diff options
Diffstat (limited to 'drivers/base/dma-buf.c')
| -rw-r--r-- | drivers/base/dma-buf.c | 82 |
1 files changed, 57 insertions, 25 deletions
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 08fe897c0b4..840c7fa8098 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -77,9 +77,36 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) return dmabuf->ops->mmap(dmabuf, vma); } +static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) +{ + struct dma_buf *dmabuf; + loff_t base; + + if (!is_dma_buf_file(file)) + return -EBADF; + + dmabuf = file->private_data; + + /* only support discovering the end of the buffer, + but also allow SEEK_SET to maintain the idiomatic + SEEK_END(0), SEEK_CUR(0) pattern */ + if (whence == SEEK_END) + base = dmabuf->size; + else if (whence == SEEK_SET) + base = 0; + else + return -EINVAL; + + if (offset != 0) + return -EINVAL; + + return base + offset; +} + static const struct file_operations dma_buf_fops = { .release = dma_buf_release, .mmap = dma_buf_mmap_internal, + .llseek = dma_buf_llseek, }; /* @@ -133,7 +160,12 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, dmabuf->exp_name = exp_name; file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags); + if (IS_ERR(file)) { + kfree(dmabuf); + return ERR_CAST(file); + } + file->f_mode |= FMODE_LSEEK; dmabuf->file = file; mutex_init(&dmabuf->lock); @@ -219,9 +251,8 @@ EXPORT_SYMBOL_GPL(dma_buf_put); * @dmabuf: [in] buffer to attach device to. * @dev: [in] device to be attached. * - * Returns struct dma_buf_attachment * for this attachment; may return negative - * error codes. - * + * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on + * error. */ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, struct device *dev) @@ -287,9 +318,8 @@ EXPORT_SYMBOL_GPL(dma_buf_detach); * @attach: [in] attachment whose scatterlist is to be returned * @direction: [in] direction of DMA transfer * - * Returns sg_table containing the scatterlist to be returned; may return NULL - * or ERR_PTR. - * + * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR + * on error. */ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, enum dma_data_direction direction) @@ -302,6 +332,8 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, return ERR_PTR(-EINVAL); sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); + if (!sg_table) + sg_table = ERR_PTR(-ENOMEM); return sg_table; } @@ -459,7 +491,7 @@ EXPORT_SYMBOL_GPL(dma_buf_kunmap); * dma-buf buffer. * * This function adjusts the passed in vma so that it points at the file of the - * dma_buf operation. It alsog adjusts the starting pgoff and does bounds + * 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. * @@ -512,6 +544,8 @@ EXPORT_SYMBOL_GPL(dma_buf_mmap); * These calls are optional in drivers. The intended use for them * is for mapping objects linear in kernel space for high use objects. * Please attempt to use kmap/kunmap before thinking about these interfaces. + * + * Returns NULL on error. */ void *dma_buf_vmap(struct dma_buf *dmabuf) { @@ -534,7 +568,9 @@ void *dma_buf_vmap(struct dma_buf *dmabuf) BUG_ON(dmabuf->vmap_ptr); ptr = dmabuf->ops->vmap(dmabuf); - if (IS_ERR_OR_NULL(ptr)) + if (WARN_ON_ONCE(IS_ERR(ptr))) + ptr = NULL; + if (!ptr) goto out_unlock; dmabuf->vmap_ptr = ptr; @@ -584,36 +620,35 @@ static int dma_buf_describe(struct seq_file *s) if (ret) return ret; - seq_printf(s, "\nDma-buf Objects:\n"); - seq_printf(s, "\texp_name\tsize\tflags\tmode\tcount\n"); + seq_puts(s, "\nDma-buf Objects:\n"); + seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); list_for_each_entry(buf_obj, &db_list.head, list_node) { ret = mutex_lock_interruptible(&buf_obj->lock); if (ret) { - seq_printf(s, - "\tERROR locking buffer object: skipping\n"); + seq_puts(s, + "\tERROR locking buffer object: skipping\n"); continue; } - seq_printf(s, "\t"); - - seq_printf(s, "\t%s\t%08zu\t%08x\t%08x\t%08ld\n", - buf_obj->exp_name, buf_obj->size, + seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", + buf_obj->size, buf_obj->file->f_flags, buf_obj->file->f_mode, - (long)(buf_obj->file->f_count.counter)); + (long)(buf_obj->file->f_count.counter), + buf_obj->exp_name); - seq_printf(s, "\t\tAttached Devices:\n"); + seq_puts(s, "\tAttached Devices:\n"); attach_count = 0; list_for_each_entry(attach_obj, &buf_obj->attachments, node) { - seq_printf(s, "\t\t"); + seq_puts(s, "\t"); - seq_printf(s, "%s\n", attach_obj->dev->init_name); + seq_printf(s, "%s\n", dev_name(attach_obj->dev)); attach_count++; } - seq_printf(s, "\n\t\tTotal %d devices attached\n", + seq_printf(s, "Total %d devices attached\n\n", attach_count); count++; @@ -680,10 +715,7 @@ int dma_buf_debugfs_create_file(const char *name, d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, write, &dma_buf_debug_fops); - if (IS_ERR(d)) - return PTR_ERR(d); - - return 0; + return PTR_ERR_OR_ZERO(d); } #else static inline int dma_buf_init_debugfs(void) |