[PATCH] sh: declared coherent memory support

[PATCH] sh: declared coherent memory support

[Magnus Damm]

sh: declared coherent memory support

This patch adds declared coherent memory support to the sh architecture. All
functions are copied straight from the x86 implementation and the header files
are adjusted to use the newfunctions instead of the former consistent_alloc()
code.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 arch/sh/mm/consistent.c      |  174 ++++++++++++++++++++++++++++++------------
 include/asm-sh/dma-mapping.h |   56 ++++---------
 2 files changed, 147 insertions(+), 83 deletions(-)

--- 0001/arch/sh/mm/consistent.c
+++ work/arch/sh/mm/consistent.c	2008-01-13 22:07:34.000000000 +0900
@@ -3,6 +3,8 @@
  *
  * Copyright (C) 2004 - 2007  Paul Mundt
  *
+ * Declared coherent memory functions taken from arch/x86/kernel/pci-dma_32.c
+ *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
@@ -13,66 +15,144 @@
 #include <asm/addrspace.h>
 #include <asm/io.h>
 
-void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
+struct dma_coherent_mem {
+	void		*virt_base;
+	u32		device_base;
+	int		size;
+	int		flags;
+	unsigned long	*bitmap;
+};
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			   dma_addr_t *dma_handle, gfp_t gfp)
 {
-	struct page *page, *end, *free;
-	void *ret, *vp;
-	int order;
-
-	size = PAGE_ALIGN(size);
-	order = get_order(size);
-
-	page = alloc_pages(gfp, order);
-	if (!page)
-		return NULL;
-	split_page(page, order);
-
-	ret = page_address(page);
-	*handle = virt_to_phys(ret);
-
-	vp = ioremap_nocache(*handle, size);
-	if (!vp) {
-		free_pages((unsigned long)ret, order);
-		return NULL;
+	void *ret;
+	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+	int order = get_order(size);
+	/* ignore region specifiers */
+	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+	if (mem) {
+		int page = bitmap_find_free_region(mem->bitmap, mem->size,
+						     order);
+		if (page >= 0) {
+			*dma_handle = mem->device_base + (page << PAGE_SHIFT);
+			ret = mem->virt_base + (page << PAGE_SHIFT);
+			memset(ret, 0, size);
+			return ret;
+		}
+		if (mem->flags & DMA_MEMORY_EXCLUSIVE)
+			return NULL;
 	}
 
-	memset(vp, 0, size);
+	if (dev = NULL || (dev->coherent_dma_mask < 0xffffffff))
+		gfp |= GFP_DMA;
 
-	/*
-	 * We must flush the cache before we pass it on to the device
-	 */
-	dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
-
-	page = virt_to_page(ret);
-	free = page + (size >> PAGE_SHIFT);
-	end  = page + (1 << order);
-
-	while (++page < end) {
-		/* Free any unused pages */
-		if (page >= free) {
-			__free_page(page);
-		}
+	ret = (void *)__get_free_pages(gfp, order);
+
+	if (ret != NULL) {
+		memset(ret, 0, size);
+		*dma_handle = virt_to_phys(ret);
 	}
+	return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
 
-	return vp;
+void dma_free_coherent(struct device *dev, size_t size,
+			 void *vaddr, dma_addr_t dma_handle)
+{
+	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+	int order = get_order(size);
+
+	WARN_ON(irqs_disabled());	/* for portability */
+	if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
+		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
+
+		bitmap_release_region(mem->bitmap, page, order);
+	} else
+		free_pages((unsigned long)vaddr, order);
 }
-EXPORT_SYMBOL(consistent_alloc);
+EXPORT_SYMBOL(dma_free_coherent);
 
