| Message ID | 20220412151838.1298956-5-bob.beckett@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: ttm for stolen region | expand |
On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote: > stolen/kernel buffers should not be mmapable by userland. > do not provide callbacks to facilitate this for these buffers. > > Signed-off-by: Robert Beckett <bob.beckett@collabora.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 +++++++++++++++++++++-- > -- > 1 file changed, 27 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > index a878910a563c..b20f81836c54 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct > drm_i915_gem_object *obj) > ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); > } > > -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { > - .name = "i915_gem_object_ttm", > +static const struct drm_i915_gem_object_ops > i915_gem_ttm_user_obj_ops = { > + .name = "i915_gem_object_ttm_user", > .flags = I915_GEM_OBJECT_IS_SHRINKABLE | > I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, > > @@ -1111,6 +1111,21 @@ static const struct drm_i915_gem_object_ops > i915_gem_ttm_obj_ops = { > .mmap_ops = &vm_ops_ttm, > }; > > +static const struct drm_i915_gem_object_ops > i915_gem_ttm_kern_obj_ops = { > + .name = "i915_gem_object_ttm_kern", > + .flags = I915_GEM_OBJECT_IS_SHRINKABLE | > + I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, > + > + .get_pages = i915_ttm_get_pages, > + .put_pages = i915_ttm_put_pages, > + .truncate = i915_ttm_truncate, > + .shrink = i915_ttm_shrink, > + > + .adjust_lru = i915_ttm_adjust_lru, > + .delayed_free = i915_ttm_delayed_free, > + .migrate = i915_ttm_migrate, > +}; Do we really need two different ops here? Since if we don't have mmap ops, basically that tells GEM it should do the mmapping rather than TTM. That might of course come in handy for the shmem backend, but I don't fully follow why we need this for stolen. Also for the framebuffer handed over from BIOS to fbdev, Does that need mmapping and if so, how do we handle that? /Thomas > + > void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) > { > struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); > @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct > intel_memory_region *mem, > .no_wait_gpu = false, > }; > enum ttm_bo_type bo_type; > + const struct drm_i915_gem_object_ops *ops; > int ret; > > drm_gem_private_object_init(&i915->drm, &obj->base, size); > - i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, > flags); > + > + if (flags & I915_BO_ALLOC_USER && > intel_region_to_ttm_type(mem) != I915_PL_STOLEN) { > + bo_type = ttm_bo_type_device; > + ops = &i915_gem_ttm_user_obj_ops; > + } else { > + bo_type = ttm_bo_type_kernel; > + ops = &i915_gem_ttm_kern_obj_ops; > + } > + i915_gem_object_init(obj, ops, &lock_class, flags); > > obj->bo_offset = offset; > > @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct > intel_memory_region *mem, > > INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | > __GFP_NOWARN); > mutex_init(&obj->ttm.get_io_page.lock); > - bo_type = (obj->flags & I915_BO_ALLOC_USER) ? > ttm_bo_type_device : > - ttm_bo_type_kernel; > > obj->base.vma_node.driver_private = i915_gem_to_ttm(obj); >
On 14/04/2022 15:05, Thomas Hellström wrote: > On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote: >> stolen/kernel buffers should not be mmapable by userland. >> do not provide callbacks to facilitate this for these buffers. >> >> Signed-off-by: Robert Beckett <bob.beckett@collabora.com> >> --- >> drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 +++++++++++++++++++++-- >> -- >> 1 file changed, 27 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> index a878910a563c..b20f81836c54 100644 >> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c >> @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct >> drm_i915_gem_object *obj) >> ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); >> } >> >> -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { >> - .name = "i915_gem_object_ttm", >> +static const struct drm_i915_gem_object_ops >> i915_gem_ttm_user_obj_ops = { >> + .name = "i915_gem_object_ttm_user", >> .flags = I915_GEM_OBJECT_IS_SHRINKABLE | >> I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, >> >> @@ -1111,6 +1111,21 @@ static const struct drm_i915_gem_object_ops >> i915_gem_ttm_obj_ops = { >> .mmap_ops = &vm_ops_ttm, >> }; >> >> +static const struct drm_i915_gem_object_ops >> i915_gem_ttm_kern_obj_ops = { >> + .name = "i915_gem_object_ttm_kern", >> + .flags = I915_GEM_OBJECT_IS_SHRINKABLE | >> + I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, >> + >> + .get_pages = i915_ttm_get_pages, >> + .put_pages = i915_ttm_put_pages, >> + .truncate = i915_ttm_truncate, >> + .shrink = i915_ttm_shrink, >> + >> + .adjust_lru = i915_ttm_adjust_lru, >> + .delayed_free = i915_ttm_delayed_free, >> + .migrate = i915_ttm_migrate, >> +}; > > Do we really need two different ops here? > > Since if we don't have mmap ops, basically that tells GEM it should do > the mmapping rather than TTM. > > That might of course come in handy for the shmem backend, but I don't > fully follow why we need this for stolen. the main rationale for doing this was to avoid drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c:can_mmap() presuming that is can use I915_MMAP_TYPE_FIXED As the original backend also did not have mmap_offset handlers for stolen, this seemed like a reasonable design. If desired, we could add a special case for the testing logic, but those special cases have tendency to multiply. > > Also for the framebuffer handed over from BIOS to fbdev, Does that need > mmapping and if so, how do we handle that? > I'm not sure of the usecase there. Do you know of any igt test that tests this? I can investigate further if you do not. > > /Thomas > > > > >> + >> void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) >> { >> struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); >> @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct >> intel_memory_region *mem, >> .no_wait_gpu = false, >> }; >> enum ttm_bo_type bo_type; >> + const struct drm_i915_gem_object_ops *ops; >> int ret; >> >> drm_gem_private_object_init(&i915->drm, &obj->base, size); >> - i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, >> flags); >> + >> + if (flags & I915_BO_ALLOC_USER && >> intel_region_to_ttm_type(mem) != I915_PL_STOLEN) { >> + bo_type = ttm_bo_type_device; >> + ops = &i915_gem_ttm_user_obj_ops; >> + } else { >> + bo_type = ttm_bo_type_kernel; >> + ops = &i915_gem_ttm_kern_obj_ops; >> + } >> + i915_gem_object_init(obj, ops, &lock_class, flags); >> >> obj->bo_offset = offset; >> >> @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct >> intel_memory_region *mem, >> >> INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | >> __GFP_NOWARN); >> mutex_init(&obj->ttm.get_io_page.lock); >> - bo_type = (obj->flags & I915_BO_ALLOC_USER) ? >> ttm_bo_type_device : >> - ttm_bo_type_kernel; >> >> obj->base.vma_node.driver_private = i915_gem_to_ttm(obj); >> > >
Sorry for late reply, On Thu, 2022-04-14 at 17:13 +0100, Robert Beckett wrote: > > > On 14/04/2022 15:05, Thomas Hellström wrote: > > On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote: > > > stolen/kernel buffers should not be mmapable by userland. > > > do not provide callbacks to facilitate this for these buffers. > > > > > > Signed-off-by: Robert Beckett <bob.beckett@collabora.com> > > > --- > > > drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 > > > +++++++++++++++++++++-- > > > -- > > > 1 file changed, 27 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > > > b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > > > index a878910a563c..b20f81836c54 100644 > > > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c > > > @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct > > > drm_i915_gem_object *obj) > > > ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); > > > } > > > > > > -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops > > > = { > > > - .name = "i915_gem_object_ttm", > > > +static const struct drm_i915_gem_object_ops > > > i915_gem_ttm_user_obj_ops = { > > > + .name = "i915_gem_object_ttm_user", > > > .flags = I915_GEM_OBJECT_IS_SHRINKABLE | > > > I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, > > > > > > @@ -1111,6 +1111,21 @@ static const struct > > > drm_i915_gem_object_ops > > > i915_gem_ttm_obj_ops = { > > > .mmap_ops = &vm_ops_ttm, > > > }; > > > > > > +static const struct drm_i915_gem_object_ops > > > i915_gem_ttm_kern_obj_ops = { > > > + .name = "i915_gem_object_ttm_kern", > > > + .flags = I915_GEM_OBJECT_IS_SHRINKABLE | > > > + I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, > > > + > > > + .get_pages = i915_ttm_get_pages, > > > + .put_pages = i915_ttm_put_pages, > > > + .truncate = i915_ttm_truncate, > > > + .shrink = i915_ttm_shrink, > > > + > > > + .adjust_lru = i915_ttm_adjust_lru, > > > + .delayed_free = i915_ttm_delayed_free, > > > + .migrate = i915_ttm_migrate, > > > +}; > > > > Do we really need two different ops here? > > > > Since if we don't have mmap ops, basically that tells GEM it should > > do > > the mmapping rather than TTM. > > > > That might of course come in handy for the shmem backend, but I > > don't > > fully follow why we need this for stolen. > > the