Re: [Intel-gfx] [RFC PATCH v3 04/17] drm/i915: Implement bind and unbind of object

Dave Airlie
2022-09-01T05:31:41Z

On Sun, 28 Aug 2022 at 05:45, Andi Shyti <andi.shyti@linux.intel.com> wrote:
>
> From: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
>
> Implement the bind and unbind of an object at the specified GPU virtual
> addresses.
>
> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
> Signed-off-by: Prathap Kumar Valsan <prathap.kumar.valsan@intel.com>
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> ---
> drivers/gpu/drm/i915/Makefile | 1 +
> drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h | 21 ++
> .../drm/i915/gem/i915_gem_vm_bind_object.c | 322 ++++++++++++++++++
> drivers/gpu/drm/i915/gt/intel_gtt.c | 10 +
> drivers/gpu/drm/i915/gt/intel_gtt.h | 9 +
> drivers/gpu/drm/i915/i915_driver.c | 1 +
> drivers/gpu/drm/i915/i915_vma.c | 3 +-
> drivers/gpu/drm/i915/i915_vma.h | 2 -
> drivers/gpu/drm/i915/i915_vma_types.h | 14 +
> include/uapi/drm/i915_drm.h | 163 +++++++++
> 10 files changed, 543 insertions(+), 3 deletions(-)
> create mode 100644 drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
> create mode 100644 drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 522ef9b4aff32..4e1627e96c6e0 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -165,6 +165,7 @@ gem-y += \
> gem/i915_gem_ttm_move.o \
> gem/i915_gem_ttm_pm.o \
> gem/i915_gem_userptr.o \
> + gem/i915_gem_vm_bind_object.o \
> gem/i915_gem_wait.o \
> gem/i915_gemfs.o
> i915-y += \
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
> new file mode 100644
> index 0000000000000..ebc493b7dafc1
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2022 Intel Corporation
> + */
> +
> +#ifndef __I915_GEM_VM_BIND_H
> +#define __I915_GEM_VM_BIND_H
> +
> +#include "i915_drv.h"
> +
> +struct i915_vma *
> +i915_gem_vm_bind_lookup_vma(struct i915_address_space *vm, u64 va);
> +void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj);
> +
> +int i915_gem_vm_bind_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file);
> +int i915_gem_vm_unbind_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file);
> +
> +void i915_gem_vm_unbind_vma_all(struct i915_address_space *vm);
> +#endif /* __I915_GEM_VM_BIND_H */
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
> new file mode 100644
> index 0000000000000..dadd1d4b1761b
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
> @@ -0,0 +1,322 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2022 Intel Corporation
> + */
> +
> +#include <linux/interval_tree_generic.h>
> +
> +#include "gem/i915_gem_vm_bind.h"
> +#include "gem/i915_gem_context.h"
> +#include "gt/gen8_engine_cs.h"
> +
> +#include "i915_drv.h"
> +#include "i915_gem_gtt.h"
> +
> +#define START(node) ((node)->start)
> +#define LAST(node) ((node)->last)
> +
> +INTERVAL_TREE_DEFINE(struct i915_vma, rb, u64, __subtree_last,
> + START, LAST, static inline, i915_vm_bind_it)
> +
> +#undef START
> +#undef LAST
> +
> +/**
> + * DOC: VM_BIND/UNBIND ioctls
> + *
> + * DRM_I915_GEM_VM_BIND/UNBIND ioctls allows UMD to bind/unbind GEM buffer
> + * objects (BOs) or sections of a BOs at specified GPU virtual addresses on a
> + * specified address space (VM). Multiple mappings can map to the same physical
> + * pages of an object (aliasing). These mappings (also referred to as persistent
> + * mappings) will be persistent across multiple GPU submissions (execbuf calls)
> + * issued by the UMD, without user having to provide a list of all required
> + * mappings during each submission (as required by older execbuf mode).
> + *
> + * The VM_BIND/UNBIND calls allow UMDs to request a timeline out fence for
> + * signaling the completion of bind/unbind operation.
> + *
> + * VM_BIND feature is advertised to user via I915_PARAM_VM_BIND_VERSION.
> + * User has to opt-in for VM_BIND mode of binding for an address space (VM)
> + * during VM creation time via I915_VM_CREATE_FLAGS_USE_VM_BIND extension.
> + *
> + * VM_BIND/UNBIND ioctl calls executed on different CPU threads concurrently
> + * are not ordered. Furthermore, parts of the VM_BIND/UNBIND operations can be
> + * done asynchronously, when valid out fence is specified.
> + *
> + * VM_BIND locking order is as below.
> + *
> + * 1) vm_bind_lock mutex will protect vm_bind lists. This lock is taken in
> + * vm_bind/vm_unbind ioctl calls, in the execbuf path and while releasing the
> + * mapping.
