rcu_read_unlock();
}
+static inline int new_hw_id(struct drm_i915_private *i915, gfp_t gfp)
+{
+ unsigned int max;
+
+ lockdep_assert_held(&i915->contexts.mutex);
+
+ if (INTEL_GEN(i915) >= 11)
+ max = GEN11_MAX_CONTEXT_HW_ID;
+ else if (USES_GUC_SUBMISSION(i915))
+ /*
+ * When using GuC in proxy submission, GuC consumes the
+ * highest bit in the context id to indicate proxy submission.
+ */
+ max = MAX_GUC_CONTEXT_HW_ID;
+ else
+ max = MAX_CONTEXT_HW_ID;
+
+ return ida_simple_get(&i915->contexts.hw_ida, 0, max, gfp);
+}
+
+static int steal_hw_id(struct drm_i915_private *i915)
+{
+ struct i915_gem_context *ctx, *cn;
+ LIST_HEAD(pinned);
+ int id = -ENOSPC;
+
+ lockdep_assert_held(&i915->contexts.mutex);
+
+ list_for_each_entry_safe(ctx, cn,
+ &i915->contexts.hw_id_list, hw_id_link) {
+ if (atomic_read(&ctx->hw_id_pin_count)) {
+ list_move_tail(&ctx->hw_id_link, &pinned);
+ continue;
+ }
+
+ GEM_BUG_ON(!ctx->hw_id); /* perma-pinned kernel context */
+ list_del_init(&ctx->hw_id_link);
+ id = ctx->hw_id;
+ break;
+ }
+
+ /*
+ * Remember how far we got up on the last repossesion scan, so the
+ * list is kept in a "least recently scanned" order.
+ */
+ list_splice_tail(&pinned, &i915->contexts.hw_id_list);
+ return id;
+}
+
+static int assign_hw_id(struct drm_i915_private *i915, unsigned int *out)
+{
+ int ret;
+
+ lockdep_assert_held(&i915->contexts.mutex);
+
+ /*
+ * We prefer to steal/stall ourselves and our users over that of the
+ * entire system. That may be a little unfair to our users, and
+ * even hurt high priority clients. The choice is whether to oomkill
+ * something else, or steal a context id.
+ */
+ ret = new_hw_id(i915, GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+ if (unlikely(ret < 0)) {
+ ret = steal_hw_id(i915);
+ if (ret < 0) /* once again for the correct errno code */
+ ret = new_hw_id(i915, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+ }
+
+ *out = ret;
+ return 0;
+}
+
+static void release_hw_id(struct i915_gem_context *ctx)
+{
+ struct drm_i915_private *i915 = ctx->i915;
+
+ if (list_empty(&ctx->hw_id_link))
+ return;
+
+ mutex_lock(&i915->contexts.mutex);
+ if (!list_empty(&ctx->hw_id_link)) {
+ ida_simple_remove(&i915->contexts.hw_ida, ctx->hw_id);
+ list_del_init(&ctx->hw_id_link);
+ }
+ mutex_unlock(&i915->contexts.mutex);
+}
+
static void i915_gem_context_free(struct i915_gem_context *ctx)
{
unsigned int n;
lockdep_assert_held(&ctx->i915->drm.struct_mutex);
GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
+ release_hw_id(ctx);
i915_ppgtt_put(ctx->ppgtt);
for (n = 0; n < ARRAY_SIZE(ctx->__engine); n++) {
list_del(&ctx->link);
- ida_simple_remove(&ctx->i915->contexts.hw_ida, ctx->hw_id);
kfree_rcu(ctx, rcu);
}
{
i915_gem_context_set_closed(ctx);
+ /*
+ * This context will never again be assinged to HW, so we can
+ * reuse its ID for the next context.
+ */
+ release_hw_id(ctx);
+
/*
* The LUT uses the VMA as a backpointer to unref the object,
* so we need to clear the LUT before we close all the VMA (inside
i915_gem_context_put(ctx);
}
-static int assign_hw_id(struct drm_i915_private *dev_priv, unsigned *out)
-{
- int ret;
- unsigned int max;
-
- if (INTEL_GEN(dev_priv) >= 11) {
- max = GEN11_MAX_CONTEXT_HW_ID;
- } else {
- /*
- * When using GuC in proxy submission, GuC consumes the
- * highest bit in the context id to indicate proxy submission.
- */
- if (USES_GUC_SUBMISSION(dev_priv))
- max = MAX_GUC_CONTEXT_HW_ID;
- else
- max = MAX_CONTEXT_HW_ID;
- }
-
-
- ret = ida_simple_get(&dev_priv->contexts.hw_ida,
- 0, max, GFP_KERNEL);
- if (ret < 0) {
- /* Contexts are only released when no longer active.
- * Flush any pending retires to hopefully release some
- * stale contexts and try again.
