[PATCH 19/27] drm/i915/gem: Use the proto-context to handle create parameters
Jason Ekstrand
jason at jlekstrand.net
Mon May 17 17:04:54 UTC 2021
On Mon, May 17, 2021 at 8:40 AM Daniel Vetter <daniel at ffwll.ch> wrote:
>
> On Fri, May 14, 2021 at 02:13:57PM -0500, Jason Ekstrand wrote:
> > On Tue, May 4, 2021 at 3:33 PM Daniel Vetter <daniel at ffwll.ch> wrote:
> > >
> > > On Mon, May 03, 2021 at 10:57:40AM -0500, Jason Ekstrand wrote:
> > > > This means that the proto-context needs to grow support for engine
> > > > configuration information as well as setparam logic. Fortunately, we'll
> > > > be deleting a lot of setparam logic on the primary context shortly so it
> > > > will hopefully balance out.
> > > >
> > > > Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
> > > > ---
> > > > drivers/gpu/drm/i915/gem/i915_gem_context.c | 546 +++++++++++++++++-
> > > > .../gpu/drm/i915/gem/i915_gem_context_types.h | 58 ++
> > > > 2 files changed, 587 insertions(+), 17 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > > > index 6dd50d669c5b9..aa4edfbf7ed48 100644
> > > > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > > > @@ -193,8 +193,15 @@ static int validate_priority(struct drm_i915_private *i915,
> > > >
> > > > static void proto_context_close(struct i915_gem_proto_context *pc)
> > > > {
> > > > + int i;
> > > > +
> > > > if (pc->vm)
> > > > i915_vm_put(pc->vm);
> > > > + if (pc->user_engines) {
> > > > + for (i = 0; i < pc->num_user_engines; i++)
> > > > + kfree(pc->user_engines[i].siblings);
> > > > + kfree(pc->user_engines);
> > >
> > > free_engines(&pc->user_engines);
> > >
> > > Maybe even stuff that if check into free_engines. Except I realized this
> > > is proto engines here now :-(
> > >
> > > > + }
> > > > kfree(pc);
> > > > }
> > > >
> > > > @@ -248,6 +255,9 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags)
> > > > if (!pc)
> > > > return ERR_PTR(-ENOMEM);
> > > >
> > > > + pc->num_user_engines = -1;
> > > > + pc->user_engines = NULL;
> > > > +
> > > > if (HAS_FULL_PPGTT(i915)) {
> > > > struct i915_ppgtt *ppgtt;
> > > >
> > > > @@ -282,6 +292,439 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags)
> > > > return err;
> > > > }
> > > >
> > > > +static int set_proto_ctx_vm(struct drm_i915_file_private *fpriv,
> > > > + struct i915_gem_proto_context *pc,
> > > > + const struct drm_i915_gem_context_param *args)
> > > > +{
> > > > + struct i915_address_space *vm;
> > > > +
> > > > + if (args->size)
> > > > + return -EINVAL;
> > > > +
> > > > + if (!pc->vm)
> > > > + return -ENODEV;
> > > > +
> > > > + if (upper_32_bits(args->value))
> > > > + return -ENOENT;
> > > > +
> > > > + rcu_read_lock();
> > > > + vm = xa_load(&fpriv->vm_xa, args->value);
> > > > + if (vm && !kref_get_unless_zero(&vm->ref))
> > > > + vm = NULL;
> > > > + rcu_read_unlock();
> > >
> > > vm lookup helpers would be nice I guess, but perhaps something that
> > > vm_bind patches should do.
> >
> > I can add those. I just don't know where to put it. We don't have an
> > i915_gem_vm.h. Suggestions?
>
> gt/intel_gtt.h seems to be the header for i915_address_space stuff. Also
> contains the i915_vma_ops but not i915_vma.
>
> It's a pretty good mess, but probably the best place for now for these :-/
The one for contexts is in i915_drv.h so I put the VM one there too.
Feel free to tell me to move it. I don't care where it goes.