-void consistent_free(void *vaddr, size_t size, dma_addr_t dma_handle)
+int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
+				dma_addr_t device_addr, size_t size, int flags)
 {
-	struct page *page;
-	unsigned long addr;
+	void __iomem *mem_base = NULL;
+	int pages = size >> PAGE_SHIFT;
+	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
+
+	if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) = 0)
+		goto out;
+	if (!size)
+		goto out;
+	if (dev->dma_mem)
+		goto out;
+
+	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
+
+	mem_base = ioremap(bus_addr, size);
+	if (!mem_base)
+		goto out;
+
+	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
+	if (!dev->dma_mem)
+		goto out;
+	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!dev->dma_mem->bitmap)
+		goto free1_out;
+
+	dev->dma_mem->virt_base = mem_base;
+	dev->dma_mem->device_base = device_addr;
+	dev->dma_mem->size = pages;
+	dev->dma_mem->flags = flags;
+
+	if (flags & DMA_MEMORY_MAP)
+		return DMA_MEMORY_MAP;
+
+	return DMA_MEMORY_IO;
+
+ free1_out:
+	kfree(dev->dma_mem);
+ out:
+	if (mem_base)
+		iounmap(mem_base);
+	return 0;
+}
+EXPORT_SYMBOL(dma_declare_coherent_memory);
 
-	addr = (unsigned long)phys_to_virt((unsigned long)dma_handle);
-	page = virt_to_page(addr);
+void dma_release_declared_memory(struct device *dev)
+{
+	struct dma_coherent_mem *mem = dev->dma_mem;
 
-	free_pages(addr, get_order(size));
+	if (!mem)
+		return;
+	dev->dma_mem = NULL;
+	iounmap(mem->virt_base);
+	kfree(mem->bitmap);
+	kfree(mem);
+}
+EXPORT_SYMBOL(dma_release_declared_memory);
 
-	iounmap(vaddr);
+void *dma_mark_declared_memory_occupied(struct device *dev,
+					dma_addr_t device_addr, size_t size)
+{
+	struct dma_coherent_mem *mem = dev->dma_mem;
+	int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	int pos, err;
+
+	if (!mem)
+		return ERR_PTR(-EINVAL);
+
+	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
+	err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
+	if (err != 0)
+		return ERR_PTR(err);
+	return mem->virt_base + (pos << PAGE_SHIFT);
 }
-EXPORT_SYMBOL(consistent_free);
+EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
 
-void consistent_sync(void *vaddr, size_t size, int direction)
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		    enum dma_data_direction direction)
 {
 #ifdef CONFIG_CPU_SH5
 	void *p1addr = vaddr;
@@ -94,4 +174,4 @@ void consistent_sync(void *vaddr, size_t
 		BUG();
 	}
 }
-EXPORT_SYMBOL(consistent_sync);
+EXPORT_SYMBOL(dma_cache_sync);
--- 0001/include/asm-sh/dma-mapping.h
+++ work/include/asm-sh/dma-mapping.h	2008-01-13 22:06:45.000000000 +0900
@@ -8,11 +8,6 @@
 
 extern struct bus_type pci_bus_type;
 
-/* arch/sh/mm/consistent.c */
-extern void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle);
-extern void consistent_free(void *vaddr, size_t size, dma_addr_t handle);
-extern void consistent_sync(void *vaddr, size_t size, int direction);
-
 #define dma_supported(dev, mask)	(1)
 
 static inline int dma_set_mask(struct device *dev, u64 mask)
@@ -25,44 +20,19 @@ static inline int dma_set_mask(struct de
 	return 0;
 }
 
-static inline void *dma_alloc_coherent(struct device *dev, size_t size,
-			 dma_addr_t *dma_handle, gfp_t flag)
-{
-	if (sh_mv.mv_consistent_alloc) {
-		void *ret;
-
-		ret = sh_mv.mv_consistent_alloc(dev, size, dma_handle, flag);
-		if (ret != NULL)
-			return ret;
-	}
-
-	return consistent_alloc(flag, size, dma_handle);
-}
-
-static inline void dma_free_coherent(struct device *dev, size_t size,
-		       void *vaddr, dma_addr_t dma_handle)
-{
-	if (sh_mv.mv_consistent_free) {
-		int ret;
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			 dma_addr_t *dma_handle, gfp_t flag);
 
-		ret = sh_mv.mv_consistent_free(dev, size, vaddr, dma_handle);
-		if (ret = 0)
-			return;
-	}
+void dma_free_coherent(struct device *dev, size_t size,
+		       void *vaddr, dma_addr_t dma_handle);
 