main rationale for doing this was to avoid > drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c:can_mmap() > presuming > that is can use I915_MMAP_TYPE_FIXED > > As the original backend also did not have mmap_offset handlers for > stolen, this seemed like a reasonable design. > > If desired, we could add a special case for the testing logic, but > those > special cases have tendency to multiply. > > > > > Also for the framebuffer handed over from BIOS to fbdev, Does that > > need > > mmapping and if so, how do we handle that? > > > > I'm not sure of the usecase there. Do you know of any igt test that > tests this? I can investigate further if you do not. It would be if we the fbdev driver at startup inherits some image that bios has preloaded into stolen, and then a client tries to write into it. Not sure that this is a real use case though, or whether, in that case, that takes a separate path for user-space mappings. /Thomas > > > > > /Thomas > > > > > > > > > > > + > > > void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) > > > { > > > struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); > > > @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct > > > intel_memory_region *mem, > > > .no_wait_gpu = false, > > > }; > > > enum ttm_bo_type bo_type; > > > + const struct drm_i915_gem_object_ops *ops; > > > int ret; > > > > > > drm_gem_private_object_init(&i915->drm, &obj->base, > > > size); > > > - i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, > > > &lock_class, > > > flags); > > > + > > > + if (flags & I915_BO_ALLOC_USER && > > > intel_region_to_ttm_type(mem) != I915_PL_STOLEN) { > > > + bo_type = ttm_bo_type_device; > > > + ops = &i915_gem_ttm_user_obj_ops; > > > + } else { > > > + bo_type = ttm_bo_type_kernel; > > > + ops = &i915_gem_ttm_kern_obj_ops; > > > + } > > > + i915_gem_object_init(obj, ops, &lock_class, flags); > > > > > > obj->bo_offset = offset; > > > > > > @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct > > > intel_memory_region *mem, > > > > > > INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL > > > | > > > __GFP_NOWARN); > > > mutex_init(&obj->ttm.get_io_page.lock); > > > - bo_type = (obj->flags & I915_BO_ALLOC_USER) ? > > > ttm_bo_type_device : > > > - ttm_bo_type_kernel; > > > > > > obj->base.vma_node.driver_private = > > > i915_gem_to_ttm(obj); > > > > > > >
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index a878910a563c..b20f81836c54 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); } -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { - .name = "i915_gem_object_ttm", +static const struct drm_i915_gem_object_ops i915_gem_ttm_user_obj_ops = { + .name = "i915_gem_object_ttm_user", .flags = I915_GEM_OBJECT_IS_SHRINKABLE | I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, @@ -1111,6 +1111,21 @@ static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { .mmap_ops = &vm_ops_ttm, }; +static const struct drm_i915_gem_object_ops i915_gem_ttm_kern_obj_ops = { + .name = "i915_gem_object_ttm_kern", + .flags = I915_GEM_OBJECT_IS_SHRINKABLE | + I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, + + .get_pages = i915_ttm_get_pages, + .put_pages = i915_ttm_put_pages, + .truncate = i915_ttm_truncate, + .shrink = i915_ttm_shrink, + + .adjust_lru = i915_ttm_adjust_lru, + .delayed_free = i915_ttm_delayed_free, + .migrate = i915_ttm_migrate, +}; + void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) { struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem, .no_wait_gpu = false, }; enum ttm_bo_type bo_type; + const struct drm_i915_gem_object_ops *ops; int ret; drm_gem_private_object_init(&i915->drm, &obj->base, size); - i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags); + + if (flags & I915_BO_ALLOC_USER && intel_region_to_ttm_type(mem) != I915_PL_STOLEN) { + bo_type = ttm_bo_type_device; + ops = &i915_gem_ttm_user_obj_ops; + } else { + bo_type = ttm_bo_type_kernel; + ops = &i915_gem_ttm_kern_obj_ops; + } + i915_gem_object_init(obj, ops, &lock_class, flags); obj->bo_offset = offset; @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem, INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN); mutex_init(&obj->ttm.get_io_page.lock); - bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device : - ttm_bo_type_kernel; obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
stolen/kernel buffers should not be mmapable by userland. do not provide callbacks to facilitate this for these buffers. Signed-off-by: Robert Beckett <bob.beckett@collabora.com> --- drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 +++++++++++++++++++++---- 1 file changed, 27 insertions(+), 5 deletions(-)