> >
> > >
> > > > + if (!vm)
> > > > + return -ENOENT;
> > > > +
> > > > + i915_vm_put(pc->vm);
> > >
> > > Ah I guess I've found why you went with "pc->vm is always set". *shrug*
> > >
> > > > + pc->vm = vm;
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +struct set_proto_ctx_engines {
> > > > + struct drm_i915_private *i915;
> > > > + unsigned num_engines;
> > > > + struct i915_gem_proto_engine *engines;
> > > > +};
> > > > +
> > > > +static int
> > > > +set_proto_ctx_engines_balance(struct i915_user_extension __user *base,
> > > > + void *data)
> > > > +{
> > > > + struct i915_context_engines_load_balance __user *ext =
> > > > + container_of_user(base, typeof(*ext), base);
> > > > + const struct set_proto_ctx_engines *set = data;
> > > > + struct drm_i915_private *i915 = set->i915;
> > > > + struct intel_engine_cs **siblings;
> > > > + u16 num_siblings, idx;
> > > > + unsigned int n;
> > > > + int err;
> > > > +
> > > > + if (!HAS_EXECLISTS(i915))
> > > > + return -ENODEV;
> > > > +
> > > > + if (intel_uc_uses_guc_submission(&i915->gt.uc))
> > > > + return -ENODEV; /* not implement yet */
> > > > +
> > > > + if (get_user(idx, &ext->engine_index))
> > > > + return -EFAULT;
> > > > +
> > > > + if (idx >= set->num_engines) {
> > > > + drm_dbg(&i915->drm, "Invalid placement value, %d >= %d\n",
> > > > + idx, set->num_engines);
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + idx = array_index_nospec(idx, set->num_engines);
> > > > + if (set->engines[idx].type != I915_GEM_ENGINE_TYPE_INVALID) {
> > > > + drm_dbg(&i915->drm,
> > > > + "Invalid placement[%d], already occupied\n", idx);
> > > > + return -EEXIST;
> > > > + }
> > > > +
> > > > + if (get_user(num_siblings, &ext->num_siblings))
> > > > + return -EFAULT;
> > > > +
> > > > + err = check_user_mbz(&ext->flags);
> > > > + if (err)
> > > > + return err;
> > > > +
> > > > + err = check_user_mbz(&ext->mbz64);
> > > > + if (err)
> > > > + return err;
> > > > +
> > > > + if (num_siblings == 0)
>
> > >
> > > You deleted the on-stack siblings micro-optimization.
> > >
> > > I'm shocked.
> >
> > Yup. If balanced engine create overhead when balancing across a
> > single engine ever becomes a bottleneck in some UMD, I'm happy to deal
> > with it then. And I intend to deal with it by banning whatever
> > developer decided balancing across single engine was a good idea.
>
> I should have annotated this with /s
I detected your sarcasm and returned it. :-P
> > > > +
> > > > + siblings = kmalloc_array(num_siblings, sizeof(*siblings), GFP_KERNEL);
> > >
> > > If you want to pay back your micro-opt budget: GFP_TEMPORARY.
> > >
> > > But then I realized much wiser heads than me removed this in 2017 from the
> > > kernel! That commit is a rather interesting story btw, if you're bored:
> > >
> > > commit 0ee931c4e31a5efb134c76440405e9219f896e33
> > > Author: Michal Hocko <mhocko at suse.com>
> > > Date: Wed Sep 13 16:28:29 2017 -0700
> > >
> > > mm: treewide: remove GFP_TEMPORARY allocation flag
> > >
> > > > + if (!siblings)
> > > > + return -ENOMEM;
> > > > +
> > > > + for (n = 0; n < num_siblings; n++) {
> > > > + struct i915_engine_class_instance ci;
> > > > +
> > > > + if (copy_from_user(&ci, &ext->engines[n], sizeof(ci))) {
> > > > + err = -EFAULT;
> > > > + goto err_siblings;
> > > > + }
> > > > +
> > > > + siblings[n] = intel_engine_lookup_user(i915,
> > > > + ci.engine_class,
> > > > + ci.engine_instance);
> > >
> > > intel_engine_user.c
> > >
> > > ...
> > >
> > > Maybe I should just stop looking.
> >
> > Don't think too hard. It hurts.
