sparc: Make sparc64 use scalable lib/iommu-common.c functions

In iperf experiments running linux as the Tx side (TCP client) with
10 threads results in a severe performance drop when TSO is disabled,
indicating a weakness in the software that can be avoided by using
the scalable IOMMU arena DMA allocation.

Baseline numbers before this patch:
   with default settings (TSO enabled) :    9-9.5 Gbps
   Disable TSO using ethtool- drops badly:  2-3 Gbps.

After this patch, iperf client with 10 threads, can give a
throughput of at least 8.5 Gbps, even when TSO is disabled.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/iommu_64.h

@@ -16,6 +16,7 @@
 #define IOPTE_WRITE   0x0000000000000002UL
 
 #define IOMMU_NUM_CTXS	4096
+#include <linux/iommu-common.h>
 
 struct iommu_arena {
 	unsigned long	*map;
@@ -24,11 +25,10 @@ struct iommu_arena {
 };
 
 struct iommu {
+	struct iommu_map_table	tbl;
 	spinlock_t		lock;
-	struct iommu_arena	arena;
-	void			(*flush_all)(struct iommu *);
+	u32			dma_addr_mask;
 	iopte_t			*page_table;
-	u32			page_table_map_base;
 	unsigned long		iommu_control;
 	unsigned long		iommu_tsbbase;
 	unsigned long		iommu_flush;
@@ -40,7 +40,6 @@ struct iommu {
 	unsigned long		dummy_page_pa;
 	unsigned long		ctx_lowest_free;
 	DECLARE_BITMAP(ctx_bitmap, IOMMU_NUM_CTXS);
-	u32			dma_addr_mask;
 };
 
 struct strbuf {

arch/sparc/kernel/iommu_common.h

@@ -48,12 +48,4 @@ static inline int is_span_boundary(unsigned long entry,
 	return iommu_is_span_boundary(entry, nr, shift, boundary_size);
 }
 
-unsigned long iommu_range_alloc(struct device *dev,
-				struct iommu *iommu,
-				unsigned long npages,
-				unsigned long *handle);
-void iommu_range_free(struct iommu *iommu,
-		      dma_addr_t dma_addr,
-		      unsigned long npages);
-
 #endif /* _IOMMU_COMMON_H */