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![Thomas Zimmermann](/assets/img/avatar_default.png)
Backmerging from drm/drm-next for v5.16-rc1. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
1454 lines
40 KiB
C
1454 lines
40 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Framework for buffer objects that can be shared across devices/subsystems.
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*
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* Copyright(C) 2011 Linaro Limited. All rights reserved.
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* Author: Sumit Semwal <sumit.semwal@ti.com>
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*
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* Many thanks to linaro-mm-sig list, and specially
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* Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and
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* Daniel Vetter <daniel@ffwll.ch> for their support in creation and
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* refining of this idea.
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*/
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/dma-buf.h>
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#include <linux/dma-fence.h>
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#include <linux/anon_inodes.h>
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#include <linux/export.h>
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#include <linux/debugfs.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/poll.h>
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#include <linux/dma-resv.h>
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#include <linux/mm.h>
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#include <linux/mount.h>
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#include <linux/pseudo_fs.h>
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#include <uapi/linux/dma-buf.h>
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#include <uapi/linux/magic.h>
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#include "dma-buf-sysfs-stats.h"
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static inline int is_dma_buf_file(struct file *);
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struct dma_buf_list {
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struct list_head head;
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struct mutex lock;
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};
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static struct dma_buf_list db_list;
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static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
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{
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struct dma_buf *dmabuf;
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char name[DMA_BUF_NAME_LEN];
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size_t ret = 0;
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dmabuf = dentry->d_fsdata;
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spin_lock(&dmabuf->name_lock);
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if (dmabuf->name)
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ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN);
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spin_unlock(&dmabuf->name_lock);
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return dynamic_dname(dentry, buffer, buflen, "/%s:%s",
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dentry->d_name.name, ret > 0 ? name : "");
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}
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static void dma_buf_release(struct dentry *dentry)
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{
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struct dma_buf *dmabuf;
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dmabuf = dentry->d_fsdata;
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if (unlikely(!dmabuf))
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return;
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BUG_ON(dmabuf->vmapping_counter);
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/*
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* If you hit this BUG() it could mean:
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* * There's a file reference imbalance in dma_buf_poll / dma_buf_poll_cb or somewhere else
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* * dmabuf->cb_in/out.active are non-0 despite no pending fence callback
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*/
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BUG_ON(dmabuf->cb_in.active || dmabuf->cb_out.active);
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dma_buf_stats_teardown(dmabuf);
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dmabuf->ops->release(dmabuf);
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if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
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dma_resv_fini(dmabuf->resv);
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WARN_ON(!list_empty(&dmabuf->attachments));
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module_put(dmabuf->owner);
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kfree(dmabuf->name);
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kfree(dmabuf);
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}
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static int dma_buf_file_release(struct inode *inode, struct file *file)
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{
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struct dma_buf *dmabuf;
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if (!is_dma_buf_file(file))
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return -EINVAL;
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dmabuf = file->private_data;
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mutex_lock(&db_list.lock);
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list_del(&dmabuf->list_node);
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mutex_unlock(&db_list.lock);
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return 0;
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}
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static const struct dentry_operations dma_buf_dentry_ops = {
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.d_dname = dmabuffs_dname,
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.d_release = dma_buf_release,
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};
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static struct vfsmount *dma_buf_mnt;
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static int dma_buf_fs_init_context(struct fs_context *fc)
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{
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struct pseudo_fs_context *ctx;
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ctx = init_pseudo(fc, DMA_BUF_MAGIC);
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if (!ctx)
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return -ENOMEM;
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ctx->dops = &dma_buf_dentry_ops;
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return 0;
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}
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static struct file_system_type dma_buf_fs_type = {
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.name = "dmabuf",
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.init_fs_context = dma_buf_fs_init_context,
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.kill_sb = kill_anon_super,
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};
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static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
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{
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struct dma_buf *dmabuf;
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if (!is_dma_buf_file(file))
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return -EINVAL;
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dmabuf = file->private_data;
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/* check if buffer supports mmap */
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if (!dmabuf->ops->mmap)
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return -EINVAL;
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/* check for overflowing the buffer's size */
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if (vma->vm_pgoff + vma_pages(vma) >
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dmabuf->size >> PAGE_SHIFT)
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return -EINVAL;
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return dmabuf->ops->mmap(dmabuf, vma);
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}
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static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
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{
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struct dma_buf *dmabuf;
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loff_t base;
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if (!is_dma_buf_file(file))
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return -EBADF;
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dmabuf = file->private_data;
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/* only support discovering the end of the buffer,
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but also allow SEEK_SET to maintain the idiomatic
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SEEK_END(0), SEEK_CUR(0) pattern */
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if (whence == SEEK_END)
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base = dmabuf->size;
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else if (whence == SEEK_SET)
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base = 0;
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else
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return -EINVAL;
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if (offset != 0)
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return -EINVAL;
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return base + offset;
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}
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/**
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* DOC: implicit fence polling
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*
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* To support cross-device and cross-driver synchronization of buffer access
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* implicit fences (represented internally in the kernel with &struct dma_fence)
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* can be attached to a &dma_buf. The glue for that and a few related things are
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* provided in the &dma_resv structure.
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*
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* Userspace can query the state of these implicitly tracked fences using poll()
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* and related system calls:
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*
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* - Checking for EPOLLIN, i.e. read access, can be use to query the state of the
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* most recent write or exclusive fence.
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*
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* - Checking for EPOLLOUT, i.e. write access, can be used to query the state of
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* all attached fences, shared and exclusive ones.
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*
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* Note that this only signals the completion of the respective fences, i.e. the
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* DMA transfers are complete. Cache flushing and any other necessary
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* preparations before CPU access can begin still need to happen.