> >
> > > > + if (!siblings[n]) {
> > > > + drm_dbg(&i915->drm,
> > > > + "Invalid sibling[%d]: { class:%d, inst:%d }\n",
> > > > + n, ci.engine_class, ci.engine_instance);
> > > > + err = -EINVAL;
> > > > + goto err_siblings;
> > > > + }
> > > > + }
> > > > +
> > > > + if (num_siblings == 1) {
> > > > + set->engines[idx].type = I915_GEM_ENGINE_TYPE_PHYSICAL;
> > > > + set->engines[idx].engine = siblings[0];
> > > > + kfree(siblings);
> > > > + } else {
> > > > + set->engines[idx].type = I915_GEM_ENGINE_TYPE_BALANCED;
> > > > + set->engines[idx].num_siblings = num_siblings;
> > > > + set->engines[idx].siblings = siblings;
> > > > + }
> > > > +
> > > > + return 0;
> > > > +
> > > > +err_siblings:
> > > > + kfree(siblings);
> > > > +
> > > > + return err;
> > > > +}
> > > > +
> > > > +static int
> > > > +set_proto_ctx_engines_bond(struct i915_user_extension __user *base, void *data)
> > > > +{
> > > > + struct i915_context_engines_bond __user *ext =
> > > > + container_of_user(base, typeof(*ext), base);
> > > > + const struct set_proto_ctx_engines *set = data;
> > > > + struct drm_i915_private *i915 = set->i915;
> > > > + struct i915_engine_class_instance ci;
> > > > + struct intel_engine_cs *master;
> > > > + u16 idx, num_bonds;
> > > > + int err, n;
> > > > +
> > > > + if (get_user(idx, &ext->virtual_index))
> > > > + return -EFAULT;
> > > > +
> > > > + if (idx >= set->num_engines) {
> > > > + drm_dbg(&i915->drm,
> > > > + "Invalid index for virtual engine: %d >= %d\n",
> > > > + idx, set->num_engines);
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + idx = array_index_nospec(idx, set->num_engines);
> > > > + if (set->engines[idx].type == I915_GEM_ENGINE_TYPE_INVALID) {
> > > > + drm_dbg(&i915->drm, "Invalid engine at %d\n", idx);
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + if (set->engines[idx].type != I915_GEM_ENGINE_TYPE_PHYSICAL) {
> > > > + drm_dbg(&i915->drm,
> > > > + "Bonding with virtual engines not allowed\n");
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + err = check_user_mbz(&ext->flags);
> > > > + if (err)
> > > > + return err;
> > > > +
> > > > + for (n = 0; n < ARRAY_SIZE(ext->mbz64); n++) {
> > > > + err = check_user_mbz(&ext->mbz64[n]);
> > > > + if (err)
> > > > + return err;
> > > > + }
> > > > +
> > > > + if (copy_from_user(&ci, &ext->master, sizeof(ci)))
> > > > + return -EFAULT;
> > > > +
> > > > + master = intel_engine_lookup_user(i915,
> > > > + ci.engine_class,
> > > > + ci.engine_instance);
> > > > + if (!master) {
> > >
> > > It's 100% orthogonal annoyance, but maybe we can start the "what's a good
> > > name here" discussion.
> > >
> > > I'm thinking s/master/first/ and s/slave/subsequent/ that reflect how this
> > > is actually used on the execbuf side. But then this entire bonded
> > > extension is so disconnected from the actual use-case, maybe we should
> > > just sun-set it before we bother.
> >
> > primary/secondary come to mind. But, also, I'd rather do that as a
> > separate patch since I was trying to make this mostly match. Happy to
> > up my i915 patch count with a rename follow-on, if you want.
>
> Yeah I think we can repaint that shed as part of merging the new parallel
> submit support.
>
> > > Since we might need to keep the execlist backend implementation the
> > > renaming might still be needed.
> > >
> > > > + drm_dbg(&i915->drm,
> > > > + "Unrecognised master engine: { class:%u, instance:%u }\n",
> > > > + ci.engine_class, ci.engine_instance);
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + if (get_user(num_bonds, &ext->num_bonds))
> > > > + return -EFAULT;
> > > > +
> > > > + for (n = 0; n < num_bonds; n++) {
> > > > + struct intel_engine_cs *bond;
> > > > +
> > > > + if (copy_from_user(&ci, &ext->engines[n], sizeof(ci)))
> > > > + return -EFAULT;
> > > > +
> > > > + bond = intel_engine_lookup_user(i915,
> > > > + ci.engine_class,
> > > > + ci.engine_instance);
> > > > + if (!bond) {
> > > > + drm_dbg(&i915->drm,
> > > > + "Unrecognised engine[%d] for bonding: { class:%d, instance: %d }\n",
> > > > + n, ci.engine_class, ci.engine_instance);
> > > > + return -EINVAL;
> > > > + }
> > > > + }
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static const i915_user_extension_fn set_proto_ctx_engines_extensions[] = {
> > > > + [I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE] = set_proto_ctx_engines_balance,
> > > > + [I915_CONTEXT_ENGINES_EXT_BOND] = set_proto_ctx_engines_bond,
> > > > +};
> > > > +
> > > > +static int set_proto_ctx_engines(struct drm_i915_file_private *fpriv,
> > > > + struct i915_gem_proto_context *pc,
> > > > + const struct drm_i915_gem_context_param *args)
> > > > +{
> > > > + struct drm_i915_private *i915 = fpriv->dev_priv;
> > > > + struct set_proto_ctx_engines set = { .i915 = i915 };
> > > > + struct i915_context_param_engines __user *user =
> > > > + u64_to_user_ptr(args->value);
> > > > + unsigned int n;
> > > > + u64 extensions;
> > > > + int err;
> > > > +
> > > > + if (!args->size) {
> > > > + kfree(pc->user_engines);
> > > > + pc->num_user_engines = -1;
> > >
> > > Is this case actually used by actual userspace, or just more stuff igt
> > > loved to do?
