Messages in this thread | | | Date | Fri, 13 Oct 2023 13:51:47 +0200 | Subject | Re: [PATCH drm-misc-next v6 1/6] drm/gpuvm: add common dma-resv per struct drm_gpuvm | From | Danilo Krummrich <> |
| |
On 10/13/23 13:38, Thomas Hellström wrote: > On Mon, 2023-10-09 at 01:32 +0200, Danilo Krummrich wrote: >> Provide a common dma-resv for GEM objects not being used outside of >> this >> GPU-VM. This is used in a subsequent patch to generalize dma-resv, >> external and evicted object handling and GEM validation. >> >> Signed-off-by: Danilo Krummrich <dakr@redhat.com> >> --- >> drivers/gpu/drm/drm_gpuvm.c | 56 >> +++++++++++++++++++++++++- >> drivers/gpu/drm/nouveau/nouveau_uvmm.c | 13 +++++- >> include/drm/drm_gpuvm.h | 35 +++++++++++++++- >> 3 files changed, 99 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_gpuvm.c >> b/drivers/gpu/drm/drm_gpuvm.c >> index 02ecb45a2544..ebda9d594165 100644 >> --- a/drivers/gpu/drm/drm_gpuvm.c >> +++ b/drivers/gpu/drm/drm_gpuvm.c >> @@ -61,6 +61,15 @@ >> * contained within struct drm_gpuva already. Hence, for inserting >> &drm_gpuva >> * entries from within dma-fence signalling critical sections it is >> enough to >> * pre-allocate the &drm_gpuva structures. >> + * >> + * &drm_gem_objects which are private to a single VM can share a >> common >> + * &dma_resv in order to improve locking efficiency (e.g. with >> &drm_exec). >> + * For this purpose drivers must pass a &drm_gem_object to >> drm_gpuvm_init(), in >> + * the following called 'root object', which serves as the container > > Nit: Perhaps resv object altough it might typically be the root page- > table object, that doesn't have any meaning to drm_gpuvm, which uses it > solely as a container for the resv?
With "root" I didn't want to refer to the object representing the root page-table object, but being *the* object every other (internal) object needs to keep a reference to. Maybe I should be more explicit here and say that drivers need to make sure every internal object requires a reference to take a reference to this root object.
> >> of the >> + * GPUVM's shared &dma_resv. This root object can be a driver >> specific >> + * &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(). >> */ >> >> /** >> @@ -652,9 +661,47 @@ drm_gpuvm_range_valid(struct drm_gpuvm *gpuvm, >> !drm_gpuvm_in_kernel_node(gpuvm, addr, range); >> } >> >> +static void >> +drm_gpuvm_gem_object_free(struct drm_gem_object *obj) >> +{ >> + drm_gem_object_release(obj); >> + kfree(obj); >> +} >> + >> +static const struct drm_gem_object_funcs drm_gpuvm_object_funcs = { >> + .free = drm_gpuvm_gem_object_free, >> +}; >> + >> +/** >> + * drm_gpuvm_root_object_alloc() - allocate a dummy &drm_gem_object >> + * @drm: the drivers &drm_device >> + * >> + * Allocates a dummy &drm_gem_object which can be passed to >> drm_gpuvm_init() in >> + * order to serve as root GEM object providing the &drm_resv shared >> across >> + * &drm_gem_objects local to a single GPUVM. >> + * >> + * Returns: the &drm_gem_object on success, NULL on failure >> + */ >> +struct drm_gem_object * >> +drm_gpuvm_root_object_alloc(struct drm_device *drm) >> +{ >> + struct drm_gem_object *obj; >> + >> + obj = kzalloc(sizeof(*obj), GFP_KERNEL); >> + if (!obj) >> + return NULL; >> + >> + obj->funcs = &drm_gpuvm_object_funcs; >> + drm_gem_private_object_init(drm, obj, 0); >> + >> + return obj; >> +} >> +EXPORT_SYMBOL_GPL(drm_gpuvm_root_object_alloc); >> + >> /** >> * drm_gpuvm_init() - initialize a &drm_gpuvm >> * @gpuvm: pointer to the &drm_gpuvm to initialize >> + * @r_obj: the root &drm_gem_object providing the GPUVM's common >> &dma_resv >> * @name: the name of the GPU VA space >> * @start_offset: the start offset of the GPU VA space >> * @range: the size of the GPU VA space >> @@ -668,7 +715,7 @@ drm_gpuvm_range_valid(struct drm_gpuvm *gpuvm, >> * &name is expected to be managed by the surrounding driver >> structures. >> */ >> void >> -drm_gpuvm_init(struct drm_gpuvm *gpuvm, >> +drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_gem_object >> *r_obj, >> const char *name, >> u64 start_offset, u64 range, >> u64 reserve_offset, u64 reserve_range, >> @@ -683,6 +730,9 @@ drm_gpuvm_init(struct drm_gpuvm *gpuvm, >> >> gpuvm->name = name ? name : "unknown"; >> gpuvm->ops = ops; >> + gpuvm->r_obj = r_obj; >> + >> + drm_gem_object_get(r_obj); >> >> memset(&gpuvm->kernel_alloc_node, 0, sizeof(struct >> drm_gpuva)); >> >> @@ -713,7 +763,9 @@ drm_gpuvm_destroy(struct drm_gpuvm *gpuvm) >> __drm_gpuva_remove(&gpuvm->kernel_alloc_node); >> >> WARN(!RB_EMPTY_ROOT(&gpuvm->rb.tree.rb_root), >> - "GPUVA tree is not empty, potentially leaking memory."); >> + "GPUVA tree is not empty, potentially leaking >> memory.\n"); > > Should we cache the drm device in struct drm_gpuvm and use drm_warn() > here instead of WARN?
