ARM: DMA: add support for DMA debugging

Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -2,6 +2,7 @@ config ARM
 	bool
 	default y
 	select HAVE_AOUT
+	select HAVE_DMA_API_DEBUG
 	select HAVE_IDE
 	select HAVE_MEMBLOCK
 	select RTC_LIB

arch/arm/common/dmabounce.c

@@ -328,7 +328,7 @@ static inline void unmap_single(struct device *dev, dma_addr_t dma_addr,
  * substitute the safe buffer for the unsafe one.
  * (basically move the buffer from an unsafe area to a safe one)
  */
-dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
+dma_addr_t __dma_map_single(struct device *dev, void *ptr, size_t size,
 		enum dma_data_direction dir)
 {
 	dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
@@ -338,7 +338,7 @@ dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
 
 	return map_single(dev, ptr, size, dir);
 }
-EXPORT_SYMBOL(dma_map_single);
+EXPORT_SYMBOL(__dma_map_single);
 
 /*
  * see if a mapped address was really a "safe" buffer and if so, copy
@@ -346,7 +346,7 @@ EXPORT_SYMBOL(dma_map_single);
  * the safe buffer.  (basically return things back to the way they
  * should be)
  */
-void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+void __dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 		enum dma_data_direction dir)
 {
 	dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
@@ -354,9 +354,9 @@ void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 
 	unmap_single(dev, dma_addr, size, dir);
 }
-EXPORT_SYMBOL(dma_unmap_single);
+EXPORT_SYMBOL(__dma_unmap_single);
 
-dma_addr_t dma_map_page(struct device *dev, struct page *page,
+dma_addr_t __dma_map_page(struct device *dev, struct page *page,
 		unsigned long offset, size_t size, enum dma_data_direction dir)
 {
 	dev_dbg(dev, "%s(page=%p,off=%#lx,size=%zx,dir=%x)\n",
@@ -372,7 +372,7 @@ dma_addr_t dma_map_page(struct device *dev, struct page *page,
 
 	return map_single(dev, page_address(page) + offset, size, dir);
 }
-EXPORT_SYMBOL(dma_map_page);
+EXPORT_SYMBOL(__dma_map_page);
 
 /*
  * see if a mapped address was really a "safe" buffer and if so, copy
@@ -380,7 +380,7 @@ EXPORT_SYMBOL(dma_map_page);
  * the safe buffer.  (basically return things back to the way they
  * should be)
  */
-void dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
+void __dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
 		enum dma_data_direction dir)
 {
 	dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
@@ -388,7 +388,7 @@ void dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
 
 	unmap_single(dev, dma_addr, size, dir);
 }
-EXPORT_SYMBOL(dma_unmap_page);
+EXPORT_SYMBOL(__dma_unmap_page);
 
 int dmabounce_sync_for_cpu(struct device *dev, dma_addr_t addr,
 		unsigned long off, size_t sz, enum dma_data_direction dir)

arch/arm/include/asm/dma-mapping.h

@@ -5,6 +5,7 @@
 
 #include <linux/mm_types.h>
 #include <linux/scatterlist.h>
+#include <linux/dma-debug.h>
 
 #include <asm-generic/dma-coherent.h>
 #include <asm/memory.h>
@@ -297,13 +298,13 @@ extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 /*
  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
  */
-extern dma_addr_t dma_map_single(struct device *, void *, size_t,
+extern dma_addr_t __dma_map_single(struct device *, void *, size_t,
 		enum dma_data_direction);
-extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
+extern void __dma_unmap_single(struct device *, dma_addr_t, size_t,
 		enum dma_data_direction);
-extern dma_addr_t dma_map_page(struct device *, struct page *,
+extern dma_addr_t __dma_map_page(struct device *, struct page *,
 		unsigned long, size_t, enum dma_data_direction);
-extern void dma_unmap_page(struct device *, dma_addr_t, size_t,
+extern void __dma_unmap_page(struct device *, dma_addr_t, size_t,
 		enum dma_data_direction);
 
 /*
@@ -327,6 +328,34 @@ static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 }
 