> > >
> > > If so more uapi to ditch, and check in an igt that it's rejected.
> > >
> > > Plus standard !args->size handling here with appropriate drm_debug line
> > > and all that.
> > >
> > > > + pc->user_engines = NULL;
> > > > + memset(&pc->legacy_rcs_sseu, 0, sizeof(pc->legacy_rcs_sseu));
> > > > + return 0;
> > > > + }
> > > > +
> > > > + BUILD_BUG_ON(!IS_ALIGNED(sizeof(*user), sizeof(*user->engines)));
> > >
> > > I frankly don't know what this is checking, but it also looks harmless.
> >
> > Yeah..... All I can see is that it lets us avoid doing a subtraction
> > in the alignment check below. Kind-of silly, IMO.
>
> I'm not seeing even that? Care to help the blind?
The array length is calculated as (args->size - sizeof(*user)) /
sizeof(*user->engines) which means that we really want (args->size -
sizeof(*user)) to be divisible by sizeof(*user->engines). However,
instead of checking
IS_ALIGNED(args->size - sizeof(*user), sizeof(*user->engines))
we first check that sizeof(*user) is divisible by
sizeof(*user->engines) with a static check and then just check the
alignment of args->size. I'm going to fix this mess.
> > > > + if (args->size < sizeof(*user) ||
> > > > + !IS_ALIGNED(args->size, sizeof(*user->engines))) {
> > > > + drm_dbg(&i915->drm, "Invalid size for engine array: %d\n",
> > > > + args->size);
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + set.num_engines = (args->size - sizeof(*user)) / sizeof(*user->engines);
> > > > + /* RING_MASK has no shift so we can use it directly here */
> > > > + if (set.num_engines > I915_EXEC_RING_MASK + 1)
> > > > + return -EINVAL;
> > > > +
> > > > + set.engines = kmalloc_array(set.num_engines, sizeof(*set.engines), GFP_KERNEL);
> > > > + if (!set.engines)
> > > > + return -ENOMEM;
> > > > +
> > > > + for (n = 0; n < set.num_engines; n++) {
> > > > + struct i915_engine_class_instance ci;
> > > > + struct intel_engine_cs *engine;
> > > > +
> > > > + if (copy_from_user(&ci, &user->engines[n], sizeof(ci))) {
> > > > + kfree(set.engines);
> > > > + return -EFAULT;
> > > > + }
> > > > +
> > > > + memset(&set.engines[n], 0, sizeof(set.engines[n]));
> > > > +
> > > > + if (ci.engine_class == (u16)I915_ENGINE_CLASS_INVALID &&
> > > > + ci.engine_instance == (u16)I915_ENGINE_CLASS_INVALID_NONE)
> > > > + continue;
> > > > +
> > > > + engine = intel_engine_lookup_user(i915,
> > > > + ci.engine_class,
> > > > + ci.engine_instance);
> > > > + if (!engine) {
> > > > + drm_dbg(&i915->drm,
> > > > + "Invalid engine[%d]: { class:%d, instance:%d }\n",
> > > > + n, ci.engine_class, ci.engine_instance);
> > > > + kfree(set.engines);
> > > > + return -ENOENT;
> > > > + }
> > > > +
> > > > + set.engines[n].type = I915_GEM_ENGINE_TYPE_PHYSICAL;
> > > > + set.engines[n].engine = engine;
> > > > + }
> > > > +
> > > > + err = -EFAULT;
> > > > + if (!get_user(extensions, &user->extensions))
> > > > + err = i915_user_extensions(u64_to_user_ptr(extensions),
> > > > + set_proto_ctx_engines_extensions,
> > > > + ARRAY_SIZE(set_proto_ctx_engines_extensions),
> > > > + &set);
> > > > + if (err) {
> > > > + kfree(set.engines);
> > > > + return err;
> > > > + }
> > > > +
> > > > + kfree(pc->user_engines);
> > >
> > > Both of these kfree potentially leak engines[].siblings. I think you need
> > > to extract a proto_context_free_engines helper and use that 2x here and
> > > once at the very top in proto_context_close().
> >
> > Good catch. Done.
