dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}

Since 2009 we have a nice asm-generic header implementing lots of DMA API
functions for architectures using struct dma_map_ops, but unfortunately
it's still missing a lot of APIs that all architectures still have to
duplicate.

This series consolidates the remaining functions, although we still need
arch opt outs for two of them as a few architectures have very
non-standard implementations.

This patch (of 5):

The coherent DMA allocator works the same over all architectures supporting
dma_map operations.

This patch consolidates them and converges the minor differences:

 - the debug_dma helpers are now called from all architectures, including
   those that were previously missing them
 - dma_alloc_from_coherent and dma_release_from_coherent are now always
   called from the generic alloc/free routines instead of the ops
   dma-mapping-common.h always includes dma-coherent.h to get the defintions
   for them, or the stubs if the architecture doesn't support this feature
 - checks for ->alloc / ->free presence are removed.  There is only one
   magic instead of dma_map_ops without them (mic_dma_ops) and that one
   is x86 only anyway.

Besides that only x86 needs special treatment to replace a default devices
if none is passed and tweak the gfp_flags.  An optional arch hook is provided
for that.

[linux@roeck-us.net: fix build]
[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 12 insertions, 53 deletions

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 1f5b7287d1ad..f9b1b6cc48b6 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -12,7 +12,6 @@
 #include <linux/dma-attrs.h>
 #include <asm/io.h>
 #include <asm/swiotlb.h>
-#include <asm-generic/dma-coherent.h>
 #include <linux/dma-contiguous.h>
 
 #ifdef CONFIG_ISA
@@ -41,6 +40,9 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
 #endif
 }
 
+bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
+#define arch_dma_alloc_attrs arch_dma_alloc_attrs
+
 #include <asm-generic/dma-mapping-common.h>
 
 /* Make sure we keep the same behaviour */
@@ -125,16 +127,4 @@ static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
        return gfp;
 }
 
-#define dma_alloc_coherent(d,s,h,f)	dma_alloc_attrs(d,s,h,f,NULL)
-
-void *
-dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		gfp_t gfp, struct dma_attrs *attrs);
-
-#define dma_free_coherent(d,s,c,h) dma_free_attrs(d,s,c,h,NULL)
-
-void dma_free_attrs(struct device *dev, size_t size,
-		    void *vaddr, dma_addr_t bus,
-		    struct dma_attrs *attrs);
-
 #endif
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 353972c1946c..bd23971e8f1d 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -140,50 +140,19 @@ void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,
 		free_pages((unsigned long)vaddr, get_order(size));
 }
 
-void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		      gfp_t gfp, struct dma_attrs *attrs)
+bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
 {
-	struct dma_map_ops *ops = get_dma_ops(dev);
-	void *memory;
-
-	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
-
-	if (dma_alloc_from_coherent(dev, size, dma_handle, &memory))
-		return memory;
-
-	if (!dev)
-		dev = &x86_dma_fallback_dev;
-
-	if (!is_device_dma_capable(dev))
-		return NULL;
-
-	if (!ops->alloc)
-		return NULL;
-
-	memory = ops->alloc(dev, size, dma_handle,
-			    dma_alloc_coherent_gfp_flags(dev, gfp), attrs);
-	debug_dma_alloc_coherent(dev, size, *dma_handle, memory);
-
-	return memory;
-}
-EXPORT_SYMBOL(dma_alloc_attrs);
-
-void dma_free_attrs(struct device *dev, size_t size,
-		    void *vaddr, dma_addr_t bus,
-		    struct dma_attrs *attrs)
-{
-	struct dma_map_ops *ops = get_dma_ops(dev);
-
-	WARN_ON(irqs_disabled());       /* for portability */
+	*gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp);
+	*gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
 
-	if (dma_release_from_coherent(dev, get_order(size), vaddr))
-		return;
+	if (!*dev)
+		*dev = &x86_dma_fallback_dev;
+	if (!is_device_dma_capable(*dev))
+		return false;
+	return true;
 
-	debug_dma_free_coherent(dev, size, vaddr, bus);
-	if (ops->free)
-		ops->free(dev, size, vaddr, bus, attrs);
 }
-EXPORT_SYMBOL(dma_free_attrs);
+EXPORT_SYMBOL(arch_dma_alloc_attrs);
 
 /*
  * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel