Re: [Intel-gfx] [PATCH 16/21] drm/i915/gem: Delay context creation

Yeah this needs some text to explain what/why you're doing this, and maybe some rough sketch of the locking design.

On Fri, Apr 23, 2021 at 05:31:26PM -0500, Jason Ekstrand wrote:

Signed-off-by: Jason Ekstrand jason@jlekstrand.net

drivers/gpu/drm/i915/gem/i915_gem_context.c | 657 ++++++++++++++++-- drivers/gpu/drm/i915/gem/i915_gem_context.h | 3 + .../gpu/drm/i915/gem/i915_gem_context_types.h | 26 + .../gpu/drm/i915/gem/selftests/mock_context.c | 5 +- drivers/gpu/drm/i915/i915_drv.h | 17 +- 5 files changed, 648 insertions(+), 60 deletions(-)

So I think the patch split here is a bit unfortunate, because you're adding the new vm/engine validation code for proto context here, but the old stuff is only removed in the next patches that make vm/engines immutable after first use.

I think a better split would be if this patch here only has all the scaffolding. You already have the EOPNOTSUPP fallback (which I hope gets removed), so moving the conversion entirely to later patches should be all fine.

Or do I miss something?

I think the only concern I'm seeing is that bisectability might be a bit lost, because we finalize the context in some cases in setparam. And if we do the conversion in a different order than the one media uses for its setparam, then later setparam might fail because the context is finalized already. But also - it's just bisectability of media functionality I think - just check which order media calls CTX_SETPARAM and use that to do the conversion

And we should be fine ... I think?

Some more thoughts below, but the proto ctx stuff itself looks fine.

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index db9153e0f85a7..aa8e61211924f 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);
  

• } kfree(pc);

}

@@ -274,12 +281,417 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags) proto_context_set_persistence(i915, pc, true); pc->sched.priority = I915_PRIORITY_NORMAL;

• pc->num_user_engines = -1;

• pc->user_engines = NULL;

• if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE) pc->single_timeline = true;

  return pc;

}

+static int proto_context_register_locked(struct drm_i915_file_private *fpriv,

• 			 struct i915_gem_proto_context *pc,
  

• 			 u32 *id)
  

+{

• int ret;
• void *old;

assert_lock_held just for consistency.

• ret = xa_alloc(&fpriv->context_xa, id, NULL, xa_limit_32b, GFP_KERNEL);
• if (ret)

• return ret;
  

• old = xa_store(&fpriv->proto_context_xa, *id, pc, GFP_KERNEL);
• if (xa_is_err(old)) {

• xa_erase(&fpriv->context_xa, *id);
  

• return xa_err(old);
  

• }
• GEM_BUG_ON(old);
• return 0;

+}

+static int proto_context_register(struct drm_i915_file_private *fpriv,

• 		  struct i915_gem_proto_context *pc,
  

• 		  u32 *id)
  

+{

• int ret;
• mutex_lock(&fpriv->proto_context_lock);
• ret = proto_context_register_locked(fpriv, pc, id);
• mutex_unlock(&fpriv->proto_context_lock);
• return ret;

+}

+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();
• if (!vm)

• return -ENOENT;
  

• i915_vm_put(pc->vm);
• 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)

• return 0;
  

• siblings = kmalloc_array(num_siblings, sizeof(*siblings), GFP_KERNEL);
• 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);
  

• 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) {

• 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;
  

• pc->user_engines = NULL;
  

• return 0;
  

• }
• BUILD_BUG_ON(!IS_ALIGNED(sizeof(*user), sizeof(*user->engines)));
• 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);
• 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);
• pc->num_user_engines = set.num_engines;
• pc->user_engines = set.engines;
• 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);
  

Atomic bitops like in previous patches: Pls no :-)

• else
  

• 	clear_bit(UCONTEXT_NO_ERROR_CAPTURE, &pc->user_flags);
  

• 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 = -ENOTSUPP;
  

• 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);
  

• 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) { @@ -450,6 +862,47 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx) return e; }

+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;
• unsigned int n;
• e = alloc_engines(num_engines);
• for (n = 0; n < num_engines; n++) {

• struct intel_context *ce;
  

• 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)) {
  

• 	__free_engines(e, n);
  

• 	return ERR_CAST(ce);
  

• }
  

• intel_context_set_gem(ce, ctx);
  

• e->engines[n] = ce;
  

• }
• e->num_engines = num_engines;
• return e;

+}

void i915_gem_context_release(struct kref *ref) { struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref); @@ -890,6 +1343,24 @@ 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);
  

• free_engines(engines);
  

• }
• if (pc->single_timeline) { ret = drm_syncobj_create(&ctx->syncobj, DRM_SYNCOBJ_CREATE_SIGNALED,

@@ -916,12 +1387,12 @@ void i915_gem_init__contexts(struct drm_i915_private *i915) init_contexts(&i915->gem.contexts); }

-static int gem_context_register(struct i915_gem_context *ctx,

• 		struct drm_i915_file_private *fpriv,
  

• 		u32 *id)
  

+static void gem_context_register(struct i915_gem_context *ctx,

• 		 struct drm_i915_file_private *fpriv,
  

• 		 u32 id)
  

{ struct drm_i915_private *i915 = ctx->i915;

• int ret;

• void *old;

  ctx->file_priv = fpriv;

@@ -930,19 +1401,12 @@ static int gem_context_register(struct i915_gem_context *ctx, current->comm, pid_nr(ctx->pid));

/* And finally expose ourselves to userspace via the idr */

• ret = xa_alloc(&fpriv->context_xa, id, ctx, xa_limit_32b, GFP_KERNEL);
• if (ret)

• goto err_pid;
  

• old = xa_store(&fpriv->context_xa, id, ctx, GFP_KERNEL);

• GEM_BUG_ON(old);

  spin_lock(&i915->gem.contexts.lock); list_add_tail(&ctx->link, &i915->gem.contexts.list); spin_unlock(&i915->gem.contexts.lock);

• return 0;

-err_pid:

• put_pid(fetch_and_zero(&ctx->pid));
• return ret;

}

int i915_gem_context_open(struct drm_i915_private *i915, @@ -952,9 +1416,12 @@ int i915_gem_context_open(struct drm_i915_private *i915, struct i915_gem_proto_context *pc; struct i915_gem_context *ctx; int err;

• u32 id;

• xa_init_flags(&file_priv->context_xa, XA_FLAGS_ALLOC);

• mutex_init(&file_priv->proto_context_lock);

• xa_init_flags(&file_priv->proto_context_xa, XA_FLAGS_ALLOC);

• /* 0 reserved for the default context */

• xa_init_flags(&file_priv->context_xa, XA_FLAGS_ALLOC1);

  /* 0 reserved for invalid/unassigned ppgtt */ xa_init_flags(&file_priv->vm_xa, XA_FLAGS_ALLOC1);

@@ -972,28 +1439,31 @@ int i915_gem_context_open(struct drm_i915_private *i915, goto err; }

• err = gem_context_register(ctx, file_priv, &id);
• if (err < 0)

• goto err_ctx;
  

• gem_context_register(ctx, file_priv, 0);

• GEM_BUG_ON(id); return 0;

-err_ctx:

• context_close(ctx);

err: xa_destroy(&file_priv->vm_xa); xa_destroy(&file_priv->context_xa);

• xa_destroy(&file_priv->proto_context_xa);
• mutex_destroy(&file_priv->proto_context_lock); return err;

}

void i915_gem_context_close(struct drm_file *file) { struct drm_i915_file_private *file_priv = file->driver_priv;

• struct i915_gem_proto_context *pc; struct i915_address_space *vm; struct i915_gem_context *ctx; unsigned long idx;

• xa_for_each(&file_priv->proto_context_xa, idx, pc)

• proto_context_close(pc);
  

• xa_destroy(&file_priv->proto_context_xa);

• mutex_destroy(&file_priv->proto_context_lock);

• xa_for_each(&file_priv->context_xa, idx, ctx) context_close(ctx); xa_destroy(&file_priv->context_xa);

@@ -1918,7 +2388,7 @@ 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;

};

@@ -1933,7 +2403,7 @@ 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) @@ -1951,12 +2421,71 @@ static bool client_is_banned(struct drm_i915_file_private *file_priv) return atomic_read(&file_priv->ban_score) >= I915_CLIENT_SCORE_BANNED; }

+static inline struct i915_gem_context * +__context_lookup(struct drm_i915_file_private *file_priv, u32 id) +{

• struct i915_gem_context *ctx;
• rcu_read_lock();
• ctx = xa_load(&file_priv->context_xa, id);
• if (ctx && !kref_get_unless_zero(&ctx->ref))

• ctx = NULL;
  

• rcu_read_unlock();
• return ctx;

+}

+struct i915_gem_context * +lazy_create_context_locked(struct drm_i915_file_private *file_priv,

• 	   struct i915_gem_proto_context *pc, u32 id)
  

+{

• struct i915_gem_context *ctx;
• void *old;

assert_lock_held is alwasy nice in all _locked functions. It entirely compiles out without CONFIG_PROVE_LOCKING enabled.

