powerpc: Merge 32 and 64-bit dma code

We essentially adopt the 64-bit dma code, with some changes to support
32-bit systems, including HIGHMEM.  dma functions on 32-bit are now
invoked via accessor functions which call the correct op for a device based
on archdata dma_ops.  If there is no archdata dma_ops, this defaults
to dma_direct_ops.

In addition, the dma_map/unmap_page functions are added to dma_ops
because we can't just fall back on map/unmap_single when HIGHMEM is
enabled. In the case of dma_direct_*, we stop using map/unmap_single
and just use the page version - this saves a lot of ugly
ifdeffing.  We leave map/unmap_single in the dma_ops definition,
though, because they are needed by the iommu code, which does not
implement map/unmap_page.  Ideally, going forward, we will completely
eliminate map/unmap_single and just have map/unmap_page, if it's
workable for 64-bit.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

8 files changed, 175 insertions, 205 deletions

diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index c7ca45f97dd2..fddb229bd74f 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -44,8 +44,6 @@ extern void __dma_sync_page(struct page *page, unsigned long offset,
 
 #endif /* ! CONFIG_NOT_COHERENT_CACHE */
 
-#ifdef CONFIG_PPC64
-
 static inline unsigned long device_to_mask(struct device *dev)
 {
         if (dev->dma_mask && *dev->dma_mask)
@@ -76,8 +74,24 @@ struct dma_mapping_ops {
                                 struct dma_attrs *attrs);
         int             (*dma_supported)(struct device *dev, u64 mask);
         int             (*set_dma_mask)(struct device *dev, u64 dma_mask);
+        dma_addr_t      (*map_page)(struct device *dev, struct page *page,
+                                unsigned long offset, size_t size,
+                                enum dma_data_direction direction,
+                                struct dma_attrs *attrs);
+        void            (*unmap_page)(struct device *dev,
+                                dma_addr_t dma_address, size_t size,
+                                enum dma_data_direction direction,
+                                struct dma_attrs *attrs);
 };
 
+/*
+ * Available generic sets of operations
+ */
+#ifdef CONFIG_PPC64
+extern struct dma_mapping_ops dma_iommu_ops;
+#endif
+extern struct dma_mapping_ops dma_direct_ops;
+
 static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
 {
         /* We don't handle the NULL dev case for ISA for now. We could
@@ -85,8 +99,19 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
          * only ISA DMA device we support is the floppy and we have a hack
          * in the floppy driver directly to get a device for us.
          */
-        if (unlikely(dev == NULL || dev->archdata.dma_ops == NULL))
+
+        if (unlikely(dev == NULL) || dev->archdata.dma_ops == NULL) {
+#ifdef CONFIG_PPC64
                 return NULL;
+#else
+                /* Use default on 32-bit if dma_ops is not set up */
+                /* TODO: Long term, we should fix drivers so that dev and
+                 * archdata dma_ops are set up for all buses.
+                 */
+                return &dma_direct_ops;
+#endif
+        }
+
         return dev->archdata.dma_ops;
 }
 
@@ -123,6 +148,12 @@ static inline int dma_set_mask(struct device *dev, u64 dma_mask)
         return 0;
 }
 
+/*
+ * TODO: map_/unmap_single will ideally go away, to be completely
+ * replaced by map/unmap_page.   Until then, we allow dma_ops to have
+ * one or the other, or both by checking to see if the specific
+ * function requested exists; and if not, falling back on the other set.
+ */
 static inline dma_addr_t dma_map_single_attrs(struct device *dev,
                                               void *cpu_addr,
                                               size_t size,
@@ -132,7 +163,14 @@ static inline dma_addr_t dma_map_single_attrs(struct device *dev,
         struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
 
         BUG_ON(!dma_ops);
-        return dma_ops->map_single(dev, cpu_addr, size, direction, attrs);
+
+        if (dma_ops->map_single)
+                return dma_ops->map_single(dev, cpu_addr, size, direction,
+                                           attrs);
+
+        return dma_ops->map_page(dev, virt_to_page(cpu_addr),
+                                 (unsigned long)cpu_addr % PAGE_SIZE, size,
+                                 direction, attrs);
 }
 
 static inline void dma_unmap_single_attrs(struct device *dev,
@@ -144,7 +182,13 @@ static inline void dma_unmap_single_attrs(struct device *dev,
         struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
 
