drivers/base/dma-mapping.c - linux - Git at Google

 /*
  * drivers/base/dma-mapping.c - arch-independent dma-mapping routines
  *
  * Copyright (c) 2006  SUSE Linux Products GmbH
  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
  *
  * This file is released under the GPLv2.
  */

 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>

 /*
  * Managed DMA API
  */
 struct dma_devres {
 	size_t		size;
 	void		*vaddr;
 	dma_addr_t	dma_handle;
 };

 static void dmam_coherent_release(struct device *dev, void *res)
 {
 	struct dma_devres *this = res;

 	dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
 }

 static void dmam_noncoherent_release(struct device *dev, void *res)
 {
 	struct dma_devres *this = res;

 	dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
 }

 static int dmam_match(struct device *dev, void *res, void *match_data)
 {
 	struct dma_devres *this = res, *match = match_data;

 	if (this->vaddr == match->vaddr) {
 		WARN_ON(this->size != match->size ||
 			this->dma_handle != match->dma_handle);
 		return 1;
 	}
 	return 0;
 }

 /**
  * dmam_alloc_coherent - Managed dma_alloc_coherent()
  * @dev: Device to allocate coherent memory for
  * @size: Size of allocation
  * @dma_handle: Out argument for allocated DMA handle
  * @gfp: Allocation flags
  *
  * Managed dma_alloc_coherent().  Memory allocated using this function
  * will be automatically released on driver detach.
  *
  * RETURNS:
  * Pointer to allocated memory on success, NULL on failure.
  */
 void *dmam_alloc_coherent(struct device *dev, size_t size,
 			   dma_addr_t *dma_handle, gfp_t gfp)
 {
 	struct dma_devres *dr;
 	void *vaddr;

 	dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
 	if (!dr)
 		return NULL;

 	vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
 	if (!vaddr) {
 		devres_free(dr);
 		return NULL;
 	}

 	dr->vaddr = vaddr;
 	dr->dma_handle = *dma_handle;
 	dr->size = size;

 	devres_add(dev, dr);

 	return vaddr;
 }
 EXPORT_SYMBOL(dmam_alloc_coherent);

 /**
  * dmam_free_coherent - Managed dma_free_coherent()
  * @dev: Device to free coherent memory for
  * @size: Size of allocation
  * @vaddr: Virtual address of the memory to free
  * @dma_handle: DMA handle of the memory to free
  *
  * Managed dma_free_coherent().
  */
 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
 			dma_addr_t dma_handle)
 {
 	struct dma_devres match_data = { size, vaddr, dma_handle };

 	dma_free_coherent(dev, size, vaddr, dma_handle);
 	WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
 			       &match_data));
 }
 EXPORT_SYMBOL(dmam_free_coherent);

 /**
  * dmam_alloc_non_coherent - Managed dma_alloc_noncoherent()
  * @dev: Device to allocate non_coherent memory for
  * @size: Size of allocation
  * @dma_handle: Out argument for allocated DMA handle
  * @gfp: Allocation flags
  *
  * Managed dma_alloc_noncoherent().  Memory allocated using this
  * function will be automatically released on driver detach.
  *
  * RETURNS:
  * Pointer to allocated memory on success, NULL on failure.
  */
 void *dmam_alloc_noncoherent(struct device *dev, size_t size,
 			     dma_addr_t *dma_handle, gfp_t gfp)
 {
 	struct dma_devres *dr;
 	void *vaddr;

 	dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
 	if (!dr)
 		return NULL;

 	vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
 	if (!vaddr) {
 		devres_free(dr);
 		return NULL;
 	}

 	dr->vaddr = vaddr;
 	dr->dma_handle = *dma_handle;
 	dr->size = size;

 	devres_add(dev, dr);

 	return vaddr;
 }
 EXPORT_SYMBOL(dmam_alloc_noncoherent);

 /**
  * dmam_free_coherent - Managed dma_free_noncoherent()
  * @dev: Device to free noncoherent memory for
  * @size: Size of allocation
  * @vaddr: Virtual address of the memory to free
  * @dma_handle: DMA handle of the memory to free
  *
  * Managed dma_free_noncoherent().
  */
 void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 			   dma_addr_t dma_handle)
 {
 	struct dma_devres match_data = { size, vaddr, dma_handle };

 	dma_free_noncoherent(dev, size, vaddr, dma_handle);
 	WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
 				&match_data));
 }
 EXPORT_SYMBOL(dmam_free_noncoherent);