• ctx = i915_gem_create_context(file_priv->dev_priv, pc);

I think we need a prep patch which changes the calling convetion of this and anything it calls to only return a NULL pointer. Then i915_gem_context_lookup below can return the ERR_PTR(-ENOMEM) below for that case, and we know that we're never returning a wrong error pointer.

• if (IS_ERR(ctx))

• return ctx;
  

• gem_context_register(ctx, file_priv, id);
• old = xa_erase(&file_priv->proto_context_xa, id);
• GEM_BUG_ON(old != pc);
• proto_context_close(pc);
• /* One for the xarray and one for the caller */
• return i915_gem_context_get(ctx);

+}

+struct i915_gem_context * +i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id) +{

• struct i915_gem_proto_context *pc;
• struct i915_gem_context *ctx;
• ctx = __context_lookup(file_priv, id);
• if (ctx)

• return ctx;
  

• mutex_lock(&file_priv->proto_context_lock);
• /* Try one more time under the lock */
• ctx = __context_lookup(file_priv, id);
• if (!ctx) {

• pc = xa_load(&file_priv->proto_context_xa, id);
  

• if (!pc)
  

• 	ctx = ERR_PTR(-ENOENT);
  

• else
  

• 	ctx = lazy_create_context_locked(file_priv, pc, id);
  

• }
• mutex_unlock(&file_priv->proto_context_lock);
• return ctx;

+}

int i915_gem_context_create_ioctl(struct drm_device *dev, void *data, struct drm_file *file) { struct drm_i915_private *i915 = to_i915(dev); struct drm_i915_gem_context_create_ext *args = data;

• struct i915_gem_proto_context *pc; struct create_ext ext_data; int ret; u32 id;

@@ -1979,14 +2508,9 @@ 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),

@@ -1994,20 +2518,20 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data, ARRAY_SIZE(create_extensions), &ext_data); if (ret)

• 	goto err_ctx;
  

• 	goto err_pc;
  

  }

• ret = gem_context_register(ext_data.ctx, ext_data.fpriv, &id);

• ret = proto_context_register(ext_data.fpriv, ext_data.pc, &id); if (ret < 0)

• goto err_ctx;
  

• goto err_pc;
  
  

  args->ctx_id = id; drm_dbg(&i915->drm, "HW context %d created\n", args->ctx_id);

  return 0;

-err_ctx:

• context_close(ext_data.ctx);

+err_pc:

• proto_context_close(ext_data.pc); return ret;

}

@@ -2016,6 +2540,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data, { struct drm_i915_gem_context_destroy *args = data; struct drm_i915_file_private *file_priv = file->driver_priv;

• struct i915_gem_proto_context *pc; struct i915_gem_context *ctx;

  if (args->pad != 0)

@@ -2024,11 +2549,21 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data, if (!args->ctx_id) return -ENOENT;

• mutex_lock(&file_priv->proto_context_lock); ctx = xa_erase(&file_priv->context_xa, args->ctx_id);

• if (!ctx)

• pc = xa_erase(&file_priv->proto_context_xa, args->ctx_id);
• mutex_unlock(&file_priv->proto_context_lock);
• if (!ctx && !pc) return -ENOENT;
• GEM_WARN_ON(ctx && pc);
• if (pc)

• proto_context_close(pc);
  

• if (ctx)

• context_close(ctx);
  
  

• context_close(ctx); return 0;

}

@@ -2161,16 +2696,48 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data, { struct drm_i915_file_private *file_priv = file->driver_priv; struct drm_i915_gem_context_param *args = data;

• struct i915_gem_proto_context *pc; struct i915_gem_context *ctx;

• int ret;

• int ret = 0;

• ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
• if (IS_ERR(ctx))

• return PTR_ERR(ctx);
  

• ctx = __context_lookup(file_priv, args->ctx_id);
• if (ctx)

• goto set_ctx_param;
  
  

• ret = ctx_setparam(file_priv, ctx, args);

• mutex_lock(&file_priv->proto_context_lock);
• ctx = __context_lookup(file_priv, args->ctx_id);
• if (ctx)

• goto unlock;
  

• pc = xa_load(&file_priv->proto_context_xa, args->ctx_id);
• if (!pc) {

• ret = -ENOENT;
  

• goto unlock;
  

• }
• ret = set_proto_ctx_param(file_priv, pc, args);

I think we should have a FIXME here of not allowing this on some future platforms because just use CTX_CREATE_EXT.

