1 files changed, 191 insertions, 106 deletions

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 2cd439203..930596425 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -41,8 +41,10 @@ struct tegra_smmu_as {
 	struct iommu_domain domain;
 	struct tegra_smmu *smmu;
 	unsigned int use_count;
-	struct page *count;
+	u32 *count;
+	struct page **pts;
 	struct page *pd;
+	dma_addr_t pd_dma;
 	unsigned id;
 	u32 attr;
 };
@@ -81,9 +83,9 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
 #define  SMMU_PTB_ASID_VALUE(x) ((x) & 0x7f)
 
 #define SMMU_PTB_DATA 0x020
-#define  SMMU_PTB_DATA_VALUE(page, attr) (page_to_phys(page) >> 12 | (attr))
+#define  SMMU_PTB_DATA_VALUE(dma, attr) ((dma) >> 12 | (attr))
 
-#define SMMU_MK_PDE(page, attr) (page_to_phys(page) >> SMMU_PTE_SHIFT | (attr))
+#define SMMU_MK_PDE(dma, attr) ((dma) >> SMMU_PTE_SHIFT | (attr))
 
 #define SMMU_TLB_FLUSH 0x030
 #define  SMMU_TLB_FLUSH_VA_MATCH_ALL     (0 << 0)
@@ -136,29 +138,49 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
 #define SMMU_PTE_ATTR		(SMMU_PTE_READABLE | SMMU_PTE_WRITABLE | \
 				 SMMU_PTE_NONSECURE)
 
-static inline void smmu_flush_ptc(struct tegra_smmu *smmu, struct page *page,
+static unsigned int iova_pd_index(unsigned long iova)
+{
+	return (iova >> SMMU_PDE_SHIFT) & (SMMU_NUM_PDE - 1);
+}
+
+static unsigned int iova_pt_index(unsigned long iova)
+{
+	return (iova >> SMMU_PTE_SHIFT) & (SMMU_NUM_PTE - 1);
+}
+
+static bool smmu_dma_addr_valid(struct tegra_smmu *smmu, dma_addr_t addr)
+{
+	addr >>= 12;
+	return (addr & smmu->pfn_mask) == addr;
+}
+
+static dma_addr_t smmu_pde_to_dma(u32 pde)
+{
+	return pde << 12;
+}
+
+static void smmu_flush_ptc_all(struct tegra_smmu *smmu)
+{
+	smmu_writel(smmu, SMMU_PTC_FLUSH_TYPE_ALL, SMMU_PTC_FLUSH);
+}
+
+static inline void smmu_flush_ptc(struct tegra_smmu *smmu, dma_addr_t dma,
 				  unsigned long offset)
 {
-	phys_addr_t phys = page ? page_to_phys(page) : 0;
 	u32 value;
 
-	if (page) {
-		offset &= ~(smmu->mc->soc->atom_size - 1);
+	offset &= ~(smmu->mc->soc->atom_size - 1);
 
-		if (smmu->mc->soc->num_address_bits > 32) {
-#ifdef CONFIG_PHYS_ADDR_T_64BIT
-			value = (phys >> 32) & SMMU_PTC_FLUSH_HI_MASK;
+	if (smmu->mc->soc->num_address_bits > 32) {
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+		value = (dma >> 32) & SMMU_PTC_FLUSH_HI_MASK;
 #else
-			value = 0;
+		value = 0;
 #endif
-			smmu_writel(smmu, value, SMMU_PTC_FLUSH_HI);
-		}
-
-		value = (phys + offset) | SMMU_PTC_FLUSH_TYPE_ADR;
-	} else {
-		value = SMMU_PTC_FLUSH_TYPE_ALL;
+		smmu_writel(smmu, value, SMMU_PTC_FLUSH_HI);
 	}
 
+	value = (dma + offset) | SMMU_PTC_FLUSH_TYPE_ADR;
 	smmu_writel(smmu, value, SMMU_PTC_FLUSH);
 }
 
@@ -238,8 +260,6 @@ static bool tegra_smmu_capable(enum iommu_cap cap)
 static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
 {
 	struct tegra_smmu_as *as;
-	unsigned int i;
-	uint32_t *pd;
 
 	if (type != IOMMU_DOMAIN_UNMANAGED)
 		return NULL;
@@ -250,32 +270,26 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
 
 	as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;
 