         BUG_ON(!dma_ops);
-        dma_ops->unmap_single(dev, dma_addr, size, direction, attrs);
+
+        if (dma_ops->unmap_single) {
+                dma_ops->unmap_single(dev, dma_addr, size, direction, attrs);
+                return;
+        }
+
+        dma_ops->unmap_page(dev, dma_addr, size, direction, attrs);
 }
 
 static inline dma_addr_t dma_map_page_attrs(struct device *dev,
@@ -156,8 +200,13 @@ static inline dma_addr_t dma_map_page_attrs(struct device *dev,
         struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
 
         BUG_ON(!dma_ops);
+
+        if (dma_ops->map_page)
+                return dma_ops->map_page(dev, page, offset, size, direction,
+                                         attrs);
+
         return dma_ops->map_single(dev, page_address(page) + offset, size,
-                        direction, attrs);
+                                   direction, attrs);
 }
 
 static inline void dma_unmap_page_attrs(struct device *dev,
@@ -169,6 +218,12 @@ static inline void dma_unmap_page_attrs(struct device *dev,
         struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
 
         BUG_ON(!dma_ops);
+
+        if (dma_ops->unmap_page) {
+                dma_ops->unmap_page(dev, dma_address, size, direction, attrs);
+                return;
+        }
+
         dma_ops->unmap_single(dev, dma_address, size, direction, attrs);
 }
 
@@ -253,126 +308,6 @@ static inline void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
         dma_unmap_sg_attrs(dev, sg, nhwentries, direction, NULL);
 }
 
-/*
- * Available generic sets of operations
- */
-extern struct dma_mapping_ops dma_iommu_ops;
-extern struct dma_mapping_ops dma_direct_ops;
-
-#else /* CONFIG_PPC64 */
-
-#define dma_supported(dev, mask)        (1)
-
-static inline int dma_set_mask(struct device *dev, u64 dma_mask)
-{
-        if (!dev->dma_mask || !dma_supported(dev, mask))
-                return -EIO;
-
-        *dev->dma_mask = dma_mask;
-
-        return 0;
-}
-
-static inline void *dma_alloc_coherent(struct device *dev, size_t size,
-                                       dma_addr_t * dma_handle,
-                                       gfp_t gfp)
-{
-#ifdef CONFIG_NOT_COHERENT_CACHE
-        return __dma_alloc_coherent(size, dma_handle, gfp);
-#else
-        void *ret;
-        /* ignore region specifiers */
-        gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
-        if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
-                gfp |= GFP_DMA;
-
-        ret = (void *)__get_free_pages(gfp, get_order(size));
-
-        if (ret != NULL) {
-                memset(ret, 0, size);
-                *dma_handle = virt_to_bus(ret);
-        }
-
-        return ret;
-#endif
-}
-
-static inline void
-dma_free_coherent(struct device *dev, size_t size, void *vaddr,
-                  dma_addr_t dma_handle)
-{
-#ifdef CONFIG_NOT_COHERENT_CACHE
-        __dma_free_coherent(size, vaddr);
-#else
-        free_pages((unsigned long)vaddr, get_order(size));
-#endif
-}
-
-static inline dma_addr_t
-dma_map_single(struct device *dev, void *ptr, size_t size,
-               enum dma_data_direction direction)
-{
-        BUG_ON(direction == DMA_NONE);
-
-        __dma_sync(ptr, size, direction);
-
-        return virt_to_bus(ptr);
-}
-
-static inline void dma_unmap_single(struct device *dev, dma_addr_t dma_addr,
-                                    size_t size,
-                                    enum dma_data_direction direction)
-{
-        /* We do nothing. */
-}
-
-static inline dma_addr_t
-dma_map_page(struct device *dev, struct page *page,
-             unsigned long offset, size_t size,
-             enum dma_data_direction direction)
-{
-        BUG_ON(direction == DMA_NONE);
-
-        __dma_sync_page(page, offset, size, direction);
-
-        return page_to_bus(page) + offset;
-}
-
-static inline void dma_unmap_page(struct device *dev, dma_addr_t dma_address,
-                                  size_t size,
-                                  enum dma_data_direction direction)
-{
-        /* We do nothing. */
-}
-
-static inline int
-dma_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
-           enum dma_data_direction direction)
-{
-        struct scatterlist *sg;
-        int i;
-
-        BUG_ON(direction == DMA_NONE);
-
-        for_each_sg(sgl, sg, nents, i) {
-                BUG_ON(!sg_page(sg));
-                __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
-                sg->dma_address = page_to_bus(sg_page(sg)) + sg->offset;
-        }
-
-        return nents;
-}
-
-static inline void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
-                                int nhwentries,
-                                enum dma_data_direction direction)
-{
-        /* We don't do anything here. */
-}
-
-#endif /* CONFIG_PPC64 */
-
 static inline void dma_sync_single_for_cpu(struct device *dev,
                 dma_addr_t dma_handle, size_t size,
                 enum dma_data_direction direction)
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 893aafd87fde..2740c44ff717 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -88,8 +88,6 @@ struct machdep_calls {
         unsigned long   (*tce_get)(struct iommu_table *tbl,
                                     long index);
         void            (*tce_flush)(struct iommu_table *tbl);
-        void            (*pci_dma_dev_setup)(struct pci_dev *dev);
-        void            (*pci_dma_bus_setup)(struct pci_bus *bus);
 
