LCOV - code coverage report
Current view: top level - include/linux - dma-buf.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 0 3 0.0 %
Date: 2023-03-27 20:00:47 Functions: 0 0 -

          Line data    Source code
       1             : /* SPDX-License-Identifier: GPL-2.0-only */
       2             : /*
       3             :  * Header file for dma buffer sharing framework.
       4             :  *
       5             :  * Copyright(C) 2011 Linaro Limited. All rights reserved.
       6             :  * Author: Sumit Semwal <sumit.semwal@ti.com>
       7             :  *
       8             :  * Many thanks to linaro-mm-sig list, and specially
       9             :  * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and
      10             :  * Daniel Vetter <daniel@ffwll.ch> for their support in creation and
      11             :  * refining of this idea.
      12             :  */
      13             : #ifndef __DMA_BUF_H__
      14             : #define __DMA_BUF_H__
      15             : 
      16             : #include <linux/iosys-map.h>
      17             : #include <linux/file.h>
      18             : #include <linux/err.h>
      19             : #include <linux/scatterlist.h>
      20             : #include <linux/list.h>
      21             : #include <linux/dma-mapping.h>
      22             : #include <linux/fs.h>
      23             : #include <linux/dma-fence.h>
      24             : #include <linux/wait.h>
      25             : 
      26             : struct device;
      27             : struct dma_buf;
      28             : struct dma_buf_attachment;
      29             : 
      30             : /**
      31             :  * struct dma_buf_ops - operations possible on struct dma_buf
      32             :  * @vmap: [optional] creates a virtual mapping for the buffer into kernel
      33             :  *        address space. Same restrictions as for vmap and friends apply.
      34             :  * @vunmap: [optional] unmaps a vmap from the buffer
      35             :  */
      36             : struct dma_buf_ops {
      37             :         /**
      38             :           * @cache_sgt_mapping:
      39             :           *
      40             :           * If true the framework will cache the first mapping made for each
      41             :           * attachment. This avoids creating mappings for attachments multiple
      42             :           * times.
      43             :           */
      44             :         bool cache_sgt_mapping;
      45             : 
      46             :         /**
      47             :          * @attach:
      48             :          *
      49             :          * This is called from dma_buf_attach() to make sure that a given
      50             :          * &dma_buf_attachment.dev can access the provided &dma_buf. Exporters
      51             :          * which support buffer objects in special locations like VRAM or
      52             :          * device-specific carveout areas should check whether the buffer could
      53             :          * be move to system memory (or directly accessed by the provided
      54             :          * device), and otherwise need to fail the attach operation.
      55             :          *
      56             :          * The exporter should also in general check whether the current
      57             :          * allocation fulfills the DMA constraints of the new device. If this
      58             :          * is not the case, and the allocation cannot be moved, it should also
      59             :          * fail the attach operation.
      60             :          *
      61             :          * Any exporter-private housekeeping data can be stored in the
      62             :          * &dma_buf_attachment.priv pointer.
      63             :          *
      64             :          * This callback is optional.
      65             :          *
      66             :          * Returns:
      67             :          *
      68             :          * 0 on success, negative error code on failure. It might return -EBUSY
      69             :          * to signal that backing storage is already allocated and incompatible
      70             :          * with the requirements of requesting device.
      71             :          */
      72             :         int (*attach)(struct dma_buf *, struct dma_buf_attachment *);
      73             : 
      74             :         /**
      75             :          * @detach:
      76             :          *
      77             :          * This is called by dma_buf_detach() to release a &dma_buf_attachment.
      78             :          * Provided so that exporters can clean up any housekeeping for an
      79             :          * &dma_buf_attachment.
      80             :          *
      81             :          * This callback is optional.
      82             :          */
      83             :         void (*detach)(struct dma_buf *, struct dma_buf_attachment *);
      84             : 
      85             :         /**
      86             :          * @pin:
      87             :          *
      88             :          * This is called by dma_buf_pin() and lets the exporter know that the
      89             :          * DMA-buf can't be moved any more. Ideally, the exporter should
      90             :          * pin the buffer so that it is generally accessible by all
      91             :          * devices.