 #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT

 static void dmam_coherent_decl_release(struct device *dev, void *res)
 {
 	dma_release_declared_memory(dev);
 }

 /**
  * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
  * @dev: Device to declare coherent memory for
  * @phys_addr: Physical address of coherent memory to be declared
  * @device_addr: Device address of coherent memory to be declared
  * @size: Size of coherent memory to be declared
  * @flags: Flags
  *
  * Managed dma_declare_coherent_memory().
  *
  * RETURNS:
  * 0 on success, -errno on failure.
  */
 int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 				 dma_addr_t device_addr, size_t size, int flags)
 {
 	void *res;
 	int rc;

 	res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
 	if (!res)
 		return -ENOMEM;

 	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
 					 flags);
 	if (rc) {
 		devres_add(dev, res);
 		rc = 0;
 	} else {
 		devres_free(res);
 		rc = -ENOMEM;
 	}

 	return rc;
 }
 EXPORT_SYMBOL(dmam_declare_coherent_memory);

 /**
  * dmam_release_declared_memory - Managed dma_release_declared_memory().
  * @dev: Device to release declared coherent memory for
  *
  * Managed dmam_release_declared_memory().
  */
 void dmam_release_declared_memory(struct device *dev)
 {
 	WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
 }
 EXPORT_SYMBOL(dmam_release_declared_memory);

 #endif

 /*
  * Create scatter-list for the already allocated DMA buffer.
  */
 int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
 		 void *cpu_addr, dma_addr_t handle, size_t size)
 {
 	struct page *page = virt_to_page(cpu_addr);
 	int ret;

 	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 	if (unlikely(ret))
 		return ret;

 	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
 	return 0;
 }
 EXPORT_SYMBOL(dma_common_get_sgtable);

 /*
  * Create userspace mapping for the DMA-coherent memory.
  */
 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;
 #if defined(CONFIG_MMU) && !defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)
 	unsigned long user_count = vma_pages(vma);
 	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
 	unsigned long off = vma->vm_pgoff;

 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

 	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 		return ret;

 	if (off < count && user_count <= (count - off)) {
 		ret = remap_pfn_range(vma, vma->vm_start,
 				      pfn + off,
 				      user_count << PAGE_SHIFT,
 				      vma->vm_page_prot);
 	}
 #endif	/* CONFIG_MMU && !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */

 	return ret;
 }
 EXPORT_SYMBOL(dma_common_mmap);

 #ifdef CONFIG_MMU
 /*
  * remaps an array of PAGE_SIZE pages into another vm_area
  * Cannot be used in non-sleeping contexts
  */
 void *dma_common_pages_remap(struct page **pages, size_t size,
 			unsigned long vm_flags, pgprot_t prot,
 			const void *caller)
 {
 	struct vm_struct *area;

 	area = get_vm_area_caller(size, vm_flags, caller);
 	if (!area)
 		return NULL;

 	area->pages = pages;

 	if (map_vm_area(area, prot, pages)) {
 		vunmap(area->addr);
 		return NULL;
 	}

 	return area->addr;
 }

 /*
  * remaps an allocated contiguous region into another vm_area.
  * Cannot be used in non-sleeping contexts
  */

 void *dma_common_contiguous_remap(struct page *page, size_t size,
 			unsigned long vm_flags,
 			pgprot_t prot, const void *caller)
 {
 	int i;
 	struct page **pages;
 	void *ptr;
 	unsigned long pfn;

 	pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
 	if (!pages)
 		return NULL;

 	for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
 		pages[i] = pfn_to_page(pfn + i);

 	ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);

 	kfree(pages);

 	return ptr;
 }

 /*
  * unmaps a range previously mapped by dma_common_*_remap
  */
 void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
 {
 	struct vm_struct *area = find_vm_area(cpu_addr);

 	if (!area || (area->flags & vm_flags) != vm_flags) {
 		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
 		return;
 	}

 	unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
 	vunmap(cpu_addr);
 }
 #endif
	/*
	* drivers/base/dma-mapping.c - arch-independent dma-mapping routines
	*
	* Copyright (c) 2006 SUSE Linux Products GmbH
	* Copyright (c) 2006 Tejun Heo <teheo@suse.de>
	*
	* This file is released under the GPLv2.
	*/

