu-vmsa.c
> > +++ b/drivers/iommu/ipmmu-vmsa.c
> > @@ -690,7 +690,8 @@ static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
> >   }
> >
> >   static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
> > -                       size_t size, struct iommu_iotlb_gather *gather)
> > +                       size_t size, struct iommu_iotlb_gather *gather,
> > +                       struct page **freelist)
> >   {
> >       struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
> >
> > diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> > index 3d8a63555c25..8a987067771c 100644
> > --- a/drivers/iommu/msm_iommu.c
> > +++ b/drivers/iommu/msm_iommu.c
> > @@ -498,7 +498,8 @@ static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                           size_t len, struct iommu_iotlb_gather *gather)
> > +                           size_t len, struct iommu_iotlb_gather *gather,
> > +                           struct page **freelist)
> >   {
> >       struct msm_priv *priv = to_msm_priv(domain);
> >       unsigned long flags;
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index 2be96f1cdbd2..b97d35a7d817 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -402,7 +402,8 @@ static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
> >
> >   static size_t mtk_iommu_unmap(struct iommu_domain *domain,
> >                             unsigned long iova, size_t size,
> > -                           struct iommu_iotlb_gather *gather)
> > +                           struct iommu_iotlb_gather *gather,
> > +                           struct page **freelist)
> >   {
> >       struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> >
> > diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
> > index c9d79cff4d17..ac44498183b7 100644
> > --- a/drivers/iommu/mtk_iommu_v1.c
> > +++ b/drivers/iommu/mtk_iommu_v1.c
> > @@ -325,7 +325,8 @@ static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
> >
> >   static size_t mtk_iommu_unmap(struct iommu_domain *domain,
> >                             unsigned long iova, size_t size,
> > -                           struct iommu_iotlb_gather *gather)
> > +                           struct iommu_iotlb_gather *gather,
> > +                           struct page **freelist)
> >   {
> >       struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> >       unsigned long flags;
> > diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> > index c8282cc212cb..17d3cfcb8cd3 100644
> > --- a/drivers/iommu/omap-iommu.c
> > +++ b/drivers/iommu/omap-iommu.c
> > @@ -1367,7 +1367,8 @@ static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
> >   }
> >
> >   static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
> > -                            size_t size, struct iommu_iotlb_gather *gather)
> > +                            size_t size, struct iommu_iotlb_gather *gather,
> > +                            struct page **freelist)
> >   {
> >       struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
> >       struct device *dev = omap_domain->dev;
> > diff --git a/drivers/iommu/qcom_iommu.c b/drivers/iommu/qcom_iommu.c
> > index d176df569af8..9c66261ce59e 100644
> > --- a/drivers/iommu/qcom_iommu.c
> > +++ b/drivers/iommu/qcom_iommu.c
> > @@ -444,7 +444,8 @@ static int qcom_iommu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t qcom_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                            size_t size, struct iommu_iotlb_gather *gather)
> > +                            size_t size, struct iommu_iotlb_gather *gather,
> > +                            struct page **freelist)
> >   {
> >       size_t ret;
> >       unsigned long flags;
> > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
> > index d25c2486ca07..d508c037081a 100644
> > --- a/drivers/iommu/rockchip-iommu.c
> > +++ b/drivers/iommu/rockchip-iommu.c
> > @@ -795,7 +795,8 @@ static int rk_iommu_map(struct iommu_domain *domain, unsigned long _iova,
> >   }
> >
> >   static size_t rk_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
> > -                          size_t size, struct iommu_iotlb_gather *gather)
> > +                          size_t size, struct iommu_iotlb_gather *gather,
> > +                          struct page **freelist)
> >   {
> >       struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
> >       unsigned long flags;
> > diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
> > index 8895dbb705eb..8c96659acbe2 100644
> > --- a/drivers/iommu/s390-iommu.c
> > +++ b/drivers/iommu/s390-iommu.c
> > @@ -305,7 +305,8 @@ static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
> >
> >   static size_t s390_iommu_unmap(struct iommu_domain *domain,
> >                              unsigned long iova, size_t size,
> > -                            struct iommu_iotlb_gather *gather)
> > +                            struct iommu_iotlb_gather *gather,
> > +                            struct page **freelist)
> >   {
> >       struct s390_domain *s390_domain = to_s390_domain(domain);
> >       int flags = ZPCI_PTE_INVALID;
> > diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
> > index 3b1bf2fb94f5..fb0558b82dfa 100644
> > --- a/drivers/iommu/sun50i-iommu.c
> > +++ b/drivers/iommu/sun50i-iommu.c
> > @@ -552,7 +552,8 @@ static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                              size_t size, struct iommu_iotlb_gather *gather)
> > +                              size_t size, struct iommu_iotlb_gather *gather,
> > +                              struct page **freelist)
> >   {
> >       struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
> >       phys_addr_t pt_phys;
> > diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
