dma-mapping: make the generic coherent dma mmap implementation optional

This series converts all remaining architectures to use dma_map_ops and
the generic implementation of the DMA API.  This not only simplifies the
code a lot, but also prepares for possible future changes like more
generic non-iommu dma_ops implementations or generic per-device
dma_map_ops.

This patch (of 16):

We have a couple architectures that do not want to support this code, so
add another Kconfig symbol that disables the code similar to what we do
for the nommu case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/Kconfig b/arch/Kconfig
index ba1b626bca002e751d60fc4e29784d7632f1a1a9..51c03efb4083c0b1701b6dc22db4c5b5dbacbf93 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -632,4 +632,7 @@ config OLD_SIGACTION
 config COMPAT_OLD_SIGACTION
        bool
 
+config ARCH_NO_COHERENT_DMA_MMAP
+       bool
+
 source "kernel/gcov/Kconfig"

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index d95c5971c2256f20f473d5744b01fc54bbf9acf2..381e39d5204e66295bcd8377870c043ed0488eb0 100644 (file)
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -247,7 +247,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
                    void *cpu_addr, dma_addr_t dma_addr, size_t size)
 {
        int ret = -ENXIO;
-#ifdef CONFIG_MMU
+#if defined(CONFIG_MMU) && !defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)
        unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
        unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
        unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
@@ -264,7 +264,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
                                      user_count << PAGE_SHIFT,
                                      vma->vm_page_prot);
        }
-#endif /* CONFIG_MMU */
+#endif /* CONFIG_MMU && !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
 
        return ret;
 }