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*/
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static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
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{
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struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb;
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struct dma_buf *dmabuf = container_of(dcb->poll, struct dma_buf, poll);
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unsigned long flags;
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spin_lock_irqsave(&dcb->poll->lock, flags);
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wake_up_locked_poll(dcb->poll, dcb->active);
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dcb->active = 0;
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spin_unlock_irqrestore(&dcb->poll->lock, flags);
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dma_fence_put(fence);
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/* Paired with get_file in dma_buf_poll */
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fput(dmabuf->file);
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}
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static bool dma_buf_poll_add_cb(struct dma_resv *resv, bool write,
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struct dma_buf_poll_cb_t *dcb)
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{
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struct dma_resv_iter cursor;
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struct dma_fence *fence;
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int r;
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dma_resv_for_each_fence(&cursor, resv, write, fence) {
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dma_fence_get(fence);
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r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
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if (!r)
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return true;
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dma_fence_put(fence);
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}
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return false;
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}
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static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
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{
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struct dma_buf *dmabuf;
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struct dma_resv *resv;
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__poll_t events;
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dmabuf = file->private_data;
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if (!dmabuf || !dmabuf->resv)
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return EPOLLERR;
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resv = dmabuf->resv;
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poll_wait(file, &dmabuf->poll, poll);
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events = poll_requested_events(poll) & (EPOLLIN | EPOLLOUT);
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if (!events)
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return 0;
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dma_resv_lock(resv, NULL);
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if (events & EPOLLOUT) {
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struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_out;
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/* Check that callback isn't busy */
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spin_lock_irq(&dmabuf->poll.lock);
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if (dcb->active)
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events &= ~EPOLLOUT;
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else
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dcb->active = EPOLLOUT;
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spin_unlock_irq(&dmabuf->poll.lock);
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if (events & EPOLLOUT) {
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/* Paired with fput in dma_buf_poll_cb */
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get_file(dmabuf->file);
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if (!dma_buf_poll_add_cb(resv, true, dcb))
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/* No callback queued, wake up any other waiters */
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dma_buf_poll_cb(NULL, &dcb->cb);
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else
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events &= ~EPOLLOUT;
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}
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}
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if (events & EPOLLIN) {
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struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_in;
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/* Check that callback isn't busy */
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spin_lock_irq(&dmabuf->poll.lock);
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if (dcb->active)
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events &= ~EPOLLIN;
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else
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dcb->active = EPOLLIN;
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spin_unlock_irq(&dmabuf->poll.lock);
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if (events & EPOLLIN) {
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/* Paired with fput in dma_buf_poll_cb */
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get_file(dmabuf->file);
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if (!dma_buf_poll_add_cb(resv, false, dcb))
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/* No callback queued, wake up any other waiters */
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dma_buf_poll_cb(NULL, &dcb->cb);
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else
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events &= ~EPOLLIN;
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}
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}
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dma_resv_unlock(resv);
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return events;
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}
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/**
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* dma_buf_set_name - Set a name to a specific dma_buf to track the usage.
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* It could support changing the name of the dma-buf if the same
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* piece of memory is used for multiple purpose between different devices.
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*
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* @dmabuf: [in] dmabuf buffer that will be renamed.
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* @buf: [in] A piece of userspace memory that contains the name of
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* the dma-buf.
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*
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* Returns 0 on success. If the dma-buf buffer is already attached to
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* devices, return -EBUSY.
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*
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*/
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static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf)
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{
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char *name = strndup_user(buf, DMA_BUF_NAME_LEN);
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if (IS_ERR(name))
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return PTR_ERR(name);
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spin_lock(&dmabuf->name_lock);
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kfree(dmabuf->name);
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dmabuf->name = name;
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spin_unlock(&dmabuf->name_lock);
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return 0;
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}
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static long dma_buf_ioctl(struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct dma_buf *dmabuf;
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struct dma_buf_sync sync;
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enum dma_data_direction direction;
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int ret;
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dmabuf = file->private_data;
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switch (cmd) {
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case DMA_BUF_IOCTL_SYNC:
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if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
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return -EFAULT;
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if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
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return -EINVAL;
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switch (sync.flags & DMA_BUF_SYNC_RW) {
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case DMA_BUF_SYNC_READ:
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direction = DMA_FROM_DEVICE;
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break;
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case DMA_BUF_SYNC_WRITE:
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direction = DMA_TO_DEVICE;
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break;
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case DMA_BUF_SYNC_RW:
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direction = DMA_BIDIRECTIONAL;
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break;
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default:
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return -EINVAL;
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}
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if (sync.flags & DMA_BUF_SYNC_END)
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ret = dma_buf_end_cpu_access(dmabuf, direction);
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else
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ret = dma_buf_begin_cpu_access(dmabuf, direction);
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return ret;
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case DMA_BUF_SET_NAME_A:
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case DMA_BUF_SET_NAME_B:
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return dma_buf_set_name(dmabuf, (const char __user *)arg);
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default:
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return -ENOTTY;
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}
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}
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static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
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{
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struct dma_buf *dmabuf = file->private_data;
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seq_printf(m, "size:\t%zu\n", dmabuf->size);
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/* Don't count the temporary reference taken inside procfs seq_show */
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seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1);
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seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name);
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spin_lock(&dmabuf->name_lock);
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if (dmabuf->name)
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seq_printf(m, "name:\t%s\n", dmabuf->name);
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spin_unlock(&dmabuf->name_lock);
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}
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static const struct file_operations dma_buf_fops = {
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.release = dma_buf_file_release,
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.mmap = dma_buf_mmap_internal,
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.llseek = dma_buf_llseek,
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.poll = dma_buf_poll,
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.unlocked_ioctl = dma_buf_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.show_fdinfo = dma_buf_show_fdinfo,
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};
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/*
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* is_dma_buf_file - Check if struct file* is associated with dma_buf
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*/
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static inline int is_dma_buf_file(struct file *file)
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{
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return file->f_op == &dma_buf_fops;
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}
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static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
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{
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struct file *file;
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struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb);
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if (IS_ERR(inode))
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return ERR_CAST(inode);
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inode->i_size = dmabuf->size;
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inode_set_bytes(inode, dmabuf->size);
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file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf",
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flags, &dma_buf_fops);
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if (IS_ERR(file))
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goto err_alloc_file;
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file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
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file->private_data = dmabuf;
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file->f_path.dentry->d_fsdata = dmabuf;
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return file;
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err_alloc_file:
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iput(inode);
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return file;
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}
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/**
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* DOC: dma buf device access
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*
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* For device DMA access to a shared DMA buffer the usual sequence of operations
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* is fairly simple:
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*
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* 1. The exporter defines his exporter instance using
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* DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private
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* buffer object into a &dma_buf. It then exports that &dma_buf to userspace
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* as a file descriptor by calling dma_buf_fd().
