lkl: add support for noop dma mappings

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>

Author: Octavian Purdila

arch/lkl/Kconfig

@@ -16,6 +16,7 @@ config LKL
        select NO_HZ_IDLE
        select NO_PREEMPT
        select ARCH_WANT_FRAME_POINTERS
+       select HAS_DMA
        select PHYS_ADDR_T_64BIT if 64BIT
        select 64BIT if OUTPUT_FORMAT = "elf64-x86-64"
        select HAVE_UNDERSCORE_SYMBOL_PREFIX if OUTPUT_FORMAT = "pe-i386"
@@ -38,9 +39,6 @@ config 64BIT
 config BIG_ENDIAN
        def_bool n
 
-config NO_DMA
-       def_bool y
-
 config GENERIC_CSUM
        def_bool y
 

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

@@ -1,6 +1,21 @@
 #ifndef _ASM_LKL_DMA_MAPPING_H
 #define _ASM_LKL_DMA_MAPPING_H
 
-#include <asm-generic/dma-mapping-broken.h>
+static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+	return &dma_noop_ops;
+}
+
+static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+				  enum dma_data_direction direction)
+{
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return false;
+	return addr + size - 1 <= *dev->dma_mask;
+}
 
 #endif