s390/dma: Allow per device dma ops

As virtio-ccw will have dma ops, we can no longer default to the
zPCI ones. Make use of dev_archdata to keep the dma_ops per device.
The pci devices now use that to override the default, and the
default is changed to use the noop ops for everything that does not
specify a device specific one.
To compile without PCI support we will enable HAS_DMA all the time,
via the default config in lib/Kconfig.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

arch/s390/Kconfig

@@ -124,6 +124,7 @@ config S390
 	select HAVE_CMPXCHG_DOUBLE
 	select HAVE_CMPXCHG_LOCAL
 	select HAVE_DEBUG_KMEMLEAK
+	select HAVE_DMA_API_DEBUG
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_FTRACE_MCOUNT_RECORD
@@ -619,10 +620,6 @@ config HAS_IOMEM
 config IOMMU_HELPER
 	def_bool PCI
 
-config HAS_DMA
-	def_bool PCI
-	select HAVE_DMA_API_DEBUG
-
 config NEED_SG_DMA_LENGTH
 	def_bool PCI
 

arch/s390/include/asm/device.h

@@ -3,5 +3,9 @@
  *
  * This file is released under the GPLv2
  */
-#include <asm-generic/device.h>
+struct dev_archdata {
+	struct dma_map_ops *dma_ops;
+};
 
+struct pdev_archdata {
+};

arch/s390/include/asm/dma-mapping.h

@@ -11,11 +11,13 @@
 
 #define DMA_ERROR_CODE		(~(dma_addr_t) 0x0)
 
-extern struct dma_map_ops s390_dma_ops;
+extern struct dma_map_ops s390_pci_dma_ops;
 
 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
 {
-	return &s390_dma_ops;
+	if (dev && dev->archdata.dma_ops)
+		return dev->archdata.dma_ops;
+	return &dma_noop_ops;
 }
 
 static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,

arch/s390/pci/pci.c

@@ -643,6 +643,7 @@ int pcibios_add_device(struct pci_dev *pdev)
 
 	zdev->pdev = pdev;
 	pdev->dev.groups = zpci_attr_groups;
+	pdev->dev.archdata.dma_ops = &s390_pci_dma_ops;
 	zpci_map_resources(pdev);
 
 	for (i = 0; i < PCI_BAR_COUNT; i++) {

arch/s390/pci/pci_dma.c

@@ -544,7 +544,7 @@ static int __init dma_debug_do_init(void)
 }
 fs_initcall(dma_debug_do_init);
 
-struct dma_map_ops s390_dma_ops = {
+struct dma_map_ops s390_pci_dma_ops = {
 	.alloc		= s390_dma_alloc,
 	.free		= s390_dma_free,
 	.map_sg		= s390_dma_map_sg,
@@ -555,7 +555,7 @@ struct dma_map_ops s390_dma_ops = {
 	.is_phys	= 0,
 	/* dma_supported is unconditionally true without a callback */
 };
-EXPORT_SYMBOL_GPL(s390_dma_ops);
+EXPORT_SYMBOL_GPL(s390_pci_dma_ops);
 
 static int __init s390_iommu_setup(char *str)
 {