> >
> > > > + pc->num_user_engines = set.num_engines;
> > > > + pc->user_engines = set.engines;
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
> > > > + struct i915_gem_proto_context *pc,
> > > > + struct drm_i915_gem_context_param *args)
> > > > +{
> > > > + struct drm_i915_private *i915 = fpriv->dev_priv;
> > > > + struct drm_i915_gem_context_param_sseu user_sseu;
> > > > + struct intel_sseu *sseu;
> > > > + int ret;
> > > > +
> > > > + if (args->size < sizeof(user_sseu))
> > > > + return -EINVAL;
> > > > +
> > > > + if (!IS_GEN(i915, 11))
> > > > + return -ENODEV;
> > > > +
> > > > + if (copy_from_user(&user_sseu, u64_to_user_ptr(args->value),
> > > > + sizeof(user_sseu)))
> > > > + return -EFAULT;
> > > > +
> > > > + if (user_sseu.rsvd)
> > > > + return -EINVAL;
> > > > +
> > > > + if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
> > > > + return -EINVAL;
> > > > +
> > > > + if (!!(user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX) != (pc->num_user_engines >= 0))
> > > > + return -EINVAL;
> > > > +
> > > > + if (pc->num_user_engines >= 0) {
> > > > + int idx = user_sseu.engine.engine_instance;
> > > > + struct i915_gem_proto_engine *pe;
> > > > +
> > > > + if (idx >= pc->num_user_engines)
> > > > + return -EINVAL;
> > > > +
> > > > + pe = &pc->user_engines[idx];
> > > > +
> > > > + /* Only render engine supports RPCS configuration. */
> > > > + if (pe->engine->class != RENDER_CLASS)
> > > > + return -EINVAL;
> > > > +
> > > > + sseu = &pe->sseu;
> > > > + } else {
> > > > + /* Only render engine supports RPCS configuration. */
> > > > + if (user_sseu.engine.engine_class != I915_ENGINE_CLASS_RENDER)
> > > > + return -EINVAL;
> > > > +
> > > > + /* There is only one render engine */
> > > > + if (user_sseu.engine.engine_instance != 0)
> > > > + return -EINVAL;
> > > > +
> > > > + sseu = &pc->legacy_rcs_sseu;
> > > > + }
> > >
> > > I think this faithfully rebuilds the convoluted and I think largely
> > > accidental semantics of SSEU for all combinations of ordering against
> > > set_engines.
> > >
> > > Maybe add a commit message note about this particular kind of fun here. I
> > > don't think a code comment is warranted since I don't think I've seen a
> > > userspace rely on how sseu interacts with set_engines
> >
> > Done.
> >
> > > > +
> > > > + ret = i915_gem_user_to_context_sseu(&i915->gt, &user_sseu, sseu);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + args->size = sizeof(user_sseu);
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
> > > > + struct i915_gem_proto_context *pc,
> > > > + struct drm_i915_gem_context_param *args)
> > > > +{
> > > > + int ret = 0;
> > > > +
> > > > + switch (args->param) {
> > > > + case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
> > > > + if (args->size)
> > > > + ret = -EINVAL;
> > > > + else if (args->value)
> > > > + __set_bit(UCONTEXT_NO_ERROR_CAPTURE, &pc->user_flags);
> > > > + else
> > > > + __clear_bit(UCONTEXT_NO_ERROR_CAPTURE, &pc->user_flags);
> > >
> > > Open code please and double check I caught them all ...
> >
> > As I commented the first time around, __set/clear_bit are static
> > inlines that unroll to "*field |= (1 << bit)" or "*field &= ~(1 <<
> > bit)" as appropriate. The non-__ versions do atomics. I could
> > hand-roll them but that seems error-prone and it gains us nothing.
>
> They do more, they treat this as a potential array of unsigned long as a
> bitfield of unlimted size. This comes from the cpuset support afaiu our
> history here, and years ago (decades by now?) linux started supporting
> more than 64 cpus cores. Our flags are definitely not unlimted and fit in
> an unsigned, so we're dropping some compiler checking here.
>
> Also it's not that bad really:
>
> if (args->value)
> pc->user_flags |= BIT(UCONTEXT_NO_ERROR_CAPTURE);
> else
> pc->user_flags &= ~BIT(UCONTEXT_NO_ERROR_CAPTURE);
>
> Fairly idiomatic construct. Final argument here is that __func() generally
> means "beware, check carefuly what's going on here", and nothing funny is
> going on here at all, so it's a bit a negative trap :-)
>
> Anyway git grep shows you're not the first (even outside of drm/i915).
> Some spot checking with grep shows that bitflag use of __set_bit is about
> a third of overall use:
>
> $ git grep '__set_bit.*)' | wc -l
> 1761
>
> $ git grep '__set_bit.*,\s*&.*)' | wc -l
> 479
>
> So whatever you feel like.
Your shed, your colors. I just wanted a reason and to know you
weren't missing something.