I'd guess the additional backtrace of WARN() isn't overly useful in this case. However, it might be a bit more obvious in dmesg due to its verboseness. Not a strong opinion on that, though.
> >> + >> + drm_gem_object_put(gpuvm->r_obj); >> } >> EXPORT_SYMBOL_GPL(drm_gpuvm_destroy); >> >> diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c >> b/drivers/gpu/drm/nouveau/nouveau_uvmm.c >> index 5cf892c50f43..4dea847ef989 100644 >> --- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c >> +++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c >> @@ -1808,8 +1808,9 @@ int >> nouveau_uvmm_init(struct nouveau_uvmm *uvmm, struct nouveau_cli >> *cli, >> u64 kernel_managed_addr, u64 kernel_managed_size) >> { >> - int ret; >> + struct drm_gem_object *r_obj; >> u64 kernel_managed_end = kernel_managed_addr + >> kernel_managed_size; >> + int ret; >> >> mutex_init(&uvmm->mutex); >> dma_resv_init(&uvmm->resv); >> @@ -1833,14 +1834,22 @@ nouveau_uvmm_init(struct nouveau_uvmm *uvmm, >> struct nouveau_cli *cli, >> goto out_unlock; >> } >> >> + r_obj = drm_gpuvm_root_object_alloc(cli->drm->dev); >> + if (!r_obj) { >> + ret = -ENOMEM; >> + goto out_unlock; >> + } >> + >> uvmm->kernel_managed_addr = kernel_managed_addr; >> uvmm->kernel_managed_size = kernel_managed_size; >> >> - drm_gpuvm_init(&uvmm->base, cli->name, >> + drm_gpuvm_init(&uvmm->base, r_obj, cli->name, >> NOUVEAU_VA_SPACE_START, >> NOUVEAU_VA_SPACE_END, >> kernel_managed_addr, kernel_managed_size, >> NULL); >> + /* GPUVM takes care from here on. */ >> + drm_gem_object_put(r_obj); >> >> ret = nvif_vmm_ctor(&cli->mmu, "uvmm", >> cli->vmm.vmm.object.oclass, RAW, >> diff --git a/include/drm/drm_gpuvm.h b/include/drm/drm_gpuvm.h >> index c7ed6bf441d4..0aec14d8b259 100644 >> --- a/include/drm/drm_gpuvm.h >> +++ b/include/drm/drm_gpuvm.h >> @@ -238,9 +238,15 @@ struct drm_gpuvm { >> * @ops: &drm_gpuvm_ops providing the split/merge steps to >> drivers >> */ >> const struct drm_gpuvm_ops *ops; >> + >> + /** >> + * @r_obj: Root GEM object; representing the GPUVM's common >> &dma_resv. >> + */ >> + struct drm_gem_object *r_obj; >> }; >> >> -void drm_gpuvm_init(struct drm_gpuvm *gpuvm, const char *name, >> +void drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_gem_object >> *r_obj, >> + const char *name, >> u64 start_offset, u64 range, >> u64 reserve_offset, u64 reserve_range, >> const struct drm_gpuvm_ops *ops); >> @@ -248,6 +254,33 @@ void drm_gpuvm_destroy(struct drm_gpuvm *gpuvm); >> >> 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() - returns the &drm_gpuvm's &dma_resv >> + * @gpuvm__: the &drm_gpuvm >> + * >> + * Returns: a pointer to the &drm_gpuvm's shared &dma_resv >> + */ >> +#define drm_gpuvm_resv(gpuvm__) ((gpuvm__)->r_obj->resv) >> + >> +/** >> + * drm_gpuvm_resv_obj() - returns the &drm_gem_object holding the >> &drm_gpuvm's >> + * &dma_resv >> + * @gpuvm__: the &drm_gpuvm >> + * >> + * Returns: a pointer to the &drm_gem_object holding the >> &drm_gpuvm's shared >> + * &dma_resv >> + */ >> +#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__)) >> + >> static inline struct drm_gpuva * >> __drm_gpuva_next(struct drm_gpuva *va) >> { > > Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> > >
| |