-	as->pd = alloc_page(GFP_KERNEL | __GFP_DMA);
+	as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
 	if (!as->pd) {
 		kfree(as);
 		return NULL;
 	}
 
-	as->count = alloc_page(GFP_KERNEL);
+	as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
 	if (!as->count) {
 		__free_page(as->pd);
 		kfree(as);
 		return NULL;
 	}
 
-	/* clear PDEs */
-	pd = page_address(as->pd);
-	SetPageReserved(as->pd);
-
-	for (i = 0; i < SMMU_NUM_PDE; i++)
-		pd[i] = 0;
-
-	/* clear PDE usage counters */
-	pd = page_address(as->count);
-	SetPageReserved(as->count);
-
-	for (i = 0; i < SMMU_NUM_PDE; i++)
-		pd[i] = 0;
+	as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
+	if (!as->pts) {
+		kfree(as->count);
+		__free_page(as->pd);
+		kfree(as);
+		return NULL;
+	}
 
 	/* setup aperture */
 	as->domain.geometry.aperture_start = 0;
@@ -290,7 +304,6 @@ static void tegra_smmu_domain_free(struct iommu_domain *domain)
 	struct tegra_smmu_as *as = to_smmu_as(domain);
 
 	/* TODO: free page directory and page tables */
-	ClearPageReserved(as->pd);
 
 	kfree(as);
 }
@@ -378,16 +391,26 @@ static int tegra_smmu_as_prepare(struct tegra_smmu *smmu,
 		return 0;
 	}
 
+	as->pd_dma = dma_map_page(smmu->dev, as->pd, 0, SMMU_SIZE_PD,
+				  DMA_TO_DEVICE);
+	if (dma_mapping_error(smmu->dev, as->pd_dma))
+		return -ENOMEM;
+
+	/* We can't handle 64-bit DMA addresses */
+	if (!smmu_dma_addr_valid(smmu, as->pd_dma)) {
+		err = -ENOMEM;
+		goto err_unmap;
+	}
+
 	err = tegra_smmu_alloc_asid(smmu, &as->id);
 	if (err < 0)
-		return err;
+		goto err_unmap;
 
-	smmu->soc->ops->flush_dcache(as->pd, 0, SMMU_SIZE_PD);
-	smmu_flush_ptc(smmu, as->pd, 0);
+	smmu_flush_ptc(smmu, as->pd_dma, 0);
 	smmu_flush_tlb_asid(smmu, as->id);
 
 	smmu_writel(smmu, as->id & 0x7f, SMMU_PTB_ASID);
-	value = SMMU_PTB_DATA_VALUE(as->pd, as->attr);
+	value = SMMU_PTB_DATA_VALUE(as->pd_dma, as->attr);
 	smmu_writel(smmu, value, SMMU_PTB_DATA);
 	smmu_flush(smmu);
 
@@ -395,6 +418,10 @@ static int tegra_smmu_as_prepare(struct tegra_smmu *smmu,
 	as->use_count++;
 
 	return 0;
+
+err_unmap:
+	dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
+	return err;
 }
 
 static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
@@ -404,6 +431,9 @@ static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
 		return;
 
 	tegra_smmu_free_asid(smmu, as->id);
+
+	dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
+
 	as->smmu = NULL;
 }
 
@@ -467,96 +497,155 @@ static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *de
 	}
 }
 