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_BANNABLE:
> > > > + if (args->size)
> > > > + ret = -EINVAL;
> > > > + else if (!capable(CAP_SYS_ADMIN) && !args->value)
> > > > + ret = -EPERM;
> > > > + else if (args->value)
> > > > + __set_bit(UCONTEXT_BANNABLE, &pc->user_flags);
> > > > + else
> > > > + __clear_bit(UCONTEXT_BANNABLE, &pc->user_flags);
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_RECOVERABLE:
> > > > + if (args->size)
> > > > + ret = -EINVAL;
> > > > + else if (args->value)
> > > > + __set_bit(UCONTEXT_RECOVERABLE, &pc->user_flags);
> > > > + else
> > > > + __clear_bit(UCONTEXT_RECOVERABLE, &pc->user_flags);
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_PRIORITY:
> > > > + ret = validate_priority(fpriv->dev_priv, args);
> > > > + if (!ret)
> > > > + pc->sched.priority = args->value;
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_SSEU:
> > > > + ret = set_proto_ctx_sseu(fpriv, pc, args);
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_VM:
> > > > + ret = set_proto_ctx_vm(fpriv, pc, args);
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_ENGINES:
> > > > + ret = set_proto_ctx_engines(fpriv, pc, args);
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_PERSISTENCE:
> > > > + if (args->size)
> > > > + ret = -EINVAL;
> > > > + else if (args->value)
> > > > + __set_bit(UCONTEXT_PERSISTENCE, &pc->user_flags);
> > > > + else
> > > > + __clear_bit(UCONTEXT_PERSISTENCE, &pc->user_flags);
> > >
> > > I think we have a nice mess here. You created this
> > > proto_context_set_persistence helper, but don't use it here. Oversight?
> >
> > Yeah, I should use it. Done.
> >
> > > Aside from the validation fun around persistence, but that's better
> > > discussed in another patch I think.
> > >
> > > > + break;
> > > > +
> > > > + case I915_CONTEXT_PARAM_NO_ZEROMAP:
> > > > + case I915_CONTEXT_PARAM_BAN_PERIOD:
> > > > + case I915_CONTEXT_PARAM_RINGSIZE:
> > > > + default:
> > > > + ret = -EINVAL;
> > > > + break;
> > > > + }
> > > > +
> > > > + return ret;
> > > > +}
> > > > +
> > > > static struct i915_address_space *
> > > > context_get_vm_rcu(struct i915_gem_context *ctx)
> > > > {
> > > > @@ -475,6 +918,56 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx,
> > > > return err;
> > > > }
> > > >
> > > > +static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
> > > > + unsigned int num_engines,
> > > > + struct i915_gem_proto_engine *pe)
> > > > +{
> > > > + struct i915_gem_engines *e, *err;
> > > > + unsigned int n;
> > > > +
> > > > + e = alloc_engines(num_engines);
> > > > + for (n = 0; n < num_engines; n++) {
> > > > + struct intel_context *ce;
> > > > + int ret;
> > > > +
> > > > + switch (pe[n].type) {
> > > > + case I915_GEM_ENGINE_TYPE_PHYSICAL:
> > > > + ce = intel_context_create(pe[n].engine);
> > > > + break;
> > > > +
> > > > + case I915_GEM_ENGINE_TYPE_BALANCED:
> > > > + ce = intel_execlists_create_virtual(pe[n].siblings,
> > > > + pe[n].num_siblings);
> > > > + break;
> > > > +
> > > > + case I915_GEM_ENGINE_TYPE_INVALID:
> > > > + default:
> > > > + GEM_WARN_ON(pe[n].type != I915_GEM_ENGINE_TYPE_INVALID);
> > > > + continue;
> > > > + }
> > > > +
> > > > + if (IS_ERR(ce)) {
> > > > + err = ERR_CAST(ce);
> > > > + goto free_engines;
> > > > + }
> > > > +
> > > > + e->engines[n] = ce;
> > > > +
> > > > + ret = intel_context_set_gem(ce, ctx, pe->sseu);
> > > > + if (ret) {
> > > > + err = ERR_PTR(ret);
> > > > + goto free_engines;
> > > > + }
> > > > + }
> > > > + e->num_engines = num_engines;
> > > > +
> > > > + return e;
> > > > +
> > > > +free_engines:
> > > > + free_engines(e);
> > > > + return err;
> > > > +}
> > > > +
> > > > void i915_gem_context_release(struct kref *ref)
> > > > {
> > > > struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref);
> > > > @@ -779,7 +1272,6 @@ __create_context(struct drm_i915_private *i915,
> > > > {
> > > > struct i915_gem_context *ctx;
> > > > struct i915_gem_engines *e;
> > > > - struct intel_sseu null_sseu = {};
> > > > int err;
> > > > int i;
> > > >
> > > > @@ -797,7 +1289,7 @@ __create_context(struct drm_i915_private *i915,
> > > > INIT_LIST_HEAD(&ctx->stale.engines);
> > > >
> > > > mutex_init(&ctx->engines_mutex);
> > > > - e = default_engines(ctx, null_sseu);
> > > > + e = default_engines(ctx, pc->legacy_rcs_sseu);
> > > > if (IS_ERR(e)) {
> > > > err = PTR_ERR(e);
> > > > goto err_free;
> > > > @@ -916,6 +1408,24 @@ i915_gem_create_context(struct drm_i915_private *i915,
> > > > mutex_unlock(&ctx->mutex);
> > > > }
> > > >
> > > > + if (pc->num_user_engines >= 0) {
> > > > + struct i915_gem_engines *engines;
> > > > +
> > > > + engines = user_engines(ctx, pc->num_user_engines,
> > > > + pc->user_engines);
> > > > + if (IS_ERR(engines)) {
> > > > + context_close(ctx);
> > > > + return ERR_CAST(engines);
> > > > + }
> > > > +
> > > > + mutex_lock(&ctx->engines_mutex);
> > > > + i915_gem_context_set_user_engines(ctx);
> > > > + engines = rcu_replace_pointer(ctx->engines, engines, 1);
> > > > + mutex_unlock(&ctx->engines_mutex);
> > >
> > > More locking code to ditch I guess.