      92             :          *
      93             :          * This is called with the &dmabuf.resv object locked and is mutual
      94             :          * exclusive with @cache_sgt_mapping.
      95             :          *
      96             :          * This is called automatically for non-dynamic importers from
      97             :          * dma_buf_attach().
      98             :          *
      99             :          * Note that similar to non-dynamic exporters in their @map_dma_buf
     100             :          * callback the driver must guarantee that the memory is available for
     101             :          * use and cleared of any old data by the time this function returns.
     102             :          * Drivers which pipeline their buffer moves internally must wait for
     103             :          * all moves and clears to complete.
     104             :          *
     105             :          * Returns:
     106             :          *
     107             :          * 0 on success, negative error code on failure.
     108             :          */
     109             :         int (*pin)(struct dma_buf_attachment *attach);
     110             : 
     111             :         /**
     112             :          * @unpin:
     113             :          *
     114             :          * This is called by dma_buf_unpin() and lets the exporter know that the
     115             :          * DMA-buf can be moved again.
     116             :          *
     117             :          * This is called with the dmabuf->resv object locked and is mutual
     118             :          * exclusive with @cache_sgt_mapping.
     119             :          *
     120             :          * This callback is optional.
     121             :          */
     122             :         void (*unpin)(struct dma_buf_attachment *attach);
     123             : 
     124             :         /**
     125             :          * @map_dma_buf:
     126             :          *
     127             :          * This is called by dma_buf_map_attachment() and is used to map a
     128             :          * shared &dma_buf into device address space, and it is mandatory. It
     129             :          * can only be called if @attach has been called successfully.
     130             :          *
     131             :          * This call may sleep, e.g. when the backing storage first needs to be
     132             :          * allocated, or moved to a location suitable for all currently attached
     133             :          * devices.
     134             :          *
     135             :          * Note that any specific buffer attributes required for this function
     136             :          * should get added to device_dma_parameters accessible via
     137             :          * &device.dma_params from the &dma_buf_attachment. The @attach callback
     138             :          * should also check these constraints.
     139             :          *
     140             :          * If this is being called for the first time, the exporter can now
     141             :          * choose to scan through the list of attachments for this buffer,
     142             :          * collate the requirements of the attached devices, and choose an
     143             :          * appropriate backing storage for the buffer.
     144             :          *
     145             :          * Based on enum dma_data_direction, it might be possible to have
     146             :          * multiple users accessing at the same time (for reading, maybe), or
     147             :          * any other kind of sharing that the exporter might wish to make
     148             :          * available to buffer-users.
     149             :          *
     150             :          * This is always called with the dmabuf->resv object locked when
     151             :          * the dynamic_mapping flag is true.
     152             :          *
     153             :          * Note that for non-dynamic exporters the driver must guarantee that
     154             :          * that the memory is available for use and cleared of any old data by
     155             :          * the time this function returns.  Drivers which pipeline their buffer
     156             :          * moves internally must wait for all moves and clears to complete.
     157             :          * Dynamic exporters do not need to follow this rule: For non-dynamic
     158             :          * importers the buffer is already pinned through @pin, which has the
     159             :          * same requirements. Dynamic importers otoh are required to obey the
     160             :          * dma_resv fences.
     161             :          *
     162             :          * Returns:
     163             :          *
     164             :          * A &sg_table scatter list of the backing storage of the DMA buffer,
     165             :          * already mapped into the device address space of the &device attached
     166             :          * with the provided &dma_buf_attachment. The addresses and lengths in
     167             :          * the scatter list are PAGE_SIZE aligned.
     168             :          *
     169             :          * On failure, returns a negative error value wrapped into a pointer.
     170             :          * May also return -EINTR when a signal was received while being
     171             :          * blocked.
     172             :          *
     173             :          * Note that exporters should not try to cache the scatter list, or
     174             :          * return the same one for multiple calls. Caching is done either by the
     175             :          * DMA-BUF code (for non-dynamic importers) or the importer. Ownership
     176             :          * of the scatter list is transferred to the caller, and returned by
     177             :          * @unmap_dma_buf.
