/* * drivers/base/dma-mapping.c - arch-independent dma-mapping routines * * Copyright (c) 2006 SUSE Linux Products GmbH * Copyright (c) 2006 Tejun Heo * * This file is released under the GPLv2. */ #include #include #include #include /* * 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_non_coherent() * @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_non_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_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 ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY 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 * @bus_addr: Bus 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, dma_addr_t bus_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, bus_addr, device_addr, size, flags); if (rc == 0) devres_add(dev, res); else devres_free(res); 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; #ifdef CONFIG_MMU unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 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 */ return ret; } EXPORT_SYMBOL(dma_common_mmap);