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*
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* 2. Userspace passes this file-descriptors to all drivers it wants this buffer
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* to share with: First the filedescriptor is converted to a &dma_buf using
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* dma_buf_get(). Then the buffer is attached to the device using
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* dma_buf_attach().
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*
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* Up to this stage the exporter is still free to migrate or reallocate the
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* backing storage.
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*
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* 3. Once the buffer is attached to all devices userspace can initiate DMA
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* access to the shared buffer. In the kernel this is done by calling
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* dma_buf_map_attachment() and dma_buf_unmap_attachment().
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*
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* 4. Once a driver is done with a shared buffer it needs to call
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* dma_buf_detach() (after cleaning up any mappings) and then release the
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* reference acquired with dma_buf_get() by calling dma_buf_put().
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*
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* For the detailed semantics exporters are expected to implement see
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* &dma_buf_ops.
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*/
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/**
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* dma_buf_export - Creates a new dma_buf, and associates an anon file
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* with this buffer, so it can be exported.
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* Also connect the allocator specific data and ops to the buffer.
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* Additionally, provide a name string for exporter; useful in debugging.
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*
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* @exp_info: [in] holds all the export related information provided
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* by the exporter. see &struct dma_buf_export_info
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* for further details.
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*
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* Returns, on success, a newly created struct dma_buf object, which wraps the
|
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* supplied private data and operations for struct dma_buf_ops. On either
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* missing ops, or error in allocating struct dma_buf, will return negative
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* error.
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*
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* For most cases the easiest way to create @exp_info is through the
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* %DEFINE_DMA_BUF_EXPORT_INFO macro.
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*/
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struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
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{
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struct dma_buf *dmabuf;
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struct dma_resv *resv = exp_info->resv;
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struct file *file;
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size_t alloc_size = sizeof(struct dma_buf);
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int ret;
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|
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if (!exp_info->resv)
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alloc_size += sizeof(struct dma_resv);
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else
|
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/* prevent &dma_buf[1] == dma_buf->resv */
|
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alloc_size += 1;
|
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|
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if (WARN_ON(!exp_info->priv
|
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|| !exp_info->ops
|
|
|| !exp_info->ops->map_dma_buf
|
|
|| !exp_info->ops->unmap_dma_buf
|
|
|| !exp_info->ops->release)) {
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
if (WARN_ON(exp_info->ops->cache_sgt_mapping &&
|
|
(exp_info->ops->pin || exp_info->ops->unpin)))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (WARN_ON(!exp_info->ops->pin != !exp_info->ops->unpin))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (!try_module_get(exp_info->owner))
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
dmabuf = kzalloc(alloc_size, GFP_KERNEL);
|
|
if (!dmabuf) {
|
|
ret = -ENOMEM;
|
|
goto err_module;
|
|
}
|
|
|
|
dmabuf->priv = exp_info->priv;
|
|
dmabuf->ops = exp_info->ops;
|
|
dmabuf->size = exp_info->size;
|
|
dmabuf->exp_name = exp_info->exp_name;
|
|
dmabuf->owner = exp_info->owner;
|
|
spin_lock_init(&dmabuf->name_lock);
|
|
init_waitqueue_head(&dmabuf->poll);
|
|
dmabuf->cb_in.poll = dmabuf->cb_out.poll = &dmabuf->poll;
|
|
dmabuf->cb_in.active = dmabuf->cb_out.active = 0;
|
|
|
|
if (!resv) {
|
|
resv = (struct dma_resv *)&dmabuf[1];
|
|
dma_resv_init(resv);
|
|
}
|
|
dmabuf->resv = resv;
|
|
|
|
file = dma_buf_getfile(dmabuf, exp_info->flags);
|
|
if (IS_ERR(file)) {
|
|
ret = PTR_ERR(file);
|
|
goto err_dmabuf;
|
|
}
|
|
|
|
file->f_mode |= FMODE_LSEEK;
|
|
dmabuf->file = file;
|
|
|
|
ret = dma_buf_stats_setup(dmabuf);
|
|
if (ret)
|
|
goto err_sysfs;
|
|
|
|
mutex_init(&dmabuf->lock);
|
|
INIT_LIST_HEAD(&dmabuf->attachments);
|
|
|
|
mutex_lock(&db_list.lock);
|
|
list_add(&dmabuf->list_node, &db_list.head);
|
|
mutex_unlock(&db_list.lock);
|
|
|
|
return dmabuf;
|
|
|
|
err_sysfs:
|
|
/*
|
|
* Set file->f_path.dentry->d_fsdata to NULL so that when
|
|
* dma_buf_release() gets invoked by dentry_ops, it exits
|
|
* early before calling the release() dma_buf op.
|
|
*/
|
|
file->f_path.dentry->d_fsdata = NULL;
|
|
fput(file);
|
|
err_dmabuf:
|
|
kfree(dmabuf);
|
|
err_module:
|
|
module_put(exp_info->owner);
|
|
return ERR_PTR(ret);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_export, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_fd - returns a file descriptor for the given struct dma_buf
|
|
* @dmabuf: [in] pointer to dma_buf for which fd is required.
|
|
* @flags: [in] flags to give to fd
|
|
*
|
|
* On success, returns an associated 'fd'. Else, returns error.
|
|
*/
|
|
int dma_buf_fd(struct dma_buf *dmabuf, int flags)
|
|
{
|
|
int fd;
|
|
|
|
if (!dmabuf || !dmabuf->file)
|
|
return -EINVAL;
|
|
|
|
fd = get_unused_fd_flags(flags);
|
|
if (fd < 0)
|
|
return fd;
|
|
|
|
fd_install(fd, dmabuf->file);
|
|
|
|
return fd;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_fd, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_get - returns the struct dma_buf related to an fd
|
|
* @fd: [in] fd associated with the struct dma_buf to be returned
|
|
*
|
|
* On success, returns the struct dma_buf associated with an fd; uses
|
|
* file's refcounting done by fget to increase refcount. returns ERR_PTR
|
|
* otherwise.