     178             :          */
     179             :         struct sg_table * (*map_dma_buf)(struct dma_buf_attachment *,
     180             :                                          enum dma_data_direction);
     181             :         /**
     182             :          * @unmap_dma_buf:
     183             :          *
     184             :          * This is called by dma_buf_unmap_attachment() and should unmap and
     185             :          * release the &sg_table allocated in @map_dma_buf, and it is mandatory.
     186             :          * For static dma_buf handling this might also unpin the backing
     187             :          * storage if this is the last mapping of the DMA buffer.
     188             :          */
     189             :         void (*unmap_dma_buf)(struct dma_buf_attachment *,
     190             :                               struct sg_table *,
     191             :                               enum dma_data_direction);
     192             : 
     193             :         /* TODO: Add try_map_dma_buf version, to return immed with -EBUSY
     194             :          * if the call would block.
     195             :          */
     196             : 
     197             :         /**
     198             :          * @release:
     199             :          *
     200             :          * Called after the last dma_buf_put to release the &dma_buf, and
     201             :          * mandatory.
     202             :          */
     203             :         void (*release)(struct dma_buf *);
     204             : 
     205             :         /**
     206             :          * @begin_cpu_access:
     207             :          *
     208             :          * This is called from dma_buf_begin_cpu_access() and allows the
     209             :          * exporter to ensure that the memory is actually coherent for cpu
     210             :          * access. The exporter also needs to ensure that cpu access is coherent
     211             :          * for the access direction. The direction can be used by the exporter
     212             :          * to optimize the cache flushing, i.e. access with a different
     213             :          * direction (read instead of write) might return stale or even bogus
     214             :          * data (e.g. when the exporter needs to copy the data to temporary
     215             :          * storage).
     216             :          *
     217             :          * Note that this is both called through the DMA_BUF_IOCTL_SYNC IOCTL
     218             :          * command for userspace mappings established through @mmap, and also
     219             :          * for kernel mappings established with @vmap.
     220             :          *
     221             :          * This callback is optional.
     222             :          *
     223             :          * Returns:
     224             :          *
     225             :          * 0 on success or a negative error code on failure. This can for
     226             :          * example fail when the backing storage can't be allocated. Can also
     227             :          * return -ERESTARTSYS or -EINTR when the call has been interrupted and
     228             :          * needs to be restarted.
     229             :          */
     230             :         int (*begin_cpu_access)(struct dma_buf *, enum dma_data_direction);
     231             : 
     232             :         /**
     233             :          * @end_cpu_access:
     234             :          *
     235             :          * This is called from dma_buf_end_cpu_access() when the importer is
     236             :          * done accessing the CPU. The exporter can use this to flush caches and
     237             :          * undo anything else done in @begin_cpu_access.
     238             :          *
     239             :          * This callback is optional.
     240             :          *
     241             :          * Returns:
     242             :          *
     243             :          * 0 on success or a negative error code on failure. Can return
     244             :          * -ERESTARTSYS or -EINTR when the call has been interrupted and needs
     245             :          * to be restarted.
     246             :          */
     247             :         int (*end_cpu_access)(struct dma_buf *, enum dma_data_direction);
     248             : 
     249             :         /**
     250             :          * @mmap:
     251             :          *
     252             :          * This callback is used by the dma_buf_mmap() function
     253             :          *
     254             :          * Note that the mapping needs to be incoherent, userspace is expected
     255             :          * to bracket CPU access using the DMA_BUF_IOCTL_SYNC interface.
     256             :          *
     257             :          * Because dma-buf buffers have invariant size over their lifetime, the
     258             :          * dma-buf core checks whether a vma is too large and rejects such
     259             :          * mappings. The exporter hence does not need to duplicate this check.
     260             :          * Drivers do not need to check this themselves.
