Re: [PATCH 06/11] drm/radeon: stop using TTM_MEMTYPE_FLAG_MAPPABLE

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Jul 22, 2020 at 1:13 PM Christian König
<christian.koenig@amd.com> wrote:
>
> Am 22.07.20 um 07:34 schrieb Daniel Vetter:
> > On Tue, Jul 21, 2020 at 4:46 PM Christian König
> > <ckoenig.leichtzumerken@gmail.com> wrote:
> >> Am 21.07.20 um 11:24 schrieb daniel@ffwll.ch:
> >>> On Tue, Jul 21, 2020 at 09:32:40AM +0200, Christian König wrote:
> >>>> The driver doesn't expose any not-mapable memory resources.
> >>>>
> >>>> Signed-off-by: Christian König <christian.koenig@amd.com>
> >>>> ---
> >>>>    drivers/gpu/drm/radeon/radeon_ttm.c | 13 ++++---------
> >>>>    1 file changed, 4 insertions(+), 9 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> >>>> index 54af06df865b..b474781a0920 100644
> >>>> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> >>>> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> >>>> @@ -76,7 +76,7 @@ static int radeon_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
> >>>>       switch (type) {
> >>>>       case TTM_PL_SYSTEM:
> >>>>               /* System memory */
> >>>> -            man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
> >>>> +            man->flags = 0;
> >>>>               man->available_caching = TTM_PL_MASK_CACHING;
> >>>>               man->default_caching = TTM_PL_FLAG_CACHED;
> >>>>               break;
> >>>> @@ -84,7 +84,7 @@ static int radeon_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
> >>>>               man->func = &ttm_bo_manager_func;
> >>>>               man->available_caching = TTM_PL_MASK_CACHING;
> >>>>               man->default_caching = TTM_PL_FLAG_CACHED;
> >>>> -            man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
> >>>> +            man->flags = 0;
> >>>>    #if IS_ENABLED(CONFIG_AGP)
> >>>>               if (rdev->flags & RADEON_IS_AGP) {
> >>>>                       if (!rdev->ddev->agp) {
> >>>> @@ -92,8 +92,6 @@ static int radeon_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
> >>>>                                         (unsigned)type);
> >>>>                               return -EINVAL;
> >>>>                       }
> >>>> -                    if (!rdev->ddev->agp->cant_use_aperture)
> >>>> -                            man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
> >>> There is a bunch of agp drivers (alpha, ppc, that kind of stuff) with this
> >>> flag set. And radeon.ko did at least once work on these. And your patch to
> >>> disable agp only changes the default, it doesn't rip out the code.
> >> The key pint is that the flags for AGP are the same as the one for the
> >> PCIe path. So no functional change at all :)
> > I misread the code somehow, I didn't spot the unconditional setting of
> > FLAG_MAPPABLE for all TTM_PL_TT, irrespective of agp or not, somehow
> > thought that's another case.
> >
> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
> And for the amdgpu patch? Otherwise I just ping Alex for an rb.

See my question over there, I'm not seeing how the code prevents mmap
for AMDGPU_PL_* domains after your patch. Once that's cleared up happy
to r-b that one and the final one too.
-Daniel

>
> Thanks,
> Christian.
>
> >
> >> The real handling of cant_use_aperture is in radeon_ttm_io_mem_reserve().
> >>
> >> Christian.
> >>
> >>> So not sure your assumption here is correct.
> >>> -Daniel
> >>>
> >>>>                       man->available_caching = TTM_PL_FLAG_UNCACHED |
> >>>>                                                TTM_PL_FLAG_WC;
> >>>>                       man->default_caching = TTM_PL_FLAG_WC;
> >>>> @@ -103,8 +101,7 @@ static int radeon_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
> >>>>       case TTM_PL_VRAM:
> >>>>               /* "On-card" video ram */
> >>>>               man->func = &ttm_bo_manager_func;
> >>>> -            man->flags = TTM_MEMTYPE_FLAG_FIXED |
> >>>> -                         TTM_MEMTYPE_FLAG_MAPPABLE;
> >>>> +            man->flags = TTM_MEMTYPE_FLAG_FIXED;
> >>>>               man->available_caching = TTM_PL_FLAG_UNCACHED | TTM_PL_FLAG_WC;
> >>>>               man->default_caching = TTM_PL_FLAG_WC;
> >>>>               break;
> >>>> @@ -394,7 +391,6 @@ static int radeon_bo_move(struct ttm_buffer_object *bo, bool evict,
> >>>>
> >>>>    static int radeon_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
> >>>>    {
> >>>> -    struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
> >>>>       struct radeon_device *rdev = radeon_get_rdev(bdev);
> >>>>
> >>>>       mem->bus.addr = NULL;
> >>>> @@ -402,8 +398,7 @@ static int radeon_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_
> >>>>       mem->bus.size = mem->num_pages << PAGE_SHIFT;
> >>>>       mem->bus.base = 0;
> >>>>       mem->bus.is_iomem = false;
> >>>> -    if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
> >>>> -            return -EINVAL;
> >>>> +
> >>>>       switch (mem->mem_type) {
> >>>>       case TTM_PL_SYSTEM:
> >>>>               /* system memory */
> >>>> --
> >>>> 2.17.1
> >>>>
> >>>> _______________________________________________
> >>>> dri-devel mailing list
> >>>> dri-devel@lists.freedesktop.org
> >>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&amp;data=02%7C01%7Cchristian.koenig%40amd.com%7C2fb0200ef32f4afcc3e208d82e00ef7d%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637309928847998899&amp;sdata=9VclRJ7e3xfohsaLsiVF6Y83c%2Bkncmbo5uqoeV6tT9M%3D&amp;reserved=0
> >
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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