|
|
*/
|
|
struct dma_buf *dma_buf_get(int fd)
|
|
{
|
|
struct file *file;
|
|
|
|
file = fget(fd);
|
|
|
|
if (!file)
|
|
return ERR_PTR(-EBADF);
|
|
|
|
if (!is_dma_buf_file(file)) {
|
|
fput(file);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
return file->private_data;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_get, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_put - decreases refcount of the buffer
|
|
* @dmabuf: [in] buffer to reduce refcount of
|
|
*
|
|
* Uses file's refcounting done implicitly by fput().
|
|
*
|
|
* If, as a result of this call, the refcount becomes 0, the 'release' file
|
|
* operation related to this fd is called. It calls &dma_buf_ops.release vfunc
|
|
* in turn, and frees the memory allocated for dmabuf when exported.
|
|
*/
|
|
void dma_buf_put(struct dma_buf *dmabuf)
|
|
{
|
|
if (WARN_ON(!dmabuf || !dmabuf->file))
|
|
return;
|
|
|
|
fput(dmabuf->file);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_put, DMA_BUF);
|
|
|
|
static void mangle_sg_table(struct sg_table *sg_table)
|
|
{
|
|
#ifdef CONFIG_DMABUF_DEBUG
|
|
int i;
|
|
struct scatterlist *sg;
|
|
|
|
/* To catch abuse of the underlying struct page by importers mix
|
|
* up the bits, but take care to preserve the low SG_ bits to
|
|
* not corrupt the sgt. The mixing is undone in __unmap_dma_buf
|
|
* before passing the sgt back to the exporter. */
|
|
for_each_sgtable_sg(sg_table, sg, i)
|
|
sg->page_link ^= ~0xffUL;
|
|
#endif
|
|
|
|
}
|
|
static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach,
|
|
enum dma_data_direction direction)
|
|
{
|
|
struct sg_table *sg_table;
|
|
|
|
sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
|
|
|
|
if (!IS_ERR_OR_NULL(sg_table))
|
|
mangle_sg_table(sg_table);
|
|
|
|
return sg_table;
|
|
}
|
|
|
|
/**
|
|
* dma_buf_dynamic_attach - Add the device to dma_buf's attachments list
|
|
* @dmabuf: [in] buffer to attach device to.
|
|
* @dev: [in] device to be attached.
|
|
* @importer_ops: [in] importer operations for the attachment
|
|
* @importer_priv: [in] importer private pointer for the attachment
|
|
*
|
|
* Returns struct dma_buf_attachment pointer for this attachment. Attachments
|
|
* must be cleaned up by calling dma_buf_detach().
|
|
*
|
|
* Optionally this calls &dma_buf_ops.attach to allow device-specific attach
|
|
* functionality.
|
|
*
|
|
* Returns:
|
|
*
|
|
* A pointer to newly created &dma_buf_attachment on success, or a negative
|
|
* error code wrapped into a pointer on failure.
|
|
*
|
|
* Note that this can fail if the backing storage of @dmabuf is in a place not
|
|
* accessible to @dev, and cannot be moved to a more suitable place. This is
|
|
* indicated with the error code -EBUSY.
|
|
*/
|
|
struct dma_buf_attachment *
|
|
dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
|
|
const struct dma_buf_attach_ops *importer_ops,
|
|
void *importer_priv)
|
|
{
|
|
struct dma_buf_attachment *attach;
|
|
int ret;
|
|
|
|
if (WARN_ON(!dmabuf || !dev))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (WARN_ON(importer_ops && !importer_ops->move_notify))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
attach = kzalloc(sizeof(*attach), GFP_KERNEL);
|
|
if (!attach)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
attach->dev = dev;
|
|
attach->dmabuf = dmabuf;
|
|
if (importer_ops)
|
|
attach->peer2peer = importer_ops->allow_peer2peer;
|
|
attach->importer_ops = importer_ops;
|
|
attach->importer_priv = importer_priv;
|
|
|
|
if (dmabuf->ops->attach) {
|
|
ret = dmabuf->ops->attach(dmabuf, attach);
|
|
if (ret)
|
|
goto err_attach;
|
|
}
|
|
dma_resv_lock(dmabuf->resv, NULL);
|
|
list_add(&attach->node, &dmabuf->attachments);
|
|
dma_resv_unlock(dmabuf->resv);
|
|
|
|
/* When either the importer or the exporter can't handle dynamic
|
|
* mappings we cache the mapping here to avoid issues with the
|
|
* reservation object lock.
|
|
*/
|
|
if (dma_buf_attachment_is_dynamic(attach) !=
|
|
dma_buf_is_dynamic(dmabuf)) {
|
|
struct sg_table *sgt;
|
|
|
|
if (dma_buf_is_dynamic(attach->dmabuf)) {
|
|
dma_resv_lock(attach->dmabuf->resv, NULL);
|
|
ret = dmabuf->ops->pin(attach);
|
|
if (ret)
|
|
goto err_unlock;
|
|
}
|
|
|
|
sgt = __map_dma_buf(attach, DMA_BIDIRECTIONAL);
|
|
if (!sgt)
|
|
sgt = ERR_PTR(-ENOMEM);
|
|
if (IS_ERR(sgt)) {
|
|
ret = PTR_ERR(sgt);
|
|
goto err_unpin;
|
|
}
|
|
if (dma_buf_is_dynamic(attach->dmabuf))
|
|
dma_resv_unlock(attach->dmabuf->resv);
|
|
attach->sgt = sgt;
|
|
attach->dir = DMA_BIDIRECTIONAL;
|
|
}
|
|
|
|
return attach;
|
|
|
|
err_attach:
|
|
kfree(attach);
|
|
return ERR_PTR(ret);
|
|
|
|
err_unpin:
|
|
if (dma_buf_is_dynamic(attach->dmabuf))
|
|
dmabuf->ops->unpin(attach);
|
|
|
|
err_unlock:
|
|
if (dma_buf_is_dynamic(attach->dmabuf))
|
|
dma_resv_unlock(attach->dmabuf->resv);
|
|
|
|
dma_buf_detach(dmabuf, attach);
|
|
return ERR_PTR(ret);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_dynamic_attach, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_attach - Wrapper for dma_buf_dynamic_attach
|
|
* @dmabuf: [in] buffer to attach device to.
