6 files changed, 96 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index dd70fac57ec8..8135e66a4bb9 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -20,6 +20,8 @@
 
 #define DMA_ERROR_CODE		(~(dma_addr_t)0x0)
 
+#define ARCH_HAS_DMA_GET_REQUIRED_MASK
+
 /* Some dma direct funcs must be visible for use in other dma_ops */
 extern void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t flag);
@@ -69,6 +71,7 @@ static inline unsigned long device_to_mask(struct device *dev)
  */
 #ifdef CONFIG_PPC64
 extern struct dma_map_ops dma_iommu_ops;
+extern u64 dma_iommu_get_required_mask(struct device *dev);
 #endif
 extern struct dma_map_ops dma_direct_ops;
 
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 47cacddb14cf..58fc21623014 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -85,8 +85,9 @@ struct machdep_calls {
 	void		(*pci_dma_dev_setup)(struct pci_dev *dev);
 	void		(*pci_dma_bus_setup)(struct pci_bus *bus);
 
-	/* Platform set_dma_mask override */
+	/* Platform set_dma_mask and dma_get_required_mask overrides */
 	int		(*dma_set_mask)(struct device *dev, u64 dma_mask);
+	u64		(*dma_get_required_mask)(struct device *dev);
 
 	int		(*probe)(void);
 	void		(*setup_arch)(void); /* Optional, may be NULL */
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index e7554154a6de..1f2a711a261e 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -90,6 +90,19 @@ static int dma_iommu_dma_supported(struct device *dev, u64 mask)
 		return 1;
 }
 
+u64 dma_iommu_get_required_mask(struct device *dev)
+{
+	struct iommu_table *tbl = get_iommu_table_base(dev);
+	u64 mask;
+	if (!tbl)
+		return 0;
+
+	mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1);
+	mask += mask - 1;
+
+	return mask;
+}
+
 struct dma_map_ops dma_iommu_ops = {
 	.alloc_coherent	= dma_iommu_alloc_coherent,
 	.free_coherent	= dma_iommu_free_coherent,
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 4f0959fbfbee..503093efa202 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -170,6 +170,45 @@ int dma_set_mask(struct device *dev, u64 dma_mask)
 }
 EXPORT_SYMBOL(dma_set_mask);
 
+u64 dma_get_required_mask(struct device *dev)
+{
+	struct dma_map_ops *dma_ops = get_dma_ops(dev);
+	u64 mask, end = 0;
+
+	if (ppc_md.dma_get_required_mask)
+		return ppc_md.dma_get_required_mask(dev);
+
+	if (unlikely(dma_ops == NULL))
+		return 0;
+
+#ifdef CONFIG_PPC64
+	else if (dma_ops == &dma_iommu_ops)
+		return dma_iommu_get_required_mask(dev);
+#endif
+#ifdef CONFIG_SWIOTLB
+	else if (dma_ops == &swiotlb_dma_ops) {
+		u64 max_direct_dma_addr = dev->archdata.max_direct_dma_addr;
+
+		end = memblock_end_of_DRAM();
+		if (max_direct_dma_addr && end > max_direct_dma_addr)
+			end = max_direct_dma_addr;
+		end += get_dma_offset(dev);
+	}
+#endif
+	else if (dma_ops == &dma_direct_ops)
+		end = memblock_end_of_DRAM() + get_dma_offset(dev);
+	else {
+		WARN_ONCE(1, "%s: unknown ops %p\n", __func__, dma_ops);
+		end = memblock_end_of_DRAM();
+	}
+
+	mask = 1ULL << (fls64(end) - 1);
+	mask += mask - 1;
+
+	return mask;
+}
+EXPORT_SYMBOL_GPL(dma_get_required_mask);
+
 static int __init dma_init(void)
 {
        dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 26a067122a54..5ef55f3b0987 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -1159,6 +1159,17 @@ static int __init setup_iommu_fixed(char *str)
 }
 __setup("iommu_fixed=", setup_iommu_fixed);
 
+static u64 cell_dma_get_required_mask(struct device *dev)
+{
+	if (!dev->dma_mask)
+		return 0;
+
+	if (iommu_fixed_disabled && get_dma_ops(dev) == &dma_iommu_ops)
+		return dma_iommu_get_required_mask(dev);
+
+	return DMA_BIT_MASK(64);
+}
+
 static int __init cell_iommu_init(void)
 {
 	struct device_node *np;
@@ -1175,6 +1186,7 @@ static int __init cell_iommu_init(void)
 
 	/* Setup various ppc_md. callbacks */
 	ppc_md.pci_dma_dev_setup = cell_pci_dma_dev_setup;
+	ppc_md.dma_get_required_mask = cell_dma_get_required_mask;
 	ppc_md.tce_build = tce_build_cell;
 	ppc_md.tce_free = tce_free_cell;
 
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 01faab9456ca..fe5ededf0d60 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1077,12 +1077,38 @@ check_mask:
 	return 0;
 }
 
+static u64 dma_get_required_mask_pSeriesLP(struct device *dev)
+{
+	if (!dev->dma_mask)
+		return 0;
+
+	if (!disable_ddw && dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+		struct device_node *dn;
+
+		dn = pci_device_to_OF_node(pdev);
+
+		/* search upwards for ibm,dma-window */
+		for (; dn && PCI_DN(dn) && !PCI_DN(dn)->iommu_table;
+				dn = dn->parent)
+			if (of_get_property(dn, "ibm,dma-window", NULL))
+				break;
+		/* if there is a ibm,ddw-applicable property require 64 bits */
+		if (dn && PCI_DN(dn) &&
+				of_get_property(dn, "ibm,ddw-applicable", NULL))
+			return DMA_BIT_MASK(64);
+	}
+
+	return dma_iommu_get_required_mask(dev);
+}
+
 #else  /* CONFIG_PCI */
 #define pci_dma_bus_setup_pSeries	NULL
 #define pci_dma_dev_setup_pSeries	NULL
 #define pci_dma_bus_setup_pSeriesLP	NULL
 #define pci_dma_dev_setup_pSeriesLP	NULL
 #define dma_set_mask_pSeriesLP		NULL
+#define dma_get_required_mask_pSeriesLP	NULL
 #endif /* !CONFIG_PCI */
 
 static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action,
@@ -1186,6 +1212,7 @@ void iommu_init_early_pSeries(void)
 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeriesLP;
 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeriesLP;
 		ppc_md.dma_set_mask = dma_set_mask_pSeriesLP;
+		ppc_md.dma_get_required_mask = dma_get_required_mask_pSeriesLP;
 	} else {
 		ppc_md.tce_build = tce_build_pSeries;
 		ppc_md.tce_free  = tce_free_pSeries;