Support read-only mapping via struct dma_attrs.

Signed-off-by: Hiroshi Doyu <[email protected]>
---
 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");
-- 
1.8.1.5

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