> + *
> + * In future, when GPU page faults are supported, we can potentially use a
> + * rwsem instead, so that multiple page fault handlers can take the read
> + * side lock to lookup the mapping and hence can run in parallel.
> + * The older execbuf mode of binding do not need this lock.
> + *
> + * 2) The object's dma-resv lock will protect i915_vma state and needs
> + * to be held while binding/unbinding a vma in the async worker and while
> + * updating dma-resv fence list of an object. Note that private BOs of a VM
> + * will all share a dma-resv object.
> + *
> + * 3) Spinlock/s to protect some of the VM's lists like the list of
> + * invalidated vmas (due to eviction and userptr invalidation) etc.
> + */
> +
> +/**
> + * i915_gem_vm_bind_lookup_vma() - lookup for the vma with a starting addr
> + * @vm: virtual address space in which vma needs to be looked for
> + * @va: starting addr of the vma
> + *
> + * retrieves the vma with a starting address from the vm's vma tree.
> + *
> + * Returns: returns vma on success, NULL on failure.
> + */
> +struct i915_vma *
> +i915_gem_vm_bind_lookup_vma(struct i915_address_space *vm, u64 va)
> +{
> + lockdep_assert_held(&vm->vm_bind_lock);
> +
> + return i915_vm_bind_it_iter_first(&vm->va, va, va);
> +}
> +
> +/**
> + * i915_gem_vm_bind_remove() - Remove vma from the vm bind list
> + * @vma: vma that needs to be removed
> + * @release_obj: object to be release or not
> + *
> + * Removes the vma from the vm's lists custom interval tree
> + */
> +void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
> +{
> + lockdep_assert_held(&vma->vm->vm_bind_lock);
> +
> + if (!list_empty(&vma->vm_bind_link)) {
> + list_del_init(&vma->vm_bind_link);
> + i915_vm_bind_it_remove(vma, &vma->vm->va);
> +
> + /* Release object */
> + if (release_obj)
> + i915_gem_object_put(vma->obj);
> + }
> +}
> +
> +static int i915_gem_vm_unbind_vma(struct i915_address_space *vm,
> + struct i915_vma *vma,
> + struct drm_i915_gem_vm_unbind *va)
> +{
> + struct drm_i915_gem_object *obj;
> + int ret;
> +
> + if (vma) {
> + obj = vma->obj;
> + i915_vma_destroy(vma);
> +
> + goto exit;
> + }
> +
> + if (!va)
> + return -EINVAL;
> +
> + ret = mutex_lock_interruptible(&vm->vm_bind_lock);
> + if (ret)
> + return ret;
> +
> + va->start = gen8_noncanonical_addr(va->start);
> + vma = i915_gem_vm_bind_lookup_vma(vm, va->start);
> +
> + if (!vma)
> + ret = -ENOENT;
> + else if (vma->size != va->length)
> + ret = -EINVAL;
> +
> + if (ret) {
> + mutex_unlock(&vm->vm_bind_lock);
> + return ret;
> + }
> +
> + i915_gem_vm_bind_remove(vma, false);
> +
> + mutex_unlock(&vm->vm_bind_lock);
> +
> + /* Destroy vma and then release object */
> + obj = vma->obj;
> + ret = i915_gem_object_lock(obj, NULL);
> + if (ret)
> + return ret;
> +
> + i915_vma_destroy(vma);
> + i915_gem_object_unlock(obj);
> +
> +exit:
> + i915_gem_object_put(obj);
> +
> + return 0;
> +}
> +
> +/**
> + * i915_gem_vm_unbind_vma_all() - Unbind all vmas from an address space
> + * @vm: Address spece from which vma binding needs to be removed
> + *
> + * Unbind all userspace requested object binding
> + */
> +void i915_gem_vm_unbind_vma_all(struct i915_address_space *vm)
> +{
> + struct i915_vma *vma, *t;
> +
> + list_for_each_entry_safe(vma, t, &vm->vm_bound_list, vm_bind_link)
> + WARN_ON(i915_gem_vm_unbind_vma(vm, vma, NULL));
> +}
> +
> +static struct i915_vma *vm_bind_get_vma(struct i915_address_space *vm,