> >
> > Sure. Is it safe to just drop it? I guess it is? I'm really shaky
> > around all the RCU requirements and things.
>
> Well the 1 in here should be replace with
> lockdep_is_held(&ctx->engines_mutex), but the engines_mutex also should
> go, so really can ditch the entire thing. Also no one can access our
> context, so we can't fail.
>
> Now if you do this naively without dropping the __rcu classifier for
> ctx->engines then static checkers will complain. So until that's done an
> rcu_assign_pointer should do.
This is all nuked by the last patch. If it's all the same to you, I'd
rather leave the re-typed stupid boiler-plate here and delete it and
do it properly there. That patch sets up an engine set once and uses
RCU_INIT_POINTER.
--Jason
> >
> > > > +
> > > > + free_engines(engines);
> > >
> > > Also I guess we shouldn't first create the legacy engines for this case?
> >
> > That's fixed in the last patch.
>
> Yeah I noticed later on.
>
> >
> > > > + }
> > > > +
> > > > if (pc->single_timeline) {
> > > > ret = drm_syncobj_create(&ctx->syncobj,
> > > > DRM_SYNCOBJ_CREATE_SIGNALED,
> > > > @@ -1956,7 +2466,7 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
> > > > }
> > > >
> > > > struct create_ext {
> > > > - struct i915_gem_context *ctx;
> > > > + struct i915_gem_proto_context *pc;
> > > > struct drm_i915_file_private *fpriv;
> > > > };
> > > >
> > > > @@ -1971,7 +2481,7 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
> > > > if (local.param.ctx_id)
> > > > return -EINVAL;
> > > >
> > > > - return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
> > > > + return set_proto_ctx_param(arg->fpriv, arg->pc, &local.param);
> > > > }
> > > >
> > > > static int invalid_ext(struct i915_user_extension __user *ext, void *data)
> > > > @@ -1994,7 +2504,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
> > > > {
> > > > struct drm_i915_private *i915 = to_i915(dev);
> > > > struct drm_i915_gem_context_create_ext *args = data;
> > > > - struct i915_gem_proto_context *pc;
> > > > + struct i915_gem_context *ctx;
> > > > struct create_ext ext_data;
> > > > int ret;
> > > > u32 id;
> > > > @@ -2017,25 +2527,27 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
> > > > return -EIO;
> > > > }
> > > >
> > > > - pc = proto_context_create(i915, args->flags);
> > > > - if (IS_ERR(pc))
> > > > - return PTR_ERR(pc);
> > > > -
> > > > - ext_data.ctx = i915_gem_create_context(i915, pc);
> > > > - proto_context_close(pc);
> > > > - if (IS_ERR(ext_data.ctx))
> > > > - return PTR_ERR(ext_data.ctx);
> > > > + ext_data.pc = proto_context_create(i915, args->flags);
> > > > + if (IS_ERR(ext_data.pc))
> > > > + return PTR_ERR(ext_data.pc);
> > > >
> > > > if (args->flags & I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS) {
> > > > ret = i915_user_extensions(u64_to_user_ptr(args->extensions),
> > > > create_extensions,
> > > > ARRAY_SIZE(create_extensions),
> > > > &ext_data);
> > > > - if (ret)
> > > > - goto err_ctx;
> > > > + if (ret) {
> > > > + proto_context_close(ext_data.pc);
> > > > + return ret;
> > > > + }
> > > > }
> > > >
> > > > - ret = gem_context_register(ext_data.ctx, ext_data.fpriv, &id);
> > > > + ctx = i915_gem_create_context(i915, ext_data.pc);
> > > > + proto_context_close(ext_data.pc);
> > > > + if (IS_ERR(ctx))
> > > > + return PTR_ERR(ctx);
> > > > +
> > > > + ret = gem_context_register(ctx, ext_data.fpriv, &id);
> > > > if (ret < 0)
> > > > goto err_ctx;
> > > >
> > > > @@ -2045,7 +2557,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
> > > > return 0;
> > > >
> > > > err_ctx:
> > > > - context_close(ext_data.ctx);
> > > > + context_close(ctx);
> > > > return ret;
> > > > }
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> > > > index 0bf337b6d89ac..2ac341f805c8f 100644
