On Tue, Jun 4, 2019 at 7:11 PM Robin Murphy <robin.murphy@xxxxxxx> wrote: > > On 06/05/2019 19:52, Tom Murphy wrote: > > Add a gfp_t parameter to the iommu_ops::map function. > > Remove the needless locking in the AMD iommu driver. > > > > The iommu_ops::map function (or the iommu_map function which calls it) > > was always supposed to be sleepable (according to Joerg's comment in > > this thread: https://lore.kernel.org/patchwork/patch/977520/ ) and so > > should probably have had a "might_sleep()" since it was written. However > > currently the dma-iommu api can call iommu_map in an atomic context, > > which it shouldn't do. This doesn't cause any problems because any iommu > > driver which uses the dma-iommu api uses gfp_atomic in it's > > iommu_ops::map function. But doing this wastes the memory allocators > > atomic pools. > > Hmm, in some cases iommu_ops::unmap may need to allocate as well, > primarily if it needs to split a hugepage mapping. Should we pass flags Are you sure that's the case? I don't see that in the amd or intel iommu_ops::unmap code and from looking at the intel code it seems like we actually unmap the whole large page: /* Cope with horrid API which requires us to unmap more than the size argument if it happens to be a large-page mapping. */ BUG_ON(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level)); if (size < VTD_PAGE_SIZE << level_to_offset_bits(level)) size = VTD_PAGE_SIZE << level_to_offset_bits(level); > through there as well, or are we prepared to assume that that case will > happen rarely enough that it's fair to just assume GFP_ATOMIC? It won't > happen for DMA ops, but it's conceivable that other users such as GPU > drivers might make partial unmaps, and I doubt we could totally rule out > the wackiest ones doing so from non-sleeping contexts. > > Robin. > > > We can remove the mutex lock from amd_iommu_map and amd_iommu_unmap. > > iommu_map doesn’t lock while mapping and so no two calls should touch > > the same iova range. The AMD driver already handles the page table page > > allocations without locks so we can safely remove the locks. > > > > Signed-off-by: Tom Murphy <tmurphy@xxxxxxxxxx> > > --- > > drivers/iommu/amd_iommu.c | 14 ++++------- > > drivers/iommu/arm-smmu-v3.c | 2 +- > > drivers/iommu/arm-smmu.c | 2 +- > > drivers/iommu/dma-iommu.c | 6 ++--- > > drivers/iommu/exynos-iommu.c | 2 +- > > drivers/iommu/intel-iommu.c | 2 +- > > drivers/iommu/iommu.c | 43 +++++++++++++++++++++++++++++----- > > drivers/iommu/ipmmu-vmsa.c | 2 +- > > drivers/iommu/msm_iommu.c | 2 +- > > drivers/iommu/mtk_iommu.c | 2 +- > > drivers/iommu/mtk_iommu_v1.c | 2 +- > > drivers/iommu/omap-iommu.c | 2 +- > > drivers/iommu/qcom_iommu.c | 2 +- > > drivers/iommu/rockchip-iommu.c | 2 +- > > drivers/iommu/s390-iommu.c | 2 +- > > drivers/iommu/tegra-gart.c | 2 +- > > drivers/iommu/tegra-smmu.c | 2 +- > > include/linux/iommu.h | 21 ++++++++++++++++- > > 18 files changed, 78 insertions(+), 34 deletions(-) > > > > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c > > index ebd062522cf5..ea3a5dc61bb0 100644 > > --- a/drivers/iommu/amd_iommu.c > > +++ b/drivers/iommu/amd_iommu.c > > @@ -3092,7 +3092,8 @@ static int amd_iommu_attach_device(struct iommu_domain *dom, > > } > > > > static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, > > - phys_addr_t paddr, size_t page_size, int iommu_prot) > > + phys_addr_t paddr, size_t page_size, int iommu_prot, > > + gfp_t gfp) > > { > > struct protection_domain *domain = to_pdomain(dom); > > int prot = 0; > > @@ -3106,9 +3107,7 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, > > if (iommu_prot & IOMMU_WRITE) > > prot |= IOMMU_PROT_IW; > > > > - mutex_lock(&domain->api_lock); > > - ret = iommu_map_page(domain, iova, paddr, page_size, prot, GFP_KERNEL); > > - mutex_unlock(&domain->api_lock); > > + ret = iommu_map_page(domain, iova, paddr, page_size, prot, gfp); > > > > domain_flush_np_cache(domain, iova, page_size); > > > > @@ -3119,16 +3118,11 @@ static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova, > > size_t page_size) > > { > > struct protection_domain *domain = to_pdomain(dom); > > - size_t unmap_size; > > > > if (domain->mode == PAGE_MODE_NONE) > > return 0; > > > > - mutex_lock(&domain->api_lock); > > - unmap_size = iommu_unmap_page(domain, iova, page_size); > > - mutex_unlock(&domain->api_lock); > > - > > - return unmap_size; > > + return iommu_unmap_page(domain, iova, page_size); > > } > > > > static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom, > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > > index d3880010c6cf..e5c48089b49f 100644 > > --- a/drivers/iommu/arm-smmu-v3.c > > +++ b/drivers/iommu/arm-smmu-v3.c > > @@ -1777,7 +1777,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > > } > > > > static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops; > > > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > > index 045d93884164..2d50db55b788 100644 > > --- a/drivers/iommu/arm-smmu.c > > +++ b/drivers/iommu/arm-smmu.c > > @@ -1286,7 +1286,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > > } > > > > static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > 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 fa5713a4f6f8..7a96c2c8f56b 100644 > > --- a/drivers/iommu/dma-iommu.c > > +++ b/drivers/iommu/dma-iommu.c > > @@ -440,7 +440,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, > > if (!iova) > > return DMA_MAPPING_ERROR; > > > > - if (iommu_map(domain, iova, phys - iova_off, size, prot)) { > > + if (iommu_map_atomic(domain, iova, phys - iova_off, size, prot)) { > > iommu_dma_free_iova(cookie, iova, size); > > return DMA_MAPPING_ERROR; > > } > > @@ -641,7 +641,7 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size, > > arch_dma_prep_coherent(sg_page(sg), sg->length); > > } > > > > - if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, ioprot) > > + if (iommu_map_sg_atomic(domain, iova, sgt.sgl, sgt.orig_nents, ioprot) > > < size) > > goto out_free_sg; > > > > @@ -1003,7 +1003,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, > > * We'll leave any physical concatenation to the IOMMU driver's > > * implementation - it knows better than we do. > > */ > > - if (iommu_map_sg(domain, iova, sg, nents, prot) < iova_len) > > + if (iommu_map_sg_atomic(domain, iova, sg, nents, prot) < iova_len) > > goto out_free_iova; > > > > return __finalise_sg(dev, sg, nents, iova); > > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c > > index 05c6bc099d62..46414234c179 100644 > > --- a/drivers/iommu/exynos-iommu.c > > +++ b/drivers/iommu/exynos-iommu.c > > @@ -1078,7 +1078,7 @@ static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size, > > */ > > static int exynos_iommu_map(struct iommu_domain *iommu_domain, > > unsigned long l_iova, phys_addr_t paddr, size_t size, > > - int prot) > > + int prot, gfp_t gfp) > > { > > struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain); > > sysmmu_pte_t *entry; > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > > index 28cb713d728c..4f0ff28f7cb9 100644 > > --- a/drivers/iommu/intel-iommu.c > > +++ b/drivers/iommu/intel-iommu.c > > @@ -5137,7 +5137,7 @@ static void intel_iommu_detach_device(struct iommu_domain *domain, > > > > static int intel_iommu_map(struct iommu_domain *domain, > > unsigned long iova, phys_addr_t hpa, > > - size_t size, int iommu_prot) > > + size_t size, int iommu_prot, gfp_t gfp) > > { > > struct dmar_domain *dmar_domain = to_dmar_domain(domain); > > u64 max_addr; > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > index 109de67d5d72..1b49841c177e 100644 > > --- a/drivers/iommu/iommu.c > > +++ b/drivers/iommu/iommu.c > > @@ -1584,8 +1584,8 @@ static size_t iommu_pgsize(struct iommu_domain *domain, > > return pgsize; > > } > > > > -int iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > +int __iommu_map(struct iommu_domain *domain, unsigned long iova, > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > const struct iommu_ops *ops = domain->ops; > > unsigned long orig_iova = iova; > > @@ -1622,8 +1622,8 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova, > > > > pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx\n", > > iova, &paddr, pgsize); > > + ret = ops->map(domain, iova, paddr, pgsize, prot, gfp); > > > > - ret = ops->map(domain, iova, paddr, pgsize, prot); > > if (ret) > > break; > > > > @@ -1643,8 +1643,22 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova, > > > > return ret; > > } > > + > > +int iommu_map(struct iommu_domain *domain, unsigned long iova, > > + phys_addr_t