         void __iomem *  (*ioremap)(phys_addr_t addr, unsigned long size,
                                    unsigned long flags);
@@ -101,6 +99,9 @@ struct machdep_calls {
 #endif
 #endif /* CONFIG_PPC64 */
 
+        void            (*pci_dma_dev_setup)(struct pci_dev *dev);
+        void            (*pci_dma_bus_setup)(struct pci_bus *bus);
+
         int             (*probe)(void);
         void            (*setup_arch)(void); /* Optional, may be NULL */
         void            (*init_early)(void);
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index a05a942b1c25..0e52c7828ea4 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -60,6 +60,14 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
         return channel ? 15 : 14;
 }
 
+#ifdef CONFIG_PCI
+extern void set_pci_dma_ops(struct dma_mapping_ops *dma_ops);
+extern struct dma_mapping_ops *get_pci_dma_ops(void);
+#else   /* CONFIG_PCI */
+#define set_pci_dma_ops(d)
+#define get_pci_dma_ops()       NULL
+#endif
+
 #ifdef CONFIG_PPC64
 
 /*
@@ -70,9 +78,6 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
 #define PCI_DISABLE_MWI
 
 #ifdef CONFIG_PCI
-extern void set_pci_dma_ops(struct dma_mapping_ops *dma_ops);
-extern struct dma_mapping_ops *get_pci_dma_ops(void);
-
 static inline void pci_dma_burst_advice(struct pci_dev *pdev,
                                         enum pci_dma_burst_strategy *strat,
                                         unsigned long *strategy_parameter)
@@ -89,9 +94,6 @@ static inline void pci_dma_burst_advice(struct pci_dev *pdev,
         *strat = PCI_DMA_BURST_MULTIPLE;
         *strategy_parameter = cacheline_size;
 }
-#else   /* CONFIG_PCI */
-#define set_pci_dma_ops(d)
-#define get_pci_dma_ops()       NULL
 #endif
 
 #else /* 32-bit */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 09b3cabf2f91..fdb58253fa5b 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -70,10 +70,10 @@ extra-$(CONFIG_8xx)		:= head_8xx.o
 extra-y                         += vmlinux.lds
 
 obj-y                           += time.o prom.o traps.o setup-common.o \
-                                   udbg.o misc.o io.o \
+                                   udbg.o misc.o io.o dma.o \
                                    misc_$(CONFIG_WORD_SIZE).o
 obj-$(CONFIG_PPC32)             += entry_32.o setup_32.o
-obj-$(CONFIG_PPC64)             += dma.o dma-iommu.o iommu.o
+obj-$(CONFIG_PPC64)             += dma-iommu.o iommu.o
 obj-$(CONFIG_KGDB)              += kgdb.o
 obj-$(CONFIG_PPC_MULTIPLATFORM) += prom_init.o
 obj-$(CONFIG_MODULES)           += ppc_ksyms.o
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 124f86743bde..41fdd48bf433 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -16,21 +16,30 @@
  * This implementation supports a per-device offset that can be applied if
  * the address at which memory is visible to devices is not 0. Platform code
  * can set archdata.dma_data to an unsigned long holding the offset. By
- * default the offset is zero.
+ * default the offset is PCI_DRAM_OFFSET.
  */
 
 static unsigned long get_dma_direct_offset(struct device *dev)
 {
-        return (unsigned long)dev->archdata.dma_data;
+        if (dev)
+                return (unsigned long)dev->archdata.dma_data;
+
+        return PCI_DRAM_OFFSET;
 }
 
