diff mbox series

[5/9] drm/xen/xen_drm_front_gem.c: Convert to use vm_insert_range

Message ID 20181115154912.GA27969@jordon-HP-15-Notebook-PC (mailing list archive)
State New, archived
Headers show
Series [1/9] mm: Introduce new vm_insert_range API | expand

Commit Message

Souptick Joarder Nov. 15, 2018, 3:49 p.m. UTC 
Convert to use vm_insert_range() to map range of kernel
memory to user vma.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
---
 drivers/gpu/drm/xen/xen_drm_front_gem.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

Comments

Oleksandr Andrushchenko Nov. 19, 2018, 9:52 a.m. UTC | #1 
On 11/15/18 5:49 PM, Souptick Joarder wrote:
> Convert to use vm_insert_range() to map range of kernel
> memory to user vma.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> Reviewed-by: Matthew Wilcox <willy@infradead.org>
> ---
>   drivers/gpu/drm/xen/xen_drm_front_gem.c | 20 ++++++--------------
>   1 file changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> index 47ff019..a3eade6 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> @@ -225,8 +225,7 @@ struct drm_gem_object *
>   static int gem_mmap_obj(struct xen_gem_object *xen_obj,
>   			struct vm_area_struct *vma)
>   {
> -	unsigned long addr = vma->vm_start;
> -	int i;
> +	int err;
I would love to keep ret, not err
>   
>   	/*
>   	 * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> @@ -247,18 +246,11 @@ static int gem_mmap_obj(struct xen_gem_object *xen_obj,
>   	 * FIXME: as we insert all the pages now then no .fault handler must
>   	 * be called, so don't provide one
>   	 */
> -	for (i = 0; i < xen_obj->num_pages; i++) {
> -		int ret;
> -
> -		ret = vm_insert_page(vma, addr, xen_obj->pages[i]);
> -		if (ret < 0) {
> -			DRM_ERROR("Failed to insert pages into vma: %d\n", ret);
> -			return ret;
> -		}
> -
> -		addr += PAGE_SIZE;
> -	}
> -	return 0;
> +	err = vm_insert_range(vma, vma->vm_start, xen_obj->pages,
> +				xen_obj->num_pages);
> +	if (err < 0)
> +		DRM_ERROR("Failed to insert pages into vma: %d\n", err);
> +	return err;
>   }
>   
>   int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)

With the above fixed,

Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Souptick Joarder Nov. 19, 2018, 10:42 a.m. UTC | #2 
On Mon, Nov 19, 2018 at 3:22 PM Oleksandr Andrushchenko
<andr2000@gmail.com> wrote:
>
> On 11/15/18 5:49 PM, Souptick Joarder wrote:
> > Convert to use vm_insert_range() to map range of kernel
> > memory to user vma.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > Reviewed-by: Matthew Wilcox <willy@infradead.org>
> > ---
> >   drivers/gpu/drm/xen/xen_drm_front_gem.c | 20 ++++++--------------
> >   1 file changed, 6 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> > index 47ff019..a3eade6 100644
> > --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
> > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> > @@ -225,8 +225,7 @@ struct drm_gem_object *
> >   static int gem_mmap_obj(struct xen_gem_object *xen_obj,
> >                       struct vm_area_struct *vma)
> >   {
> > -     unsigned long addr = vma->vm_start;
> > -     int i;
> > +     int err;
> I would love to keep ret, not err

Sure, will add it in v2.
But I think, err is more appropriate here.

> >
> >       /*
> >        * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> > @@ -247,18 +246,11 @@ static int gem_mmap_obj(struct xen_gem_object *xen_obj,
> >        * FIXME: as we insert all the pages now then no .fault handler must
> >        * be called, so don't provide one
> >        */
> > -     for (i = 0; i < xen_obj->num_pages; i++) {
> > -             int ret;
> > -
> > -             ret = vm_insert_page(vma, addr, xen_obj->pages[i]);
> > -             if (ret < 0) {
> > -                     DRM_ERROR("Failed to insert pages into vma: %d\n", ret);
> > -                     return ret;
> > -             }
> > -
> > -             addr += PAGE_SIZE;
> > -     }
> > -     return 0;
> > +     err = vm_insert_range(vma, vma->vm_start, xen_obj->pages,
> > +                             xen_obj->num_pages);
> > +     if (err < 0)
> > +             DRM_ERROR("Failed to insert pages into vma: %d\n", err);
> > +     return err;
> >   }
> >
> >   int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>
> With the above fixed,
>
> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>
Oleksandr Andrushchenko Nov. 19, 2018, 11:02 a.m. UTC | #3 
On 11/19/18 12:42 PM, Souptick Joarder wrote:
> On Mon, Nov 19, 2018 at 3:22 PM Oleksandr Andrushchenko
> <andr2000@gmail.com> wrote:
>> On 11/15/18 5:49 PM, Souptick Joarder wrote:
>>> Convert to use vm_insert_range() to map range of kernel
>>> memory to user vma.
>>>
>>> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
>>> Reviewed-by: Matthew Wilcox <willy@infradead.org>
>>> ---
>>>    drivers/gpu/drm/xen/xen_drm_front_gem.c | 20 ++++++--------------
>>>    1 file changed, 6 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
>>> index 47ff019..a3eade6 100644
>>> --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
>>> +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
>>> @@ -225,8 +225,7 @@ struct drm_gem_object *
>>>    static int gem_mmap_obj(struct xen_gem_object *xen_obj,
>>>                        struct vm_area_struct *vma)
>>>    {
>>> -     unsigned long addr = vma->vm_start;
>>> -     int i;
>>> +     int err;
>> I would love to keep ret, not err
> Sure, will add it in v2.
> But I think, err is more appropriate here.

