Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Header file for dma buffer sharing framework. |
| 3 | * |
| 4 | * Copyright(C) 2011 Linaro Limited. All rights reserved. |
| 5 | * Author: Sumit Semwal <sumit.semwal@ti.com> |
| 6 | * |
| 7 | * Many thanks to linaro-mm-sig list, and specially |
| 8 | * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and |
| 9 | * Daniel Vetter <daniel@ffwll.ch> for their support in creation and |
| 10 | * refining of this idea. |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify it |
| 13 | * under the terms of the GNU General Public License version 2 as published by |
| 14 | * the Free Software Foundation. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 17 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 19 | * more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License along with |
| 22 | * this program. If not, see <http://www.gnu.org/licenses/>. |
| 23 | */ |
| 24 | #ifndef __DMA_BUF_H__ |
| 25 | #define __DMA_BUF_H__ |
| 26 | |
| 27 | #include <linux/file.h> |
| 28 | #include <linux/err.h> |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 29 | #include <linux/scatterlist.h> |
| 30 | #include <linux/list.h> |
| 31 | #include <linux/dma-mapping.h> |
Rob Clark | f9a24d1 | 2012-03-16 11:04:41 -0500 | [diff] [blame] | 32 | #include <linux/fs.h> |
Maarten Lankhorst | 9b495a5 | 2014-07-01 12:57:43 +0200 | [diff] [blame] | 33 | #include <linux/fence.h> |
| 34 | #include <linux/wait.h> |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 35 | |
Paul Gortmaker | 313162d | 2012-01-30 11:46:54 -0500 | [diff] [blame] | 36 | struct device; |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 37 | struct dma_buf; |
| 38 | struct dma_buf_attachment; |
| 39 | |
| 40 | /** |
| 41 | * struct dma_buf_ops - operations possible on struct dma_buf |
| 42 | * @attach: [optional] allows different devices to 'attach' themselves to the |
| 43 | * given buffer. It might return -EBUSY to signal that backing storage |
| 44 | * is already allocated and incompatible with the requirements |
| 45 | * of requesting device. |
| 46 | * @detach: [optional] detach a given device from this buffer. |
| 47 | * @map_dma_buf: returns list of scatter pages allocated, increases usecount |
| 48 | * of the buffer. Requires atleast one attach to be called |
| 49 | * before. Returned sg list should already be mapped into |
| 50 | * _device_ address space. This call may sleep. May also return |
| 51 | * -EINTR. Should return -EINVAL if attach hasn't been called yet. |
| 52 | * @unmap_dma_buf: decreases usecount of buffer, might deallocate scatter |
| 53 | * pages. |
| 54 | * @release: release this buffer; to be called after the last dma_buf_put. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 55 | * @begin_cpu_access: [optional] called before cpu access to invalidate cpu |
| 56 | * caches and allocate backing storage (if not yet done) |
Tiago Vignatti | 831e9da | 2015-12-22 19:36:45 -0200 | [diff] [blame] | 57 | * respectively pin the object into memory. |
Masanari Iida | 8a168ca | 2012-12-29 02:00:09 +0900 | [diff] [blame] | 58 | * @end_cpu_access: [optional] called after cpu access to flush caches. |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 59 | * @kmap_atomic: maps a page from the buffer into kernel address |
| 60 | * space, users may not block until the subsequent unmap call. |
| 61 | * This callback must not sleep. |
| 62 | * @kunmap_atomic: [optional] unmaps a atomically mapped page from the buffer. |
| 63 | * This Callback must not sleep. |
| 64 | * @kmap: maps a page from the buffer into kernel address space. |
