2017-12-25 14:43:41

by Alexander Kapshuk

Subject: [PATCH] vboxvideo: Fix incorrect type in assignment sparse warning

Sparse emitted the following warning:
../drivers/staging/vboxvideo/vbox_fb.c:173:27: warning: incorrect type in assignment (different address spaces)
../drivers/staging/vboxvideo/vbox_fb.c:173:27: expected char [noderef] <asn:2>*screen_base
../drivers/staging/vboxvideo/vbox_fb.c:173:27: got void *virtual

The vbox_bo buffer object kernel mapping is handled by a call
to ttm_bo_kmap() prior to the assignment of bo->kmap.virtual to
info->screen_base of type char __iomem*.
Casting bo->kmap.virtual to char __iomem* in this assignment fixes
the warning.

vboxvideo: Fix address space of expression removal sparse warning

Sparse emitted the following warning:
../drivers/staging/vboxvideo/vbox_main.c:64:25: warning: cast removes address space of expression

vbox->vbva_buffers iomapping is handled by calling vbox_accel_init()
from vbox_hw_init().
__force attribute is used in assignment to vbva to fix the warning.

Signed-off-by: Alexander Kapshuk <[email protected]>
---
drivers/staging/vboxvideo/vbox_fb.c | 2 +-
drivers/staging/vboxvideo/vbox_main.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/vboxvideo/vbox_fb.c b/drivers/staging/vboxvideo/vbox_fb.c
index 8aed248db6e2..43c39eca4ae1 100644
--- a/drivers/staging/vboxvideo/vbox_fb.c
+++ b/drivers/staging/vboxvideo/vbox_fb.c
@@ -170,7 +170,7 @@ static int vboxfb_create(struct drm_fb_helper *helper,
drm_fb_helper_fill_var(info, &fbdev->helper, sizes->fb_width,
sizes->fb_height);

- info->screen_base = bo->kmap.virtual;
+ info->screen_base = (char __iomem *)bo->kmap.virtual;
info->screen_size = size;

#ifdef CONFIG_DRM_KMS_FB_HELPER
diff --git a/drivers/staging/vboxvideo/vbox_main.c b/drivers/staging/vboxvideo/vbox_main.c
index 80bd039fa08e..973b3bcc04b1 100644
--- a/drivers/staging/vboxvideo/vbox_main.c
+++ b/drivers/staging/vboxvideo/vbox_main.c
@@ -61,7 +61,7 @@ void vbox_enable_accel(struct vbox_private *vbox)
if (vbox->vbva_info[i].vbva)
continue;

- vbva = (void *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
+ vbva = (void __force *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
if (!vbva_enable(&vbox->vbva_info[i],
vbox->guest_pool, vbva, i)) {
/* very old host or driver error. */
--
2.13.6

2018-01-06 14:21:00

by Alexander Kapshuk

Subject: [PATCH] vboxvideo: Fix incorrect type in assignment sparse warning

On Mon, Dec 25, 2017 at 04:42:59PM +0200, Alexander Kapshuk wrote:
> Sparse emitted the following warning:
> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: warning: incorrect type in assignment (different address spaces)
> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: expected char [noderef] <asn:2>*screen_base
> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: got void *virtual
>
> The vbox_bo buffer object kernel mapping is handled by a call
> to ttm_bo_kmap() prior to the assignment of bo->kmap.virtual to
> info->screen_base of type char __iomem*.
> Casting bo->kmap.virtual to char __iomem* in this assignment fixes
> the warning.
>
> vboxvideo: Fix address space of expression removal sparse warning
>
> Sparse emitted the following warning:
> ../drivers/staging/vboxvideo/vbox_main.c:64:25: warning: cast removes address space of expression
>
> vbox->vbva_buffers iomapping is handled by calling vbox_accel_init()
> from vbox_hw_init().
> __force attribute is used in assignment to vbva to fix the warning.
>
> Signed-off-by: Alexander Kapshuk <[email protected]>
> ---
> drivers/staging/vboxvideo/vbox_fb.c | 2 +-
> drivers/staging/vboxvideo/vbox_main.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/vboxvideo/vbox_fb.c b/drivers/staging/vboxvideo/vbox_fb.c
> index 8aed248db6e2..43c39eca4ae1 100644
> --- a/drivers/staging/vboxvideo/vbox_fb.c
> +++ b/drivers/staging/vboxvideo/vbox_fb.c
> @@ -170,7 +170,7 @@ static int vboxfb_create(struct drm_fb_helper *helper,
> drm_fb_helper_fill_var(info, &fbdev->helper, sizes->fb_width,
> sizes->fb_height);
>
> - info->screen_base = bo->kmap.virtual;
> + info->screen_base = (char __iomem *)bo->kmap.virtual;
> info->screen_size = size;
>
> #ifdef CONFIG_DRM_KMS_FB_HELPER
> diff --git a/drivers/staging/vboxvideo/vbox_main.c b/drivers/staging/vboxvideo/vbox_main.c
> index 80bd039fa08e..973b3bcc04b1 100644
> --- a/drivers/staging/vboxvideo/vbox_main.c
> +++ b/drivers/staging/vboxvideo/vbox_main.c
> @@ -61,7 +61,7 @@ void vbox_enable_accel(struct vbox_private *vbox)
> if (vbox->vbva_info[i].vbva)
> continue;
>
> - vbva = (void *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
> + vbva = (void __force *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
> if (!vbva_enable(&vbox->vbva_info[i],
> vbox->guest_pool, vbva, i)) {
> /* very old host or driver error. */
> --
> 2.13.6
>
Ping.

