On Fri, Oct 13, 2023 at 02:30:29PM +0200, Thomas Hellström wrote:
> On Mon, 2023-10-09 at 01:32 +0200, Danilo Krummrich wrote:
> > Add an abstraction layer between the drm_gpuva mappings of a
> > particular
> > drm_gem_object and this GEM object itself. The abstraction represents
> > a
> > combination of a drm_gem_object and drm_gpuvm. The drm_gem_object
> > holds
> > a list of drm_gpuvm_bo structures (the structure representing this
> > abstraction), while each drm_gpuvm_bo contains list of mappings of
> > this
> > GEM object.
> >
> > This has multiple advantages:
> >
> > 1) We can use the drm_gpuvm_bo structure to attach it to various
> > lists
> > of the drm_gpuvm. This is useful for tracking external and evicted
> > objects per VM, which is introduced in subsequent patches.
> >
> > 2) Finding mappings of a certain drm_gem_object mapped in a certain
> > drm_gpuvm becomes much cheaper.
> >
> > 3) Drivers can derive and extend the structure to easily represent
> > driver specific states of a BO for a certain GPUVM.
> >
> > The idea of this abstraction was taken from amdgpu, hence the credit
> > for
> > this idea goes to the developers of amdgpu.
> >
> > Cc: Christian König <christian.koenig@xxxxxxx>
> > Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
> > ---
> > drivers/gpu/drm/drm_gpuvm.c | 332 +++++++++++++++++++++--
> > --
> > drivers/gpu/drm/nouveau/nouveau_uvmm.c | 64 +++--
> > include/drm/drm_gem.h | 32 +--
> > include/drm/drm_gpuvm.h | 177 ++++++++++++-
> > 4 files changed, 521 insertions(+), 84 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_gpuvm.c
> > b/drivers/gpu/drm/drm_gpuvm.c
> > index 6368dfdbe9dd..28282283ddaf 100644
> > --- a/drivers/gpu/drm/drm_gpuvm.c
> > +++ b/drivers/gpu/drm/drm_gpuvm.c
> > @@ -70,6 +70,18 @@
> > * &drm_gem_object, such as the &drm_gem_object containing the root
> > page table,
> > * but it can also be a 'dummy' object, which can be allocated with
> > * drm_gpuvm_root_object_alloc().
> > + *
> > + * In order to connect a struct drm_gpuva its backing
> > &drm_gem_object each
> NIT: Same as previous patch regarding kerneldoc references
I was intentionally using generic references here to make the documentation
more readable while still keeping references to be able to look up the
structure's fields.
>
> > + * &drm_gem_object maintains a list of &drm_gpuvm_bo structures, and
> > each
> > + * &drm_gpuvm_bo contains a list of &&drm_gpuva structures.
> > + *
> > + * A &drm_gpuvm_bo is an abstraction that represents a combination
> > of a
> > + * &drm_gpuvm and a &drm_gem_object. Every such combination should
> > be unique.
> > + * This is ensured by the API through drm_gpuvm_bo_obtain() and
> > + * drm_gpuvm_bo_obtain_prealloc() which first look into the
> > corresponding
> > + * &drm_gem_object list of &drm_gpuvm_bos for an existing instance
> > of this
> > + * particular combination. If not existent a new instance is created
> > and linked
> > + * to the &drm_gem_object.
> > */
> >
> > /**
> > @@ -395,21 +407,28 @@
> > /**
> > * DOC: Locking
> > *
> > - * Generally, the GPU VA manager does not take care of locking
> > itself, it is
> > - * the drivers responsibility to take care about locking. Drivers
> > might want to
> > - * protect the following operations: inserting, removing and
> > iterating
> > - * &drm_gpuva objects as well as generating all kinds of operations,
> > such as
> > - * split / merge or prefetch.
> > - *
> > - * The GPU VA manager also does not take care of the locking of the
> > backing
> > - * &drm_gem_object buffers GPU VA lists by itself; drivers are
> > responsible to
> > - * enforce mutual exclusion using either the GEMs dma_resv lock or
> > alternatively
> > - * a driver specific external lock. For the latter see also
> > - * drm_gem_gpuva_set_lock().
> > - *
> > - * However, the GPU VA manager contains lockdep checks to ensure
> > callers of its
> > - * API hold the corresponding lock whenever the &drm_gem_objects GPU
> > VA list is
> > - * accessed by functions such as drm_gpuva_link() or
> > drm_gpuva_unlink().
> > + * In terms of managing &drm_gpuva entries DRM GPUVM does not take
> > care of
> > + * locking itself, it is the drivers responsibility to take care
> > about locking.
> > + * Drivers might want to protect the following operations:
> > inserting, removing
> > + * and iterating &drm_gpuva objects as well as generating all kinds
> > of
> > + * operations, such as split / merge or prefetch.
> > + *
> > + * DRM GPUVM also does not take care of the locking of the backing
> > + * &drm_gem_object buffers GPU VA lists and &drm_gpuvm_bo
> > abstractions by
> > + * itself; drivers are responsible to enforce mutual exclusion using
> > either the
> > + * GEMs dma_resv lock or alternatively a driver specific external
> > lock. For the
> > + * latter see also drm_gem_gpuva_set_lock().
> > + *
> > + * However, DRM GPUVM contains lockdep checks to ensure callers of
> > its API hold
> > + * the corresponding lock whenever the &drm_gem_objects GPU VA list
> > is accessed
> > + * by functions such as drm_gpuva_link() or drm_gpuva_unlink(), but
> > also
> > + * drm_gpuvm_bo_obtain() and drm_gpuvm_bo_put().
> > + *
> > + * The latter is required since on creation and destruction of a
> > &drm_gpuvm_bo
> > + * the &drm_gpuvm_bo is attached / removed from the &drm_gem_objects
> > gpuva list.
> > + * Subsequent calls to drm_gpuvm_bo_obtain() for the same &drm_gpuvm
> > and
> > + * &drm_gem_object must be able to observe previous creations and
> > destructions
> > + * of &drm_gpuvm_bos in order to keep instances unique.