-	consistent_free(vaddr, size, dma_handle);
-}
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		    enum dma_data_direction dir);
 
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 #define dma_is_consistent(d, h) (1)
 
-static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
-				  enum dma_data_direction dir)
-{
-	consistent_sync(vaddr, size, (int)dir);
-}
-
 static inline dma_addr_t dma_map_single(struct device *dev,
 					void *ptr, size_t size,
 					enum dma_data_direction dir)
@@ -205,4 +175,18 @@ static inline int dma_mapping_error(dma_
 {
 	return dma_addr = 0;
 }
+
+#define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
+
+extern int
+dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
+			    dma_addr_t device_addr, size_t size, int flags);
+
+extern void
+dma_release_declared_memory(struct device *dev);
+
+extern void *
+dma_mark_declared_memory_occupied(struct device *dev,
+				  dma_addr_t device_addr, size_t size);
+
 #endif /* __ASM_SH_DMA_MAPPING_H */

Re: [PATCH] sh: declared coherent memory support

[Paul Mundt]

On Sun, Jan 13, 2008 at 10:54:47PM +0900, Magnus Damm wrote:
> This patch adds declared coherent memory support to the sh architecture. All
> functions are copied straight from the x86 implementation and the header files
> are adjusted to use the newfunctions instead of the former consistent_alloc()
> code.
> 
[snip]

> -	memset(vp, 0, size);
> +	if (dev = NULL || (dev->coherent_dma_mask < 0xffffffff))
> +		gfp |= GFP_DMA;
>  
This is obviously not something we care about, we don't have a ZONE_DMA,
and GFP_DMA has no meaning here. The page allocator will obviously still
do the right thing, but it's a bit ambiguous to suggest that we have some
sort of bogus limitation. The coherent_dma_mask is basically unintersting
in the general case, there are two situations in which we care about it,
and those are > 32-bits physical, or a restricted address space. In the
latter case we have to bounce it anyways, so a bogus DMA zone isn't going
to make a difference there. Likewise, in the > 32-bits physical case, we
also just don't care.

> +	ret = (void *)__get_free_pages(gfp, order);
> +
> +	if (ret != NULL) {
> +		memset(ret, 0, size);
> +		*dma_handle = virt_to_phys(ret);
>  	}
> +	return ret;
> +}
> +EXPORT_SYMBOL(dma_alloc_coherent);
>  
I do wonder whether it's sane to forego the dma_cache_sync() in the
allocation path in this case. If the allocation is satisfied by the
bitmap, it can probably be skipped, but as far as data we're fetching and
remapping from the page allocator, I suspect this is still going to need
a sync.

> +	mem_base = ioremap(bus_addr, size);
> +	if (!mem_base)
> +		goto out;
> +

This should be ioremap_nocache().

> +	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
> +	if (!dev->dma_mem)
> +		goto out;

This can probably be kmalloc(), since everything is being initialized
anyways, no point in zeroing it out.

> +void dma_release_declared_memory(struct device *dev)
> +{
> +	struct dma_coherent_mem *mem = dev->dma_mem;
>  
> -	free_pages(addr, get_order(size));
> +	if (!mem)
> +		return;
> +	dev->dma_mem = NULL;
> +	iounmap(mem->virt_base);
> +	kfree(mem->bitmap);
> +	kfree(mem);
> +}
What happens if someone is still using the bitmap?

[PATCH] sh: declared coherent memory support V2

[Magnus Damm]

sh: declared coherent memory support V2

This patch adds declared coherent memory support to the sh architecture. All
functions are based on the x86 implementation. Header files are adjusted to
use the new functions instead of the former consistent_alloc() code.

