[PATCH 2/3] ARM: support generic per-device coherent dma mem

[PATCH 2/3] ARM: support generic per-device coherent dma mem

[Dmitry Baryshkov]

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
---
 arch/arm/Kconfig              |    1 +
 arch/arm/mm/consistent.c      |    8 ++++++++
 include/asm-arm/dma-mapping.h |    2 ++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b786e68..828e09d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -14,6 +14,7 @@ config ARM
 	select HAVE_OPROFILE
 	select HAVE_KPROBES if (!XIP_KERNEL)
 	select HAVE_KRETPROBES if (HAVE_KPROBES)
+	select HAVE_GENERIC_DMA_COHERENT
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c
index 333a82a..db7b3e3 100644
--- a/arch/arm/mm/consistent.c
+++ b/arch/arm/mm/consistent.c
@@ -274,6 +274,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
 void *
 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
 {
+	void *memory;
+
+	if (dma_alloc_from_coherent(dev, size, handle, &memory))
+		return memory;
+
 	if (arch_is_coherent()) {
 		void *virt;
 
@@ -362,6 +367,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 
 	WARN_ON(irqs_disabled());
 
+	if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
+		return;
+
 	if (arch_is_coherent()) {
 		kfree(cpu_addr);
 		return;
diff --git a/include/asm-arm/dma-mapping.h b/include/asm-arm/dma-mapping.h
index e99406a..943f23b 100644
--- a/include/asm-arm/dma-mapping.h
+++ b/include/asm-arm/dma-mapping.h
@@ -7,6 +7,8 @@
 
 #include <linux/scatterlist.h>
 
+#include <asm-generic/dma-coherent.h>
+
 /*
  * DMA-consistent mapping functions.  These allocate/free a region of
  * uncached, unwrite-buffered mapped memory space for use with DMA
-- 
1.5.6.2


-- 
With best wishes
Dmitry

[PATCH 3/3] Sh: use generic per-device coherent dma allocator

[Dmitry Baryshkov]

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
---
 arch/sh/Kconfig              |    1 +
 arch/sh/mm/consistent.c      |   98 +----------------------------------------
 include/asm-sh/dma-mapping.h |    1 +
 3 files changed, 5 insertions(+), 95 deletions(-)

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 9a854c8..893df17 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -10,6 +10,7 @@ config SUPERH
 	select EMBEDDED
 	select HAVE_IDE
 	select HAVE_OPROFILE
+	select HAVE_GENERIC_DMA_COHERENT
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index d3c33fc..3095d95 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -27,21 +27,10 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
 			   dma_addr_t *dma_handle, gfp_t gfp)
 {
 	void *ret, *ret_nocache;
-	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;
-	}
+	if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
+		return ret;
 
 	ret = (void *)__get_free_pages(gfp, order);
 	if (!ret)
@@ -71,11 +60,7 @@ void dma_free_coherent(struct device *dev, size_t size,
 	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
 	int order = get_order(size);
 
-	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 {
+	if (!dma_release_from_coherent(dev, order, vaddr)) {
 		WARN_ON(irqs_disabled());	/* for portability */
 		BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
 		free_pages((unsigned long)phys_to_virt(dma_handle), order);
@@ -84,83 +69,6 @@ void dma_free_coherent(struct device *dev, size_t size,
 }
 EXPORT_SYMBOL(dma_free_coherent);
 
-int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
-				dma_addr_t device_addr, size_t size, int flags)
-{
-	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);
-
-void dma_release_declared_memory(struct device *dev)
-{
-	struct dma_coherent_mem *mem = dev->dma_mem;
-
-	if (!mem)
-		return;
-	dev->dma_mem = NULL;
-	iounmap(mem->virt_base);
-	kfree(mem->bitmap);
-	kfree(mem);
-}
-EXPORT_SYMBOL(dma_release_declared_memory);
-
-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(dma_mark_declared_memory_occupied);
-
 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 		    enum dma_data_direction direction)
 {
diff --git a/include/asm-sh/dma-mapping.h b/include/asm-sh/dma-mapping.h
index 22cc419..5956c5d 100644
--- a/include/asm-sh/dma-mapping.h
+++ b/include/asm-sh/dma-mapping.h
@@ -5,6 +5,7 @@
 #include <linux/scatterlist.h>
 #include <asm/cacheflush.h>
 #include <asm/io.h>
+#include <asm-generic/dma-coherent.h>
 
 extern struct bus_type pci_bus_type;
 
-- 
1.5.6.2


-- 
With best wishes
Dmitry

Re: [PATCH 3/3] Sh: use generic per-device coherent dma allocator

[Ingo Molnar]

* Dmitry Baryshkov <dbaryshkov@gmail.com> wrote:

> Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
> Cc: Paul Mundt <lethal@linux-sh.org>

applied all 3 patches to core/generic-dma-coherent, which is at:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core/generic-dma-coherent

------------------>
Dmitry Baryshkov (5):
      generic: per-device coherent dma allocator
      x86: use generic per-device dma coherent allocator
      Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE
      ARM: support generic per-device coherent dma mem
      Sh: use generic per-device coherent dma allocator


 arch/arm/Kconfig                   |    1 +
 arch/arm/mm/consistent.c           |    8 ++
 arch/sh/Kconfig                    |    1 +
 arch/sh/mm/consistent.c            |   98 +---------------------------
 arch/x86/Kconfig                   |    1 +
 arch/x86/kernel/pci-dma.c          |  122 +----------------------------------
 include/asm-arm/dma-mapping.h      |    2 +
 include/asm-generic/dma-coherent.h |   32 +++++++++
 include/asm-sh/dma-mapping.h       |    1 +
 include/asm-x86/dma-mapping.h      |   22 +------
 init/Kconfig                       |    4 +
 kernel/Makefile                    |    1 +
 kernel/dma-coherent.c              |  126 ++++++++++++++++++++++++++++++++++++
 13 files changed, 183 insertions(+), 236 deletions(-)
 create mode 100644 include/asm-generic/dma-coherent.h
 create mode 100644 kernel/dma-coherent.c