     261             :          *
     262             :          * If an exporter needs to manually flush caches and hence needs to fake
     263             :          * coherency for mmap support, it needs to be able to zap all the ptes
     264             :          * pointing at the backing storage. Now linux mm needs a struct
     265             :          * address_space associated with the struct file stored in vma->vm_file
     266             :          * to do that with the function unmap_mapping_range. But the dma_buf
     267             :          * framework only backs every dma_buf fd with the anon_file struct file,
     268             :          * i.e. all dma_bufs share the same file.
     269             :          *
     270             :          * Hence exporters need to setup their own file (and address_space)
     271             :          * association by setting vma->vm_file and adjusting vma->vm_pgoff in
     272             :          * the dma_buf mmap callback. In the specific case of a gem driver the
     273             :          * exporter could use the shmem file already provided by gem (and set
     274             :          * vm_pgoff = 0). Exporters can then zap ptes by unmapping the
     275             :          * corresponding range of the struct address_space associated with their
     276             :          * own file.
     277             :          *
     278             :          * This callback is optional.
     279             :          *
     280             :          * Returns:
     281             :          *
     282             :          * 0 on success or a negative error code on failure.
     283             :          */
     284             :         int (*mmap)(struct dma_buf *, struct vm_area_struct *vma);
     285             : 
     286             :         int (*vmap)(struct dma_buf *dmabuf, struct iosys_map *map);
     287             :         void (*vunmap)(struct dma_buf *dmabuf, struct iosys_map *map);
     288             : };
     289             : 
     290             : /**
     291             :  * struct dma_buf - shared buffer object
     292             :  *
     293             :  * This represents a shared buffer, created by calling dma_buf_export(). The
     294             :  * userspace representation is a normal file descriptor, which can be created by
     295             :  * calling dma_buf_fd().
     296             :  *
     297             :  * Shared dma buffers are reference counted using dma_buf_put() and
     298             :  * get_dma_buf().
     299             :  *
     300             :  * Device DMA access is handled by the separate &struct dma_buf_attachment.
     301             :  */
     302             : struct dma_buf {
     303             :         /**
     304             :          * @size:
     305             :          *
     306             :          * Size of the buffer; invariant over the lifetime of the buffer.
     307             :          */
     308             :         size_t size;
     309             : 
     310             :         /**
     311             :          * @file:
     312             :          *
     313             :          * File pointer used for sharing buffers across, and for refcounting.
     314             :          * See dma_buf_get() and dma_buf_put().
     315             :          */
     316             :         struct file *file;
     317             : 
     318             :         /**
     319             :          * @attachments:
     320             :          *
     321             :          * List of dma_buf_attachment that denotes all devices attached,
     322             :          * protected by &dma_resv lock @resv.
     323             :          */
     324             :         struct list_head attachments;
     325             : 
     326             :         /** @ops: dma_buf_ops associated with this buffer object. */
     327             :         const struct dma_buf_ops *ops;
     328             : 
     329             :         /**
     330             :          * @vmapping_counter:
     331             :          *
     332             :          * Used internally to refcnt the vmaps returned by dma_buf_vmap().
     333             :          * Protected by @lock.
     334             :          */
     335             :         unsigned vmapping_counter;
     336             : 
     337             :         /**
     338             :          * @vmap_ptr:
     339             :          * The current vmap ptr if @vmapping_counter > 0. Protected by @lock.
     340             :          */
     341             :         struct iosys_map vmap_ptr;
     342             : 
     343             :         /**
     344             :          * @exp_name:
     345             :          *
     346             :          * Name of the exporter; useful for debugging. See the
     347             :          * DMA_BUF_SET_NAME IOCTL.
     348             :          */
     349             :         const char *exp_name;
     350             : 
     351             :         /**
     352             :          * @name:
     353             :          *
     354             :          * Userspace-provided name; useful for accounting and debugging,
     355             :          * protected by dma_resv_lock() on @resv and @name_lock for read access.
