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Diffstat (limited to 'include/linux/ion.h')
| -rw-r--r-- | include/linux/ion.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/include/linux/ion.h b/include/linux/ion.h new file mode 100644 index 00000000..2cc8e0c7 --- /dev/null +++ b/include/linux/ion.h @@ -0,0 +1,365 @@ +/* + * include/linux/ion.h + * + * Copyright (C) 2011 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#ifndef _LINUX_ION_H +#define _LINUX_ION_H + +#include <linux/types.h> + +struct ion_handle; +/** + * enum ion_heap_types - list of all possible types of heaps + * @ION_HEAP_TYPE_SYSTEM: memory allocated via vmalloc + * @ION_HEAP_TYPE_SYSTEM_CONTIG: memory allocated via kmalloc + * @ION_HEAP_TYPE_CARVEOUT: memory allocated from a prereserved + * carveout heap, allocations are physically + * contiguous + * @ION_HEAP_END: helper for iterating over heaps + */ +enum ion_heap_type { + ION_HEAP_TYPE_SYSTEM, + ION_HEAP_TYPE_SYSTEM_CONTIG, + ION_HEAP_TYPE_CARVEOUT, + ION_HEAP_TYPE_CUSTOM, /* must be last so device specific heaps always + are at the end of this enum */ + ION_NUM_HEAPS, +}; + +#define ION_HEAP_SYSTEM_MASK (1 << ION_HEAP_TYPE_SYSTEM) +#define ION_HEAP_SYSTEM_CONTIG_MASK (1 << ION_HEAP_TYPE_SYSTEM_CONTIG) +#define ION_HEAP_CARVEOUT_MASK (1 << ION_HEAP_TYPE_CARVEOUT) + +#ifdef __KERNEL__ +struct ion_device; +struct ion_heap; +struct ion_mapper; +struct ion_client; +struct ion_buffer; + +/* This should be removed some day when phys_addr_t's are fully + plumbed in the kernel, and all instances of ion_phys_addr_t should + be converted to phys_addr_t. For the time being many kernel interfaces + do not accept phys_addr_t's that would have to */ +#define ion_phys_addr_t unsigned long + +/** + * struct ion_platform_heap - defines a heap in the given platform + * @type: type of the heap from ion_heap_type enum + * @id: unique identifier for heap. When allocating (lower numbers + * will be allocated from first) + * @name: used for debug purposes + * @base: base address of heap in physical memory if applicable + * @size: size of the heap in bytes if applicable + * + * Provided by the board file. + */ +struct ion_platform_heap { + enum ion_heap_type type; + unsigned int id; + const char *name; + ion_phys_addr_t base; + size_t size; +}; + +/** + * struct ion_platform_data - array of platform heaps passed from board file + * @nr: number of structures in the array + * @heaps: array of platform_heap structions + * + * Provided by the board file in the form of platform data to a platform device. + */ +struct ion_platform_data { + int nr; + struct ion_platform_heap heaps[]; +}; + +/** + * ion_client_create() - allocate a client and returns it + * @dev: the global ion device + * @heap_mask: mask of heaps this client can allocate from + * @name: used for debugging + */ +struct ion_client *ion_client_create(struct ion_device *dev, + unsigned int heap_mask, const char *name); + +/** + * ion_client_destroy() - free's a client and all it's handles + * @client: the client + * + * Free the provided client and all it's resources including + * any handles it is holding. + */ +void ion_client_destroy(struct ion_client *client); + +/** + * ion_alloc - allocate ion memory + * @client: the client + * @len: size of the allocation + * @align: requested allocation alignment, lots of hardware blocks have + * alignment requirements of some kind + * @flags: mask of heaps to allocate from, if multiple bits are set + * heaps will be tried in order from lowest to highest order bit + * + * Allocate memory in one of the heaps provided in heap mask and return + * an opaque handle to it. + */ +struct ion_handle *ion_alloc(struct ion_client *client, size_t len, + size_t align, unsigned int flags); + +/** + * ion_free - free a handle + * @client: the client + * @handle: the handle to free + * + * Free the provided handle. + */ +void ion_free(struct ion_client *client, struct ion_handle *handle); + +/** + * ion_phys - returns the physical address and len of a handle + * @client: the client + * @handle: the handle + * @addr: a pointer to put the address in + * @len: a pointer to put the length in + * + * This function queries the heap for a particular handle to get the + * handle's physical address. It't output is only correct if + * a heap returns physically contiguous memory -- in other cases + * this api should not be implemented -- ion_map_dma should be used + * instead. Returns -EINVAL if the handle is invalid. This has + * no implications on the reference counting of the handle -- + * the returned value may not be valid if the caller is not + * holding a reference. + */ +int ion_phys(struct ion_client *client, struct ion_handle *handle, + ion_phys_addr_t *addr, size_t *len); + +/** + * ion_map_kernel - create mapping for the given handle + * @client: the client + * @handle: handle to map + * + * Map the given handle into the kernel and return a kernel address that + * can be used to access this address. + */ +void *ion_map_kernel(struct ion_client *client, struct ion_handle *handle); + +/** + * ion_unmap_kernel() - destroy a kernel mapping for a handle + * @client: the client + * @handle: handle to unmap + */ +void ion_unmap_kernel(struct ion_client *client, struct ion_handle *handle); + +/** + * ion_map_dma - create a dma mapping for a given handle + * @client: the client + * @handle: handle to map + * + * Return an sglist describing the given handle + */ +struct scatterlist *ion_map_dma(struct ion_client *client, + struct ion_handle *handle); + +/** + * ion_unmap_dma() - destroy a dma mapping for a handle + * @client: the client + * @handle: handle to unmap + */ +void ion_unmap_dma(struct ion_client *client, struct ion_handle *handle); + +/** + * ion_share() - given a handle, obtain a buffer to pass to other clients + * @client: the client + * @handle: the handle to share + * + * Given a handle, return a buffer, which exists in a global name + * space, and can be passed to other clients. Should be passed into ion_import + * to obtain a new handle for this buffer. + * + * NOTE: This function does do not an extra reference. The burden is on the + * caller to make sure the buffer doesn't go away while it's being passed to + * another client. That is, ion_free should not be called on this handle until + * the buffer has been imported into the other client. + */ +struct ion_buffer *ion_share(struct ion_client *client, + struct ion_handle *handle); + +/** + * ion_import() - given an buffer in another client, import it + * @client: this blocks client + * @buffer: the buffer to import (as obtained from ion_share) + * + * Given a buffer, add it to the client and return the handle to use to refer + * to it further. This is called to share a handle from one kernel client to + * another. + */ +struct ion_handle *ion_import(struct ion_client *client, + struct ion_buffer *buffer); + +/** + * ion_import_fd() - given an fd obtained via ION_IOC_SHARE ioctl, import it + * @client: this blocks client + * @fd: the fd + * + * A helper function for drivers that will be recieving ion buffers shared + * with them from userspace. These buffers are represented by a file + * descriptor obtained as the return from the ION_IOC_SHARE ioctl. + * This function coverts that fd into the underlying buffer, and returns + * the handle to use to refer to it further. + */ +struct ion_handle *ion_import_fd(struct ion_client *client, int fd); +#endif /* __KERNEL__ */ + +/** + * DOC: Ion Userspace API + * + * create a client by opening /dev/ion + * most operations handled via following ioctls + * + */ + +/** + * struct ion_allocation_data - metadata passed from userspace for allocations + * @len: size of the allocation + * @align: required alignment of the allocation + * @flags: flags passed to heap + * @handle: pointer that will be populated with a cookie to use to refer + * to this allocation + * + * Provided by userspace as an argument to the ioctl + */ +struct ion_allocation_data { + size_t len; + size_t align; + unsigned int flags; + struct ion_handle *handle; +}; + +/** + * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair + * @handle: a handle + * @fd: a file descriptor representing that handle + * + * For ION_IOC_SHARE or ION_IOC_MAP userspace populates the handle field with + * the handle returned from ion alloc, and the kernel returns the file + * descriptor to share or map in the fd field. For ION_IOC_IMPORT, userspace + * provides the file descriptor and the kernel returns the handle. + */ +struct ion_fd_data { + struct ion_handle *handle; + int fd; +}; + +/** + * struct ion_phys_data - passed to/from userspace for a handle/phys addr pair + * @handle: a handle + * @phys: a return physcial address + * + * For ION_IOC_PHYS ioctl + * the phys return the ion phys address + */ +struct ion_phys_data { + struct ion_handle *handle; + unsigned long phys; +}; + +/** + * struct ion_handle_data - a handle passed to/from the kernel + * @handle: a handle + */ +struct ion_handle_data { + struct ion_handle *handle; +}; + +/** + * struct ion_custom_data - metadata passed to/from userspace for a custom ioctl + * @cmd: the custom ioctl function to call + * @arg: additional data to pass to the custom ioctl, typically a user + * pointer to a predefined structure + * + * This works just like the regular cmd and arg fields of an ioctl. + */ +struct ion_custom_data { + unsigned int cmd; + unsigned long arg; +}; + +#define ION_IOC_MAGIC 'I' + +/** + * DOC: ION_IOC_ALLOC - allocate memory + * + * Takes an ion_allocation_data struct and returns it with the handle field + * populated with the opaque handle for the allocation. + */ +#define ION_IOC_ALLOC _IOWR(ION_IOC_MAGIC, 0, \ + struct ion_allocation_data) + +/** + * DOC: ION_IOC_FREE - free memory + * + * Takes an ion_handle_data struct and frees the handle. + */ +#define ION_IOC_FREE _IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data) + +/** + * DOC: ION_IOC_MAP - get a file descriptor to mmap + * + * Takes an ion_fd_data struct with the handle field populated with a valid + * opaque handle. Returns the struct with the fd field set to a file + * descriptor open in the current address space. This file descriptor + * can then be used as an argument to mmap. + */ +#define ION_IOC_MAP _IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data) + +/** + * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation + * + * Takes an ion_fd_data struct with the handle field populated with a valid + * opaque handle. Returns the struct with the fd field set to a file + * descriptor open in the current address space. This file descriptor + * can then be passed to another process. The corresponding opaque handle can + * be retrieved via ION_IOC_IMPORT. + */ +#define ION_IOC_SHARE _IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data) + +/** + * DOC: ION_IOC_IMPORT - imports a shared file descriptor + * + * Takes an ion_fd_data struct with the fd field populated with a valid file + * descriptor obtained from ION_IOC_SHARE and returns the struct with the handle + * filed set to the corresponding opaque handle. + */ +#define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, int) + +/** + * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl + * + * Takes the argument of the architecture specific ioctl to call and + * passes appropriate userdata for that ioctl + */ +#define ION_IOC_CUSTOM _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data) + +/** + * DOC: ION_IOC_PHYS - get allocated memory physical address + * + * Takes an ion_fd_data struct with the handle field populated with a valid + * opaque handle. Returns the address + */ +#define ION_IOC_PHYS _IOWR(ION_IOC_MAGIC, 7, struct ion_phys_data) + +#endif /* _LINUX_ION_H */ |