+static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
+			       u32 value)
+{
+	unsigned int pd_index = iova_pd_index(iova);
+	struct tegra_smmu *smmu = as->smmu;
+	u32 *pd = page_address(as->pd);
+	unsigned long offset = pd_index * sizeof(*pd);
+
+	/* Set the page directory entry first */
+	pd[pd_index] = value;
+
+	/* The flush the page directory entry from caches */
+	dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,
+					 sizeof(*pd), DMA_TO_DEVICE);
+
+	/* And flush the iommu */
+	smmu_flush_ptc(smmu, as->pd_dma, offset);
+	smmu_flush_tlb_section(smmu, as->id, iova);
+	smmu_flush(smmu);
+}
+
+static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova)
+{
+	u32 *pt = page_address(pt_page);
+
+	return pt + iova_pt_index(iova);
+}
+
+static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
+				  dma_addr_t *dmap)
+{
+	unsigned int pd_index = iova_pd_index(iova);
+	struct page *pt_page;
+	u32 *pd;
+
+	pt_page = as->pts[pd_index];
+	if (!pt_page)
+		return NULL;
+
+	pd = page_address(as->pd);
+	*dmap = smmu_pde_to_dma(pd[pd_index]);
+
+	return tegra_smmu_pte_offset(pt_page, iova);
+}
+
 static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
-		       struct page **pagep)
+		       dma_addr_t *dmap)
 {
-	u32 *pd = page_address(as->pd), *pt, *count;
-	u32 pde = (iova >> SMMU_PDE_SHIFT) & 0x3ff;
-	u32 pte = (iova >> SMMU_PTE_SHIFT) & 0x3ff;
+	unsigned int pde = iova_pd_index(iova);
 	struct tegra_smmu *smmu = as->smmu;
-	struct page *page;
-	unsigned int i;
 
-	if (pd[pde] == 0) {
-		page = alloc_page(GFP_KERNEL | __GFP_DMA);
+	if (!as->pts[pde]) {
+		struct page *page;
+		dma_addr_t dma;
+
+		page = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
 		if (!page)
 			return NULL;
 
-		pt = page_address(page);
-		SetPageReserved(page);
+		dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT,
+				   DMA_TO_DEVICE);
+		if (dma_mapping_error(smmu->dev, dma)) {
+			__free_page(page);
+			return NULL;
+		}
 
-		for (i = 0; i < SMMU_NUM_PTE; i++)
-			pt[i] = 0;
+		if (!smmu_dma_addr_valid(smmu, dma)) {
+			dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT,
+				       DMA_TO_DEVICE);
+			__free_page(page);
+			return NULL;
+		}
 
-		smmu->soc->ops->flush_dcache(page, 0, SMMU_SIZE_PT);
+		as->pts[pde] = page;
 
-		pd[pde] = SMMU_MK_PDE(page, SMMU_PDE_ATTR | SMMU_PDE_NEXT);
+		tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR |
+							      SMMU_PDE_NEXT));
 
-		smmu->soc->ops->flush_dcache(as->pd, pde << 2, 4);
-		smmu_flush_ptc(smmu, as->pd, pde << 2);
-		smmu_flush_tlb_section(smmu, as->id, iova);
-		smmu_flush(smmu);
+		*dmap = dma;
 	} else {
-		page = pfn_to_page(pd[pde] & smmu->pfn_mask);
-		pt = page_address(page);
+		u32 *pd = page_address(as->pd);
+
+		*dmap = smmu_pde_to_dma(pd[pde]);
 	}
 
-	*pagep = page;
+	return tegra_smmu_pte_offset(as->pts[pde], iova);
+}
 
-	/* Keep track of entries in this page table. */
-	count = page_address(as->count);
-	if (pt[pte] == 0)
-		count[pde]++;
+static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
+{
+	unsigned int pd_index = iova_pd_index(iova);
 
-	return &pt[pte];
+	as->count[pd_index]++;
 }
 
-static void as_put_pte(struct tegra_smmu_as *as, dma_addr_t iova)
+static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
 {
-	u32 pde = (iova >> SMMU_PDE_SHIFT) & 0x3ff;
-	u32 pte = (iova >> SMMU_PTE_SHIFT) & 0x3ff;
-	u32 *count = page_address(as->count);
-	u32 *pd = page_address(as->pd), *pt;
-	struct page *page;
-
-	page = pfn_to_page(pd[pde] & as->smmu->pfn_mask);
-	pt = page_address(page);
+	unsigned int pde = iova_pd_index(iova);
+	struct page *page = as->pts[pde];
 