I used "ret" throughout the driver, so this is just to remain consistent:

grep -rnw err drivers/gpu/drm/xen/ | wc -l
0
grep -rnw ret drivers/gpu/drm/xen/ | wc -l
204

>>>        /*
>>>         * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
>>> @@ -247,18 +246,11 @@ static int gem_mmap_obj(struct xen_gem_object *xen_obj,
>>>         * FIXME: as we insert all the pages now then no .fault handler must
>>>         * be called, so don't provide one
>>>         */
>>> -     for (i = 0; i < xen_obj->num_pages; i++) {
>>> -             int ret;
>>> -
>>> -             ret = vm_insert_page(vma, addr, xen_obj->pages[i]);
>>> -             if (ret < 0) {
>>> -                     DRM_ERROR("Failed to insert pages into vma: %d\n", ret);
>>> -                     return ret;
>>> -             }
>>> -
>>> -             addr += PAGE_SIZE;
>>> -     }
>>> -     return 0;
>>> +     err = vm_insert_range(vma, vma->vm_start, xen_obj->pages,
>>> +                             xen_obj->num_pages);
>>> +     if (err < 0)
>>> +             DRM_ERROR("Failed to insert pages into vma: %d\n", err);
>>> +     return err;
>>>    }
>>>
>>>    int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>> With the above fixed,
>>
>> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>>
Matthew Wilcox Nov. 19, 2018, 12:29 p.m. UTC | #4 
On Mon, Nov 19, 2018 at 01:02:46PM +0200, Oleksandr Andrushchenko wrote:
> On 11/19/18 12:42 PM, Souptick Joarder wrote:
> > On Mon, Nov 19, 2018 at 3:22 PM Oleksandr Andrushchenko
> > <andr2000@gmail.com> wrote:
> > > > -     unsigned long addr = vma->vm_start;
> > > > -     int i;
> > > > +     int err;
> > > I would love to keep ret, not err
> > Sure, will add it in v2.
> > But I think, err is more appropriate here.
> 
> I used "ret" throughout the driver, so this is just to remain consistent:
> 
> grep -rnw err drivers/gpu/drm/xen/ | wc -l
> 0
> grep -rnw ret drivers/gpu/drm/xen/ | wc -l
> 204

It's your driver, so that's fine.  The reason we chose 'err' over 'ret'
is that there's a history of errno vs VM_FAULT_xxx code confusion in
this area.  Naming a variable 'err' makes it clear this is an errno and
not a vm_fault_t.

> > > With the above fixed,
> > > 
> > > Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Thanks.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 47ff019..a3eade6 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -225,8 +225,7 @@  struct drm_gem_object *
 static int gem_mmap_obj(struct xen_gem_object *xen_obj,
 			struct vm_area_struct *vma)
 {
-	unsigned long addr = vma->vm_start;
-	int i;
+	int err;
 
 	/*
 	 * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
@@ -247,18 +246,11 @@  static int gem_mmap_obj(struct xen_gem_object *xen_obj,
 	 * FIXME: as we insert all the pages now then no .fault handler must
 	 * be called, so don't provide one
 	 */
-	for (i = 0; i < xen_obj->num_pages; i++) {
-		int ret;
-
-		ret = vm_insert_page(vma, addr, xen_obj->pages[i]);
-		if (ret < 0) {
-			DRM_ERROR("Failed to insert pages into vma: %d\n", ret);
-			return ret;
-		}
-
-		addr += PAGE_SIZE;
-	}
-	return 0;
+	err = vm_insert_range(vma, vma->vm_start, xen_obj->pages,
+				xen_obj->num_pages);
+	if (err < 0)
+		DRM_ERROR("Failed to insert pages into vma: %d\n", err);
+	return err;
 }
 
 int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)