|
|
* @dev: [in] device to be attached.
|
|
*
|
|
* Wrapper to call dma_buf_dynamic_attach() for drivers which still use a static
|
|
* mapping.
|
|
*/
|
|
struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
|
|
struct device *dev)
|
|
{
|
|
return dma_buf_dynamic_attach(dmabuf, dev, NULL, NULL);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_attach, DMA_BUF);
|
|
|
|
static void __unmap_dma_buf(struct dma_buf_attachment *attach,
|
|
struct sg_table *sg_table,
|
|
enum dma_data_direction direction)
|
|
{
|
|
/* uses XOR, hence this unmangles */
|
|
mangle_sg_table(sg_table);
|
|
|
|
attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction);
|
|
}
|
|
|
|
/**
|
|
* dma_buf_detach - Remove the given attachment from dmabuf's attachments list
|
|
* @dmabuf: [in] buffer to detach from.
|
|
* @attach: [in] attachment to be detached; is free'd after this call.
|
|
*
|
|
* Clean up a device attachment obtained by calling dma_buf_attach().
|
|
*
|
|
* Optionally this calls &dma_buf_ops.detach for device-specific detach.
|
|
*/
|
|
void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
|
|
{
|
|
if (WARN_ON(!dmabuf || !attach))
|
|
return;
|
|
|
|
if (attach->sgt) {
|
|
if (dma_buf_is_dynamic(attach->dmabuf))
|
|
dma_resv_lock(attach->dmabuf->resv, NULL);
|
|
|
|
__unmap_dma_buf(attach, attach->sgt, attach->dir);
|
|
|
|
if (dma_buf_is_dynamic(attach->dmabuf)) {
|
|
dmabuf->ops->unpin(attach);
|
|
dma_resv_unlock(attach->dmabuf->resv);
|
|
}
|
|
}
|
|
|
|
dma_resv_lock(dmabuf->resv, NULL);
|
|
list_del(&attach->node);
|
|
dma_resv_unlock(dmabuf->resv);
|
|
if (dmabuf->ops->detach)
|
|
dmabuf->ops->detach(dmabuf, attach);
|
|
|
|
kfree(attach);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_detach, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_pin - Lock down the DMA-buf
|
|
* @attach: [in] attachment which should be pinned
|
|
*
|
|
* Only dynamic importers (who set up @attach with dma_buf_dynamic_attach()) may
|
|
* call this, and only for limited use cases like scanout and not for temporary
|
|
* pin operations. It is not permitted to allow userspace to pin arbitrary
|
|
* amounts of buffers through this interface.
|
|
*
|
|
* Buffers must be unpinned by calling dma_buf_unpin().
|
|
*
|
|
* Returns:
|
|
* 0 on success, negative error code on failure.
|
|
*/
|
|
int dma_buf_pin(struct dma_buf_attachment *attach)
|
|
{
|
|
struct dma_buf *dmabuf = attach->dmabuf;
|
|
int ret = 0;
|
|
|
|
WARN_ON(!dma_buf_attachment_is_dynamic(attach));
|
|
|
|
dma_resv_assert_held(dmabuf->resv);
|
|
|
|
if (dmabuf->ops->pin)
|
|
ret = dmabuf->ops->pin(attach);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_pin, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_unpin - Unpin a DMA-buf
|
|
* @attach: [in] attachment which should be unpinned
|
|
*
|
|
* This unpins a buffer pinned by dma_buf_pin() and allows the exporter to move
|
|
* any mapping of @attach again and inform the importer through
|
|
* &dma_buf_attach_ops.move_notify.
|
|
*/
|
|
void dma_buf_unpin(struct dma_buf_attachment *attach)
|
|
{
|
|
struct dma_buf *dmabuf = attach->dmabuf;
|
|
|
|
WARN_ON(!dma_buf_attachment_is_dynamic(attach));
|
|
|
|
dma_resv_assert_held(dmabuf->resv);
|
|
|
|
if (dmabuf->ops->unpin)
|
|
dmabuf->ops->unpin(attach);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_unpin, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_map_attachment - Returns the scatterlist table of the attachment;
|
|
* mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
|
|
* dma_buf_ops.
|
|
* @attach: [in] attachment whose scatterlist is to be returned
|
|
* @direction: [in] direction of DMA transfer
|
|
*
|
|
* Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
|
|
* on error. May return -EINTR if it is interrupted by a signal.
|
|
*
|
|
* On success, the DMA addresses and lengths in the returned scatterlist are
|
|
* PAGE_SIZE aligned.
|
|
*
|
|
* A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that
|
|
* the underlying backing storage is pinned for as long as a mapping exists,
|
|
* therefore users/importers should not hold onto a mapping for undue amounts of
|
|
* time.
|
|
*
|
|
* Important: Dynamic importers must wait for the exclusive fence of the struct
|
|
* dma_resv attached to the DMA-BUF first.
|
|
*/
|
|
struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
|
|
enum dma_data_direction direction)
|
|
{
|
|
struct sg_table *sg_table;
|
|
int r;
|
|
|
|
might_sleep();
|
|
|
|
if (WARN_ON(!attach || !attach->dmabuf))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (dma_buf_attachment_is_dynamic(attach))
|
|
dma_resv_assert_held(attach->dmabuf->resv);
|
|
|
|
if (attach->sgt) {
|
|
/*
|
|
* Two mappings with different directions for the same
|
|
* attachment are not allowed.