 	/*
 	 * When no entries in this page table are used anymore, return the
 	 * memory page to the system.
 	 */
-	if (pt[pte] != 0) {
-		if (--count[pde] == 0) {
-			ClearPageReserved(page);
-			__free_page(page);
-			pd[pde] = 0;
-		}
+	if (--as->count[pde] == 0) {
+		struct tegra_smmu *smmu = as->smmu;
+		u32 *pd = page_address(as->pd);
+		dma_addr_t pte_dma = smmu_pde_to_dma(pd[pde]);
+
+		tegra_smmu_set_pde(as, iova, 0);
 
-		pt[pte] = 0;
+		dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
+		__free_page(page);
+		as->pts[pde] = NULL;
 	}
 }
 
+static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova,
+			       u32 *pte, dma_addr_t pte_dma, u32 val)
+{
+	struct tegra_smmu *smmu = as->smmu;
+	unsigned long offset = offset_in_page(pte);
+
+	*pte = val;
+
+	dma_sync_single_range_for_device(smmu->dev, pte_dma, offset,
+					 4, DMA_TO_DEVICE);
+	smmu_flush_ptc(smmu, pte_dma, offset);
+	smmu_flush_tlb_group(smmu, as->id, iova);
+	smmu_flush(smmu);
+}
+
 static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
 			  phys_addr_t paddr, size_t size, int prot)
 {
 	struct tegra_smmu_as *as = to_smmu_as(domain);
-	struct tegra_smmu *smmu = as->smmu;
-	unsigned long offset;
-	struct page *page;
+	dma_addr_t pte_dma;
 	u32 *pte;
 
-	pte = as_get_pte(as, iova, &page);
+	pte = as_get_pte(as, iova, &pte_dma);
 	if (!pte)
 		return -ENOMEM;
 
-	*pte = __phys_to_pfn(paddr) | SMMU_PTE_ATTR;
-	offset = offset_in_page(pte);
+	/* If we aren't overwriting a pre-existing entry, increment use */
+	if (*pte == 0)
+		tegra_smmu_pte_get_use(as, iova);
 
-	smmu->soc->ops->flush_dcache(page, offset, 4);
-	smmu_flush_ptc(smmu, page, offset);
-	smmu_flush_tlb_group(smmu, as->id, iova);
-	smmu_flush(smmu);
+	tegra_smmu_set_pte(as, iova, pte, pte_dma,
+			   __phys_to_pfn(paddr) | SMMU_PTE_ATTR);
 
 	return 0;
 }
@@ -565,22 +654,15 @@ static size_t tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
 			       size_t size)
 {
 	struct tegra_smmu_as *as = to_smmu_as(domain);
-	struct tegra_smmu *smmu = as->smmu;
-	unsigned long offset;
-	struct page *page;
+	dma_addr_t pte_dma;
 	u32 *pte;
 
-	pte = as_get_pte(as, iova, &page);
-	if (!pte)
+	pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
+	if (!pte || !*pte)
 		return 0;
 
-	offset = offset_in_page(pte);
-	as_put_pte(as, iova);
-
-	smmu->soc->ops->flush_dcache(page, offset, 4);
-	smmu_flush_ptc(smmu, page, offset);
-	smmu_flush_tlb_group(smmu, as->id, iova);
-	smmu_flush(smmu);
+	tegra_smmu_set_pte(as, iova, pte, pte_dma, 0);
+	tegra_smmu_pte_put_use(as, iova);
 
 	return size;
 }
@@ -589,11 +671,14 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
 					   dma_addr_t iova)
 {
 	struct tegra_smmu_as *as = to_smmu_as(domain);
-	struct page *page;
 	unsigned long pfn;
+	dma_addr_t pte_dma;
 	u32 *pte;
 
-	pte = as_get_pte(as, iova, &page);
+	pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
+	if (!pte || !*pte)
+		return 0;
+
 	pfn = *pte & as->smmu->pfn_mask;
 
 	return PFN_PHYS(pfn);
@@ -837,7 +922,7 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
 
 	smmu_writel(smmu, value, SMMU_TLB_CONFIG);
 
-	smmu_flush_ptc(smmu, NULL, 0);
+	smmu_flush_ptc_all(smmu);
 	smmu_flush_tlb(smmu);
 	smmu_writel(smmu, SMMU_CONFIG_ENABLE, SMMU_CONFIG);
 	smmu_flush(smmu);