> + struct drm_i915_gem_object *obj,
> + struct drm_i915_gem_vm_bind *va)
> +{
> + struct i915_ggtt_view view;
> + struct i915_vma *vma;
> +
> + va->start = gen8_noncanonical_addr(va->start);
> + vma = i915_gem_vm_bind_lookup_vma(vm, va->start);
> + if (vma)
> + return ERR_PTR(-EEXIST);
> +
> + view.type = I915_GGTT_VIEW_PARTIAL;
> + view.partial.offset = va->offset >> PAGE_SHIFT;
> + view.partial.size = va->length >> PAGE_SHIFT;
> + vma = i915_vma_instance(obj, vm, &view);
> + if (IS_ERR(vma))
> + return vma;
> +
> + vma->start = va->start;
> + vma->last = va->start + va->length - 1;
> +
> + return vma;
> +}
> +
> +static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
> + struct drm_i915_gem_vm_bind *va,
> + struct drm_file *file)
> +{
> + struct drm_i915_gem_object *obj;
> + struct i915_vma *vma = NULL;
> + struct i915_gem_ww_ctx ww;
> + u64 pin_flags;
> + int ret = 0;
> +
> + if (!vm->vm_bind_mode)
> + return -EOPNOTSUPP;
> +
> + obj = i915_gem_object_lookup(file, va->handle);
> + if (!obj)
> + return -ENOENT;
> +
> + if (!va->length ||
> + !IS_ALIGNED(va->offset | va->length,
> + i915_gem_object_max_page_size(obj->mm.placements,
> + obj->mm.n_placements)) ||
> + range_overflows_t(u64, va->offset, va->length, obj->base.size)) {
> + ret = -EINVAL;
> + goto put_obj;
> + }
> +
> + ret = mutex_lock_interruptible(&vm->vm_bind_lock);
> + if (ret)
> + goto put_obj;
> +
> + vma = vm_bind_get_vma(vm, obj, va);
> + if (IS_ERR(vma)) {
> + ret = PTR_ERR(vma);
> + goto unlock_vm;
> + }
> +
> + for_i915_gem_ww(&ww, ret, true) {
> +retry:
> + ret = i915_gem_object_lock(vma->obj, &ww);
> + if (ret)
> + goto out_ww;
> +
> + ret = i915_vma_pin_ww(vma, &ww, 0, 0, pin_flags);
> + if (ret)
> + goto out_ww;
> +
> + /* Make it evictable */
> + __i915_vma_unpin(vma);
> +
> + list_add_tail(&vma->vm_bind_link, &vm->vm_bound_list);
> + i915_vm_bind_it_insert(vma, &vm->va);
> +
> +out_ww:
> + if (ret == -EDEADLK) {
> + ret = i915_gem_ww_ctx_backoff(&ww);
> + if (!ret)
> + goto retry;
> + } else {
> + /* Hold object reference until vm_unbind */
> + i915_gem_object_get(vma->obj);
> + }
> + }
> +
> +unlock_vm:
> + mutex_unlock(&vm->vm_bind_lock);
> +
> +put_obj:
> + i915_gem_object_put(obj);
> +
> + return ret;
> +}
> +
> +/**
> + * i915_gem_vm_bind_ioctl() - ioctl function for binding an obj into
> + * virtual address
> + * @dev: drm device associated to the virtual address
> + * @data: data related to the vm bind required
> + * @file: drm_file related to he ioctl
> + *
> + * Implements a function to bind the object into the virtual address
> + *
> + * Returns 0 on success, error code on failure.
> + */
> +int i915_gem_vm_bind_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file)
> +{
> + struct drm_i915_gem_vm_bind *args = data;
> + struct i915_address_space *vm;
> + int ret;
> +
> + vm = i915_gem_vm_lookup(file->driver_priv, args->vm_id);
> + if (unlikely(!vm))
> + return -ENOENT;
> +
> + ret = i915_gem_vm_bind_obj(vm, args, file);
> +
> + i915_vm_put(vm);
> + return ret;
> +}
> +
> +/**
> + * i915_gem_vm_unbind_ioctl() - ioctl function for unbinding an obj from
> + * virtual address
> + * @dev: drm device associated to the virtual address
> + * @data: data related to the binding that needs to be unbinded
> + * @file: drm_file related to the ioctl
> + *
> + * Implements a function to unbind the object from the virtual address
> + *
> + * Returns 0 on success, error code on failure.
