Hi
On Wed, Mar 19, 2014 at 12:33 PM, Thomas Hellstrom
<thellstrom@xxxxxxxxxx> wrote:
> By handing the authentication mechanism tokens in the form of const void
> pointers instead of struct file pointers, drivers are free to provide whatever
> file pointers they find appropriate. The pointers are never dereferenced in
> the drm_vma_manager so that shouldn't be a problem.
>
> As an example, the vmwgfx driver would like to provide struct ttm_object_file
> pointers.
I guess a "struct file*" pointer in tmm_object_file would be easier,
but if that reverse dependency is not wanted, I'm fine with that. Just
make sure you don't use drm_vma_node_verify_access for TTM directly as
TTM passes in a file pointer.
Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>
Thanks
David
> Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_vma_manager.c | 22 +++++++++++-----------
> include/drm/drm_vma_manager.h | 12 ++++++------
> 2 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_vma_manager.c b/drivers/gpu/drm/drm_vma_manager.c
> index 63b4712..93676c1 100644
> --- a/drivers/gpu/drm/drm_vma_manager.c
> +++ b/drivers/gpu/drm/drm_vma_manager.c
> @@ -291,24 +291,24 @@ EXPORT_SYMBOL(drm_vma_offset_remove);
> /**
> * drm_vma_node_allow - Add open-file to list of allowed users
> * @node: Node to modify
> - * @filp: Open file to add
> + * @filp: Authentication token (typically pointer to open file) to add
> *
> - * Add @filp to the list of allowed open-files for this node. If @filp is
> - * already on this list, the ref-count is incremented.
> + * Add @filp to the list of allowed authentication tokens for this node.
> + * If @filp is already on this list, the ref-count is incremented.
> *
> * The list of allowed-users is preserved across drm_vma_offset_add() and
> * drm_vma_offset_remove() calls. You may even call it if the node is currently
> * not added to any offset-manager.
> *
> - * You must remove all open-files the same number of times as you added them
> - * before destroying the node. Otherwise, you will leak memory.
> + * You must remove all authentication tokens the same number of times as you
> + * added them before destroying the node. Otherwise, you will leak memory.
> *
> * This is locked against concurrent access internally.
> *
> * RETURNS:
> * 0 on success, negative error code on internal failure (out-of-mem)
> */
> -int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp)
> +int drm_vma_node_allow(struct drm_vma_offset_node *node, const void *filp)
> {
> struct rb_node **iter;
> struct rb_node *parent = NULL;
> @@ -360,7 +360,7 @@ EXPORT_SYMBOL(drm_vma_node_allow);
> /**
> * drm_vma_node_revoke - Remove open-file from list of allowed users
> * @node: Node to modify
> - * @filp: Open file to remove
> + * @filp: Authentication token to remove
> *
> * Decrement the ref-count of @filp in the list of allowed open-files on @node.
> * If the ref-count drops to zero, remove @filp from the list. You must call
> @@ -370,7 +370,7 @@ EXPORT_SYMBOL(drm_vma_node_allow);
> *
> * If @filp is not on the list, nothing is done.
> */
> -void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp)
> +void drm_vma_node_revoke(struct drm_vma_offset_node *node, const void *filp)
> {
> struct drm_vma_offset_file *entry;
> struct rb_node *iter;
> @@ -400,10 +400,10 @@ EXPORT_SYMBOL(drm_vma_node_revoke);
> /**
> * drm_vma_node_is_allowed - Check whether an open-file is granted access
> * @node: Node to check
> - * @filp: Open-file to check for
> + * @filp: Authentication token to check for
> *
> * Search the list in @node whether @filp is currently on the list of allowed
> - * open-files (see drm_vma_node_allow()).
> + * authentication tokens (see drm_vma_node_allow()).
> *
> * This is locked against concurrent access internally.
> *
> @@ -411,7 +411,7 @@ EXPORT_SYMBOL(drm_vma_node_revoke);
> * true iff @filp is on the list
> */
> bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,
> - struct file *filp)
> + const void *filp)
> {
> struct drm_vma_offset_file *entry;
> struct rb_node *iter;
> diff --git a/include/drm/drm_vma_manager.h b/include/drm/drm_vma_manager.h
> index c18a593..d7ff1e5 100644
> --- a/include/drm/drm_vma_manager.h
> +++ b/include/drm/drm_vma_manager.h
> @@ -33,7 +33,7 @@
>
> struct drm_vma_offset_file {
> struct rb_node vm_rb;
> - struct file *vm_filp;
> + const void *vm_filp;
> unsigned long vm_count;
> };
>
> @@ -65,10 +65,10 @@ int drm_vma_offset_add(struct drm_vma_offset_manager *mgr,
> void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr,
> struct drm_vma_offset_node *node);
>
> -int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp);
> -void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp);
> +int drm_vma_node_allow(struct drm_vma_offset_node *node, const void *filp);
> +void drm_vma_node_revoke(struct drm_vma_offset_node *node, const void *filp);
> bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,
> - struct file *filp);
> + const void *filp);
>
> /**
> * drm_vma_offset_exact_lookup() - Look up node by exact address
> @@ -239,7 +239,7 @@ static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node,
> /**
> * drm_vma_node_verify_access() - Access verification helper for TTM
> * @node: Offset node
> - * @filp: Open-file
> + * @filp: Authentication token. Typically pointer to open file
> *
> * This checks whether @filp is granted access to @node. It is the same as
> * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM
> @@ -249,7 +249,7 @@ static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node,
> * 0 if access is granted, -EACCES otherwise.
> */
> static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node,
> - struct file *filp)
> + const void *filp)
> {
> return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES;
> }
> --
> 1.7.10.4
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