Could someone please comment on the patch above?

Thanks.

2018-01-06 16:01:01

by Hans de Goede

Subject: Re: [PATCH] vboxvideo: Fix incorrect type in assignment sparse warning

Hi,

On 06-01-18 15:20, Alexander Kapshuk wrote:
> On Mon, Dec 25, 2017 at 04:42:59PM +0200, Alexander Kapshuk wrote:
>> Sparse emitted the following warning:
>> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: warning: incorrect type in assignment (different address spaces)
>> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: expected char [noderef] <asn:2>*screen_base
>> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: got void *virtual
>>
>> The vbox_bo buffer object kernel mapping is handled by a call
>> to ttm_bo_kmap() prior to the assignment of bo->kmap.virtual to
>> info->screen_base of type char __iomem*.
>> Casting bo->kmap.virtual to char __iomem* in this assignment fixes
>> the warning.
>>
>> vboxvideo: Fix address space of expression removal sparse warning
>>
>> Sparse emitted the following warning:
>> ../drivers/staging/vboxvideo/vbox_main.c:64:25: warning: cast removes address space of expression
>>
>> vbox->vbva_buffers iomapping is handled by calling vbox_accel_init()
>> from vbox_hw_init().
>> __force attribute is used in assignment to vbva to fix the warning.
>>
>> Signed-off-by: Alexander Kapshuk <[email protected]>
>> ---
>> drivers/staging/vboxvideo/vbox_fb.c | 2 +-
>> drivers/staging/vboxvideo/vbox_main.c | 2 +-
>> 2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/vboxvideo/vbox_fb.c b/drivers/staging/vboxvideo/vbox_fb.c
>> index 8aed248db6e2..43c39eca4ae1 100644
>> --- a/drivers/staging/vboxvideo/vbox_fb.c
>> +++ b/drivers/staging/vboxvideo/vbox_fb.c
>> @@ -170,7 +170,7 @@ static int vboxfb_create(struct drm_fb_helper *helper,
>> drm_fb_helper_fill_var(info, &fbdev->helper, sizes->fb_width,
>> sizes->fb_height);
>>
>> - info->screen_base = bo->kmap.virtual;
>> + info->screen_base = (char __iomem *)bo->kmap.virtual;
>> info->screen_size = size;
>>
>> #ifdef CONFIG_DRM_KMS_FB_HELPER

This fix looks good to me.

>> diff --git a/drivers/staging/vboxvideo/vbox_main.c b/drivers/staging/vboxvideo/vbox_main.c
>> index 80bd039fa08e..973b3bcc04b1 100644
>> --- a/drivers/staging/vboxvideo/vbox_main.c
>> +++ b/drivers/staging/vboxvideo/vbox_main.c
>> @@ -61,7 +61,7 @@ void vbox_enable_accel(struct vbox_private *vbox)
>> if (vbox->vbva_info[i].vbva)
>> continue;
>>
>> - vbva = (void *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
>> + vbva = (void __force *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
>> if (!vbva_enable(&vbox->vbva_info[i],
>> vbox->guest_pool, vbva, i)) {
>> /* very old host or driver error. */

Hmm, isn't there a cleaner way to fix this ? Maybe make vbva_enable's
argument (and the local vbva variable) of type u8 __iomem * too ?

Regards,

Hans