This version includes the few changes what were included in the fix patch
together with modifications based on feedback from Paul.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 arch/sh/mm/consistent.c      |  176 ++++++++++++++++++++++++++++++------------
 include/asm-sh/dma-mapping.h |   56 ++++---------
 2 files changed, 149 insertions(+), 83 deletions(-)

--- 0001/arch/sh/mm/consistent.c
+++ work/arch/sh/mm/consistent.c	2008-01-24 14:44:03.000000000 +0900
@@ -3,6 +3,8 @@
  *
  * Copyright (C) 2004 - 2007  Paul Mundt
  *
+ * Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
+ *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
@@ -13,66 +15,146 @@
 #include <asm/addrspace.h>
 #include <asm/io.h>
 
-void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
+struct dma_coherent_mem {
+	void		*virt_base;
+	u32		device_base;
+	int		size;
+	int		flags;
+	unsigned long	*bitmap;
+};
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			   dma_addr_t *dma_handle, gfp_t gfp)
 {
-	struct page *page, *end, *free;
-	void *ret, *vp;
-	int order;
-
-	size = PAGE_ALIGN(size);
-	order = get_order(size);
-
-	page = alloc_pages(gfp, order);
-	if (!page)
-		return NULL;
-	split_page(page, order);
-
-	ret = page_address(page);
-	*handle = virt_to_phys(ret);
-
-	vp = ioremap_nocache(*handle, size);
-	if (!vp) {
-		free_pages((unsigned long)ret, order);
-		return NULL;
+	void *ret;
+	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+	int order = get_order(size);
+
+	if (mem) {
+		int page = bitmap_find_free_region(mem->bitmap, mem->size,
+						     order);
+		if (page >= 0) {
+			*dma_handle = mem->device_base + (page << PAGE_SHIFT);
+			ret = mem->virt_base + (page << PAGE_SHIFT);
+			memset(ret, 0, size);
+			return ret;
+		}
+		if (mem->flags & DMA_MEMORY_EXCLUSIVE)
+			return NULL;
 	}
 
-	memset(vp, 0, size);
+	ret = (void *)__get_free_pages(gfp, order);
 
-	/*
-	 * We must flush the cache before we pass it on to the device
-	 */
-	dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
-
-	page = virt_to_page(ret);
-	free = page + (size >> PAGE_SHIFT);
-	end  = page + (1 << order);
-
-	while (++page < end) {
-		/* Free any unused pages */
-		if (page >= free) {
-			__free_page(page);
-		}
+	if (ret != NULL) {
+		memset(ret, 0, size);
+		/*
+		 * Pages from the page allocator may have data present in
+		 * cache. So flush the cache before using uncached memory.
+		 */
+		dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
+		*dma_handle = virt_to_phys(ret);
 	}
+	return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void dma_free_coherent(struct device *dev, size_t size,
+			 void *vaddr, dma_addr_t dma_handle)
+{
+	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+	int order = get_order(size);
 
-	return vp;
+	if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
+		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
+
+		bitmap_release_region(mem->bitmap, page, order);
+	} else {
+		WARN_ON(irqs_disabled());	/* for portability */
+		BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
+		free_pages((unsigned long)vaddr, order);
+	}
 }
-EXPORT_SYMBOL(consistent_alloc);
+EXPORT_SYMBOL(dma_free_coherent);
 
-void consistent_free(void *vaddr, size_t size, dma_addr_t dma_handle)
+int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
+				dma_addr_t device_addr, size_t size, int flags)
 {
-	struct page *page;
-	unsigned long addr;
+	void __iomem *mem_base = NULL;
+	int pages = size >> PAGE_SHIFT;
+	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
+
+	if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) = 0)
+		goto out;
+	if (!size)
+		goto out;
+	if (dev->dma_mem)
+		goto out;
+
+	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
+
+	mem_base = ioremap_nocache(bus_addr, size);
+	if (!mem_base)
+		goto out;
+
+	dev->dma_mem = kmalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
+	if (!dev->dma_mem)
+		goto out;
+	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!dev->dma_mem->bitmap)
+		goto free1_out;
+
+	dev->dma_mem->virt_base = mem_base;
+	dev->dma_mem->device_base = device_addr;
+	dev->dma_mem->size = pages;
+	dev->dma_mem->flags = flags;
+
+	if (flags & DMA_MEMORY_MAP)
+		return DMA_MEMORY_MAP;
+
+	return DMA_MEMORY_IO;
+
+ free1_out:
+	kfree(dev->dma_mem);
+ out:
+	if (mem_base)
+		iounmap(mem_base);
+	return 0;
+}
+EXPORT_SYMBOL(dma_declare_coherent_memory);
 