paddr, size_t size, int prot) > > +{ > > + might_sleep(); > > + return __iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL); > > +} > > EXPORT_SYMBOL_GPL(iommu_map); > > > > +int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova, > > + phys_addr_t paddr, size_t size, int prot) > > +{ > > + return __iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC); > > +} > > +EXPORT_SYMBOL_GPL(iommu_map_atomic); > > + > > static size_t __iommu_unmap(struct iommu_domain *domain, > > unsigned long iova, size_t size, > > bool sync) > > @@ -1719,8 +1733,9 @@ size_t iommu_unmap_fast(struct iommu_domain *domain, > > } > > EXPORT_SYMBOL_GPL(iommu_unmap_fast); > > > > -size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > > - struct scatterlist *sg, unsigned int nents, int prot) > > +size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > > + struct scatterlist *sg, unsigned int nents, int prot, > > + gfp_t gfp) > > { > > size_t len = 0, mapped = 0; > > phys_addr_t start; > > @@ -1731,7 +1746,9 @@ size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > > phys_addr_t s_phys = sg_phys(sg); > > > > if (len && s_phys != start + len) { > > - ret = iommu_map(domain, iova + mapped, start, len, prot); > > + ret = __iommu_map(domain, iova + mapped, start, > > + len, prot, gfp); > > + > > if (ret) > > goto out_err; > > > > @@ -1759,8 +1776,22 @@ size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > > return 0; > > > > } > > + > > +size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > > + struct scatterlist *sg, unsigned int nents, int prot) > > +{ > > + might_sleep(); > > + return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_KERNEL); > > +} > > EXPORT_SYMBOL_GPL(iommu_map_sg); > > > > +size_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova, > > + struct scatterlist *sg, unsigned int nents, int prot) > > +{ > > + return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC); > > +} > > +EXPORT_SYMBOL_GPL(iommu_map_sg_atomic); > > + > > int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr, > > phys_addr_t paddr, u64 size, int prot) > > { > > diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c > > index 9a380c10655e..e005c83d49d8 100644 > > --- a/drivers/iommu/ipmmu-vmsa.c > > +++ b/drivers/iommu/ipmmu-vmsa.c > > @@ -707,7 +707,7 @@ static void ipmmu_detach_device(struct iommu_domain *io_domain, > > } > > > > static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > 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 9fb0eb7a4d02..3f6bf3653aa2 100644 > > --- a/drivers/iommu/msm_iommu.c > > +++ b/drivers/iommu/msm_iommu.c > > @@ -508,7 +508,7 @@ static void msm_iommu_detach_dev(struct iommu_domain *domain, > > } > > > > static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t pa, size_t len, int prot) > > + phys_addr_t pa, size_t len, int prot, gfp_t gfp) > > { > > 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 de3e02277b70..3176b9b54d4d 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -364,7 +364,7 @@ static void mtk_iommu_detach_device(struct iommu_domain *domain, > > } > > > > static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > struct mtk_iommu_domain *dom = to_mtk_domain(domain); > > unsigned long flags; > > diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c > > index 52b01e3a49df..e7b1907faec1 100644 > > --- a/drivers/iommu/mtk_iommu_v1.c > > +++ b/drivers/iommu/mtk_iommu_v1.c > > @@ -303,7 +303,7 @@ static void mtk_iommu_detach_device(struct iommu_domain *domain, > > } > > > > static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > struct mtk_iommu_domain *dom = to_mtk_domain(domain); > > unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT; > > diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c > > index d2fb347aa4ff..c1d5a71285dc 100644 > > --- a/drivers/iommu/omap-iommu.c > > +++ b/drivers/iommu/omap-iommu.c > > @@ -1109,7 +1109,7 @@ static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz) > > } > > > > static int omap_iommu_map(struct iommu_domain *domain, unsigned long da, > > - phys_addr_t pa, size_t bytes, int prot) > > + phys_addr_t pa, size_t bytes, int prot, gfp_t gfp) > > { > > 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 8cdd3f059513..a01e07a4e76f 100644 > > --- a/drivers/iommu/qcom_iommu.c > > +++ b/drivers/iommu/qcom_iommu.c > > @@ -411,7 +411,7 @@ static void qcom_iommu_detach_dev(struct iommu_domain *domain, struct device *de > > } > > > > static int qcom_iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > int ret; > > unsigned long flags; > > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > > index 77d4bd93fe4b..aa3507f35107 100644 > > --- a/drivers/iommu/rockchip-iommu.c > > +++ b/drivers/iommu/rockchip-iommu.c > > @@ -760,7 +760,7 @@ static int rk_iommu_map_iova(struct rk_iommu_domain *rk_domain, u32 *pte_addr, > > } > > > > static int rk_iommu_map(struct iommu_domain *domain, unsigned long _iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > 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 22d4db302c1c..efa6aa68521d 100644 > > --- a/drivers/iommu/s390-iommu.c > > +++ b/drivers/iommu/s390-iommu.c > > @@ -265,7 +265,7 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain, > > } > > > > static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > struct s390_domain *s390_domain = to_s390_domain(domain); > > int flags = ZPCI_PTE_VALID, rc = 0; > > diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c > > index 4d8057916552..f300099852b1 100644 > > --- a/drivers/iommu/tegra-gart.c > > +++ b/drivers/iommu/tegra-gart.c > > @@ -190,7 +190,7 @@ static inline int __gart_iommu_map(struct gart_device *gart, unsigned long iova, > > } > > > > static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t pa, size_t bytes, int prot) > > + phys_addr_t pa, size_t bytes, int prot, gfp_t gfp) > > { > > struct gart_device *gart = gart_handle; > > int ret; > > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > > index 5182c7d6171e..e1bf867e0607 100644 > > --- a/drivers/iommu/tegra-smmu.c > > +++ b/drivers/iommu/tegra-smmu.c > > @@ -641,7 +641,7 @@ static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova, > > } > > > > static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot) > > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > > { > > struct tegra_smmu_as *as = to_smmu_as(domain); > > dma_addr_t pte_dma; > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > > index ffbbc7e39cee..76b8e7fe3ed0 100644 > > --- a/include/linux/iommu.h > > +++ b/include/linux/iommu.h > > @@ -198,7 +198,7 @@ struct iommu_ops { > > int (*attach_dev)(struct iommu_domain *domain, struct device *dev); > > void (*detach_dev)(struct iommu_domain *domain, struct device *dev); > > int (*map)(struct iommu_domain *domain, unsigned long iova, > > - phys_addr_t paddr, size_t size, int prot); > > + 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); > > void (*flush_iotlb_all)(struct iommu_domain *domain); > > @@ -295,12 +295,17 @@ extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); > > extern struct iommu_domain *iommu_get_dma_domain(struct device *dev); > > extern int iommu_map(struct iommu_domain *domain, unsigned long iova, > > phys_addr_t paddr, size_t size, int prot); > > +extern int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova, > > + phys_addr_t paddr, size_t size, int prot); > > 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); > > 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, > > + unsigned long iova, struct scatterlist *sg, > > + unsigned int nents, int prot); > > extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova); > > extern void iommu_set_fault_handler(struct iommu_domain *domain, > > iommu_fault_handler_t handler, void *token); > > @@ -469,6 +474,13 @@ static inline int iommu_map(struct iommu_domain *domain, unsigned long iova, > > return -ENODEV; > > } > > > > +static inline int iommu_map_atomic(struct iommu_domain *domain, > > + unsigned long iova, phys_addr_t paddr, > > + size_t size, int prot) > > +{ > > + return -ENODEV; > > +} > > + > > static inline size_t iommu_unmap(struct iommu_domain *domain, > > unsigned long iova, size_t size) > > { > > @@ -488,6 +500,13 @@ static inline size_t iommu_map_sg(struct iommu_domain *domain, > > return 0; > > } > > > > +static inline size_t iommu_map_sg_atomic(struct iommu_domain *domain, > > + unsigned long iova, struct scatterlist *sg, > > + unsigned int nents, int prot) > > +{ > > + return 0; > > +} > > + > > static inline void iommu_flush_tlb_all(struct iommu_domain *domain) > > { > > } > >
