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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm/include/asm/dma-mapping.h | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
-rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h new file mode 100644 index 000000000..77082246a --- /dev/null +++ b/arch/arm/include/asm/dma-mapping.h @@ -0,0 +1,128 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef ASMARM_DMA_MAPPING_H +#define ASMARM_DMA_MAPPING_H + +#ifdef __KERNEL__ + +#include <linux/mm_types.h> +#include <linux/scatterlist.h> + +#include <xen/xen.h> +#include <asm/xen/hypervisor.h> + +extern const struct dma_map_ops arm_dma_ops; +extern const struct dma_map_ops arm_coherent_dma_ops; + +static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) +{ + if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE)) + return &arm_dma_ops; + return NULL; +} + +/** + * arm_dma_alloc - allocate consistent memory for DMA + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @size: required memory size + * @handle: bus-specific DMA address + * @attrs: optinal attributes that specific mapping properties + * + * Allocate some memory for a device for performing DMA. This function + * allocates pages, and will return the CPU-viewed address, and sets @handle + * to be the device-viewed address. + */ +extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t gfp, unsigned long attrs); + +/** + * arm_dma_free - free memory allocated by arm_dma_alloc + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @size: size of memory originally requested in dma_alloc_coherent + * @cpu_addr: CPU-view address returned from dma_alloc_coherent + * @handle: device-view address returned from dma_alloc_coherent + * @attrs: optinal attributes that specific mapping properties + * + * Free (and unmap) a DMA buffer previously allocated by + * arm_dma_alloc(). + * + * References to memory and mappings associated with cpu_addr/handle + * during and after this call executing are illegal. + */ +extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, unsigned long attrs); + +/** + * arm_dma_mmap - map a coherent DMA allocation into user space + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @vma: vm_area_struct describing requested user mapping + * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent + * @handle: device-view address returned from dma_alloc_coherent + * @size: size of memory originally requested in dma_alloc_coherent + * @attrs: optinal attributes that specific mapping properties + * + * Map a coherent DMA buffer previously allocated by dma_alloc_coherent + * into user space. The coherent DMA buffer must not be freed by the + * driver until the user space mapping has been released. + */ +extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs); + +/* + * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic" + * and utilize bounce buffers as needed to work around limited DMA windows. + * + * On the SA-1111, a bug limits DMA to only certain regions of RAM. + * On the IXP425, the PCI inbound window is 64MB (256MB total RAM) + * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM) + * + * The following are helper functions used by the dmabounce subystem + * + */ + +/** + * dmabounce_register_dev + * + * @dev: valid struct device pointer + * @small_buf_size: size of buffers to use with small buffer pool + * @large_buf_size: size of buffers to use with large buffer pool (can be 0) + * @needs_bounce_fn: called to determine whether buffer needs bouncing + * + * This function should be called by low-level platform code to register + * a device as requireing DMA buffer bouncing. The function will allocate + * appropriate DMA pools for the device. + */ +extern int dmabounce_register_dev(struct device *, unsigned long, + unsigned long, int (*)(struct device *, dma_addr_t, size_t)); + +/** + * dmabounce_unregister_dev + * + * @dev: valid struct device pointer + * + * This function should be called by low-level platform code when device + * that was previously registered with dmabounce_register_dev is removed + * from the system. + * + */ +extern void dmabounce_unregister_dev(struct device *); + + + +/* + * The scatter list versions of the above methods. + */ +extern int arm_dma_map_sg(struct device *, struct scatterlist *, int, + enum dma_data_direction, unsigned long attrs); +extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int, + enum dma_data_direction, unsigned long attrs); +extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int, + enum dma_data_direction); +extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int, + enum dma_data_direction); +extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs); + +#endif /* __KERNEL__ */ +#endif |