> > */
> >
> > /**
> > @@ -439,6 +458,7 @@
> > * {
> > * struct drm_gpuva_ops *ops;
> > * struct drm_gpuva_op *op
> > + * struct drm_gpuvm_bo *vm_bo;
> > *
> > * driver_lock_va_space();
> > * ops = drm_gpuvm_sm_map_ops_create(gpuvm, addr, range,
> > @@ -446,6 +466,10 @@
> > * if (IS_ERR(ops))
> > * return PTR_ERR(ops);
> > *
> > + * vm_bo = drm_gpuvm_bo_obtain(gpuvm, obj);
> > + * if (IS_ERR(vm_bo))
> > + * return PTR_ERR(vm_bo);
> > + *
> > * drm_gpuva_for_each_op(op, ops) {
> > * struct drm_gpuva *va;
> > *
> > @@ -458,7 +482,7 @@
> > *
> > * driver_vm_map();
> > * drm_gpuva_map(gpuvm, va, &op->map);
> > - * drm_gpuva_link(va);
> > + * drm_gpuva_link(va, vm_bo);
> > *
> > * break;
> > * case DRM_GPUVA_OP_REMAP: {
> > @@ -485,11 +509,11 @@
> > * driver_vm_remap();
> > * drm_gpuva_remap(prev, next, &op-
> > >remap);
> > *
> > - * drm_gpuva_unlink(va);
> > * if (prev)
> > - * drm_gpuva_link(prev);
> > + * drm_gpuva_link(prev, va-
> > >vm_bo);
> > * if (next)
> > - * drm_gpuva_link(next);
> > + * drm_gpuva_link(next, va-
> > >vm_bo);
> > + * drm_gpuva_unlink(va);
> > *
> > * break;
> > * }
> > @@ -505,6 +529,7 @@
> > * break;
> > * }
> > * }
> > + * drm_gpuvm_bo_put(vm_bo);
> > * driver_unlock_va_space();
> > *
> > * return 0;
> > @@ -514,6 +539,7 @@
> > *
> > * struct driver_context {
> > * struct drm_gpuvm *gpuvm;
> > + * struct drm_gpuvm_bo *vm_bo;
> > * struct drm_gpuva *new_va;
> > * struct drm_gpuva *prev_va;
> > * struct drm_gpuva *next_va;
> > @@ -534,6 +560,7 @@
> > * struct drm_gem_object *obj, u64
> > offset)
> > * {
> > * struct driver_context ctx;
> > + * struct drm_gpuvm_bo *vm_bo;
> > * struct drm_gpuva_ops *ops;
> > * struct drm_gpuva_op *op;
> > * int ret = 0;
> > @@ -543,16 +570,23 @@
> > * ctx.new_va = kzalloc(sizeof(*ctx.new_va),
> > GFP_KERNEL);
> > * ctx.prev_va = kzalloc(sizeof(*ctx.prev_va),
> > GFP_KERNEL);
> > * ctx.next_va = kzalloc(sizeof(*ctx.next_va),
> > GFP_KERNEL);
> > - * if (!ctx.new_va || !ctx.prev_va || !ctx.next_va) {
> > + * ctx.vm_bo = drm_gpuvm_bo_create(gpuvm, obj);
> > + * if (!ctx.new_va || !ctx.prev_va || !ctx.next_va ||
> > !vm_bo) {
> > * ret = -ENOMEM;
> > * goto out;
> > * }
> > *
> > + * // Typically protected with a driver specific GEM
> > gpuva lock
> > + * // used in the fence signaling path for
> > drm_gpuva_link() and
> > + * // drm_gpuva_unlink(), hence pre-allocate.
> > + * ctx.vm_bo = drm_gpuvm_bo_obtain_prealloc(ctx.vm_bo);
> > + *
> > * driver_lock_va_space();
> > * ret = drm_gpuvm_sm_map(gpuvm, &ctx, addr, range, obj,
> > offset);
> > * driver_unlock_va_space();
> > *
> > * out:
> > + * drm_gpuvm_bo_put(ctx.vm_bo);
> > * kfree(ctx.new_va);
> > * kfree(ctx.prev_va);
> > * kfree(ctx.next_va);
> > @@ -565,7 +599,7 @@
> > *
> > * drm_gpuva_map(ctx->vm, ctx->new_va, &op->map);
> > *
> > - * drm_gpuva_link(ctx->new_va);
> > + * drm_gpuva_link(ctx->new_va, ctx->vm_bo);
> > *
> > * // prevent the new GPUVA from being freed in
> > * // driver_mapping_create()
> > @@ -577,22 +611,23 @@
> > * int driver_gpuva_remap(struct drm_gpuva_op *op, void *__ctx)
> > * {
> > * struct driver_context *ctx = __ctx;
> > + * struct drm_gpuva *va = op->remap.unmap->va;
> > *
> > * drm_gpuva_remap(ctx->prev_va, ctx->next_va, &op-
> > >remap);
> > *
> > - * drm_gpuva_unlink(op->remap.unmap->va);
> > - * kfree(op->remap.unmap->va);
> > - *
> > * if (op->remap.prev) {
> > - * drm_gpuva_link(ctx->prev_va);
> > + * drm_gpuva_link(ctx->prev_va, va->vm_bo);
> > * ctx->prev_va = NULL;
> > * }
> > *
> > * if (op->remap.next) {
> > - * drm_gpuva_link(ctx->next_va);
> > + * drm_gpuva_link(ctx->next_va, va->vm_bo);
> > * ctx->next_va = NULL;
> > * }
> > *
> > + * drm_gpuva_unlink(va);
> > + * kfree(va);
> > + *
> > * return 0;
> > * }
> > *
> > @@ -771,6 +806,194 @@ drm_gpuvm_destroy(struct drm_gpuvm *gpuvm)
> > }
> > EXPORT_SYMBOL_GPL(drm_gpuvm_destroy);
> >
> > +/**
> > + * drm_gpuvm_bo_create() - create a new instance of struct
> > drm_gpuvm_bo
> > + * @gpuvm: The &drm_gpuvm the @obj is mapped in.
> > + * @obj: The &drm_gem_object being mapped in the @gpuvm.
> > + *
> > + * If provided by the driver, this function uses the &drm_gpuvm_ops
> > + * vm_bo_alloc() callback to allocate.
> > + *
> > + * Returns: a pointer to the &drm_gpuvm_bo on success, NULL on
>
> Kerneldoc uses "Return:" rather than "Returns:", (This seems to a
> common thing throughout the series).
Gonna fix.
