pci-dma: add include/linux/pci-dma.h

This patch adds include/linux/pci-dma.h that defines the pci_unmap state
API:

DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)
DECLARE_PCI_UNMAP_LEN(LEN_NAME)
pci_unmap_addr(PTR, ADDR_NAME)
pci_unmap_addr_set(PTR, ADDR_NAME, VAL)
pci_unmap_len(PTR, LEN_NAME)
pci_unmap_len_set(PTR, LEN_NAME, VAL)

This enables us to remove lots of the duplication in architecture
implementations since there are only two ways to define the API.

If architectures define CONFIG_NEED_DMA_MAP_STATE, they get the real
definition of pci_unmap state API.  If not, they get the noop definition.

In the long term, it's better to replace the API with the generic device
model API such as DECLARE_DMA_UNMAP_ADDR.  We can map the API to the
generic one (like dma-mapping-compat.h does).  This patch also makes the
migration process easier.  We can remove this file after the migration.

It might be simpler to add the API to include/linux/pci.h but looks it's
already too large.  We'll remove pci-dma.h after finishing moving to the
generic device model.  So I put the API to a separate file.

Signed-off-by: FUJITA Tomonori <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: David Howells <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Kyle McMartin <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Chris Zankel <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Cc: Jesse Barnes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/pci-dma.h b/include/linux/pci-dma.h
new file mode 100644
index 000000000000..cfd63ab09abc
--- /dev/null
+++ b/include/linux/pci-dma.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_PCI_DMA_H
+#define _LINUX_PCI_DMA_H
+
+#ifdef CONFIG_NEED_DMA_MAP_STATE
+#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME;
+#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME;
+#define pci_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
+#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL)  (((PTR)->ADDR_NAME) = (VAL))
+#define pci_unmap_len(PTR, LEN_NAME)             ((PTR)->LEN_NAME)
+#define pci_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
+#else
+#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)
+#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)
+#define pci_unmap_addr(PTR, ADDR_NAME)           (0)
+#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL)  do { } while (0)
+#define pci_unmap_len(PTR, LEN_NAME)             (0)
+#define pci_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
+#endif
+
+#endif