| 65 | * @kunmap: [optional] unmaps a page from the buffer. |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 66 | * @mmap: used to expose the backing storage to userspace. Note that the |
| 67 | * mapping needs to be coherent - if the exporter doesn't directly |
| 68 | * support this, it needs to fake coherency by shooting down any ptes |
| 69 | * when transitioning away from the cpu domain. |
Sumit Semwal | 12c4727 | 2012-05-23 15:27:40 +0530 | [diff] [blame] | 70 | * @vmap: [optional] creates a virtual mapping for the buffer into kernel |
| 71 | * address space. Same restrictions as for vmap and friends apply. |
| 72 | * @vunmap: [optional] unmaps a vmap from the buffer |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 73 | */ |
| 74 | struct dma_buf_ops { |
| 75 | int (*attach)(struct dma_buf *, struct device *, |
| 76 | struct dma_buf_attachment *); |
| 77 | |
| 78 | void (*detach)(struct dma_buf *, struct dma_buf_attachment *); |
| 79 | |
| 80 | /* For {map,unmap}_dma_buf below, any specific buffer attributes |
| 81 | * required should get added to device_dma_parameters accessible |
| 82 | * via dev->dma_params. |
| 83 | */ |
| 84 | struct sg_table * (*map_dma_buf)(struct dma_buf_attachment *, |
| 85 | enum dma_data_direction); |
| 86 | void (*unmap_dma_buf)(struct dma_buf_attachment *, |
Sumit Semwal | 33ea2dc | 2012-01-27 15:09:27 +0530 | [diff] [blame] | 87 | struct sg_table *, |
| 88 | enum dma_data_direction); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 89 | /* TODO: Add try_map_dma_buf version, to return immed with -EBUSY |
| 90 | * if the call would block. |
| 91 | */ |
| 92 | |
| 93 | /* after final dma_buf_put() */ |
| 94 | void (*release)(struct dma_buf *); |
| 95 | |
Tiago Vignatti | 831e9da | 2015-12-22 19:36:45 -0200 | [diff] [blame] | 96 | int (*begin_cpu_access)(struct dma_buf *, enum dma_data_direction); |
Chris Wilson | 18b862d | 2016-03-18 20:02:39 +0000 | [diff] [blame] | 97 | int (*end_cpu_access)(struct dma_buf *, enum dma_data_direction); |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 98 | void *(*kmap_atomic)(struct dma_buf *, unsigned long); |
| 99 | void (*kunmap_atomic)(struct dma_buf *, unsigned long, void *); |
| 100 | void *(*kmap)(struct dma_buf *, unsigned long); |
| 101 | void (*kunmap)(struct dma_buf *, unsigned long, void *); |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 102 | |
| 103 | int (*mmap)(struct dma_buf *, struct vm_area_struct *vma); |
Dave Airlie | 98f86c9 | 2012-05-20 12:33:56 +0530 | [diff] [blame] | 104 | |
| 105 | void *(*vmap)(struct dma_buf *); |
| 106 | void (*vunmap)(struct dma_buf *, void *vaddr); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 107 | }; |
| 108 | |
| 109 | /** |
| 110 | * struct dma_buf - shared buffer object |
| 111 | * @size: size of the buffer |
| 112 | * @file: file pointer used for sharing buffers across, and for refcounting. |
| 113 | * @attachments: list of dma_buf_attachment that denotes all devices attached. |
| 114 | * @ops: dma_buf_ops associated with this buffer object. |
Sumit Semwal | 78df969 | 2013-03-22 18:22:16 +0530 | [diff] [blame] | 115 | * @exp_name: name of the exporter; useful for debugging. |
Sumit Semwal | 9abdffe | 2015-05-05 14:56:15 +0530 | [diff] [blame] | 116 | * @owner: pointer to exporter module; used for refcounting when exporter is a |
| 117 | * kernel module. |
Sumit Semwal | b89e356 | 2013-04-04 11:44:37 +0530 | [diff] [blame] | 118 | * @list_node: node for dma_buf accounting and debugging. |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 119 | * @priv: exporter specific private data for this buffer object. |
