s390/pci: use physical addresses in DMA tables

The entries in the DMA translation tables for our IOMMU must specify
physical addresses of either the next level table or the final page
to be mapped for DMA. Currently however the code simply passes the
virtual addresses of both. On the other hand we still need to walk the
tables via their virtual addresses so we need to do a phys_to_virt()
when setting the entries and a virt_to_phys() when getting them.
Similarly when passing the I/O translation anchor to the hardware we
must also specify its physical address.

As the DMA and IOMMU APIs we are implementing already use the correct
phys_addr_t type for the address to be mapped let's also thread this
through instead of treating it as just an unsigned long.

Note: this currently doesn't fix a real bug, since virtual addresses
are indentical to physical ones.
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/include/asm/pci_dma.h

@@ -97,23 +97,23 @@ static inline unsigned int calc_px(dma_addr_t ptr)
 	return ((unsigned long) ptr >> PAGE_SHIFT) & ZPCI_PT_MASK;
 }
 
-static inline void set_pt_pfaa(unsigned long *entry, void *pfaa)
+static inline void set_pt_pfaa(unsigned long *entry, phys_addr_t pfaa)
 {
 	*entry &= ZPCI_PTE_FLAG_MASK;
-	*entry |= ((unsigned long) pfaa & ZPCI_PTE_ADDR_MASK);
+	*entry |= (pfaa & ZPCI_PTE_ADDR_MASK);
 }
 
-static inline void set_rt_sto(unsigned long *entry, void *sto)
+static inline void set_rt_sto(unsigned long *entry, phys_addr_t sto)
 {
 	*entry &= ZPCI_RTE_FLAG_MASK;
-	*entry |= ((unsigned long) sto & ZPCI_RTE_ADDR_MASK);
+	*entry |= (sto & ZPCI_RTE_ADDR_MASK);
 	*entry |= ZPCI_TABLE_TYPE_RTX;
 }
 
-static inline void set_st_pto(unsigned long *entry, void *pto)
+static inline void set_st_pto(unsigned long *entry, phys_addr_t pto)
 {
 	*entry &= ZPCI_STE_FLAG_MASK;
-	*entry |= ((unsigned long) pto & ZPCI_STE_ADDR_MASK);
+	*entry |= (pto & ZPCI_STE_ADDR_MASK);
 	*entry |= ZPCI_TABLE_TYPE_SX;
 }
 
@@ -169,16 +169,19 @@ static inline int pt_entry_isvalid(unsigned long entry)
 
 static inline unsigned long *get_rt_sto(unsigned long entry)
 {
-	return ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_RTX)
-		? (unsigned long *) (entry & ZPCI_RTE_ADDR_MASK)
-		: NULL;
+	if ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_RTX)
+		return phys_to_virt(entry & ZPCI_RTE_ADDR_MASK);
+	else
+		return NULL;
+
 }
 
 static inline unsigned long *get_st_pto(unsigned long entry)
 {
-	return ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_SX)
-		? (unsigned long *) (entry & ZPCI_STE_ADDR_MASK)
-		: NULL;
+	if ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_SX)
+		return phys_to_virt(entry & ZPCI_STE_ADDR_MASK);
+	else
+		return NULL;
 }
 
 /* Prototypes */
@@ -186,7 +189,7 @@ void dma_free_seg_table(unsigned long);
 unsigned long *dma_alloc_cpu_table(void);
 void dma_cleanup_tables(unsigned long *);
 unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr);
-void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags);
+void dma_update_cpu_trans(unsigned long *entry, phys_addr_t page_addr, int flags);
 
 extern const struct dma_map_ops s390_pci_dma_ops;
 

arch/s390/pci/pci.c

@@ -771,7 +771,7 @@ int zpci_hot_reset_device(struct zpci_dev *zdev)
 
 	if (zdev->dma_table)
 		rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-					(u64)zdev->dma_table);
+					virt_to_phys(zdev->dma_table));
 	else
 		rc = zpci_dma_init_device(zdev);
 	if (rc) {

arch/s390/pci/pci_dma.c

@@ -74,7 +74,7 @@ static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
 		if (!sto)
 			return NULL;
 
-		set_rt_sto(entry, sto);
+		set_rt_sto(entry, virt_to_phys(sto));
 		validate_rt_entry(entry);
 		entry_clr_protected(entry);
 	}
@@ -91,7 +91,7 @@ static unsigned long *dma_get_page_table_origin(unsigned long *entry)
 		pto = dma_alloc_page_table();
 		if (!pto)
 			return NULL;
-		set_st_pto(entry, pto);
+		set_st_pto(entry, virt_to_phys(pto));
 		validate_st_entry(entry);
 		entry_clr_protected(entry);
 	}
@@ -117,7 +117,7 @@ unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
 	return &pto[px];
 }
 