>
> > failure
> > + */
> > +struct drm_gpuvm_bo *
>
> Any particular reason there's line-break after the function type even
> when it fits the ~100 char limit?
Nope, just for consistency thoughout this source file.
>
> > +drm_gpuvm_bo_create(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj)
>
>
>
> > +{
> > + const struct drm_gpuvm_ops *ops = gpuvm->ops;
> > + struct drm_gpuvm_bo *vm_bo;
> > +
> > + if (ops && ops->vm_bo_alloc)
> > + vm_bo = ops->vm_bo_alloc();
> > + else
> > + vm_bo = kzalloc(sizeof(*vm_bo), GFP_KERNEL);
> > +
> > + if (unlikely(!vm_bo))
> > + return NULL;
> > +
> > + vm_bo->vm = gpuvm;
> > + vm_bo->obj = obj;
> > +
> > + kref_init(&vm_bo->kref);
> > + INIT_LIST_HEAD(&vm_bo->list.gpuva);
> > + INIT_LIST_HEAD(&vm_bo->list.entry.gem);
> > +
> > + drm_gem_object_get(obj);
>
> Perhaps group this with the vm_bo->obj assignment to emphasize that
> that's the pointer that gets the reference?
Yep, makes sense.
>
> > +
> > + return vm_bo;
> > +}
> > +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_create);
> > +
> > +static void
> > +drm_gpuvm_bo_destroy(struct kref *kref)
> > +{
> > + struct drm_gpuvm_bo *vm_bo = container_of(kref, struct
> > drm_gpuvm_bo,
> > + kref);
> > + struct drm_gpuvm *gpuvm = vm_bo->vm;
> > + const struct drm_gpuvm_ops *ops = gpuvm->ops;
> > + struct drm_gem_object *obj = vm_bo->obj;
> > + bool lock = !drm_gpuvm_resv_protected(gpuvm);
> > +
> > + drm_gem_gpuva_assert_lock_held(obj);
> > + if (!lock)
> > + drm_gpuvm_resv_assert_held(gpuvm);
> > +
> > + list_del(&vm_bo->list.entry.gem);
> > +
> > + drm_gem_object_put(obj);
>
> Not sure if we have any drivers utilizing vm_bo_free() yet, but it
> might make sense to move the drm_gem_object_put() until after the
> freeing below, in case vm_bo_free() wants to use it?
Good point, gonna fix.
>
> > +
> > + if (ops && ops->vm_bo_free)
> > + ops->vm_bo_free(vm_bo);
> > + else
> > + kfree(vm_bo);
> > +}
> > +
> > +/**
> > + * drm_gpuvm_bo_put() - drop a struct drm_gpuvm_bo reference
> > + * @vm_bo: the &drm_gpuvm_bo to release the reference of
> > + *
> > + * This releases a reference to @vm_bo.
> > + *
> > + * If the reference count drops to zero, the &gpuvm_bo is destroyed,
> > which
> > + * includes removing it from the GEMs gpuva list. Hence, if a call
> > to this
> > + * function can potentially let the reference count to zero the
> > caller must
> > + * hold the dma-resv or driver specific GEM gpuva lock.
> > + */
> > +void
> > +drm_gpuvm_bo_put(struct drm_gpuvm_bo *vm_bo)
> > +{
> > + if (vm_bo)
> > + kref_put(&vm_bo->kref, drm_gpuvm_bo_destroy);
> > +}
> > +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_put);
> > +
> > +static struct drm_gpuvm_bo *
> > +__drm_gpuvm_bo_find(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj)
> > +{
> > + struct drm_gpuvm_bo *vm_bo;
> > +
> > + drm_gem_gpuva_assert_lock_held(obj);
> > +
> > + drm_gem_for_each_gpuvm_bo(vm_bo, obj)
> > + if (vm_bo->vm == gpuvm)
> > + return vm_bo;
> > +
> > + return NULL;
> > +}
> > +
> > +/**
> > + * drm_gpuvm_bo_find() - find the &drm_gpuvm_bo for the given
> > + * &drm_gpuvm and &drm_gem_object
> > + * @gpuvm: The &drm_gpuvm the @obj is mapped in.
> > + * @obj: The &drm_gem_object being mapped in the @gpuvm.
> > + *
> > + * Find the &drm_gpuvm_bo representing the combination of the given
> > + * &drm_gpuvm and &drm_gem_object. If found, increases the reference
> > + * count of the &drm_gpuvm_bo accordingly.
> > + *
> > + * Returns: a pointer to the &drm_gpuvm_bo on success, NULL on
> > failure
> > + */
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_find(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj)
> > +{
> > + struct drm_gpuvm_bo *vm_bo = __drm_gpuvm_bo_find(gpuvm, obj);
> > +
> > + return vm_bo ? drm_gpuvm_bo_get(vm_bo) : NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_find);
> > +
> > +/**
> > + * drm_gpuvm_bo_obtain() - obtains and instance of the &drm_gpuvm_bo
> > for the
> > + * given &drm_gpuvm and &drm_gem_object
> > + * @gpuvm: The &drm_gpuvm the @obj is mapped in.
> > + * @obj: The &drm_gem_object being mapped in the @gpuvm.
> > + *
> > + * Find the &drm_gpuvm_bo representing the combination of the given
> > + * &drm_gpuvm and &drm_gem_object. If found, increases the reference
> > + * count of the &drm_gpuvm_bo accordingly. If not found, allocates a
> > new
> > + * &drm_gpuvm_bo.
> > + *
> > + * A new &drm_gpuvm_bo is added to the GEMs gpuva list.
> > + *
> > + * Returns: a pointer to the &drm_gpuvm_bo on success, an ERR_PTR on
> > failure
> > + */
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_obtain(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj)
> > +{
> > + struct drm_gpuvm_bo *vm_bo;
> > +
> > + vm_bo = drm_gpuvm_bo_find(gpuvm, obj);
> > + if (vm_bo)
> > + return vm_bo;
> > +
> > + vm_bo = drm_gpuvm_bo_create(gpuvm, obj);
> > + if (!vm_bo)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + list_add_tail(&vm_bo->list.entry.gem, &obj->gpuva.list);
>
> Lockdep check?
Is inherited by drm_gpuvm_bo_find(), but I can also be explicit here.