• if (ret == -ENOTSUPP) {

• /* Some params, specifically SSEU, can only be set on fully
  

I think this needs a FIXME: that this only holds during the conversion? Otherwise we kinda have a bit a problem me thinks ...

•  * created contexts.
  

•  */
  

• ret = 0;
  

• ctx = lazy_create_context_locked(file_priv, pc, args->ctx_id);
  

• if (IS_ERR(ctx)) {
  

• 	ret = PTR_ERR(ctx);
  

• 	ctx = NULL;
  

• }
  

• }

+unlock:

• mutex_unlock(&file_priv->proto_context_lock);

+set_ctx_param:

• if (!ret && ctx)

• ret = ctx_setparam(file_priv, ctx, args);
  

• if (ctx)

• i915_gem_context_put(ctx);
  
  

• i915_gem_context_put(ctx); return ret;

}

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h index b5c908f3f4f22..20411db84914a 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h @@ -133,6 +133,9 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data, int i915_gem_context_reset_stats_ioctl(struct drm_device *dev, void *data, struct drm_file *file);

+struct i915_gem_context * +i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id);

static inline struct i915_gem_context * i915_gem_context_get(struct i915_gem_context *ctx) { 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 a42c429f94577..067ea3030ac91 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h @@ -46,6 +46,26 @@ struct i915_gem_engines_iter { const struct i915_gem_engines *engines; };

+enum i915_gem_engine_type {

• I915_GEM_ENGINE_TYPE_INVALID = 0,
• I915_GEM_ENGINE_TYPE_PHYSICAL,
• I915_GEM_ENGINE_TYPE_BALANCED,

+};

Some kerneldoc missing?

+struct i915_gem_proto_engine {

• /** @type: Type of this engine */
• enum i915_gem_engine_type type;
• /** @num_siblings: Engine, for physical */
• struct intel_engine_cs *engine;
• /** @num_siblings: Number of balanced siblings */
• unsigned int num_siblings;
• /** @num_siblings: Balanced siblings */
• struct intel_engine_cs **siblings;

I guess you're stuffing both balanced and siblings into one?

+};

/**

• struct i915_gem_proto_context - prototype context

@@ -64,6 +84,12 @@ 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;
• /** @num_user_engines: User-specified engines */
• struct i915_gem_proto_engine *user_engines;
• bool single_timeline;

};

diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c b/drivers/gpu/drm/i915/gem/selftests/mock_context.c index e0f512ef7f3c6..32cf2103828f9 100644 --- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c +++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c @@ -80,6 +80,7 @@ void mock_init_contexts(struct drm_i915_private *i915) struct i915_gem_context * live_context(struct drm_i915_private *i915, struct file *file) {

• struct drm_i915_file_private *fpriv = to_drm_file(file)->driver_priv; struct i915_gem_proto_context *pc; struct i915_gem_context *ctx; int err;

@@ -96,10 +97,12 @@ live_context(struct drm_i915_private *i915, struct file *file)

i915_gem_context_set_no_error_capture(ctx);

• err = gem_context_register(ctx, to_drm_file(file)->driver_priv, &id);

• err = xa_alloc(&fpriv->context_xa, &id, NULL, xa_limit_32b, GFP_KERNEL); if (err < 0) goto err_ctx;

• gem_context_register(ctx, fpriv, id);

• return ctx;

err_ctx: diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 004ed0e59c999..365c042529d72 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -200,6 +200,9 @@ struct drm_i915_file_private { struct rcu_head rcu; };

• struct mutex proto_context_lock;
• struct xarray proto_context_xa;

Kerneldoc here please. Ideally also for the context_xa below (but maybe that's for later).

Also please add a hint to the proto context struct that it's all fully protected by proto_context_lock above and is never visible outside of that.

• struct xarray context_xa; struct xarray vm_xa;

@@ -1840,20 +1843,6 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,

struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags);

-static inline struct i915_gem_context * -i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id) -{

• struct i915_gem_context *ctx;
• rcu_read_lock();
• ctx = xa_load(&file_priv->context_xa, id);
• if (ctx && !kref_get_unless_zero(&ctx->ref))

• ctx = NULL;
  

• rcu_read_unlock();
• return ctx ? ctx : ERR_PTR(-ENOENT);

-}

/* i915_gem_evict.c */ int __must_check i915_gem_evict_something(struct i915_address_space *vm, u64 min_size, u64 alignment,

I think I'll check details when I'm not getting distracted by the vm/engines validation code that I think shouldn't be here :-) -Daniel