> + */
> +int i915_gem_vm_unbind_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file)
> +{
> + struct drm_i915_gem_vm_unbind *args = data;
> + struct i915_address_space *vm;
> + int ret;
> +
> + vm = i915_gem_vm_lookup(file->driver_priv, args->vm_id);
> + if (unlikely(!vm))
> + return -ENOENT;
> +
> + ret = i915_gem_vm_unbind_vma(vm, NULL, args);
> +
> + i915_vm_put(vm);
> + return ret;
> +}
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
> index b67831833c9a3..cb188377b7bd9 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
> @@ -12,6 +12,7 @@
>
> #include "gem/i915_gem_internal.h"
> #include "gem/i915_gem_lmem.h"
> +#include "gem/i915_gem_vm_bind.h"
> #include "i915_trace.h"
> #include "i915_utils.h"
> #include "intel_gt.h"
> @@ -176,6 +177,8 @@ int i915_vm_lock_objects(struct i915_address_space *vm,
> void i915_address_space_fini(struct i915_address_space *vm)
> {
> drm_mm_takedown(&vm->mm);
> + GEM_BUG_ON(!RB_EMPTY_ROOT(&vm->va.rb_root));
> + mutex_destroy(&vm->vm_bind_lock);
> }
>
> /**
> @@ -204,6 +207,8 @@ static void __i915_vm_release(struct work_struct *work)
>
> __i915_vm_close(vm);
>
> + i915_gem_vm_unbind_vma_all(vm);
> +
> /* Synchronize async unbinds. */
> i915_vma_resource_bind_dep_sync_all(vm);
>
> @@ -282,6 +287,11 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
>
> INIT_LIST_HEAD(&vm->bound_list);
> INIT_LIST_HEAD(&vm->unbound_list);
> +
> + vm->va = RB_ROOT_CACHED;
> + INIT_LIST_HEAD(&vm->vm_bind_list);
> + INIT_LIST_HEAD(&vm->vm_bound_list);
> + mutex_init(&vm->vm_bind_lock);
> }
>
> void *__px_vaddr(struct drm_i915_gem_object *p)
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
> index da21088890b3b..06a259475816b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
> @@ -259,6 +259,15 @@ struct i915_address_space {
> */
> struct list_head unbound_list;
>
> + /** @vm_bind_lock: Mutex to protect @vm_bind_list and @vm_bound_list */
> + struct mutex vm_bind_lock;
> + /** @vm_bind_list: List of vm_binding in process */
> + struct list_head vm_bind_list;
> + /** @vm_bound_list: List of vm_binding completed */
> + struct list_head vm_bound_list;
> + /* @va: tree of persistent vmas */
> + struct rb_root_cached va;
> +
> /* Global GTT */
> bool is_ggtt:1;
>
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index 1332c70370a68..9a9010fd9ecfa 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -68,6 +68,7 @@
> #include "gem/i915_gem_ioctls.h"
> #include "gem/i915_gem_mman.h"
> #include "gem/i915_gem_pm.h"
> +#include "gem/i915_gem_vm_bind.h"
> #include "gt/intel_gt.h"
> #include "gt/intel_gt_pm.h"
> #include "gt/intel_rc6.h"
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index 2603717164900..092ae4309d8a1 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -29,6 +29,7 @@
> #include "display/intel_frontbuffer.h"
> #include "gem/i915_gem_lmem.h"
> #include "gem/i915_gem_tiling.h"
> +#include "gem/i915_gem_vm_bind.h"
> #include "gt/intel_engine.h"
> #include "gt/intel_engine_heartbeat.h"
> #include "gt/intel_gt.h"
> @@ -234,6 +235,7 @@ vma_create(struct drm_i915_gem_object *obj,
> spin_unlock(&obj->vma.lock);
> mutex_unlock(&vm->mutex);
>
> + INIT_LIST_HEAD(&vma->vm_bind_link);
> return vma;
>
> err_unlock:
> @@ -290,7 +292,6 @@ i915_vma_instance(struct drm_i915_gem_object *obj,
> {
> struct i915_vma *vma;
>
> - GEM_BUG_ON(view && !i915_is_ggtt_or_dpt(vm));
> GEM_BUG_ON(!kref_read(&vm->ref));
>
> spin_lock(&obj->vma.lock);
> diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
> index 33a58f605d75c..15eac55a3e274 100644
> --- a/drivers/gpu/drm/i915/i915_vma.h
> +++ b/drivers/gpu/drm/i915/i915_vma.h
> @@ -164,8 +164,6 @@ i915_vma_compare(struct i915_vma *vma,
> {
> ptrdiff_t cmp;
>
> - GEM_BUG_ON(view && !i915_is_ggtt_or_dpt(vm));
> -
> cmp = ptrdiff(vma->vm, vm);
> if (cmp)
> return cmp;
> diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
> index be6e028c3b57d..f746fecae85ed 100644
> --- a/drivers/gpu/drm/i915/i915_vma_types.h
> +++ b/drivers/gpu/drm/i915/i915_vma_types.h
> @@ -289,6 +289,20 @@ struct i915_vma {
> /** This object's place on the active/inactive lists */
> struct list_head vm_link;
>
> + /** @vm_bind_link: node for the vm_bind related lists of vm */
> + struct list_head vm_bind_link;
> +
> + /** Interval tree structures for persistent vma */
> +
> + /** @rb: node for the interval tree of vm for persistent vmas */
> + struct rb_node rb;
> + /** @start: start endpoint of the rb node */
> + u64 start;
> + /** @last: Last endpoint of the rb node */
> + u64 last;
> + /** @__subtree_last: last in subtree */
> + u64 __subtree_last;

Was a drm_mm node considered for this or was it overkill?

Dave.