>
> > +
> > + return vm_bo;
> > +}
> > +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_obtain);
> > +
> > +/**
> > + * drm_gpuvm_bo_obtain_prealloc() - obtains and instance of the
> > &drm_gpuvm_bo
> > + * for the given &drm_gpuvm and &drm_gem_object
> > + * @__vm_bo: A pre-allocated struct drm_gpuvm_bo.
> > + *
> > + * Find the &drm_gpuvm_bo representing the combination of the given
> > + * &drm_gpuvm and &drm_gem_object. If found, increases the reference
> > + * count of the found &drm_gpuvm_bo accordingly, while the @__vm_bo
> > reference
> > + * count is decreased. If not found @__vm_bo is returned without
> > further
> > + * increase of the reference count.
> > + *
> > + * A new &drm_gpuvm_bo is added to the GEMs gpuva list.
> > + *
> > + * Returns: a pointer to the found &drm_gpuvm_bo or @__vm_bo if no
> > existing
> > + * &drm_gpuvm_bo was found
> > + */
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_obtain_prealloc(struct drm_gpuvm_bo *__vm_bo)
> > +{
> > + struct drm_gpuvm *gpuvm = __vm_bo->vm;
> > + struct drm_gem_object *obj = __vm_bo->obj;
> > + struct drm_gpuvm_bo *vm_bo;
> > +
> > + vm_bo = drm_gpuvm_bo_find(gpuvm, obj);
> > + if (vm_bo) {
> > + drm_gpuvm_bo_put(__vm_bo);
> > + return vm_bo;
> > + }
> > +
> > + list_add_tail(&__vm_bo->list.entry.gem, &obj->gpuva.list);
>
> Perhaps a lockdep check here?
Same as above.
>
> > +
> > + return __vm_bo;
> > +}
> > +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_obtain_prealloc);
> > +
> > static int
> > __drm_gpuva_insert(struct drm_gpuvm *gpuvm,
> > struct drm_gpuva *va)
> > @@ -860,24 +1083,33 @@ EXPORT_SYMBOL_GPL(drm_gpuva_remove);
> > /**
> > * drm_gpuva_link() - link a &drm_gpuva
> > * @va: the &drm_gpuva to link
> > + * @vm_bo: the &drm_gpuvm_bo to add the &drm_gpuva to
> > *
> > - * This adds the given &va to the GPU VA list of the &drm_gem_object
> > it is
> > - * associated with.
> > + * This adds the given &va to the GPU VA list of the &drm_gpuvm_bo
> > and the
> > + * &drm_gpuvm_bo to the &drm_gem_object it is associated with.
> > + *
> > + * For every &drm_gpuva entry added to the &drm_gpuvm_bo an
> > additional
> > + * reference of the latter is taken.
> > *
> > * This function expects the caller to protect the GEM's GPUVA list
> > against
>
> NIT: Referring to a "gem object" as a "GEM" catches my eye every time.
> Perhaps that has become common practice? With my "it used to be like.."
> hat on, I'd use gem object.
I think this is the way it referred to in a lot of places, e.g. drm_exe.c,
drm_gem.c, etc. Hence, I'd like to stick with that.
>
> > - * concurrent access using the GEMs dma_resv lock.
> > + * concurrent access using either the GEMs dma_resv lock or a driver
> > specific
> > + * lock set through drm_gem_gpuva_set_lock().
> > */
> > void
> > -drm_gpuva_link(struct drm_gpuva *va)
> > +drm_gpuva_link(struct drm_gpuva *va, struct drm_gpuvm_bo *vm_bo)
> > {
> > struct drm_gem_object *obj = va->gem.obj;
> >
> > if (unlikely(!obj))
> > return;
> >
> > + WARN_ON(obj != vm_bo->obj);
>
> Can we use drm_WARN here?
Sure!
>
> > drm_gem_gpuva_assert_lock_held(obj);
> >
> > - list_add_tail(&va->gem.entry, &obj->gpuva.list);
> > + drm_gpuvm_bo_get(vm_bo);
> > +
> > + va->vm_bo = vm_bo;
> > + list_add_tail(&va->gem.entry, &vm_bo->list.gpuva);
> > }
> > EXPORT_SYMBOL_GPL(drm_gpuva_link);
> >
> > @@ -888,13 +1120,22 @@ EXPORT_SYMBOL_GPL(drm_gpuva_link);
> > * This removes the given &va from the GPU VA list of the
> > &drm_gem_object it is
> > * associated with.
> > *
> > + * This removes the given &va from the GPU VA list of the
> > &drm_gpuvm_bo and
> > + * the &drm_gpuvm_bo from the &drm_gem_object it is associated with
> > in case
> > + * this call unlinks the last &drm_gpuva from the &drm_gpuvm_bo.
> > + *
> > + * For every &drm_gpuva entry removed from the &drm_gpuvm_bo a
> > reference of
> > + * the latter is dropped.
> > + *
> > * This function expects the caller to protect the GEM's GPUVA list
> > against
> > - * concurrent access using the GEMs dma_resv lock.
> > + * concurrent access using either the GEMs dma_resv lock or a driver
> > specific
> > + * lock set through drm_gem_gpuva_set_lock().
> > */
> > void
> > drm_gpuva_unlink(struct drm_gpuva *va)
> > {
> > struct drm_gem_object *obj = va->gem.obj;
> > + struct drm_gpuvm_bo *vm_bo = va->vm_bo;
> >
> > if (unlikely(!obj))
> > return;
> > @@ -902,6 +1143,9 @@ drm_gpuva_unlink(struct drm_gpuva *va)
> > drm_gem_gpuva_assert_lock_held(obj);
> >
> > list_del_init(&va->gem.entry);
> > + va->vm_bo = NULL;
> > +
> > + drm_gpuvm_bo_put(vm_bo);
> > }
> > EXPORT_SYMBOL_GPL(drm_gpuva_unlink);
> >
> > @@ -1046,10 +1290,10 @@ drm_gpuva_remap(struct drm_gpuva *prev,
> > struct drm_gpuva *next,
> > struct drm_gpuva_op_remap *op)
> > {
> > - struct drm_gpuva *curr = op->unmap->va;
> > - struct drm_gpuvm *gpuvm = curr->vm;
> > + struct drm_gpuva *va = op->unmap->va;
> > + struct drm_gpuvm *gpuvm = va->vm;
> >
> > - drm_gpuva_remove(curr);
> > + drm_gpuva_remove(va);
> >
> > if (op->prev) {
> > drm_gpuva_init_from_op(prev, op->prev);
> > @@ -1693,9 +1937,8 @@ drm_gpuvm_prefetch_ops_create(struct drm_gpuvm
> > *gpuvm,
> > EXPORT_SYMBOL_GPL(drm_gpuvm_prefetch_ops_create);
> >
> > /**
> > - * drm_gpuvm_gem_unmap_ops_create() - creates the &drm_gpuva_ops to
> > unmap a GEM
> > - * @gpuvm: the &drm_gpuvm representing the GPU VA space
> > - * @obj: the &drm_gem_object to unmap
> > + * drm_gpuvm_bo_unmap_ops_create() - creates the &drm_gpuva_ops to
> > unmap a GEM
> > + * @vm_bo: the &drm_gpuvm_bo abstraction
> > *
> > * This function creates a list of operations to perform unmapping
> > for every
> > * GPUVA attached to a GEM.
