diff options
Diffstat (limited to 'drivers/base/dma-mapping.c')
| -rw-r--r-- | drivers/base/dma-mapping.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c new file mode 100644 index 00000000..6f3676f1 --- /dev/null +++ b/drivers/base/dma-mapping.c @@ -0,0 +1,220 @@ +/* + * 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> + +/* + * 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 |