Maarten Lankhorst | 3aac450 | 2014-07-01 12:57:26 +0200 | [diff] [blame] | 120 | * @resv: reservation object linked to this dma-buf |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 121 | */ |
| 122 | struct dma_buf { |
| 123 | size_t size; |
| 124 | struct file *file; |
| 125 | struct list_head attachments; |
| 126 | const struct dma_buf_ops *ops; |
Daniel Vetter | f00b4da | 2012-12-20 14:14:23 +0100 | [diff] [blame] | 127 | /* mutex to serialize list manipulation, attach/detach and vmap/unmap */ |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 128 | struct mutex lock; |
Daniel Vetter | f00b4da | 2012-12-20 14:14:23 +0100 | [diff] [blame] | 129 | unsigned vmapping_counter; |
| 130 | void *vmap_ptr; |
Sumit Semwal | 78df969 | 2013-03-22 18:22:16 +0530 | [diff] [blame] | 131 | const char *exp_name; |
Sumit Semwal | 9abdffe | 2015-05-05 14:56:15 +0530 | [diff] [blame] | 132 | struct module *owner; |
Sumit Semwal | b89e356 | 2013-04-04 11:44:37 +0530 | [diff] [blame] | 133 | struct list_head list_node; |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 134 | void *priv; |
Maarten Lankhorst | 3aac450 | 2014-07-01 12:57:26 +0200 | [diff] [blame] | 135 | struct reservation_object *resv; |
Maarten Lankhorst | 9b495a5 | 2014-07-01 12:57:43 +0200 | [diff] [blame] | 136 | |
| 137 | /* poll support */ |
| 138 | wait_queue_head_t poll; |
| 139 | |
| 140 | struct dma_buf_poll_cb_t { |
| 141 | struct fence_cb cb; |
| 142 | wait_queue_head_t *poll; |
| 143 | |
| 144 | unsigned long active; |
| 145 | } cb_excl, cb_shared; |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 146 | }; |
| 147 | |
| 148 | /** |
| 149 | * struct dma_buf_attachment - holds device-buffer attachment data |
| 150 | * @dmabuf: buffer for this attachment. |
| 151 | * @dev: device attached to the buffer. |
| 152 | * @node: list of dma_buf_attachment. |
| 153 | * @priv: exporter specific attachment data. |
| 154 | * |
| 155 | * This structure holds the attachment information between the dma_buf buffer |
| 156 | * and its user device(s). The list contains one attachment struct per device |
| 157 | * attached to the buffer. |
| 158 | */ |
| 159 | struct dma_buf_attachment { |
| 160 | struct dma_buf *dmabuf; |
| 161 | struct device *dev; |
| 162 | struct list_head node; |
| 163 | void *priv; |
| 164 | }; |
| 165 | |
Rob Clark | f9a24d1 | 2012-03-16 11:04:41 -0500 | [diff] [blame] | 166 | /** |
Sumit Semwal | d8fbe34 | 2015-01-23 12:53:43 +0530 | [diff] [blame] | 167 | * struct dma_buf_export_info - holds information needed to export a dma_buf |
Sumit Semwal | 9abdffe | 2015-05-05 14:56:15 +0530 | [diff] [blame] | 168 | * @exp_name: name of the exporter - useful for debugging. |
| 169 | * @owner: pointer to exporter module - used for refcounting kernel module |
Sumit Semwal | d8fbe34 | 2015-01-23 12:53:43 +0530 | [diff] [blame] | 170 | * @ops: Attach allocator-defined dma buf ops to the new buffer |
| 171 | * @size: Size of the buffer |
| 172 | * @flags: mode flags for the file |
| 173 | * @resv: reservation-object, NULL to allocate default one |
| 174 | * @priv: Attach private data of allocator to this buffer |
| 175 | * |
| 176 | * This structure holds the information required to export the buffer. Used |
| 177 | * with dma_buf_export() only. |
| 178 | */ |
| 179 | struct dma_buf_export_info { |
| 180 | const char *exp_name; |
Sumit Semwal | 9abdffe | 2015-05-05 14:56:15 +0530 | [diff] [blame] | 181 | struct module *owner; |
Sumit Semwal | d8fbe34 | 2015-01-23 12:53:43 +0530 | [diff] [blame] | 182 | const struct dma_buf_ops *ops; |
| 183 | size_t size; |