-static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
-                                       dma_addr_t *dma_handle, gfp_t flag)
+void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+                                dma_addr_t *dma_handle, gfp_t flag)
 {
+#ifdef CONFIG_NOT_COHERENT_CACHE
+        return __dma_alloc_coherent(size, dma_handle, flag);
+#else
         struct page *page;
         void *ret;
         int node = dev_to_node(dev);
 
+        /* ignore region specifiers */
+        flag  &= ~(__GFP_HIGHMEM);
+
         page = alloc_pages_node(node, flag, get_order(size));
         if (page == NULL)
                 return NULL;
@@ -39,27 +48,17 @@ static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
         *dma_handle = virt_to_abs(ret) + get_dma_direct_offset(dev);
 
         return ret;
+#endif
 }
 
-static void dma_direct_free_coherent(struct device *dev, size_t size,
-                                     void *vaddr, dma_addr_t dma_handle)
+void dma_direct_free_coherent(struct device *dev, size_t size,
+                              void *vaddr, dma_addr_t dma_handle)
 {
+#ifdef CONFIG_NOT_COHERENT_CACHE
+        __dma_free_coherent(size, vaddr);
+#else
         free_pages((unsigned long)vaddr, get_order(size));
-}
-
-static dma_addr_t dma_direct_map_single(struct device *dev, void *ptr,
-                                        size_t size,
-                                        enum dma_data_direction direction,
-                                        struct dma_attrs *attrs)
-{
-        return virt_to_abs(ptr) + get_dma_direct_offset(dev);
-}
-
-static void dma_direct_unmap_single(struct device *dev, dma_addr_t dma_addr,
-                                    size_t size,
-                                    enum dma_data_direction direction,
-                                    struct dma_attrs *attrs)
-{
+#endif
 }
 
 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
@@ -85,20 +84,44 @@ static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
 
 static int dma_direct_dma_supported(struct device *dev, u64 mask)
 {
+#ifdef CONFIG_PPC64
         /* Could be improved to check for memory though it better be
          * done via some global so platforms can set the limit in case
          * they have limited DMA windows
          */
         return mask >= DMA_32BIT_MASK;
+#else
+        return 1;
+#endif
+}
+
+static inline dma_addr_t dma_direct_map_page(struct device *dev,
+                                             struct page *page,
+                                             unsigned long offset,
+                                             size_t size,
+                                             enum dma_data_direction dir,
+                                             struct dma_attrs *attrs)
+{
+        BUG_ON(dir == DMA_NONE);
+        __dma_sync_page(page, offset, size, dir);
+        return page_to_phys(page) + offset + get_dma_direct_offset(dev);
+}
+
+static inline void dma_direct_unmap_page(struct device *dev,
+                                         dma_addr_t dma_address,
+                                         size_t size,
+                                         enum dma_data_direction direction,
+                                         struct dma_attrs *attrs)
+{
 }
 
 struct dma_mapping_ops dma_direct_ops = {
         .alloc_coherent = dma_direct_alloc_coherent,
         .free_coherent  = dma_direct_free_coherent,
-        .map_single     = dma_direct_map_single,
-        .unmap_single   = dma_direct_unmap_single,
         .map_sg         = dma_direct_map_sg,
         .unmap_sg       = dma_direct_unmap_sg,
         .dma_supported  = dma_direct_dma_supported,
+        .map_page       = dma_direct_map_page,
+        .unmap_page     = dma_direct_unmap_page,
 };
 EXPORT_SYMBOL(dma_direct_ops);
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index ea0c61e09b76..52ccfed416ad 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -56,6 +56,34 @@ resource_size_t isa_mem_base;
 /* Default PCI flags is 0 */
 unsigned int ppc_pci_flags;
 
+static struct dma_mapping_ops *pci_dma_ops;
+
+void set_pci_dma_ops(struct dma_mapping_ops *dma_ops)
+{
+        pci_dma_ops = dma_ops;
+}
+
+struct dma_mapping_ops *get_pci_dma_ops(void)
+{
+        return pci_dma_ops;
+}
+EXPORT_SYMBOL(get_pci_dma_ops);
+
+int pci_set_dma_mask(struct pci_dev *dev, u64 mask)
+{
+        return dma_set_mask(&dev->dev, mask);
+}
+
+int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
+{
+        int rc;
+
+        rc = dma_set_mask(&dev->dev, mask);
+        dev->dev.coherent_dma_mask = dev->dma_mask;
+
+        return rc;
+}
+
 struct pci_controller *pcibios_alloc_controller(struct device_node *dev)
 {
         struct pci_controller *phb;
@@ -180,6 +208,26 @@ char __devinit *pcibios_setup(char *str)
         return str;
 }
 