-void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
+void dma_update_cpu_trans(unsigned long *entry, phys_addr_t page_addr, int flags)
 {
 	if (flags & ZPCI_PTE_INVALID) {
 		invalidate_pt_entry(entry);
@@ -132,11 +132,11 @@ void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
 		entry_clr_protected(entry);
 }
 
-static int __dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
+static int __dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa,
 			      dma_addr_t dma_addr, size_t size, int flags)
 {
 	unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	u8 *page_addr = (u8 *) (pa & PAGE_MASK);
+	phys_addr_t page_addr = (pa & PAGE_MASK);
 	unsigned long irq_flags;
 	unsigned long *entry;
 	int i, rc = 0;
@@ -217,7 +217,7 @@ static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
 	return ret;
 }
 
-static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
+static int dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa,
 			    dma_addr_t dma_addr, size_t size, int flags)
 {
 	int rc;
@@ -400,7 +400,7 @@ static void *s390_dma_alloc(struct device *dev, size_t size,
 {
 	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 	struct page *page;
-	unsigned long pa;
+	phys_addr_t pa;
 	dma_addr_t map;
 
 	size = PAGE_ALIGN(size);
@@ -411,18 +411,18 @@ static void *s390_dma_alloc(struct device *dev, size_t size,
 	pa = page_to_phys(page);
 	map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0);
 	if (dma_mapping_error(dev, map)) {
-		free_pages(pa, get_order(size));
+		__free_pages(page, get_order(size));
 		return NULL;
 	}
 
 	atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
 	if (dma_handle)
 		*dma_handle = map;
-	return (void *) pa;
+	return phys_to_virt(pa);
 }
 
 static void s390_dma_free(struct device *dev, size_t size,
-			  void *pa, dma_addr_t dma_handle,
+			  void *vaddr, dma_addr_t dma_handle,
 			  unsigned long attrs)
 {
 	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
@@ -430,7 +430,7 @@ static void s390_dma_free(struct device *dev, size_t size,
 	size = PAGE_ALIGN(size);
 	atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
 	s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0);
-	free_pages((unsigned long) pa, get_order(size));
+	free_pages((unsigned long)vaddr, get_order(size));
 }
 
 /* Map a segment into a contiguous dma address area */
@@ -443,7 +443,7 @@ static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	dma_addr_t dma_addr_base, dma_addr;
 	int flags = ZPCI_PTE_VALID;
 	struct scatterlist *s;
-	unsigned long pa = 0;
+	phys_addr_t pa = 0;
 	int ret;
 
 	dma_addr_base = dma_alloc_address(dev, nr_pages);
@@ -598,7 +598,7 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
 
 	}
 	if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-			       (u64)zdev->dma_table)) {
+			       virt_to_phys(zdev->dma_table))) {
 		rc = -EIO;
 		goto free_bitmap;
 	}

drivers/iommu/s390-iommu.c

@@ -109,7 +109,7 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
 
 	zdev->dma_table = s390_domain->dma_table;
 	cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-				(u64) zdev->dma_table);
+				virt_to_phys(zdev->dma_table));
 	if (cc) {
 		rc = -EIO;
 		goto out_restore;
@@ -205,11 +205,11 @@ static void s390_iommu_release_device(struct device *dev)
 }
 
 static int s390_iommu_update_trans(struct s390_domain *s390_domain,
-				   unsigned long pa, dma_addr_t dma_addr,
+				   phys_addr_t pa, dma_addr_t dma_addr,
 				   size_t size, int flags)
 {
 	struct s390_domain_device *domain_device;
-	u8 *page_addr = (u8 *) (pa & PAGE_MASK);
+	phys_addr_t page_addr = pa & PAGE_MASK;
 	dma_addr_t start_dma_addr = dma_addr;
 	unsigned long irq_flags, nr_pages, i;
 	unsigned long *entry;
@@ -274,7 +274,7 @@ static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova,
 	if (!(prot & IOMMU_WRITE))
 		flags |= ZPCI_TABLE_PROTECTED;
 
-	rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
+	rc = s390_iommu_update_trans(s390_domain, paddr, iova,
 				     size, flags);
 
 	return rc;
@@ -324,7 +324,7 @@ static size_t s390_iommu_unmap(struct iommu_domain *domain,
 	if (!paddr)
 		return 0;
 
-	rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
+	rc = s390_iommu_update_trans(s390_domain, paddr, iova,
 				     size, flags);
 	if (rc)
 		return 0;