Merge tag 'dma-mapping-4.17' of git://git.infradead.org/users/hch/dma-mapping

[sfrench/cifs-2.6.git] / include / linux / dma-mapping.h

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 12fedcba9a9a1dea18654e91759f9f4183fbb55f..f8ab1c0f589ea5c9530b24c5995c2086ca2b5de8 100644 (file)
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -212,14 +212,14 @@ static inline void set_dma_ops(struct device *dev,
 }
 #else
 /*
- * Define the dma api to allow compilation but not linking of
- * dma dependent code.  Code that depends on the dma-mapping
- * API needs to set 'depends on HAS_DMA' in its Kconfig
+ * Define the dma api to allow compilation of dma dependent code.
+ * Code that depends on the dma-mapping API needs to set 'depends on HAS_DMA'
+ * in its Kconfig, unless it already depends on <something> || COMPILE_TEST,
+ * where <something> guarantuees the availability of the dma-mapping API.
  */
-extern const struct dma_map_ops bad_dma_ops;
 static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
 {
-       return &bad_dma_ops;
+       return NULL;
 }
 #endif
 
@@ -772,10 +772,19 @@ static inline void dma_deconfigure(struct device *dev) {}
 /*
  * Managed DMA API
  */
+#ifdef CONFIG_HAS_DMA
 extern void *dmam_alloc_coherent(struct device *dev, size_t size,
                                 dma_addr_t *dma_handle, gfp_t gfp);
 extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
                               dma_addr_t dma_handle);
+#else /* !CONFIG_HAS_DMA */
+static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
+                                       dma_addr_t *dma_handle, gfp_t gfp)
+{ return NULL; }
+static inline void dmam_free_coherent(struct device *dev, size_t size,
+                                     void *vaddr, dma_addr_t dma_handle) { }
+#endif /* !CONFIG_HAS_DMA */
+
 extern void *dmam_alloc_attrs(struct device *dev, size_t size,
                              dma_addr_t *dma_handle, gfp_t gfp,
                              unsigned long attrs);