	#include <linux/dma-mapping.h>
	#include <linux/export.h>
	#include <linux/gfp.h>
	#include <linux/slab.h>
	#include <linux/vmalloc.h>

	/*
	* Managed DMA API
	*/
	struct dma_devres {
	size_t size;
	void *vaddr;
	dma_addr_t dma_handle;
	};

	static void dmam_coherent_release(struct device dev, void res)
	{
	struct dma_devres *this = res;

	dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
	}

	static void dmam_noncoherent_release(struct device dev, void res)
	{
	struct dma_devres *this = res;

	dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
	}

	static int dmam_match(struct device dev, void res, void *match_data)
	{
	struct dma_devres this = res, match = match_data;

	if (this->vaddr == match->vaddr) {
	WARN_ON(this->size != match->size \|\|
	this->dma_handle != match->dma_handle);
	return 1;
	}
	return 0;
	}

	/**
	* dmam_alloc_coherent - Managed dma_alloc_coherent()
	* @dev: Device to allocate coherent memory for
	* @size: Size of allocation
	* @dma_handle: Out argument for allocated DMA handle
	* @gfp: Allocation flags
	*
	* Managed dma_alloc_coherent(). Memory allocated using this function
	* will be automatically released on driver detach.
	*
	* RETURNS:
	* Pointer to allocated memory on success, NULL on failure.
	*/
	void dmam_alloc_coherent(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t gfp)
	{
	struct dma_devres *dr;
	void *vaddr;

	dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
	if (!dr)
	return NULL;

	vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
	if (!vaddr) {
	devres_free(dr);
	return NULL;
	}

	dr->vaddr = vaddr;
	dr->dma_handle = *dma_handle;
	dr->size = size;

	devres_add(dev, dr);

	return vaddr;
	}
	EXPORT_SYMBOL(dmam_alloc_coherent);

	/**
	* dmam_free_coherent - Managed dma_free_coherent()
	* @dev: Device to free coherent memory for
	* @size: Size of allocation
	* @vaddr: Virtual address of the memory to free
	* @dma_handle: DMA handle of the memory to free
	*
	* Managed dma_free_coherent().
	*/
	void dmam_free_coherent(struct device dev, size_t size, void vaddr,
	dma_addr_t dma_handle)
	{
	struct dma_devres match_data = { size, vaddr, dma_handle };

	dma_free_coherent(dev, size, vaddr, dma_handle);
	WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
	&match_data));
	}
	EXPORT_SYMBOL(dmam_free_coherent);

	/**
	* dmam_alloc_non_coherent - Managed dma_alloc_noncoherent()
	* @dev: Device to allocate non_coherent memory for
	* @size: Size of allocation
	* @dma_handle: Out argument for allocated DMA handle
	* @gfp: Allocation flags
	*
	* Managed dma_alloc_noncoherent(). Memory allocated using this
	* function will be automatically released on driver detach.
	*
	* RETURNS:
	* Pointer to allocated memory on success, NULL on failure.
	*/
	void dmam_alloc_noncoherent(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t gfp)
	{
	struct dma_devres *dr;
	void *vaddr;

	dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
	if (!dr)
	return NULL;

	vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
	if (!vaddr) {
	devres_free(dr);
	return NULL;
	}

	dr->vaddr = vaddr;
	dr->dma_handle = *dma_handle;
	dr->size = size;

	devres_add(dev, dr);

	return vaddr;
	}
	EXPORT_SYMBOL(dmam_alloc_noncoherent);

	/**
	* dmam_free_coherent - Managed dma_free_noncoherent()
	* @dev: Device to free noncoherent memory for
	* @size: Size of allocation
	* @vaddr: Virtual address of the memory to free
	* @dma_handle: DMA handle of the memory to free
	*
	* Managed dma_free_noncoherent().
	*/
	void dmam_free_noncoherent(struct device dev, size_t size, void vaddr,
	dma_addr_t dma_handle)
	{
	struct dma_devres match_data = { size, vaddr, dma_handle };

	dma_free_noncoherent(dev, size, vaddr, dma_handle);
	WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
	&match_data));
	}
	EXPORT_SYMBOL(dmam_free_noncoherent);