> > @@ -1712,15 +1955,14 @@
> > EXPORT_SYMBOL_GPL(drm_gpuvm_prefetch_ops_create);
> > * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR
> > on failure
> > */
> > struct drm_gpuva_ops *
> > -drm_gpuvm_gem_unmap_ops_create(struct drm_gpuvm *gpuvm,
> > - struct drm_gem_object *obj)
> > +drm_gpuvm_bo_unmap_ops_create(struct drm_gpuvm_bo *vm_bo)
> > {
> > struct drm_gpuva_ops *ops;
> > struct drm_gpuva_op *op;
> > struct drm_gpuva *va;
> > int ret;
> >
> > - drm_gem_gpuva_assert_lock_held(obj);
> > + drm_gem_gpuva_assert_lock_held(vm_bo->obj);
> >
> > ops = kzalloc(sizeof(*ops), GFP_KERNEL);
> > if (!ops)
> > @@ -1728,8 +1970,8 @@ drm_gpuvm_gem_unmap_ops_create(struct drm_gpuvm
> > *gpuvm,
> >
> > INIT_LIST_HEAD(&ops->list);
> >
> > - drm_gem_for_each_gpuva(va, obj) {
> > - op = gpuva_op_alloc(gpuvm);
> > + drm_gpuvm_bo_for_each_va(va, vm_bo) {
> > + op = gpuva_op_alloc(vm_bo->vm);
> > if (!op) {
> > ret = -ENOMEM;
> > goto err_free_ops;
> > @@ -1743,10 +1985,10 @@ drm_gpuvm_gem_unmap_ops_create(struct
> > drm_gpuvm *gpuvm,
> > return ops;
> >
> > err_free_ops:
> > - drm_gpuva_ops_free(gpuvm, ops);
> > + drm_gpuva_ops_free(vm_bo->vm, ops);
> > return ERR_PTR(ret);
> > }
> > -EXPORT_SYMBOL_GPL(drm_gpuvm_gem_unmap_ops_create);
> > +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_unmap_ops_create);
> >
> > /**
> > * drm_gpuva_ops_free() - free the given &drm_gpuva_ops
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> > b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> > index 93ad2ba7ec8b..4e46f850e65f 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> > @@ -62,6 +62,8 @@ struct bind_job_op {
> > enum vm_bind_op op;
> > u32 flags;
> >
> > + struct drm_gpuvm_bo *vm_bo;
> > +
> > struct {
> > u64 addr;
> > u64 range;
> > @@ -1113,22 +1115,28 @@ bind_validate_region(struct nouveau_job *job)
> > }
> >
> > static void
> > -bind_link_gpuvas(struct drm_gpuva_ops *ops, struct
> > nouveau_uvma_prealloc *new)
> > +bind_link_gpuvas(struct bind_job_op *bop)
> > {
> > + struct nouveau_uvma_prealloc *new = &bop->new;
> > + struct drm_gpuvm_bo *vm_bo = bop->vm_bo;
> > + struct drm_gpuva_ops *ops = bop->ops;
> > struct drm_gpuva_op *op;
> >
> > drm_gpuva_for_each_op(op, ops) {
> > switch (op->op) {
> > case DRM_GPUVA_OP_MAP:
> > - drm_gpuva_link(&new->map->va);
> > + drm_gpuva_link(&new->map->va, vm_bo);
> > break;
> > - case DRM_GPUVA_OP_REMAP:
> > + case DRM_GPUVA_OP_REMAP: {
> > + struct drm_gpuva *va = op->remap.unmap->va;
> > +
> > if (op->remap.prev)
> > - drm_gpuva_link(&new->prev->va);
> > + drm_gpuva_link(&new->prev->va, va-
> > >vm_bo);
> > if (op->remap.next)
> > - drm_gpuva_link(&new->next->va);
> > - drm_gpuva_unlink(op->remap.unmap->va);
> > + drm_gpuva_link(&new->next->va, va-
> > >vm_bo);
> > + drm_gpuva_unlink(va);
> > break;
> > + }
> > case DRM_GPUVA_OP_UNMAP:
> > drm_gpuva_unlink(op->unmap.va);
> > break;
> > @@ -1150,10 +1158,18 @@ nouveau_uvmm_bind_job_submit(struct
> > nouveau_job *job)
> >
> > list_for_each_op(op, &bind_job->ops) {
> > if (op->op == OP_MAP) {
> > - op->gem.obj = drm_gem_object_lookup(job-
> > >file_priv,
> > - op-
> > >gem.handle);
> > - if (!op->gem.obj)
> > + struct drm_gem_object *obj;
> > +
> > + obj = drm_gem_object_lookup(job->file_priv,
> > + op->gem.handle);
> > + if (!(op->gem.obj = obj))
> > return -ENOENT;
> > +
> > + dma_resv_lock(obj->resv, NULL);
> > + op->vm_bo = drm_gpuvm_bo_obtain(&uvmm->base,
> > obj);
> > + dma_resv_unlock(obj->resv);
> > + if (IS_ERR(op->vm_bo))
> > + return PTR_ERR(op->vm_bo);
> > }
> >
> > ret = bind_validate_op(job, op);
> > @@ -1364,7 +1380,7 @@ nouveau_uvmm_bind_job_submit(struct nouveau_job
> > *job)
> > case OP_UNMAP_SPARSE:
> > case OP_MAP:
> > case OP_UNMAP:
> > - bind_link_gpuvas(op->ops, &op->new);
> > + bind_link_gpuvas(op);
> > break;
> > default:
> > break;
> > @@ -1511,6 +1527,12 @@ nouveau_uvmm_bind_job_free_work_fn(struct
> > work_struct *work)
> > if (!IS_ERR_OR_NULL(op->ops))
> > drm_gpuva_ops_free(&uvmm->base, op->ops);
> >
> > + if (!IS_ERR_OR_NULL(op->vm_bo)) {
> > + dma_resv_lock(obj->resv, NULL);
> > + drm_gpuvm_bo_put(op->vm_bo);