+void __devinit pcibios_setup_new_device(struct pci_dev *dev)
+{
+        struct dev_archdata *sd = &dev->dev.archdata;
+
+        sd->of_node = pci_device_to_OF_node(dev);
+
+        DBG("PCI: device %s OF node: %s\n", pci_name(dev),
+            sd->of_node ? sd->of_node->full_name : "<none>");
+
+        sd->dma_ops = pci_dma_ops;
+#ifdef CONFIG_PPC32
+        sd->dma_data = (void *)PCI_DRAM_OFFSET;
+#endif
+        set_dev_node(&dev->dev, pcibus_to_node(dev->bus));
+
+        if (ppc_md.pci_dma_dev_setup)
+                ppc_md.pci_dma_dev_setup(dev);
+}
+EXPORT_SYMBOL(pcibios_setup_new_device);
+
 /*
  * Reads the interrupt pin to determine if interrupt is use by card.
  * If the interrupt is used, then gets the interrupt line from the
diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 88db4ffaf11c..174b77ee18ff 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -424,6 +424,7 @@ void __devinit pcibios_do_bus_setup(struct pci_bus *bus)
         unsigned long io_offset;
         struct resource *res;
         int i;
+        struct pci_dev *dev;
 
         /* Hookup PHB resources */
         io_offset = (unsigned long)hose->io_base_virt - isa_io_base;
@@ -457,6 +458,12 @@ void __devinit pcibios_do_bus_setup(struct pci_bus *bus)
                         bus->resource[i+1] = res;
                 }
         }
+
+        if (ppc_md.pci_dma_bus_setup)
+                ppc_md.pci_dma_bus_setup(bus);
+
+        list_for_each_entry(dev, &bus->devices, bus_list)
+                pcibios_setup_new_device(dev);
 }
 
 /* the next one is stolen from the alpha port... */
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index 1f75bf03446f..8247cff1cb3e 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -52,35 +52,6 @@ EXPORT_SYMBOL(pci_io_base);
 
 LIST_HEAD(hose_list);
 
-static struct dma_mapping_ops *pci_dma_ops;
-
-void set_pci_dma_ops(struct dma_mapping_ops *dma_ops)
-{
-        pci_dma_ops = dma_ops;
-}
-
-struct dma_mapping_ops *get_pci_dma_ops(void)
-{
-        return pci_dma_ops;
-}
-EXPORT_SYMBOL(get_pci_dma_ops);
-
-
-int pci_set_dma_mask(struct pci_dev *dev, u64 mask)
-{
-        return dma_set_mask(&dev->dev, mask);
-}
-
-int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
-{
-        int rc;
-
-        rc = dma_set_mask(&dev->dev, mask);
-        dev->dev.coherent_dma_mask = dev->dma_mask;
-
-        return rc;
-}
-
 static void fixup_broken_pcnet32(struct pci_dev* dev)
 {
         if ((dev->class>>8 == PCI_CLASS_NETWORK_ETHERNET)) {
@@ -548,23 +519,6 @@ int __devinit pcibios_map_io_space(struct pci_bus *bus)
 }
 EXPORT_SYMBOL_GPL(pcibios_map_io_space);
 
-void __devinit pcibios_setup_new_device(struct pci_dev *dev)
-{
-        struct dev_archdata *sd = &dev->dev.archdata;
-
-        sd->of_node = pci_device_to_OF_node(dev);
-
-        DBG("PCI: device %s OF node: %s\n", pci_name(dev),
-            sd->of_node ? sd->of_node->full_name : "<none>");
-
-        sd->dma_ops = pci_dma_ops;
-        set_dev_node(&dev->dev, pcibus_to_node(dev->bus));
-
-        if (ppc_md.pci_dma_dev_setup)
-                ppc_md.pci_dma_dev_setup(dev);
-}
-EXPORT_SYMBOL(pcibios_setup_new_device);
-
 void __devinit pcibios_do_bus_setup(struct pci_bus *bus)
 {
         struct pci_dev *dev;