- */
- i915_retire_requests(dev_priv);
- ret = ida_simple_get(&dev_priv->contexts.hw_ida,
- 0, max, GFP_KERNEL);
- if (ret < 0)
- return ret;
- }
-
- *out = ret;
- return 0;
-}
-
static u32 default_desc_template(const struct drm_i915_private *i915,
const struct i915_hw_ppgtt *ppgtt)
{
if (ctx == NULL)
return ERR_PTR(-ENOMEM);
- ret = assign_hw_id(dev_priv, &ctx->hw_id);
- if (ret) {
- kfree(ctx);
- return ERR_PTR(ret);
- }
-
kref_init(&ctx->ref);
list_add_tail(&ctx->link, &dev_priv->contexts.list);
ctx->i915 = dev_priv;
INIT_RADIX_TREE(&ctx->handles_vma, GFP_KERNEL);
INIT_LIST_HEAD(&ctx->handles_list);
+ INIT_LIST_HEAD(&ctx->hw_id_link);
/* Default context will never have a file_priv */
ret = DEFAULT_CONTEXT_HANDLE;
return ctx;
}
+static void
+destroy_kernel_context(struct i915_gem_context **ctxp)
+{
+ struct i915_gem_context *ctx;
+
+ /* Keep the context ref so that we can free it immediately ourselves */
+ ctx = i915_gem_context_get(fetch_and_zero(ctxp));
+ GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
+
+ context_close(ctx);
+ i915_gem_context_free(ctx);
+}
+
struct i915_gem_context *
i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio)
{
struct i915_gem_context *ctx;
+ int err;
ctx = i915_gem_create_context(i915, NULL);
if (IS_ERR(ctx))
return ctx;
+ err = i915_gem_context_pin_hw_id(ctx);
+ if (err) {
+ destroy_kernel_context(&ctx);
+ return ERR_PTR(err);
+ }
+
i915_gem_context_clear_bannable(ctx);
ctx->sched.priority = prio;
ctx->ring_size = PAGE_SIZE;
return ctx;
}
-static void
-destroy_kernel_context(struct i915_gem_context **ctxp)
+static void init_contexts(struct drm_i915_private *i915)
{
- struct i915_gem_context *ctx;
+ mutex_init(&i915->contexts.mutex);
+ INIT_LIST_HEAD(&i915->contexts.list);
- /* Keep the context ref so that we can free it immediately ourselves */
- ctx = i915_gem_context_get(fetch_and_zero(ctxp));
- GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
+ /* Using the simple ida interface, the max is limited by sizeof(int) */
+ BUILD_BUG_ON(MAX_CONTEXT_HW_ID > INT_MAX);
+ BUILD_BUG_ON(GEN11_MAX_CONTEXT_HW_ID > INT_MAX);
+ ida_init(&i915->contexts.hw_ida);
+ INIT_LIST_HEAD(&i915->contexts.hw_id_list);
- context_close(ctx);
- i915_gem_context_free(ctx);
+ INIT_WORK(&i915->contexts.free_work, contexts_free_worker);
+ init_llist_head(&i915->contexts.free_list);
}
static bool needs_preempt_context(struct drm_i915_private *i915)
if (ret)
return ret;
- INIT_LIST_HEAD(&dev_priv->contexts.list);
- INIT_WORK(&dev_priv->contexts.free_work, contexts_free_worker);
- init_llist_head(&dev_priv->contexts.free_list);
-
- /* Using the simple ida interface, the max is limited by sizeof(int) */
- BUILD_BUG_ON(MAX_CONTEXT_HW_ID > INT_MAX);
- BUILD_BUG_ON(GEN11_MAX_CONTEXT_HW_ID > INT_MAX);
- ida_init(&dev_priv->contexts.hw_ida);
+ init_contexts(dev_priv);
/* lowest priority; idle task */
ctx = i915_gem_context_create_kernel(dev_priv, I915_PRIORITY_MIN);
}
/*
* For easy recognisablity, we want the kernel context to be 0 and then
- * all user contexts will have non-zero hw_id.
+ * all user contexts will have non-zero hw_id. Kernel contexts are
+ * permanently pinned, so that we never suffer a stall and can
+ * use them from any allocation context (e.g. for evicting other
+ * contexts and from inside the shrinker).
*/
GEM_BUG_ON(ctx->hw_id);
+ GEM_BUG_ON(!atomic_read(&ctx->hw_id_pin_count));
dev_priv->kernel_context = ctx;
/* highest priority; preempting task */
destroy_kernel_context(&i915->kernel_context);
/* Must free all deferred contexts (via flush_workqueue) first */
+ GEM_BUG_ON(!list_empty(&i915->contexts.hw_id_list));
ida_destroy(&i915->contexts.hw_ida);
}
return ret;
}
+int __i915_gem_context_pin_hw_id(struct i915_gem_context *ctx)
+{
+ struct drm_i915_private *i915 = ctx->i915;
+ int err = 0;
+
+ mutex_lock(&i915->contexts.mutex);
+
+ GEM_BUG_ON(i915_gem_context_is_closed(ctx));
+
+ if (list_empty(&ctx->hw_id_link)) {
+ GEM_BUG_ON(atomic_read(&ctx->hw_id_pin_count));
+
+ err = assign_hw_id(i915, &ctx->hw_id);
+ if (err)
+ goto out_unlock;
+
+ list_add_tail(&ctx->hw_id_link, &i915->contexts.hw_id_list);
+ }
+
+ GEM_BUG_ON(atomic_read(&ctx->hw_id_pin_count) == ~0u);
+ atomic_inc(&ctx->hw_id_pin_count);
+
+out_unlock:
+ mutex_unlock(&i915->contexts.mutex);
+ return err;
+}
+
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/mock_context.c"
#include "selftests/i915_gem_context.c"
projects / openwrt / staging / blogic.git / commitdiff