dma-mapping.h: add the dma_unmap state API

Adds the following macros:

DECLARE_DMA_UNMAP_ADDR(ADDR_NAME)
DECLARE_DMA_UNMAP_LEN(LEN_NAME)
dma_unmap_addr(PTR, ADDR_NAME)
dma_unmap_addr_set(PTR, ADDR_NAME, VAL)
dma_unmap_len(PTR, LEN_NAME)
dma_unmap_len_set(PTR, LEN_NAME, VAL)

The API corresponds to the pci_unmap state API.  We'll move to this new
generic API from the PCI specific API in the long term.  As
include/asm-generic/pci-dma-compat.h does, the pci_unmap API simply calls
the new generic API for some time.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 91b761846061..c5ac9d49cc06 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -232,4 +232,20 @@ struct dma_attrs;
 
 #endif /* CONFIG_HAVE_DMA_ATTRS */
 
+#ifdef CONFIG_NEED_DMA_MAP_STATE
+#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME
+#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME
+#define dma_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
+#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  (((PTR)->ADDR_NAME) = (VAL))
+#define dma_unmap_len(PTR, LEN_NAME)             ((PTR)->LEN_NAME)
+#define dma_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
+#else
+#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
+#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
+#define dma_unmap_addr(PTR, ADDR_NAME)           (0)
+#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  do { } while (0)
+#define dma_unmap_len(PTR, LEN_NAME)             (0)
+#define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
+#endif
+
 #endif