     356             :          */
     357             :         const char *name;
     358             : 
     359             :         /** @name_lock: Spinlock to protect name access for read access. */
     360             :         spinlock_t name_lock;
     361             : 
     362             :         /**
     363             :          * @owner:
     364             :          *
     365             :          * Pointer to exporter module; used for refcounting when exporter is a
     366             :          * kernel module.
     367             :          */
     368             :         struct module *owner;
     369             : 
     370             :         /** @list_node: node for dma_buf accounting and debugging. */
     371             :         struct list_head list_node;
     372             : 
     373             :         /** @priv: exporter specific private data for this buffer object. */
     374             :         void *priv;
     375             : 
     376             :         /**
     377             :          * @resv:
     378             :          *
     379             :          * Reservation object linked to this dma-buf.
     380             :          *
     381             :          * IMPLICIT SYNCHRONIZATION RULES:
     382             :          *
     383             :          * Drivers which support implicit synchronization of buffer access as
     384             :          * e.g. exposed in `Implicit Fence Poll Support`_ must follow the
     385             :          * below rules.
     386             :          *
     387             :          * - Drivers must add a read fence through dma_resv_add_fence() with the
     388             :          *   DMA_RESV_USAGE_READ flag for anything the userspace API considers a
     389             :          *   read access. This highly depends upon the API and window system.
     390             :          *
     391             :          * - Similarly drivers must add a write fence through
     392             :          *   dma_resv_add_fence() with the DMA_RESV_USAGE_WRITE flag for
     393             :          *   anything the userspace API considers write access.
     394             :          *
     395             :          * - Drivers may just always add a write fence, since that only
     396             :          *   causes unnecessary synchronization, but no correctness issues.
     397             :          *
     398             :          * - Some drivers only expose a synchronous userspace API with no
     399             :          *   pipelining across drivers. These do not set any fences for their
     400             :          *   access. An example here is v4l.
     401             :          *
     402             :          * - Driver should use dma_resv_usage_rw() when retrieving fences as
     403             :          *   dependency for implicit synchronization.
     404             :          *
     405             :          * DYNAMIC IMPORTER RULES:
     406             :          *
     407             :          * Dynamic importers, see dma_buf_attachment_is_dynamic(), have
     408             :          * additional constraints on how they set up fences:
     409             :          *
     410             :          * - Dynamic importers must obey the write fences and wait for them to
     411             :          *   signal before allowing access to the buffer's underlying storage
     412             :          *   through the device.
     413             :          *
     414             :          * - Dynamic importers should set fences for any access that they can't
     415             :          *   disable immediately from their &dma_buf_attach_ops.move_notify
     416             :          *   callback.
     417             :          *
     418             :          * IMPORTANT:
     419             :          *
     420             :          * All drivers and memory management related functions must obey the
     421             :          * struct dma_resv rules, specifically the rules for updating and
     422             :          * obeying fences. See enum dma_resv_usage for further descriptions.
     423             :          */
     424             :         struct dma_resv *resv;
     425             : 
     426             :         /** @poll: for userspace poll support */
     427             :         wait_queue_head_t poll;
     428             : 
     429             :         /** @cb_in: for userspace poll support */
     430             :         /** @cb_out: for userspace poll support */
     431             :         struct dma_buf_poll_cb_t {
     432             :                 struct dma_fence_cb cb;
     433             :                 wait_queue_head_t *poll;
     434             : 
     435             :                 __poll_t active;
     436             :         } cb_in, cb_out;
     437             : #ifdef CONFIG_DMABUF_SYSFS_STATS
     438             :         /**
     439             :          * @sysfs_entry:
     440             :          *
     441             :          * For exposing information about this buffer in sysfs. See also
     442             :          * `DMA-BUF statistics`_ for the uapi this enables.
     443             :          */
     444             :         struct dma_buf_sysfs_entry {
     445             :                 struct kobject kobj;
     446             :                 struct dma_buf *dmabuf;
     447             :         } *sysfs_entry;
     448             : #endif
     449             : };
     450             : 
     451             : /**
     452             :  * struct dma_buf_attach_ops - importer operations for an attachment
     453             :  *
     454             :  * Attachment operations implemented by the importer.