> > + dma_resv_unlock(obj->resv);
> > + }
> > +
> > if (obj)
> > drm_gem_object_put(obj);
> > }
> > @@ -1776,15 +1798,18 @@ void
> > nouveau_uvmm_bo_map_all(struct nouveau_bo *nvbo, struct nouveau_mem
> > *mem)
> > {
> > struct drm_gem_object *obj = &nvbo->bo.base;
> > + struct drm_gpuvm_bo *vm_bo;
> > struct drm_gpuva *va;
> >
> > dma_resv_assert_held(obj->resv);
> >
> > - drm_gem_for_each_gpuva(va, obj) {
> > - struct nouveau_uvma *uvma = uvma_from_va(va);
> > + drm_gem_for_each_gpuvm_bo(vm_bo, obj) {
> > + drm_gpuvm_bo_for_each_va(va, vm_bo) {
> > + struct nouveau_uvma *uvma = uvma_from_va(va);
> >
> > - nouveau_uvma_map(uvma, mem);
> > - drm_gpuva_invalidate(va, false);
> > + nouveau_uvma_map(uvma, mem);
> > + drm_gpuva_invalidate(va, false);
> > + }
> > }
> > }
> >
> > @@ -1792,15 +1817,18 @@ void
> > nouveau_uvmm_bo_unmap_all(struct nouveau_bo *nvbo)
> > {
> > struct drm_gem_object *obj = &nvbo->bo.base;
> > + struct drm_gpuvm_bo *vm_bo;
> > struct drm_gpuva *va;
> >
> > dma_resv_assert_held(obj->resv);
> >
> > - drm_gem_for_each_gpuva(va, obj) {
> > - struct nouveau_uvma *uvma = uvma_from_va(va);
> > + drm_gem_for_each_gpuvm_bo(vm_bo, obj) {
> > + drm_gpuvm_bo_for_each_va(va, vm_bo) {
> > + struct nouveau_uvma *uvma = uvma_from_va(va);
> >
> > - nouveau_uvma_unmap(uvma);
> > - drm_gpuva_invalidate(va, true);
> > + nouveau_uvma_unmap(uvma);
> > + drm_gpuva_invalidate(va, true);
> > + }
> > }
> > }
> >
> > diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> > index 16364487fde9..369505447acd 100644
> > --- a/include/drm/drm_gem.h
> > +++ b/include/drm/drm_gem.h
> > @@ -580,7 +580,7 @@ int drm_gem_evict(struct drm_gem_object *obj);
> > * drm_gem_gpuva_init() - initialize the gpuva list of a GEM object
> > * @obj: the &drm_gem_object
> > *
> > - * This initializes the &drm_gem_object's &drm_gpuva list.
> > + * This initializes the &drm_gem_object's &drm_gpuvm_bo list.
> > *
> > * Calling this function is only necessary for drivers intending to
> > support the
> > * &drm_driver_feature DRIVER_GEM_GPUVA.
> > @@ -593,28 +593,28 @@ static inline void drm_gem_gpuva_init(struct
> > drm_gem_object *obj)
> > }
> >
> > /**
> > - * drm_gem_for_each_gpuva() - iternator to walk over a list of
> > gpuvas
> > - * @entry__: &drm_gpuva structure to assign to in each iteration
> > step
> > - * @obj__: the &drm_gem_object the &drm_gpuvas to walk are
> > associated with
> > + * drm_gem_for_each_gpuvm_bo() - iterator to walk over a list of
> > &drm_gpuvm_bo
> > + * @entry__: &drm_gpuvm_bo structure to assign to in each iteration
> > step
> > + * @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are
> > associated with
> > *
> > - * This iterator walks over all &drm_gpuva structures associated
> > with the
> > - * &drm_gpuva_manager.
> > + * This iterator walks over all &drm_gpuvm_bo structures associated
> > with the
> > + * &drm_gem_object.
> > */
> > -#define drm_gem_for_each_gpuva(entry__, obj__) \
> > - list_for_each_entry(entry__, &(obj__)->gpuva.list, gem.entry)
> > +#define drm_gem_for_each_gpuvm_bo(entry__, obj__) \
> > + list_for_each_entry(entry__, &(obj__)->gpuva.list,
> > list.entry.gem)
> >
> > /**
> > - * drm_gem_for_each_gpuva_safe() - iternator to safely walk over a
> > list of
> > - * gpuvas
> > - * @entry__: &drm_gpuva structure to assign to in each iteration
> > step
> > - * @next__: &next &drm_gpuva to store the next step
> > - * @obj__: the &drm_gem_object the &drm_gpuvas to walk are
> > associated with
> > + * drm_gem_for_each_gpuvm_bo_safe() - iterator to safely walk over a
> > list of
> > + * &drm_gpuvm_bo
> > + * @entry__: &drm_gpuvm_bostructure to assign to in each iteration
> > step
> > + * @next__: &next &drm_gpuvm_bo to store the next step
> > + * @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are
> > associated with
> > *
> > - * This iterator walks over all &drm_gpuva structures associated
> > with the
> > + * This iterator walks over all &drm_gpuvm_bo structures associated
> > with the
> > * &drm_gem_object. It is implemented with
> > list_for_each_entry_safe(), hence
> > * it is save against removal of elements.
