[ARM] Move ISA DMA bus_to_virt() out of set_dma_addr()

Allow the compiler to optimise the bus_to_virt(virt_to_bus())
transformation in the ARM ISA DMA interface.

Signed-off-by: Russell King <[e-mail]>

arch/arm/kernel/dma.c

···
  *
  * Copy address to the structure, and set the invalid bit
  */
-void set_dma_addr (dmach_t channel, unsigned long physaddr)
+void __set_dma_addr (dmach_t channel, void *addr)
 {
 	dma_t *dma = dma_chan + channel;
 
···
 
 	dma->sg = &dma->buf;
 	dma->sgcount = 1;
-	dma->buf.__address = bus_to_virt(physaddr);
+	dma->buf.__address = addr;
 	dma->using_sg = 0;
 	dma->invalid = 1;
 }
···
 GLOBAL_ALIAS(set_dma_mode, get_dma_residue);
 GLOBAL_ALIAS(set_dma_page, get_dma_residue);
 GLOBAL_ALIAS(set_dma_count, get_dma_residue);
-GLOBAL_ALIAS(set_dma_addr, get_dma_residue);
+GLOBAL_ALIAS(__set_dma_addr, get_dma_residue);
 GLOBAL_ALIAS(set_dma_sg, get_dma_residue);
 GLOBAL_ALIAS(set_dma_speed, get_dma_residue);
 GLOBAL_ALIAS(init_dma, get_dma_residue);
···
 EXPORT_SYMBOL(free_dma);
 EXPORT_SYMBOL(enable_dma);
 EXPORT_SYMBOL(disable_dma);
-EXPORT_SYMBOL(set_dma_addr);
+EXPORT_SYMBOL(__set_dma_addr);
 EXPORT_SYMBOL(set_dma_count);
 EXPORT_SYMBOL(set_dma_mode);
 EXPORT_SYMBOL(set_dma_page);

include/asm-arm/dma.h

···
  * especially since some DMA architectures don't update the
  * DMA address immediately, but defer it to the enable_dma().
  */
-extern void set_dma_addr(dmach_t channel, unsigned long physaddr);
+extern void __set_dma_addr(dmach_t channel, void *addr);
+#define set_dma_addr(channel, addr)				\
+	__set_dma_addr(channel, bus_to_virt(addr))
 
 /* Set the DMA byte count for this channel
  *