-	addr = (unsigned long)phys_to_virt((unsigned long)dma_handle);
-	page = virt_to_page(addr);
+void dma_release_declared_memory(struct device *dev)
+{
+	struct dma_coherent_mem *mem = dev->dma_mem;
 
-	free_pages(addr, get_order(size));
+	if (!mem)
+		return;
+	dev->dma_mem = NULL;
+	iounmap(mem->virt_base);
+	kfree(mem->bitmap);
+	kfree(mem);
+}
+EXPORT_SYMBOL(dma_release_declared_memory);
 
-	iounmap(vaddr);
+void *dma_mark_declared_memory_occupied(struct device *dev,
+					dma_addr_t device_addr, size_t size)
+{
+	struct dma_coherent_mem *mem = dev->dma_mem;
+	int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	int pos, err;
+
+	if (!mem)
+		return ERR_PTR(-EINVAL);
+
+	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
+	err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
+	if (err != 0)
+		return ERR_PTR(err);
+	return mem->virt_base + (pos << PAGE_SHIFT);
 }
-EXPORT_SYMBOL(consistent_free);
+EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
 
-void consistent_sync(void *vaddr, size_t size, int direction)
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		    enum dma_data_direction direction)
 {
 #ifdef CONFIG_CPU_SH5
 	void *p1addr = vaddr;
@@ -94,4 +176,4 @@ void consistent_sync(void *vaddr, size_t
 		BUG();
 	}
 }
-EXPORT_SYMBOL(consistent_sync);
+EXPORT_SYMBOL(dma_cache_sync);
--- 0001/include/asm-sh/dma-mapping.h
+++ work/include/asm-sh/dma-mapping.h	2008-01-24 14:29:59.000000000 +0900
@@ -8,11 +8,6 @@
 
 extern struct bus_type pci_bus_type;
 
-/* arch/sh/mm/consistent.c */
-extern void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle);
-extern void consistent_free(void *vaddr, size_t size, dma_addr_t handle);
-extern void consistent_sync(void *vaddr, size_t size, int direction);
-
 #define dma_supported(dev, mask)	(1)
 
 static inline int dma_set_mask(struct device *dev, u64 mask)
@@ -25,44 +20,19 @@ static inline int dma_set_mask(struct de
 	return 0;
 }
 
-static inline void *dma_alloc_coherent(struct device *dev, size_t size,
-			 dma_addr_t *dma_handle, gfp_t flag)
-{
-	if (sh_mv.mv_consistent_alloc) {
-		void *ret;
-
-		ret = sh_mv.mv_consistent_alloc(dev, size, dma_handle, flag);
-		if (ret != NULL)
-			return ret;
-	}
-
-	return consistent_alloc(flag, size, dma_handle);
-}
-
-static inline void dma_free_coherent(struct device *dev, size_t size,
-		       void *vaddr, dma_addr_t dma_handle)
-{
-	if (sh_mv.mv_consistent_free) {
-		int ret;
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			 dma_addr_t *dma_handle, gfp_t flag);
 
-		ret = sh_mv.mv_consistent_free(dev, size, vaddr, dma_handle);
-		if (ret = 0)
-			return;
-	}
+void dma_free_coherent(struct device *dev, size_t size,
+		       void *vaddr, dma_addr_t dma_handle);
 
-	consistent_free(vaddr, size, dma_handle);
-}
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		    enum dma_data_direction dir);
 
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 #define dma_is_consistent(d, h) (1)
 
-static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
-				  enum dma_data_direction dir)
-{
-	consistent_sync(vaddr, size, (int)dir);
-}
-
 static inline dma_addr_t dma_map_single(struct device *dev,
 					void *ptr, size_t size,
 					enum dma_data_direction dir)
@@ -205,4 +175,18 @@ static inline int dma_mapping_error(dma_
 {
 	return dma_addr = 0;
 }
+
+#define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
+
+extern int
+dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
+			    dma_addr_t device_addr, size_t size, int flags);
+
+extern void
+dma_release_declared_memory(struct device *dev);
+
+extern void *
+dma_mark_declared_memory_occupied(struct device *dev,
+				  dma_addr_t device_addr, size_t size);
+
 #endif /* __ASM_SH_DMA_MAPPING_H */