> > */
> > -#define drm_gem_for_each_gpuva_safe(entry__, next__, obj__) \
> > - list_for_each_entry_safe(entry__, next__, &(obj__)-
> > >gpuva.list, gem.entry)
> > +#define drm_gem_for_each_gpuvm_bo_safe(entry__, next__, obj__) \
> > + list_for_each_entry_safe(entry__, next__, &(obj__)-
> > >gpuva.list, list.entry.gem)
> >
> > #endif /* __DRM_GEM_H__ */
> > diff --git a/include/drm/drm_gpuvm.h b/include/drm/drm_gpuvm.h
> > index 13539f32c2e2..ddb0b8d323cf 100644
> > --- a/include/drm/drm_gpuvm.h
> > +++ b/include/drm/drm_gpuvm.h
> > @@ -26,12 +26,14 @@
> > */
> >
> > #include <linux/list.h>
> > +#include <linux/dma-resv.h>
> > #include <linux/rbtree.h>
> > #include <linux/types.h>
> >
> > #include <drm/drm_gem.h>
> >
> > struct drm_gpuvm;
> > +struct drm_gpuvm_bo;
> > struct drm_gpuvm_ops;
> >
> > /**
> > @@ -72,6 +74,12 @@ struct drm_gpuva {
> > */
> > struct drm_gpuvm *vm;
> >
> > + /**
> > + * @vm_bo: the &drm_gpuvm_bo abstraction for the mapped
> > + * &drm_gem_object
> > + */
> > + struct drm_gpuvm_bo *vm_bo;
> > +
> > /**
> > * @flags: the &drm_gpuva_flags for this mapping
> > */
> > @@ -107,7 +115,7 @@ struct drm_gpuva {
> > struct drm_gem_object *obj;
> >
> > /**
> > - * @entry: the &list_head to attach this object to a
> > &drm_gem_object
> > + * @entry: the &list_head to attach this object to a
> > &drm_gpuvm_bo
> > */
> > struct list_head entry;
> > } gem;
> > @@ -140,7 +148,7 @@ struct drm_gpuva {
> > int drm_gpuva_insert(struct drm_gpuvm *gpuvm, struct drm_gpuva *va);
> > void drm_gpuva_remove(struct drm_gpuva *va);
> >
> > -void drm_gpuva_link(struct drm_gpuva *va);
> > +void drm_gpuva_link(struct drm_gpuva *va, struct drm_gpuvm_bo
> > *vm_bo);
> > void drm_gpuva_unlink(struct drm_gpuva *va);
> >
> > struct drm_gpuva *drm_gpuva_find(struct drm_gpuvm *gpuvm,
> > @@ -187,10 +195,16 @@ static inline bool drm_gpuva_invalidated(struct
> > drm_gpuva *va)
> > * enum drm_gpuvm_flags - flags for struct drm_gpuvm
> > */
> > enum drm_gpuvm_flags {
> > + /**
> > + * @DRM_GPUVM_RESV_PROTECTED: GPUVM is protected externally
> > by the
> > + * GPUVM's &dma_resv lock
> > + */
> > + DRM_GPUVM_RESV_PROTECTED = (1 << 0),
> > +
> > /**
> > * @DRM_GPUVM_USERBITS: user defined bits
> > */
> > - DRM_GPUVM_USERBITS = (1 << 0),
> > + DRM_GPUVM_USERBITS = (1 << 1),
> > };
> >
> > /**
> > @@ -272,6 +286,19 @@ bool drm_gpuvm_interval_empty(struct drm_gpuvm
> > *gpuvm, u64 addr, u64 range);
> > struct drm_gem_object *
> > drm_gpuvm_root_object_alloc(struct drm_device *drm);
> >
> > +/**
> > + * drm_gpuvm_resv_protected() - indicates whether
> > &DRM_GPUVM_RESV_PROTECTED is
> > + * set
> > + * @gpuvm: the &drm_gpuvm
> > + *
> > + * Returns: true if &DRM_GPUVM_RESV_PROTECTED is set, false
> > otherwise.
> > + */
> > +static inline bool
> > +drm_gpuvm_resv_protected(struct drm_gpuvm *gpuvm)
> > +{
> > + return gpuvm->flags & DRM_GPUVM_RESV_PROTECTED;
> > +}
> > +
> > /**
> > * drm_gpuvm_resv() - returns the &drm_gpuvm's &dma_resv
> > * @gpuvm__: the &drm_gpuvm
> > @@ -290,6 +317,12 @@ drm_gpuvm_root_object_alloc(struct drm_device
> > *drm);
> > */
> > #define drm_gpuvm_resv_obj(gpuvm__) ((gpuvm__)->r_obj)
> >
> > +#define drm_gpuvm_resv_held(gpuvm__) \
> > + dma_resv_held(drm_gpuvm_resv(gpuvm__))
> > +
> > +#define drm_gpuvm_resv_assert_held(gpuvm__) \
> > + dma_resv_assert_held(drm_gpuvm_resv(gpuvm__))
> > +
> > #define drm_gpuvm_resv_held(gpuvm__) \
> > dma_resv_held(drm_gpuvm_resv(gpuvm__))
> >
> > @@ -374,6 +407,117 @@ __drm_gpuva_next(struct drm_gpuva *va)
> > #define drm_gpuvm_for_each_va_safe(va__, next__, gpuvm__) \
> > list_for_each_entry_safe(va__, next__, &(gpuvm__)->rb.list,
> > rb.entry)
> >
> > +/**
> > + * struct drm_gpuvm_bo - structure representing a &drm_gpuvm and
> > + * &drm_gem_object combination
> > + *
> > + * This structure is an abstraction representing a &drm_gpuvm and
> > + * &drm_gem_object combination. It serves as an indirection to
> > accelerate
> > + * iterating all &drm_gpuvas within a &drm_gpuvm backed by the same
> > + * &drm_gem_object.
> > + *
> > + * Furthermore it is used cache evicted GEM objects for a certain
> > GPU-VM to
> > + * accelerate validation.
> > + *
> > + * Typically, drivers want to create an instance of a struct
> > drm_gpuvm_bo once
> > + * a GEM object is mapped first in a GPU-VM and release the instance
> > once the
> > + * last mapping of the GEM object in this GPU-VM is unmapped.
> > + */
> > +struct drm_gpuvm_bo {
> > +
> > + /**
> > + * @vm: The &drm_gpuvm the @obj is mapped in.
> Not refcounted. @vm may potentially be freed under us in the
> !RESV_PROTECTED case.