> > index 5fbdff6ff41a..22168376c429 100644
> > --- a/drivers/iommu/tegra-gart.c
> > +++ b/drivers/iommu/tegra-gart.c
> > @@ -207,7 +207,8 @@ static inline int __gart_iommu_unmap(struct gart_device *gart,
> >   }
> >
> >   static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                            size_t bytes, struct iommu_iotlb_gather *gather)
> > +                            size_t bytes, struct iommu_iotlb_gather *gather,
> > +                            struct page **freelist)
> >   {
> >       struct gart_device *gart = gart_handle;
> >       int err;
> > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> > index 7426b7666e2b..1ac2ac851cfe 100644
> > --- a/drivers/iommu/tegra-smmu.c
> > +++ b/drivers/iommu/tegra-smmu.c
> > @@ -686,7 +686,8 @@ static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                            size_t size, struct iommu_iotlb_gather *gather)
> > +                            size_t size, struct iommu_iotlb_gather *gather,
> > +                            struct page **freelist)
> >   {
> >       struct tegra_smmu_as *as = to_smmu_as(domain);
> >       dma_addr_t pte_dma;
> > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> > index f6f07489a9aa..ea4d527b5e64 100644
> > --- a/drivers/iommu/virtio-iommu.c
> > +++ b/drivers/iommu/virtio-iommu.c
> > @@ -762,7 +762,8 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova,
> >   }
> >
> >   static size_t viommu_unmap(struct iommu_domain *domain, unsigned long iova,
> > -                        size_t size, struct iommu_iotlb_gather *gather)
> > +                        size_t size, struct iommu_iotlb_gather *gather,
> > +                        struct page **freelist)
> >   {
> >       int ret = 0;
> >       size_t unmapped;
> > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> > index 5e556ac9102a..570ebf878fea 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -812,7 +812,7 @@ static size_t unmap_unpin_fast(struct vfio_domain *domain,
> >
> >       if (entry) {
> >               unmapped = iommu_unmap_fast(domain->domain, *iova, len,
> > -                                         iotlb_gather);
> > +                                         iotlb_gather, NULL);
> >
> >               if (!unmapped) {
> >                       kfree(entry);
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index 5f0b7859d2eb..77e773d03f22 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -198,6 +198,7 @@ struct iommu_iotlb_gather {
> >    * @map: map a physically contiguous memory region to an iommu domain
> >    * @unmap: unmap a physically contiguous memory region from an iommu domain
> >    * @flush_iotlb_all: Synchronously flush all hardware TLBs for this domain
> > + * @flush_iotlb_range: Flush given iova range of hardware TLBs for this domain
> >    * @iotlb_sync_map: Sync mappings created recently using @map to the hardware
> >    * @iotlb_sync: Flush all queued ranges from the hardware TLBs and empty flush
> >    *            queue
> > @@ -248,8 +249,12 @@ struct iommu_ops {
> >       int (*map)(struct iommu_domain *domain, unsigned long iova,
> >                  phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
> >       size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
> > -                  size_t size, struct iommu_iotlb_gather *iotlb_gather);
> > +                  size_t size, struct iommu_iotlb_gather *iotlb_gather,
> > +                  struct page **freelist);
> >       void (*flush_iotlb_all)(struct iommu_domain *domain);
> > +     void (*flush_iotlb_range)(struct iommu_domain *domain,
> > +                               unsigned long iova, size_t size,
> > +                               struct page *freelist);
> >       void (*iotlb_sync_map)(struct iommu_domain *domain);
> >       void (*iotlb_sync)(struct iommu_domain *domain,
> >                          struct iommu_iotlb_gather *iotlb_gather);
> > @@ -447,7 +452,8 @@ extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> >                         size_t size);
> >   extern size_t iommu_unmap_fast(struct iommu_domain *domain,
> >                              unsigned long iova, size_t size,
> > -                            struct iommu_iotlb_gather *iotlb_gather);
> > +                            struct iommu_iotlb_gather *iotlb_gather,
> > +                            struct page **freelist);
> >   extern size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
> >                          struct scatterlist *sg,unsigned int nents, int prot);
> >   extern size_t iommu_map_sg_atomic(struct iommu_domain *domain,
> > @@ -542,6 +548,14 @@ static inline void iommu_flush_tlb_all(struct iommu_domain *domain)
> >               domain->ops->flush_iotlb_all(domain);
> >   }
> >
> > +static inline void flush_iotlb_range(struct iommu_domain *domain,
> > +                                  unsigned long iova, size_t size,
> > +                                  struct page *freelist)
> > +{
> > +     if (domain->ops->flush_iotlb_range)
> > +             domain->ops->flush_iotlb_range(domain, iova, size, freelist);
> > +}
> > +
> >   static inline void iommu_tlb_sync(struct iommu_domain *domain,
> >                                 struct iommu_iotlb_gather *iotlb_gather)
> >   {
> > @@ -728,7 +742,8 @@ static inline size_t iommu_unmap(struct iommu_domain *domain,
> >
> >   static inline size_t iommu_unmap_fast(struct iommu_domain *domain,
> >                                     unsigned long iova, int gfp_order,
> > -                                   struct iommu_iotlb_gather *iotlb_gather)
> > +                                   struct iommu_iotlb_gather *iotlb_gather,
> > +                                   struct page **freelist)
> >   {
> >       return 0;
> >   }
> >