staging: android: lowmemorykiller: Change default debug_level to 1

[karo-tx-linux.git] / drivers / base / dma-buf.c

diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index ff5b745c470525c5e1a19560cb81be188a76100c..2a7cb0df176bb9494b5f660c30a0a3962738868b 100644 (file)
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -39,6 +39,8 @@ static int dma_buf_release(struct inode *inode, struct file *file)
 
        dmabuf = file->private_data;
 
+       BUG_ON(dmabuf->vmapping_counter);
+
        dmabuf->ops->release(dmabuf);
        kfree(dmabuf);
        return 0;
@@ -445,6 +447,9 @@ EXPORT_SYMBOL_GPL(dma_buf_kunmap);
 int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
                 unsigned long pgoff)
 {
+       struct file *oldfile;
+       int ret;
+
        if (WARN_ON(!dmabuf || !vma))
                return -EINVAL;
 
@@ -458,14 +463,22 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
                return -EINVAL;
 
        /* readjust the vma */
-       if (vma->vm_file)
-               fput(vma->vm_file);
-
-       vma->vm_file = get_file(dmabuf->file);
-
+       get_file(dmabuf->file);
+       oldfile = vma->vm_file;
+       vma->vm_file = dmabuf->file;
        vma->vm_pgoff = pgoff;
 
-       return dmabuf->ops->mmap(dmabuf, vma);
+       ret = dmabuf->ops->mmap(dmabuf, vma);
+       if (ret) {
+               /* restore old parameters on failure */
+               vma->vm_file = oldfile;
+               fput(dmabuf->file);
+       } else {
+               if (oldfile)
+                       fput(oldfile);
+       }
+       return ret;
+
 }
 EXPORT_SYMBOL_GPL(dma_buf_mmap);
 
@@ -481,12 +494,34 @@ EXPORT_SYMBOL_GPL(dma_buf_mmap);
  */
 void *dma_buf_vmap(struct dma_buf *dmabuf)
 {
+       void *ptr;
+
        if (WARN_ON(!dmabuf))
                return NULL;
 
-       if (dmabuf->ops->vmap)
-               return dmabuf->ops->vmap(dmabuf);
-       return NULL;
+       if (!dmabuf->ops->vmap)
+               return NULL;
+
+       mutex_lock(&dmabuf->lock);
+       if (dmabuf->vmapping_counter) {
+               dmabuf->vmapping_counter++;
+               BUG_ON(!dmabuf->vmap_ptr);
+               ptr = dmabuf->vmap_ptr;
+               goto out_unlock;
+       }
+
+       BUG_ON(dmabuf->vmap_ptr);
+
+       ptr = dmabuf->ops->vmap(dmabuf);
+       if (IS_ERR_OR_NULL(ptr))
+               goto out_unlock;
+
+       dmabuf->vmap_ptr = ptr;
+       dmabuf->vmapping_counter = 1;
+
+out_unlock:
+       mutex_unlock(&dmabuf->lock);
+       return ptr;
 }
 EXPORT_SYMBOL_GPL(dma_buf_vmap);
 
@@ -500,7 +535,16 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
        if (WARN_ON(!dmabuf))
                return;
 
-       if (dmabuf->ops->vunmap)
-               dmabuf->ops->vunmap(dmabuf, vaddr);
+       BUG_ON(!dmabuf->vmap_ptr);
+       BUG_ON(dmabuf->vmapping_counter == 0);
+       BUG_ON(dmabuf->vmap_ptr != vaddr);
+
+       mutex_lock(&dmabuf->lock);
+       if (--dmabuf->vmapping_counter == 0) {
+               if (dmabuf->ops->vunmap)
+                       dmabuf->ops->vunmap(dmabuf, vaddr);
+               dmabuf->vmap_ptr = NULL;
+       }
+       mutex_unlock(&dmabuf->lock);
 }
 EXPORT_SYMBOL_GPL(dma_buf_vunmap);