     455             :  */
     456             : struct dma_buf_attach_ops {
     457             :         /**
     458             :          * @allow_peer2peer:
     459             :          *
     460             :          * If this is set to true the importer must be able to handle peer
     461             :          * resources without struct pages.
     462             :          */
     463             :         bool allow_peer2peer;
     464             : 
     465             :         /**
     466             :          * @move_notify: [optional] notification that the DMA-buf is moving
     467             :          *
     468             :          * If this callback is provided the framework can avoid pinning the
     469             :          * backing store while mappings exists.
     470             :          *
     471             :          * This callback is called with the lock of the reservation object
     472             :          * associated with the dma_buf held and the mapping function must be
     473             :          * called with this lock held as well. This makes sure that no mapping
     474             :          * is created concurrently with an ongoing move operation.
     475             :          *
     476             :          * Mappings stay valid and are not directly affected by this callback.
     477             :          * But the DMA-buf can now be in a different physical location, so all
     478             :          * mappings should be destroyed and re-created as soon as possible.
     479             :          *
     480             :          * New mappings can be created after this callback returns, and will
     481             :          * point to the new location of the DMA-buf.
     482             :          */
     483             :         void (*move_notify)(struct dma_buf_attachment *attach);
     484             : };
     485             : 
     486             : /**
     487             :  * struct dma_buf_attachment - holds device-buffer attachment data
     488             :  * @dmabuf: buffer for this attachment.
     489             :  * @dev: device attached to the buffer.
     490             :  * @node: list of dma_buf_attachment, protected by dma_resv lock of the dmabuf.
     491             :  * @sgt: cached mapping.
     492             :  * @dir: direction of cached mapping.
     493             :  * @peer2peer: true if the importer can handle peer resources without pages.
     494             :  * @priv: exporter specific attachment data.
     495             :  * @importer_ops: importer operations for this attachment, if provided
     496             :  * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held.
     497             :  * @importer_priv: importer specific attachment data.
     498             :  *
     499             :  * This structure holds the attachment information between the dma_buf buffer
     500             :  * and its user device(s). The list contains one attachment struct per device
     501             :  * attached to the buffer.
     502             :  *
     503             :  * An attachment is created by calling dma_buf_attach(), and released again by
     504             :  * calling dma_buf_detach(). The DMA mapping itself needed to initiate a
     505             :  * transfer is created by dma_buf_map_attachment() and freed again by calling
     506             :  * dma_buf_unmap_attachment().
     507             :  */
     508             : struct dma_buf_attachment {
     509             :         struct dma_buf *dmabuf;
     510             :         struct device *dev;
     511             :         struct list_head node;
     512             :         struct sg_table *sgt;
     513             :         enum dma_data_direction dir;
     514             :         bool peer2peer;
     515             :         const struct dma_buf_attach_ops *importer_ops;
     516             :         void *importer_priv;
     517             :         void *priv;
     518             : };
     519             : 
     520             : /**
     521             :  * struct dma_buf_export_info - holds information needed to export a dma_buf
     522             :  * @exp_name:   name of the exporter - useful for debugging.
     523             :  * @owner:      pointer to exporter module - used for refcounting kernel module
     524             :  * @ops:        Attach allocator-defined dma buf ops to the new buffer
     525             :  * @size:       Size of the buffer - invariant over the lifetime of the buffer
     526             :  * @flags:      mode flags for the file
     527             :  * @resv:       reservation-object, NULL to allocate default one
     528             :  * @priv:       Attach private data of allocator to this buffer
     529             :  *
     530             :  * This structure holds the information required to export the buffer. Used
     531             :  * with dma_buf_export() only.
     532             :  */
     533             : struct dma_buf_export_info {
     534             :         const char *exp_name;
     535             :         struct module *owner;
     536             :         const struct dma_buf_ops *ops;
     537             :         size_t size;
     538             :         int flags;
     539             :         struct dma_resv *resv;
     540             :         void *priv;
     541             : };
     542             : 
     543             : /**
     544             :  * DEFINE_DMA_BUF_EXPORT_INFO - helper macro for exporters
     545             :  * @name: export-info name
     546             :  *
     547             :  * DEFINE_DMA_BUF_EXPORT_INFO macro defines the &struct dma_buf_export_info,
     548             :  * zeroes it out and pre-populates exp_name in it.
