[Linaro-mm-sig] [PATCH 3/3] iommu/tegra: smmu: Support read-only mapping

Support read-only mapping via struct dma_attrs.

Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com --- drivers/iommu/tegra-smmu.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index fab1f19..3aff4cd 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -862,12 +862,13 @@ static size_t __smmu_iommu_unmap_largepage(struct smmu_as *as, dma_addr_t iova) }

static int __smmu_iommu_map_pfn(struct smmu_as *as, dma_addr_t iova, - unsigned long pfn) + unsigned long pfn, int prot) { struct smmu_device *smmu = as->smmu; unsigned long *pte; unsigned int *count; struct page *page; + int attrs = as->pte_attr;

pte = locate_pte(as, iova, true, &page, &count); if (WARN_ON(!pte)) @@ -875,7 +876,11 @@ static int __smmu_iommu_map_pfn(struct smmu_as *as, dma_addr_t iova,

if (*pte == _PTE_VACANT(iova)) (*count)++; - *pte = SMMU_PFN_TO_PTE(pfn, as->pte_attr); + + if (dma_get_attr(DMA_ATTR_READ_ONLY, (struct dma_attrs *)prot)) + attrs &= ~_WRITABLE; + + *pte = SMMU_PFN_TO_PTE(pfn, attrs); FLUSH_CPU_DCACHE(pte, page, sizeof(*pte)); flush_ptc_and_tlb(smmu, as, iova, pte, page, 0); put_signature(as, iova, pfn); @@ -883,23 +888,27 @@ static int __smmu_iommu_map_pfn(struct smmu_as *as, dma_addr_t iova, }

static int __smmu_iommu_map_page(struct smmu_as *as, dma_addr_t iova, - phys_addr_t pa) + phys_addr_t pa, int prot) { unsigned long pfn = __phys_to_pfn(pa);

- return __smmu_iommu_map_pfn(as, iova, pfn); + return __smmu_iommu_map_pfn(as, iova, pfn, prot); }

static int __smmu_iommu_map_largepage(struct smmu_as *as, dma_addr_t iova, - phys_addr_t pa) + phys_addr_t pa, int prot) { unsigned long pdn = SMMU_ADDR_TO_PDN(iova); unsigned long *pdir = (unsigned long *)page_address(as->pdir_page); + int attrs = _PDE_ATTR;

if (pdir[pdn] != _PDE_VACANT(pdn)) return -EINVAL;

- pdir[pdn] = SMMU_ADDR_TO_PDN(pa) << 10 | _PDE_ATTR; + if (dma_get_attr(DMA_ATTR_READ_ONLY, (struct dma_attrs *)prot)) + attrs &= ~_WRITABLE; + + pdir[pdn] = SMMU_ADDR_TO_PDN(pa) << 10 | attrs; FLUSH_CPU_DCACHE(&pdir[pdn], as->pdir_page, sizeof pdir[pdn]); flush_ptc_and_tlb(as->smmu, as, iova, &pdir[pdn], as->pdir_page, 1);

@@ -912,7 +921,8 @@ static int smmu_iommu_map(struct iommu_domain *domain, unsigned long iova, struct smmu_as *as = domain->priv; unsigned long flags; int err; - int (*fn)(struct smmu_as *as, dma_addr_t iova, phys_addr_t pa); + int (*fn)(struct smmu_as *as, dma_addr_t iova, phys_addr_t pa, + int prot);

dev_dbg(as->smmu->dev, "[%d] %08lx:%08x\n", as->asid, iova, pa);

@@ -929,7 +939,7 @@ static int smmu_iommu_map(struct iommu_domain *domain, unsigned long iova, }

spin_lock_irqsave(&as->lock, flags); - err = fn(as, iova, pa); + err = fn(as, iova, pa, prot); spin_unlock_irqrestore(&as->lock, flags); return err; } @@ -943,6 +953,10 @@ static int smmu_iommu_map_pages(struct iommu_domain *domain, unsigned long iova, unsigned long *pdir = page_address(as->pdir_page); int err = 0; bool flush_all = (total > SZ_512) ? true : false; + int attrs = as->pte_attr; + + if (dma_get_attr(DMA_ATTR_READ_ONLY, (struct dma_attrs *)prot)) + attrs &= ~_WRITABLE;

spin_lock_irqsave(&as->lock, flags);

@@ -977,8 +991,7 @@ static int smmu_iommu_map_pages(struct iommu_domain *domain, unsigned long iova, if (*pte == _PTE_VACANT(iova + i * PAGE_SIZE)) (*rest)++;

- *pte = SMMU_PFN_TO_PTE(page_to_pfn(pages[i]), - as->pte_attr); + *pte = SMMU_PFN_TO_PTE(page_to_pfn(pages[i]), attrs); }

pte = &ptbl[ptn]; @@ -1010,6 +1023,10 @@ static int smmu_iommu_map_sg(struct iommu_domain *domain, unsigned long iova, bool flush_all = (nents * PAGE_SIZE > SZ_512) ? true : false; struct smmu_as *as = domain->priv; struct smmu_device *smmu = as->smmu; + int attrs = as->pte_attr; + + if (dma_get_attr(DMA_ATTR_READ_ONLY, (struct dma_attrs *)prot)) + attrs &= ~_WRITABLE;

for (count = 0, s = sgl; count < nents; s = sg_next(s)) { phys_addr_t phys = page_to_phys(sg_page(s)); @@ -1053,7 +1070,7 @@ static int smmu_iommu_map_sg(struct iommu_domain *domain, unsigned long iova, (*rest)++; }

- *pte = SMMU_PFN_TO_PTE(pfn + i, as->pte_attr); + *pte = SMMU_PFN_TO_PTE(pfn + i, attrs); }

pte = &ptbl[ptn]; @@ -1191,7 +1208,7 @@ static int smmu_iommu_attach_dev(struct iommu_domain *domain, struct page *page;

page = as->smmu->avp_vector_page; - __smmu_iommu_map_pfn(as, 0, page_to_pfn(page)); + __smmu_iommu_map_pfn(as, 0, page_to_pfn(page), 0);

pr_debug("Reserve "page zero" \ for AVP vectors using a common dummy\n");