 
+static inline dma_addr_t __dma_map_single(struct device *dev, void *cpu_addr,
+		size_t size, enum dma_data_direction dir)
+{
+	__dma_single_cpu_to_dev(cpu_addr, size, dir);
+	return virt_to_dma(dev, cpu_addr);
+}
+
+static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page,
+	     unsigned long offset, size_t size, enum dma_data_direction dir)
+{
+	__dma_page_cpu_to_dev(page, offset, size, dir);
+	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+}
+
+static inline void __dma_unmap_single(struct device *dev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir)
+{
+	__dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir);
+}
+
+static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir)
+{
+	__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
+		handle & ~PAGE_MASK, size, dir);
+}
+#endif /* CONFIG_DMABOUNCE */
+
 /**
  * dma_map_single - map a single buffer for streaming DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
@@ -344,11 +373,16 @@ static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 		size_t size, enum dma_data_direction dir)
 {
+	dma_addr_t addr;
+
 	BUG_ON(!valid_dma_direction(dir));
 
-	__dma_single_cpu_to_dev(cpu_addr, size, dir);
+	addr = __dma_map_single(dev, cpu_addr, size, dir);
+	debug_dma_map_page(dev, virt_to_page(cpu_addr),
+			(unsigned long)cpu_addr & ~PAGE_MASK, size,
+			dir, addr, true);
 
-	return virt_to_dma(dev, cpu_addr);
+	return addr;
 }
 
 /**
@@ -368,11 +402,14 @@ static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 	     unsigned long offset, size_t size, enum dma_data_direction dir)
 {
+	dma_addr_t addr;
+
 	BUG_ON(!valid_dma_direction(dir));
 
-	__dma_page_cpu_to_dev(page, offset, size, dir);
+	addr = __dma_map_page(dev, page, offset, size, dir);
+	debug_dma_map_page(dev, page, offset, size, dir, addr, false);
 
-	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+	return addr;
 }
 
 /**
@@ -392,7 +429,8 @@ static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir)
 {
-	__dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir);
+	debug_dma_unmap_page(dev, handle, size, dir, true);
+	__dma_unmap_single(dev, handle, size, dir);
 }
 
 /**
@@ -412,10 +450,9 @@ static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir)
 {
-	__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
-		handle & ~PAGE_MASK, size, dir);
+	debug_dma_unmap_page(dev, handle, size, dir, false);
+	__dma_unmap_page(dev, handle, size, dir);
 }
-#endif /* CONFIG_DMABOUNCE */
 
 /**
  * dma_sync_single_range_for_cpu
@@ -441,6 +478,8 @@ static inline void dma_sync_single_range_for_cpu(struct device *dev,
 {
 	BUG_ON(!valid_dma_direction(dir));
 
+	debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir);
+
 	if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 		return;
 
@@ -453,6 +492,8 @@ static inline void dma_sync_single_range_for_device(struct device *dev,
 {
 	BUG_ON(!valid_dma_direction(dir));
 
+	debug_dma_sync_single_for_device(dev, handle + offset, size, dir);
+
 	if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 		return;
 

arch/arm/mm/dma-mapping.c

@@ -554,17 +554,20 @@ int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 	struct scatterlist *s;
 	int i, j;
 
+	BUG_ON(!valid_dma_direction(dir));
+
 	for_each_sg(sg, s, nents, i) {
-		s->dma_address = dma_map_page(dev, sg_page(s), s->offset,
+		s->dma_address = __dma_map_page(dev, sg_page(s), s->offset,
 						s->length, dir);
 		if (dma_mapping_error(dev, s->dma_address))
 			goto bad_mapping;
 	}
+	debug_dma_map_sg(dev, sg, nents, nents, dir);
 	return nents;
 
  bad_mapping:
 	for_each_sg(sg, s, i, j)
-		dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
+		__dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
 	return 0;
 }
 EXPORT_SYMBOL(dma_map_sg);
@@ -585,8 +588,10 @@ void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 	struct scatterlist *s;
 	int i;
 
+	debug_dma_unmap_sg(dev, sg, nents, dir);
+
 	for_each_sg(sg, s, nents, i)
-		dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
+		__dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
 }
 EXPORT_SYMBOL(dma_unmap_sg);
 
@@ -611,6 +616,8 @@ void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 		__dma_page_dev_to_cpu(sg_page(s), s->offset,
 				      s->length, dir);
 	}
+
+	debug_dma_sync_sg_for_cpu(dev, sg, nents, dir);
 }
 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
 
@@ -635,5 +642,16 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 		__dma_page_cpu_to_dev(sg_page(s), s->offset,
 				      s->length, dir);
 	}
+
+	debug_dma_sync_sg_for_device(dev, sg, nents, dir);
 }
 EXPORT_SYMBOL(dma_sync_sg_for_device);
+
+#define PREALLOC_DMA_DEBUG_ENTRIES	4096
+
+static int __init dma_debug_do_init(void)
+{
+	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
+	return 0;
+}
+fs_initcall(dma_debug_do_init);