Re: [PATCH] sh: declared coherent memory support V2

[Paul Mundt]

On Thu, Jan 24, 2008 at 06:35:10PM +0900, Magnus Damm wrote:
> sh: declared coherent memory support V2

On Thu, Jan 24, 2008 at 06:40:50PM +0900, Magnus Damm wrote:
> sh: use declared coherent memory for dreamcast pci ethernet adapter

On Thu, Jan 24, 2008 at 06:45:45PM +0900, Magnus Damm wrote:
> sh: remove consistent alloc stuff from the machine vector

Applied, thanks.

It would be good if the Dreamcast folk(s) can ensure that there are no
regressions with the BBA with the curreng git kernel.

[PATCH] sh: declared coherent memory support V2 fix

[Magnus Damm]

sh: declared coherent memory support V2 fix

This patch fixes the recently introduced declared coherent memory support.
Without this fix a cached memory area is returned by dma_alloc_coherent() -
unless dma_declare_coherent_memory() has setup a separate area.

This patch makes sure an uncached memory area is returned. With this patch
it is now possible to ping through an rtl8139 interface on r2d-plus.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 arch/sh/mm/consistent.c |   30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

--- 0002/arch/sh/mm/consistent.c
+++ work/arch/sh/mm/consistent.c	2008-01-25 11:21:12.000000000 +0900
@@ -26,7 +26,7 @@ struct dma_coherent_mem {
 void *dma_alloc_coherent(struct device *dev, size_t size,
 			   dma_addr_t *dma_handle, gfp_t gfp)
 {
-	void *ret;
+	void *ret, *ret_nocache;
 	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
 	int order = get_order(size);
 
@@ -44,17 +44,24 @@ void *dma_alloc_coherent(struct device *
 	}
 
 	ret = (void *)__get_free_pages(gfp, order);
+	if (!ret)
+		return NULL;
 
-	if (ret != NULL) {
-		memset(ret, 0, size);
-		/*
-		 * Pages from the page allocator may have data present in
-		 * cache. So flush the cache before using uncached memory.
-		 */
-		dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
-		*dma_handle = virt_to_phys(ret);
+	memset(ret, 0, size);
+	/*
+	 * Pages from the page allocator may have data present in
+	 * cache. So flush the cache before using uncached memory.
+	 */
+	dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
+
+	ret_nocache = ioremap_nocache(virt_to_phys(ret), size);
+	if (!ret_nocache) {
+		free_pages((unsigned long)ret, order);
+		return NULL;
 	}
-	return ret;
+
+	*dma_handle = virt_to_phys(ret);
+	return ret_nocache;
 }
 EXPORT_SYMBOL(dma_alloc_coherent);
 
@@ -71,7 +78,8 @@ void dma_free_coherent(struct device *de
 	} else {
 		WARN_ON(irqs_disabled());	/* for portability */
 		BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
-		free_pages((unsigned long)vaddr, order);
+		free_pages((unsigned long)phys_to_virt(dma_handle), order);
+		iounmap(vaddr);
 	}
 }
 EXPORT_SYMBOL(dma_free_coherent);

Re: [PATCH] sh: declared coherent memory support V2 fix

[Paul Mundt]

On Fri, Jan 25, 2008 at 12:42:48PM +0900, Magnus Damm wrote:
> sh: declared coherent memory support V2 fix
> 
> This patch fixes the recently introduced declared coherent memory support.
> Without this fix a cached memory area is returned by dma_alloc_coherent() -
> unless dma_declare_coherent_memory() has setup a separate area.
> 
> This patch makes sure an uncached memory area is returned. With this patch
> it is now possible to ping through an rtl8139 interface on r2d-plus.
> 
> Signed-off-by: Magnus Damm <damm@igel.co.jp>

Grr, missed this one. For some reason my eyes stopped at 'V2' and didn't
see the 'fix' part, so I thought I had already applied this one. I'll
roll it in to the next -rc1 batch.