| 184 | int flags; |
| 185 | struct reservation_object *resv; |
| 186 | void *priv; |
| 187 | }; |
| 188 | |
| 189 | /** |
| 190 | * helper macro for exporters; zeros and fills in most common values |
| 191 | */ |
| 192 | #define DEFINE_DMA_BUF_EXPORT_INFO(a) \ |
Sumit Semwal | 9abdffe | 2015-05-05 14:56:15 +0530 | [diff] [blame] | 193 | struct dma_buf_export_info a = { .exp_name = KBUILD_MODNAME, \ |
| 194 | .owner = THIS_MODULE } |
Sumit Semwal | d8fbe34 | 2015-01-23 12:53:43 +0530 | [diff] [blame] | 195 | |
| 196 | /** |
Rob Clark | f9a24d1 | 2012-03-16 11:04:41 -0500 | [diff] [blame] | 197 | * get_dma_buf - convenience wrapper for get_file. |
| 198 | * @dmabuf: [in] pointer to dma_buf |
| 199 | * |
| 200 | * Increments the reference count on the dma-buf, needed in case of drivers |
| 201 | * that either need to create additional references to the dmabuf on the |
| 202 | * kernel side. For example, an exporter that needs to keep a dmabuf ptr |
| 203 | * so that subsequent exports don't create a new dmabuf. |
| 204 | */ |
| 205 | static inline void get_dma_buf(struct dma_buf *dmabuf) |
| 206 | { |
| 207 | get_file(dmabuf->file); |
| 208 | } |
| 209 | |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 210 | struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, |
| 211 | struct device *dev); |
| 212 | void dma_buf_detach(struct dma_buf *dmabuf, |
| 213 | struct dma_buf_attachment *dmabuf_attach); |
Sumit Semwal | 78df969 | 2013-03-22 18:22:16 +0530 | [diff] [blame] | 214 | |
Sumit Semwal | d8fbe34 | 2015-01-23 12:53:43 +0530 | [diff] [blame] | 215 | struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info); |
Sumit Semwal | 78df969 | 2013-03-22 18:22:16 +0530 | [diff] [blame] | 216 | |
Dave Airlie | 55c1c4c | 2012-03-16 10:34:02 +0000 | [diff] [blame] | 217 | int dma_buf_fd(struct dma_buf *dmabuf, int flags); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 218 | struct dma_buf *dma_buf_get(int fd); |
| 219 | void dma_buf_put(struct dma_buf *dmabuf); |
| 220 | |
| 221 | struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, |
| 222 | enum dma_data_direction); |
Sumit Semwal | 33ea2dc | 2012-01-27 15:09:27 +0530 | [diff] [blame] | 223 | void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, |
| 224 | enum dma_data_direction); |
Tiago Vignatti | 831e9da | 2015-12-22 19:36:45 -0200 | [diff] [blame] | 225 | int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 226 | enum dma_data_direction dir); |
Chris Wilson | 18b862d | 2016-03-18 20:02:39 +0000 | [diff] [blame] | 227 | int dma_buf_end_cpu_access(struct dma_buf *dma_buf, |
| 228 | enum dma_data_direction dir); |
Daniel Vetter | fc13020 | 2012-03-20 00:02:37 +0100 | [diff] [blame] | 229 | void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long); |
| 230 | void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, void *); |
| 231 | void *dma_buf_kmap(struct dma_buf *, unsigned long); |
| 232 | void dma_buf_kunmap(struct dma_buf *, unsigned long, void *); |
Daniel Vetter | 4c78513 | 2012-04-24 14:38:52 +0530 | [diff] [blame] | 233 | |
| 234 | int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *, |
| 235 | unsigned long); |
Dave Airlie | 98f86c9 | 2012-05-20 12:33:56 +0530 | [diff] [blame] | 236 | void *dma_buf_vmap(struct dma_buf *); |
| 237 | void dma_buf_vunmap(struct dma_buf *, void *vaddr); |
Sumit Semwal | b89e356 | 2013-04-04 11:44:37 +0530 | [diff] [blame] | 238 | int dma_buf_debugfs_create_file(const char *name, |
| 239 | int (*write)(struct seq_file *)); |
Sumit Semwal | d15bd7e | 2011-12-26 14:53:15 +0530 | [diff] [blame] | 240 | #endif /* __DMA_BUF_H__ */ |