	#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT

	static void dmam_coherent_decl_release(struct device dev, void res)
	{
	dma_release_declared_memory(dev);
	}

	/**
	* dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
	* @dev: Device to declare coherent memory for
	* @phys_addr: Physical address of coherent memory to be declared
	* @device_addr: Device address of coherent memory to be declared
	* @size: Size of coherent memory to be declared
	* @flags: Flags
	*
	* Managed dma_declare_coherent_memory().
	*
	* RETURNS:
	* 0 on success, -errno on failure.
	*/
	int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
	dma_addr_t device_addr, size_t size, int flags)
	{
	void *res;
	int rc;

	res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
	if (!res)
	return -ENOMEM;

	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
	flags);
	if (rc) {
	devres_add(dev, res);
	rc = 0;
	} else {
	devres_free(res);
	rc = -ENOMEM;
	}

	return rc;
	}
	EXPORT_SYMBOL(dmam_declare_coherent_memory);

	/**
	* dmam_release_declared_memory - Managed dma_release_declared_memory().
	* @dev: Device to release declared coherent memory for
	*
	* Managed dmam_release_declared_memory().
	*/
	void dmam_release_declared_memory(struct device *dev)
	{
	WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
	}
	EXPORT_SYMBOL(dmam_release_declared_memory);

	#endif

	/*
	* Create scatter-list for the already allocated DMA buffer.
	*/
	int dma_common_get_sgtable(struct device dev, struct sg_table sgt,
	void *cpu_addr, dma_addr_t handle, size_t size)
	{
	struct page *page = virt_to_page(cpu_addr);
	int ret;

	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
	if (unlikely(ret))
	return ret;

	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
	return 0;
	}
	EXPORT_SYMBOL(dma_common_get_sgtable);

	/*
	* Create userspace mapping for the DMA-coherent memory.
	*/
	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;
	#if defined(CONFIG_MMU) && !defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)
	unsigned long user_count = vma_pages(vma);
	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
	unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
	unsigned long off = vma->vm_pgoff;

	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
	return ret;

	if (off < count && user_count <= (count - off)) {
	ret = remap_pfn_range(vma, vma->vm_start,
	pfn + off,
	user_count << PAGE_SHIFT,
	vma->vm_page_prot);
	}
	#endif /* CONFIG_MMU && !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */

	return ret;
	}
	EXPORT_SYMBOL(dma_common_mmap);

	#ifdef CONFIG_MMU
	/*
	* remaps an array of PAGE_SIZE pages into another vm_area
	* Cannot be used in non-sleeping contexts
	*/
	void dma_common_pages_remap(struct page *pages, size_t size,
	unsigned long vm_flags, pgprot_t prot,
	const void *caller)
	{
	struct vm_struct *area;

	area = get_vm_area_caller(size, vm_flags, caller);
	if (!area)
	return NULL;

	area->pages = pages;

	if (map_vm_area(area, prot, pages)) {
	vunmap(area->addr);
	return NULL;
	}

	return area->addr;
	}

	/*
	* remaps an allocated contiguous region into another vm_area.
	* Cannot be used in non-sleeping contexts
	*/

	void dma_common_contiguous_remap(struct page page, size_t size,
	unsigned long vm_flags,
	pgprot_t prot, const void *caller)
	{
	int i;
	struct page **pages;
	void *ptr;
	unsigned long pfn;

	pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
	if (!pages)
	return NULL;

	for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
	pages[i] = pfn_to_page(pfn + i);

	ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);

	kfree(pages);

	return ptr;
	}

	/*
	* unmaps a range previously mapped by dma_common_*_remap
	*/
	void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
	{
	struct vm_struct *area = find_vm_area(cpu_addr);

	if (!area \|\| (area->flags & vm_flags) != vm_flags) {
	WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
	return;
	}

	unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
	vunmap(cpu_addr);
	}
	#endif