     549             :  */
     550             : #define DEFINE_DMA_BUF_EXPORT_INFO(name)        \
     551             :         struct dma_buf_export_info name = { .exp_name = KBUILD_MODNAME, \
     552             :                                          .owner = THIS_MODULE }
     553             : 
     554             : /**
     555             :  * get_dma_buf - convenience wrapper for get_file.
     556             :  * @dmabuf:     [in]    pointer to dma_buf
     557             :  *
     558             :  * Increments the reference count on the dma-buf, needed in case of drivers
     559             :  * that either need to create additional references to the dmabuf on the
     560             :  * kernel side.  For example, an exporter that needs to keep a dmabuf ptr
     561             :  * so that subsequent exports don't create a new dmabuf.
     562             :  */
     563             : static inline void get_dma_buf(struct dma_buf *dmabuf)
     564             : {
     565           0 :         get_file(dmabuf->file);
     566             : }
     567             : 
     568             : /**
     569             :  * dma_buf_is_dynamic - check if a DMA-buf uses dynamic mappings.
     570             :  * @dmabuf: the DMA-buf to check
     571             :  *
     572             :  * Returns true if a DMA-buf exporter wants to be called with the dma_resv
     573             :  * locked for the map/unmap callbacks, false if it doesn't wants to be called
     574             :  * with the lock held.
     575             :  */
     576             : static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf)
     577             : {
     578           0 :         return !!dmabuf->ops->pin;
     579             : }
     580             : 
     581             : /**
     582             :  * dma_buf_attachment_is_dynamic - check if a DMA-buf attachment uses dynamic
     583             :  * mappings
     584             :  * @attach: the DMA-buf attachment to check
     585             :  *
     586             :  * Returns true if a DMA-buf importer wants to call the map/unmap functions with
     587             :  * the dma_resv lock held.
     588             :  */
     589             : static inline bool
     590             : dma_buf_attachment_is_dynamic(struct dma_buf_attachment *attach)
     591             : {
     592           0 :         return !!attach->importer_ops;
     593             : }
     594             : 
     595             : struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
     596             :                                           struct device *dev);
     597             : struct dma_buf_attachment *
     598             : dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
     599             :                        const struct dma_buf_attach_ops *importer_ops,
     600             :                        void *importer_priv);
     601             : void dma_buf_detach(struct dma_buf *dmabuf,
     602             :                     struct dma_buf_attachment *attach);
     603             : int dma_buf_pin(struct dma_buf_attachment *attach);
     604             : void dma_buf_unpin(struct dma_buf_attachment *attach);
     605             : 
     606             : struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info);
     607             : 
     608             : int dma_buf_fd(struct dma_buf *dmabuf, int flags);
     609             : struct dma_buf *dma_buf_get(int fd);
     610             : void dma_buf_put(struct dma_buf *dmabuf);
     611             : 
     612             : struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
     613             :                                         enum dma_data_direction);
     614             : void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
     615             :                                 enum dma_data_direction);
     616             : void dma_buf_move_notify(struct dma_buf *dma_buf);
     617             : int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
     618             :                              enum dma_data_direction dir);
     619             : int dma_buf_end_cpu_access(struct dma_buf *dma_buf,
     620             :                            enum dma_data_direction dir);
     621             : struct sg_table *
     622             : dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
     623             :                                 enum dma_data_direction direction);
     624             : void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,
     625             :                                        struct sg_table *sg_table,
     626             :                                        enum dma_data_direction direction);
     627             : 
     628             : int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
     629             :                  unsigned long);
     630             : int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map);
     631             : void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map);
     632             : int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map);
     633             : void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map);
     634             : #endif /* __DMA_BUF_H__ */

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