|
|
*/
|
|
if (attach->dir != direction &&
|
|
attach->dir != DMA_BIDIRECTIONAL)
|
|
return ERR_PTR(-EBUSY);
|
|
|
|
return attach->sgt;
|
|
}
|
|
|
|
if (dma_buf_is_dynamic(attach->dmabuf)) {
|
|
dma_resv_assert_held(attach->dmabuf->resv);
|
|
if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
|
|
r = attach->dmabuf->ops->pin(attach);
|
|
if (r)
|
|
return ERR_PTR(r);
|
|
}
|
|
}
|
|
|
|
sg_table = __map_dma_buf(attach, direction);
|
|
if (!sg_table)
|
|
sg_table = ERR_PTR(-ENOMEM);
|
|
|
|
if (IS_ERR(sg_table) && dma_buf_is_dynamic(attach->dmabuf) &&
|
|
!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY))
|
|
attach->dmabuf->ops->unpin(attach);
|
|
|
|
if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) {
|
|
attach->sgt = sg_table;
|
|
attach->dir = direction;
|
|
}
|
|
|
|
#ifdef CONFIG_DMA_API_DEBUG
|
|
if (!IS_ERR(sg_table)) {
|
|
struct scatterlist *sg;
|
|
u64 addr;
|
|
int len;
|
|
int i;
|
|
|
|
for_each_sgtable_dma_sg(sg_table, sg, i) {
|
|
addr = sg_dma_address(sg);
|
|
len = sg_dma_len(sg);
|
|
if (!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(len)) {
|
|
pr_debug("%s: addr %llx or len %x is not page aligned!\n",
|
|
__func__, addr, len);
|
|
}
|
|
}
|
|
}
|
|
#endif /* CONFIG_DMA_API_DEBUG */
|
|
return sg_table;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
|
|
* deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
|
|
* dma_buf_ops.
|
|
* @attach: [in] attachment to unmap buffer from
|
|
* @sg_table: [in] scatterlist info of the buffer to unmap
|
|
* @direction: [in] direction of DMA transfer
|
|
*
|
|
* This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment().
|
|
*/
|
|
void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
|
|
struct sg_table *sg_table,
|
|
enum dma_data_direction direction)
|
|
{
|
|
might_sleep();
|
|
|
|
if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
|
|
return;
|
|
|
|
if (dma_buf_attachment_is_dynamic(attach))
|
|
dma_resv_assert_held(attach->dmabuf->resv);
|
|
|
|
if (attach->sgt == sg_table)
|
|
return;
|
|
|
|
if (dma_buf_is_dynamic(attach->dmabuf))
|
|
dma_resv_assert_held(attach->dmabuf->resv);
|
|
|
|
__unmap_dma_buf(attach, sg_table, direction);
|
|
|
|
if (dma_buf_is_dynamic(attach->dmabuf) &&
|
|
!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY))
|
|
dma_buf_unpin(attach);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_move_notify - notify attachments that DMA-buf is moving
|
|
*
|
|
* @dmabuf: [in] buffer which is moving
|
|
*
|
|
* Informs all attachmenst that they need to destroy and recreated all their
|
|
* mappings.
|
|
*/
|
|
void dma_buf_move_notify(struct dma_buf *dmabuf)
|
|
{
|
|
struct dma_buf_attachment *attach;
|
|
|
|
dma_resv_assert_held(dmabuf->resv);
|
|
|
|
list_for_each_entry(attach, &dmabuf->attachments, node)
|
|
if (attach->importer_ops)
|
|
attach->importer_ops->move_notify(attach);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_move_notify, DMA_BUF);
|
|
|
|
/**
|
|
* DOC: cpu access
|
|
*
|
|
* There are mutliple reasons for supporting CPU access to a dma buffer object:
|
|
*
|
|
* - Fallback operations in the kernel, for example when a device is connected
|
|
* over USB and the kernel needs to shuffle the data around first before
|
|
* sending it away. Cache coherency is handled by braketing any transactions
|
|
* with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access()
|
|
* access.
|
|
*
|
|
* Since for most kernel internal dma-buf accesses need the entire buffer, a
|
|
* vmap interface is introduced. Note that on very old 32-bit architectures
|
|
* vmalloc space might be limited and result in vmap calls failing.
|
|
*
|
|
* Interfaces::
|
|
*
|
|
* void \*dma_buf_vmap(struct dma_buf \*dmabuf, struct dma_buf_map \*map)
|
|
* void dma_buf_vunmap(struct dma_buf \*dmabuf, struct dma_buf_map \*map)
|
|
*
|
|
* The vmap call can fail if there is no vmap support in the exporter, or if
|
|
* it runs out of vmalloc space. Note that the dma-buf layer keeps a reference
|
|
* count for all vmap access and calls down into the exporter's vmap function
|
|
* only when no vmapping exists, and only unmaps it once. Protection against
|
|
* concurrent vmap/vunmap calls is provided by taking the &dma_buf.lock mutex.
|
|
*
|
|
* - For full compatibility on the importer side with existing userspace
|
|
* interfaces, which might already support mmap'ing buffers. This is needed in
|
|
* many processing pipelines (e.g. feeding a software rendered image into a
|
|
* hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION
|
|
* framework already supported this and for DMA buffer file descriptors to
|
|
* replace ION buffers mmap support was needed.
|
|
*
|
|
* There is no special interfaces, userspace simply calls mmap on the dma-buf
|
|
* fd. But like for CPU access there's a need to braket the actual access,
|
|
* which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that
|
|
* DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must
|
|
* be restarted.
|
|
*
|
|
* Some systems might need some sort of cache coherency management e.g. when
|
|
* CPU and GPU domains are being accessed through dma-buf at the same time.
|
|
* To circumvent this problem there are begin/end coherency markers, that
|
|
* forward directly to existing dma-buf device drivers vfunc hooks. Userspace
|
|
* can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The
|
|
* sequence would be used like following:
|
|
*
|
|
* - mmap dma-buf fd
|
|
* - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
|
|
* to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
|
|
* want (with the new data being consumed by say the GPU or the scanout
|
|
* device)
|
|
* - munmap once you don't need the buffer any more
|
|
*
|
|
* For correctness and optimal performance, it is always required to use
|
|
* SYNC_START and SYNC_END before and after, respectively, when accessing the
|
|
* mapped address. Userspace cannot rely on coherent access, even when there
|
|
* are systems where it just works without calling these ioctls.
|
|
*
|
|
* - And as a CPU fallback in userspace processing pipelines.
