ARC: remove the unused platform helpers from dma mapping API

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Kconfig

@@ -117,10 +117,6 @@ config CPU_BIG_ENDIAN
 	help
 	  Build kernel for Big Endian Mode of ARC CPU
 
-# If a platform can't work with 0x8000_0000 based dma_addr_t
-config ARC_PLAT_NEEDS_CPU_TO_DMA
-	bool
-
 config SMP
 	bool "Symmetric Multi-Processing (Incomplete)"
 	default n

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

@@ -14,23 +14,6 @@
 #include <asm-generic/dma-coherent.h>
 #include <asm/cacheflush.h>
 
-#ifndef CONFIG_ARC_PLAT_NEEDS_CPU_TO_DMA
-/*
- * dma_map_* API take cpu addresses, which is kernel logical address in the
- * untranslated address space (0x8000_0000) based. The dma address (bus addr)
- * ideally needs to be 0x0000_0000 based hence these glue routines.
- * However given that intermediate bus bridges can ignore the high bit, we can
- * do with these routines being no-ops.
- * If a platform/device comes up which sriclty requires 0 based bus addr
- * (e.g. AHB-PCI bridge on Angel4 board), then it can provide it's own versions
- */
-#define plat_dma_addr_to_kernel(dev, addr) ((unsigned long)(addr))
-#define plat_kernel_addr_to_dma(dev, ptr) ((dma_addr_t)(ptr))
-
-#else
-#include <plat/dma_addr.h>
-#endif
-
 void *dma_alloc_noncoherent(struct device *dev, size_t size,
 			    dma_addr_t *dma_handle, gfp_t gfp);
 
@@ -94,7 +77,7 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size,
 	       enum dma_data_direction dir)
 {
 	_dma_cache_sync((unsigned long)cpu_addr, size, dir);
-	return plat_kernel_addr_to_dma(dev, cpu_addr);
+	return (dma_addr_t)cpu_addr;
 }
 
 static inline void
@@ -147,16 +130,14 @@ static inline void
 dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 			size_t size, enum dma_data_direction dir)
 {
-	_dma_cache_sync(plat_dma_addr_to_kernel(dev, dma_handle), size,
-			DMA_FROM_DEVICE);
+	_dma_cache_sync(dma_handle, size, DMA_FROM_DEVICE);
 }
 
 static inline void
 dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
 			   size_t size, enum dma_data_direction dir)
 {
-	_dma_cache_sync(plat_dma_addr_to_kernel(dev, dma_handle), size,
-			DMA_TO_DEVICE);
+	_dma_cache_sync(dma_handle, size, DMA_TO_DEVICE);
 }
 
 static inline void
@@ -164,8 +145,7 @@ dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
 			      unsigned long offset, size_t size,
 			      enum dma_data_direction direction)
 {
-	_dma_cache_sync(plat_dma_addr_to_kernel(dev, dma_handle) + offset,
-			size, DMA_FROM_DEVICE);
+	_dma_cache_sync(dma_handle + offset, size, DMA_FROM_DEVICE);
 }
 
 static inline void
@@ -173,8 +153,7 @@ dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
 				 unsigned long offset, size_t size,
 				 enum dma_data_direction direction)
 {
-	_dma_cache_sync(plat_dma_addr_to_kernel(dev, dma_handle) + offset,
-			size, DMA_TO_DEVICE);
+	_dma_cache_sync(dma_handle + offset, size, DMA_TO_DEVICE);
 }
 
 static inline void

arch/arc/mm/dma.c

@@ -14,8 +14,6 @@
  * Cache bit off in the TLB entry.
  *
  * The default DMA address == Phy address which is 0x8000_0000 based.
- * A platform/device can make it zero based, by over-riding
- * plat_{dma,kernel}_addr_to_{kernel,dma}
  */
 
 #include <linux/dma-mapping.h>
@@ -37,7 +35,7 @@ void *dma_alloc_noncoherent(struct device *dev, size_t size,
 		return NULL;
 
 	/* This is bus address, platform dependent */
-	*dma_handle = plat_kernel_addr_to_dma(dev, paddr);
+	*dma_handle = (dma_addr_t)paddr;
 
 	return paddr;
 }
@@ -46,8 +44,7 @@ EXPORT_SYMBOL(dma_alloc_noncoherent);
 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 			  dma_addr_t dma_handle)
 {
-	free_pages_exact((void *)plat_dma_addr_to_kernel(dev, dma_handle),
-			 size);
+	free_pages_exact((void *)dma_handle, size);
 }
 EXPORT_SYMBOL(dma_free_noncoherent);
 
@@ -67,7 +64,7 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
 		memset(kvaddr, 0, size);
 
 	/* This is bus address, platform dependent */
-	*dma_handle = plat_kernel_addr_to_dma(dev, paddr);
+	*dma_handle = (dma_addr_t)paddr;
 
 	return kvaddr;
 }
@@ -78,8 +75,7 @@ void dma_free_coherent(struct device *dev, size_t size, void *kvaddr,
 {
 	iounmap((void __force __iomem *)kvaddr);
 
-	free_pages_exact((void *)plat_dma_addr_to_kernel(dev, dma_handle),
-			 size);
+	free_pages_exact((void *)dma_handle, size);
 }
 EXPORT_SYMBOL(dma_free_coherent);