> > > > --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> > > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> > > > @@ -66,6 +66,55 @@ struct i915_gem_engines_iter {
> > > > const struct i915_gem_engines *engines;
> > > > };
> > > >
> > > > +/**
> > > > + * enum i915_gem_engine_type - Describes the type of an i915_gem_proto_engine
> > > > + */
> > > > +enum i915_gem_engine_type {
> > > > + /** @I915_GEM_ENGINE_TYPE_INVALID: An invalid engine */
> > > > + I915_GEM_ENGINE_TYPE_INVALID = 0,
> > > > +
> > > > + /** @I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine */
> > > > + I915_GEM_ENGINE_TYPE_PHYSICAL,
> > > > +
> > > > + /** @I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set */
> > > > + I915_GEM_ENGINE_TYPE_BALANCED,
> > > > +};
> > > > +
> > > > +/**
> > > > + * struct i915_gem_proto_engine - prototype engine
> > > > + *
> > > > + * This struct describes an engine that a context may contain. Engines
> > > > + * have three types:
> > > > + *
> > > > + * - I915_GEM_ENGINE_TYPE_INVALID: Invalid engines can be created but they
> > > > + * show up as a NULL in i915_gem_engines::engines[i] and any attempt to
> > > > + * use them by the user results in -EINVAL. They are also useful during
> > > > + * proto-context construction because the client may create invalid
> > > > + * engines and then set them up later as bonded engines.
> > > > + *
> > > > + * - I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine, described by
> > > > + * i915_gem_proto_engine::engine.
> > > > + *
> > > > + * - I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set, described
> > > > + * i915_gem_proto_engine::num_siblings and i915_gem_proto_engine::siblings.
> > > > + */
> > > > +struct i915_gem_proto_engine {
> > > > + /** @type: Type of this engine */
> > > > + enum i915_gem_engine_type type;
> > > > +
> > > > + /** @engine: Engine, for physical */
> > > > + struct intel_engine_cs *engine;
> > > > +
> > > > + /** @num_siblings: Number of balanced siblings */
> > > > + unsigned int num_siblings;
> > > > +
> > > > + /** @siblings: Balanced siblings */
> > > > + struct intel_engine_cs **siblings;
> > > > +
> > > > + /** @sseu: Client-set SSEU parameters */
> > > > + struct intel_sseu sseu;
> > > > +};
> > > > +
> > > > /**
> > > > * struct i915_gem_proto_context - prototype context
> > > > *
> > > > @@ -84,6 +133,15 @@ struct i915_gem_proto_context {
> > > > /** @sched: See i915_gem_context::sched */
> > > > struct i915_sched_attr sched;
> > > >
> > > > + /** @num_user_engines: Number of user-specified engines or -1 */
> > > > + int num_user_engines;
> > > > +
> > > > + /** @user_engines: User-specified engines */
> > > > + struct i915_gem_proto_engine *user_engines;
> > > > +
> > > > + /** @sseu: Client-set SSEU parameters for the legacy RCS */
> > > > + struct intel_sseu legacy_rcs_sseu;
> > > > +
> > > > /** @single_timeline: See See i915_gem_context::syncobj */
> > > > bool single_timeline;
> > > > };
> > > > --
> > > > 2.31.1
> > >
> > > Man is this all nasty. Since I don't want to re-review the entire pile,
> > > assuming we figure out solutions to all the real issues I've raised (and
> > > not the snarky bikesheds) this is
> > >
> > > Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> >
> > Ok. I'm leaving it off for now to remind myself to ensure that we
> > close on everything. I'll add it once I've heard back from you on my
> > questions above.
>
> I think we're all good. Mostly :-/
> -Daniel
>
> >
> > --Jason
> >
> > > >
> > > > _______________________________________________
> > > > dri-devel mailing list
> > > > dri-devel at lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > >
> > > --
> > > Daniel Vetter
> > > Software Engineer, Intel Corporation
> > > http://blog.ffwll.ch
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
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