|
|
*
|
|
* Similar to the motivation for kernel cpu access it is again important that
|
|
* the userspace code of a given importing subsystem can use the same
|
|
* interfaces with a imported dma-buf buffer object as with a native buffer
|
|
* object. This is especially important for drm where the userspace part of
|
|
* contemporary OpenGL, X, and other drivers is huge, and reworking them to
|
|
* use a different way to mmap a buffer rather invasive.
|
|
*
|
|
* The assumption in the current dma-buf interfaces is that redirecting the
|
|
* initial mmap is all that's needed. A survey of some of the existing
|
|
* subsystems shows that no driver seems to do any nefarious thing like
|
|
* syncing up with outstanding asynchronous processing on the device or
|
|
* allocating special resources at fault time. So hopefully this is good
|
|
* enough, since adding interfaces to intercept pagefaults and allow pte
|
|
* shootdowns would increase the complexity quite a bit.
|
|
*
|
|
* Interface::
|
|
*
|
|
* int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*,
|
|
* unsigned long);
|
|
*
|
|
* If the importing subsystem simply provides a special-purpose mmap call to
|
|
* set up a mapping in userspace, calling do_mmap with &dma_buf.file will
|
|
* equally achieve that for a dma-buf object.
|
|
*/
|
|
|
|
static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
|
|
enum dma_data_direction direction)
|
|
{
|
|
bool write = (direction == DMA_BIDIRECTIONAL ||
|
|
direction == DMA_TO_DEVICE);
|
|
struct dma_resv *resv = dmabuf->resv;
|
|
long ret;
|
|
|
|
/* Wait on any implicit rendering fences */
|
|
ret = dma_resv_wait_timeout(resv, write, true, MAX_SCHEDULE_TIMEOUT);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
|
|
* cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
|
|
* preparations. Coherency is only guaranteed in the specified range for the
|
|
* specified access direction.
|
|
* @dmabuf: [in] buffer to prepare cpu access for.
|
|
* @direction: [in] length of range for cpu access.
|
|
*
|
|
* After the cpu access is complete the caller should call
|
|
* dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is
|
|
* it guaranteed to be coherent with other DMA access.
|
|
*
|
|
* This function will also wait for any DMA transactions tracked through
|
|
* implicit synchronization in &dma_buf.resv. For DMA transactions with explicit
|
|
* synchronization this function will only ensure cache coherency, callers must
|
|
* ensure synchronization with such DMA transactions on their own.
|
|
*
|
|
* Can return negative error values, returns 0 on success.
|
|
*/
|
|
int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
|
|
enum dma_data_direction direction)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (WARN_ON(!dmabuf))
|
|
return -EINVAL;
|
|
|
|
might_lock(&dmabuf->resv->lock.base);
|
|
|
|
if (dmabuf->ops->begin_cpu_access)
|
|
ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
|
|
|
|
/* Ensure that all fences are waited upon - but we first allow
|
|
* the native handler the chance to do so more efficiently if it
|
|
* chooses. A double invocation here will be reasonably cheap no-op.
|
|
*/
|
|
if (ret == 0)
|
|
ret = __dma_buf_begin_cpu_access(dmabuf, direction);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_begin_cpu_access, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
|
|
* cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
|
|
* actions. Coherency is only guaranteed in the specified range for the
|
|
* specified access direction.
|
|
* @dmabuf: [in] buffer to complete cpu access for.
|
|
* @direction: [in] length of range for cpu access.
|
|
*
|
|
* This terminates CPU access started with dma_buf_begin_cpu_access().
|
|
*
|
|
* Can return negative error values, returns 0 on success.
|
|
*/
|
|
int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
|
|
enum dma_data_direction direction)
|
|
{
|
|
int ret = 0;
|
|
|
|
WARN_ON(!dmabuf);
|
|
|
|
might_lock(&dmabuf->resv->lock.base);
|
|
|
|
if (dmabuf->ops->end_cpu_access)
|
|
ret = dmabuf->ops->end_cpu_access(dmabuf, direction);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
|
|
|
|
|
|
/**
|
|
* dma_buf_mmap - Setup up a userspace mmap with the given vma
|
|
* @dmabuf: [in] buffer that should back the vma
|
|
* @vma: [in] vma for the mmap
|
|
* @pgoff: [in] offset in pages where this mmap should start within the
|
|
* dma-buf buffer.
|
|
*
|
|
* This function adjusts the passed in vma so that it points at the file of the
|
|
* dma_buf operation. It also adjusts the starting pgoff and does bounds
|
|
* checking on the size of the vma. Then it calls the exporters mmap function to
|
|
* set up the mapping.
|
|
*
|
|
* Can return negative error values, returns 0 on success.
|
|
*/
|
|
int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
|
|
unsigned long pgoff)
|
|
{
|
|
if (WARN_ON(!dmabuf || !vma))
|
|
return -EINVAL;
|
|
|
|
/* check if buffer supports mmap */
|
|
if (!dmabuf->ops->mmap)
|
|
return -EINVAL;
|
|
|
|
/* check for offset overflow */
|
|
if (pgoff + vma_pages(vma) < pgoff)
|
|
return -EOVERFLOW;
|
|
|
|
/* check for overflowing the buffer's size */
|
|
if (pgoff + vma_pages(vma) >
|
|
dmabuf->size >> PAGE_SHIFT)
|
|
return -EINVAL;
|
|
|
|
/* readjust the vma */
|
|
vma_set_file(vma, dmabuf->file);
|
|
vma->vm_pgoff = pgoff;
|
|
|
|
return dmabuf->ops->mmap(dmabuf, vma);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_vmap - Create virtual mapping for the buffer object into kernel
|
|
* address space. Same restrictions as for vmap and friends apply.
|
|
* @dmabuf: [in] buffer to vmap
|
|
* @map: [out] returns the vmap pointer
|
|
*
|
|
* This call may fail due to lack of virtual mapping address space.
|
|
* These calls are optional in drivers. The intended use for them
|
|
* is for mapping objects linear in kernel space for high use objects.
|
|
*
|
|
* To ensure coherency users must call dma_buf_begin_cpu_access() and
|
|
* dma_buf_end_cpu_access() around any cpu access performed through this
|
|
* mapping.
|
|
*
|
|
* Returns 0 on success, or a negative errno code otherwise.
