return 0;
}
+static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
+{
+ struct dma_buf *dmabuf;
+
+ if (!is_dma_buf_file(file))
+ return -EINVAL;
+
+ dmabuf = file->private_data;
+
+ /* check for overflowing the buffer's size */
+ if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
+ dmabuf->size >> PAGE_SHIFT)
+ return -EINVAL;
+
+ return dmabuf->ops->mmap(dmabuf, vma);
+}
+
static const struct file_operations dma_buf_fops = {
.release = dma_buf_release,
+ .mmap = dma_buf_mmap_internal,
};
/*
|| !ops->unmap_dma_buf
|| !ops->release
|| !ops->kmap_atomic
- || !ops->kmap)) {
+ || !ops->kmap
+ || !ops->mmap)) {
return ERR_PTR(-EINVAL);
}
* 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.
- * @dma_buf: [in] buffer to prepare cpu access for.
+ * @dmabuf: [in] buffer to prepare cpu access for.
* @start: [in] start of range for cpu access.
* @len: [in] length of range for cpu access.
* @direction: [in] length of range for cpu access.
* 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.
- * @dma_buf: [in] buffer to complete cpu access for.
+ * @dmabuf: [in] buffer to complete cpu access for.
* @start: [in] start of range for cpu access.
* @len: [in] length of range for cpu access.
* @direction: [in] length of range for cpu access.
/**
* dma_buf_kmap_atomic - Map a page of the buffer object into kernel address
* space. The same restrictions as for kmap_atomic and friends apply.
- * @dma_buf: [in] buffer to map page from.
+ * @dmabuf: [in] buffer to map page from.
* @page_num: [in] page in PAGE_SIZE units to map.
*
* This call must always succeed, any necessary preparations that might fail
/**
* dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
- * @dma_buf: [in] buffer to unmap page from.
+ * @dmabuf: [in] buffer to unmap page from.
* @page_num: [in] page in PAGE_SIZE units to unmap.
* @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic.
*
/**
* dma_buf_kmap - Map a page of the buffer object into kernel address space. The
* same restrictions as for kmap and friends apply.
- * @dma_buf: [in] buffer to map page from.
+ * @dmabuf: [in] buffer to map page from.
* @page_num: [in] page in PAGE_SIZE units to map.
*
* This call must always succeed, any necessary preparations that might fail
/**
* dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
- * @dma_buf: [in] buffer to unmap page from.
+ * @dmabuf: [in] buffer to unmap page from.
* @page_num: [in] page in PAGE_SIZE units to unmap.
* @vaddr: [in] kernel space pointer obtained from dma_buf_kmap.
*
dmabuf->ops->kunmap(dmabuf, page_num, vaddr);
}
EXPORT_SYMBOL_GPL(dma_buf_kunmap);
+
+
+/**
+ * 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 alsog 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 for offset overflow */
+ if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff)
+ return -EOVERFLOW;
+
+ /* check for overflowing the buffer's size */
+ if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
+ dmabuf->size >> PAGE_SHIFT)
+ return -EINVAL;
+
+ /* readjust the vma */
+ if (vma->vm_file)
+ fput(vma->vm_file);
+
+ vma->vm_file = dmabuf->file;
+ get_file(vma->vm_file);
+
+ vma->vm_pgoff = pgoff;
+
+ return dmabuf->ops->mmap(dmabuf, vma);
+}
+EXPORT_SYMBOL_GPL(dma_buf_mmap);
+
+/**
+ * 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
+ *
+ * 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.
+ * Please attempt to use kmap/kunmap before thinking about these interfaces.
+ */
+void *dma_buf_vmap(struct dma_buf *dmabuf)
+{
+ if (WARN_ON(!dmabuf))
+ return NULL;
+
+ if (dmabuf->ops->vmap)
+ return dmabuf->ops->vmap(dmabuf);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(dma_buf_vmap);
+
+/**
+ * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf: [in] buffer to vunmap
+ */
+void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
+{
+ if (WARN_ON(!dmabuf))
+ return;
+
+ if (dmabuf->ops->vunmap)
+ dmabuf->ops->vunmap(dmabuf, vaddr);
+}
+EXPORT_SYMBOL_GPL(dma_buf_vunmap);
projects / ~andy / linux / blobdiff