It's the drivers responsibility to ensure the VM is not freed up as long as
VM_BOs with this VM do exist. However, this is nothing drivers need to care
about explicitly, since drivers are responsible to keep the VM alive as long
as mappings exist anyway. And all mappings being gone implies also all VM_BOs
being gone, since the lifetime of a VM_BO goes from the first mapping backed by
a certain object is created to the last mapping backed by this object is
removed. drm_gpuvm_destroy() will also warn if the GPUVM still contains
mappings.
I will document this more explicitly somewhere.
>
> > + */
> > + struct drm_gpuvm *vm;
> > +
> > + /**
> > + * @obj: The &drm_gem_object being mapped in @vm.
>
> Refcounted pointer.
Guess you want me to document that.
>
> > + */
> > + struct drm_gem_object *obj;
> > +
> > + /**
> > + * @kref: The reference count for this &drm_gpuvm_bo.
> > + */
> > + struct kref kref;
> > +
> > + /**
> > + * @list: Structure containing all &list_heads.
> > + */
> > + struct {
> > + /**
> > + * @gpuva: The list of linked &drm_gpuvas.
> > + */
>
> Here we should also document how we ensure gpvuas are kept alive.
> (which I presume is the lock protecting the gem object's vm_bo list
> must be held all the time any gpuva obtained from this list is being
> accessed).
Correct, gonna document that.
>
> > + struct list_head gpuva;
> > +
> > + /**
> > + * @entry: Structure containing all &list_heads
> > serving as
> > + * entry.
> > + */
> > + struct {
> > + /**
> > + * @gem: List entry to attach to the
> > &drm_gem_objects
> > + * gpuva list.
> > + */
> > + struct list_head gem;
> > + } entry;
> > + } list;
> > +};
> > +
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_create(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj);
> > +
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_obtain(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj);
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_obtain_prealloc(struct drm_gpuvm_bo *vm_bo);
> > +
> > +/**
> > + * drm_gpuvm_bo_get() - acquire a struct drm_gpuvm_bo reference
> > + * @vm_bo: the &drm_gpuvm_bo to acquire the reference of
> > + *
> > + * This function acquires an additional reference to @vm_bo. It is
> > illegal to
> > + * call this without already holding a reference. No locks required.
> > + */
> > +static inline struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_get(struct drm_gpuvm_bo *vm_bo)
> > +{
> > + kref_get(&vm_bo->kref);
> > + return vm_bo;
> > +}
> > +
> > +void drm_gpuvm_bo_put(struct drm_gpuvm_bo *vm_bo);
> > +
> > +struct drm_gpuvm_bo *
> > +drm_gpuvm_bo_find(struct drm_gpuvm *gpuvm,
> > + struct drm_gem_object *obj);
> > +
> > +/**
> > + * drm_gpuvm_bo_for_each_va() - iterator to walk over a list of
> > &drm_gpuva
> > + * @va__: &drm_gpuva structure to assign to in each iteration step
> > + * @vm_bo__: the &drm_gpuvm_bo the &drm_gpuva to walk are associated
> > with
> > + *
> > + * This iterator walks over all &drm_gpuva structures associated
> > with the
> > + * &drm_gpuvm_bo.
>
> Must hold the ... lock.
Gonna fix here...
>
>
> > + */
> > +#define drm_gpuvm_bo_for_each_va(va__, vm_bo__) \
> > + list_for_each_entry(va__, &(vm_bo)->list.gpuva, gem.entry)
> > +
> > +/**
> > + * drm_gpuvm_bo_for_each_va_safe() - iterator to safely walk over a
> > list of
> > + * &drm_gpuva
> > + * @va__: &drm_gpuva structure to assign to in each iteration step
> > + * @next__: &next &drm_gpuva to store the next step
> > + * @vm_bo__: the &drm_gpuvm_bo the &drm_gpuva to walk are associated
> > with
> > + *
> > + * This iterator walks over all &drm_gpuva structures associated
> > with the
> > + * &drm_gpuvm_bo. It is implemented with list_for_each_entry_safe(),
> > hence
> > + * it is save against removal of elements.
> > + */
> > +#define drm_gpuvm_bo_for_each_va_safe(va__, next__, vm_bo__) \
> > + list_for_each_entry_safe(va__, next__, &(vm_bo)->list.gpuva,
> > gem.entry)
>
> Same here.
and here.
>
> > +
> > /**
> > * enum drm_gpuva_op_type - GPU VA operation type
> > *
> > @@ -643,8 +787,7 @@ drm_gpuvm_prefetch_ops_create(struct drm_gpuvm
> > *gpuvm,
> > u64 addr, u64 range);
> >
> > struct drm_gpuva_ops *
> > -drm_gpuvm_gem_unmap_ops_create(struct drm_gpuvm *gpuvm,
> > - struct drm_gem_object *obj);
> > +drm_gpuvm_bo_unmap_ops_create(struct drm_gpuvm_bo *vm_bo);
> >
> > void drm_gpuva_ops_free(struct drm_gpuvm *gpuvm,
> > struct drm_gpuva_ops *ops);
> > @@ -688,6 +831,30 @@ struct drm_gpuvm_ops {
> > */
> > void (*op_free)(struct drm_gpuva_op *op);
> >
> > + /**
> > + * @vm_bo_alloc: called when the &drm_gpuvm allocates
> > + * a struct drm_gpuvm_bo
> > + *
> > + * Some drivers may want to embed struct drm_gpuvm_bo into
> > driver
> > + * specific structures. By implementing this callback drivers
> > can
> > + * allocate memory accordingly.
> > + *
> > + * This callback is optional.
> > + */
> > + struct drm_gpuvm_bo *(*vm_bo_alloc)(void);
> > +
> > + /**
> > + * @vm_bo_free: called when the &drm_gpuvm frees a
> > + * struct drm_gpuvm_bo
> > + *
> > + * Some drivers may want to embed struct drm_gpuvm_bo into
> > driver
> > + * specific structures. By implementing this callback drivers
> > can
> > + * free the previously allocated memory accordingly.
> > + *
> > + * This callback is optional.
> > + */
> > + void (*vm_bo_free)(struct drm_gpuvm_bo *vm_bo);
> > +
> > /**
> > * @sm_step_map: called from &drm_gpuvm_sm_map to finally
> > insert the
> > * mapping once all previous steps were completed
>
> Thanks,
> Thomas
>