|
|
*/
|
|
int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
|
|
{
|
|
struct dma_buf_map ptr;
|
|
int ret = 0;
|
|
|
|
dma_buf_map_clear(map);
|
|
|
|
if (WARN_ON(!dmabuf))
|
|
return -EINVAL;
|
|
|
|
if (!dmabuf->ops->vmap)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&dmabuf->lock);
|
|
if (dmabuf->vmapping_counter) {
|
|
dmabuf->vmapping_counter++;
|
|
BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));
|
|
*map = dmabuf->vmap_ptr;
|
|
goto out_unlock;
|
|
}
|
|
|
|
BUG_ON(dma_buf_map_is_set(&dmabuf->vmap_ptr));
|
|
|
|
ret = dmabuf->ops->vmap(dmabuf, &ptr);
|
|
if (WARN_ON_ONCE(ret))
|
|
goto out_unlock;
|
|
|
|
dmabuf->vmap_ptr = ptr;
|
|
dmabuf->vmapping_counter = 1;
|
|
|
|
*map = dmabuf->vmap_ptr;
|
|
|
|
out_unlock:
|
|
mutex_unlock(&dmabuf->lock);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
|
|
|
|
/**
|
|
* dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
|
|
* @dmabuf: [in] buffer to vunmap
|
|
* @map: [in] vmap pointer to vunmap
|
|
*/
|
|
void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
|
|
{
|
|
if (WARN_ON(!dmabuf))
|
|
return;
|
|
|
|
BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));
|
|
BUG_ON(dmabuf->vmapping_counter == 0);
|
|
BUG_ON(!dma_buf_map_is_equal(&dmabuf->vmap_ptr, map));
|
|
|
|
mutex_lock(&dmabuf->lock);
|
|
if (--dmabuf->vmapping_counter == 0) {
|
|
if (dmabuf->ops->vunmap)
|
|
dmabuf->ops->vunmap(dmabuf, map);
|
|
dma_buf_map_clear(&dmabuf->vmap_ptr);
|
|
}
|
|
mutex_unlock(&dmabuf->lock);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
static int dma_buf_debug_show(struct seq_file *s, void *unused)
|
|
{
|
|
struct dma_buf *buf_obj;
|
|
struct dma_buf_attachment *attach_obj;
|
|
int count = 0, attach_count;
|
|
size_t size = 0;
|
|
int ret;
|
|
|
|
ret = mutex_lock_interruptible(&db_list.lock);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
seq_puts(s, "\nDma-buf Objects:\n");
|
|
seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\t%-8s\n",
|
|
"size", "flags", "mode", "count", "ino");
|
|
|
|
list_for_each_entry(buf_obj, &db_list.head, list_node) {
|
|
|
|
ret = dma_resv_lock_interruptible(buf_obj->resv, NULL);
|
|
if (ret)
|
|
goto error_unlock;
|
|
|
|
|
|
spin_lock(&buf_obj->name_lock);
|
|
seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n",
|
|
buf_obj->size,
|
|
buf_obj->file->f_flags, buf_obj->file->f_mode,
|
|
file_count(buf_obj->file),
|
|
buf_obj->exp_name,
|
|
file_inode(buf_obj->file)->i_ino,
|
|
buf_obj->name ?: "");
|
|
spin_unlock(&buf_obj->name_lock);
|
|
|
|
dma_resv_describe(buf_obj->resv, s);
|
|
|
|
seq_puts(s, "\tAttached Devices:\n");
|
|
attach_count = 0;
|
|
|
|
list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
|
|
seq_printf(s, "\t%s\n", dev_name(attach_obj->dev));
|
|
attach_count++;
|
|
}
|
|
dma_resv_unlock(buf_obj->resv);
|
|
|
|
seq_printf(s, "Total %d devices attached\n\n",
|
|
attach_count);
|
|
|
|
count++;
|
|
size += buf_obj->size;
|
|
}
|
|
|
|
seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
|
|
|
|
mutex_unlock(&db_list.lock);
|
|
return 0;
|
|
|
|
error_unlock:
|
|
mutex_unlock(&db_list.lock);
|
|
return ret;
|
|
}
|
|
|
|
DEFINE_SHOW_ATTRIBUTE(dma_buf_debug);
|
|
|
|
static struct dentry *dma_buf_debugfs_dir;
|
|
|
|
static int dma_buf_init_debugfs(void)
|
|
{
|
|
struct dentry *d;
|
|
int err = 0;
|
|
|
|
d = debugfs_create_dir("dma_buf", NULL);
|
|
if (IS_ERR(d))
|
|
return PTR_ERR(d);
|
|
|
|
dma_buf_debugfs_dir = d;
|
|
|
|
d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir,
|
|
NULL, &dma_buf_debug_fops);
|
|
if (IS_ERR(d)) {
|
|
pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
|
|
debugfs_remove_recursive(dma_buf_debugfs_dir);
|
|
dma_buf_debugfs_dir = NULL;
|
|
err = PTR_ERR(d);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void dma_buf_uninit_debugfs(void)
|
|
{
|
|
debugfs_remove_recursive(dma_buf_debugfs_dir);
|
|
}
|
|
#else
|
|
static inline int dma_buf_init_debugfs(void)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void dma_buf_uninit_debugfs(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static int __init dma_buf_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = dma_buf_init_sysfs_statistics();
|
|
if (ret)
|
|
return ret;
|
|
|
|
dma_buf_mnt = kern_mount(&dma_buf_fs_type);
|
|
if (IS_ERR(dma_buf_mnt))
|
|
return PTR_ERR(dma_buf_mnt);
|
|
|
|
mutex_init(&db_list.lock);
|
|
INIT_LIST_HEAD(&db_list.head);
|
|
dma_buf_init_debugfs();
|
|
return 0;
|
|
}
|
|
subsys_initcall(dma_buf_init);
|
|
|
|
static void __exit dma_buf_deinit(void)
|
|
{
|
|
dma_buf_uninit_debugfs();
|
|
kern_unmount(dma_buf_mnt);
|
|
dma_buf_uninit_sysfs_statistics();
|
|
}
|
|
__exitcall(dma_buf_deinit);
|