drm/i915: Remove intel_context.active_link

We no longer need to track the active intel_contexts within each engine,
allowing us to drop a tricky mutex_lock from inside unpin (which may
occur inside fs_reclaim).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-8-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 5e506e648454ee9cecb449f9b1af83079e2ff8b9..1f1761fc6597d09ab6446c277fded7aceae96215 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -49,7 +49,6 @@ int __intel_context_do_pin(struct intel_context *ce)
                return -EINTR;
 
        if (likely(!atomic_read(&ce->pin_count))) {
-               struct i915_gem_context *ctx = ce->gem_context;
                intel_wakeref_t wakeref;
 
                err = 0;
@@ -58,11 +57,7 @@ int __intel_context_do_pin(struct intel_context *ce)
                if (err)
                        goto err;
 
-               i915_gem_context_get(ctx);
-
-               mutex_lock(&ctx->mutex);
-               list_add(&ce->active_link, &ctx->active_engines);
-               mutex_unlock(&ctx->mutex);
+               i915_gem_context_get(ce->gem_context); /* for ctx->ppgtt */
 
                intel_context_get(ce);
                smp_mb__before_atomic(); /* flush pin before it is visible */
@@ -91,10 +86,6 @@ void intel_context_unpin(struct intel_context *ce)
        if (likely(atomic_dec_and_test(&ce->pin_count))) {
                ce->ops->unpin(ce);
 
-               mutex_lock(&ce->gem_context->mutex);
-               list_del(&ce->active_link);
-               mutex_unlock(&ce->gem_context->mutex);
-
                i915_gem_context_put(ce->gem_context);
                intel_context_put(ce);
        }

diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 3579c2708321da8b2382f8b1bf7cd3016f714bfd..d5a7dbd0daeeff553b2cfaeab2c0541c4c796964 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -38,7 +38,6 @@ struct intel_context {
        struct intel_engine_cs *engine;
        struct intel_engine_cs *active;
 
-       struct list_head active_link;
        struct list_head signal_link;
        struct list_head signals;
 

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index bc94b778da6f00dd1d3cde8b744c3c06269ac199..ffbf5d920429df9bfbcbf64a4b4890a6e4d17b97 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -34,6 +34,7 @@
 
 #include "gt/intel_reset.h"
 
+#include "i915_gem_context.h"
 #include "intel_dp.h"
 #include "intel_drv.h"
 #include "intel_fbc.h"
@@ -397,14 +398,17 @@ static void print_context_stats(struct seq_file *m,
        struct i915_gem_context *ctx;
 
        list_for_each_entry(ctx, &i915->contexts.list, link) {
+               struct i915_gem_engines_iter it;
                struct intel_context *ce;
 
-               list_for_each_entry(ce, &ctx->active_engines, active_link) {
+               for_each_gem_engine(ce,
+                                   i915_gem_context_lock_engines(ctx), it) {
                        if (ce->state)
                                per_file_stats(0, ce->state->obj, &kstats);
                        if (ce->ring)
                                per_file_stats(0, ce->ring->vma->obj, &kstats);
                }
+               i915_gem_context_unlock_engines(ctx);
 
                if (!IS_ERR_OR_NULL(ctx->file_priv)) {
                        struct file_stats stats = { .vm = &ctx->ppgtt->vm, };
@@ -1882,6 +1886,7 @@ static int i915_context_status(struct seq_file *m, void *unused)
                return ret;
 
        list_for_each_entry(ctx, &dev_priv->contexts.list, link) {
+               struct i915_gem_engines_iter it;
                struct intel_context *ce;
 
                seq_puts(m, "HW context ");
@@ -1906,7 +1911,8 @@ static int i915_context_status(struct seq_file *m, void *unused)
                seq_putc(m, ctx->remap_slice ? 'R' : 'r');
                seq_putc(m, '\n');
 
-               list_for_each_entry(ce, &ctx->active_engines, active_link) {
+               for_each_gem_engine(ce,
+                                   i915_gem_context_lock_engines(ctx), it) {
                        seq_printf(m, "%s: ", ce->engine->name);
                        if (ce->state)
                                describe_obj(m, ce->state->obj);
@@ -1914,6 +1920,7 @@ static int i915_context_status(struct seq_file *m, void *unused)
                                describe_ctx_ring(m, ce->ring);
                        seq_putc(m, '\n');
                }
+               i915_gem_context_unlock_engines(ctx);
 
                seq_putc(m, '\n');
        }

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 3ea199ca834bd9904c544084b58661f847ad05e4..939c1707078062ea48db412b2ce54a8c3bb910e9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -289,7 +289,6 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 {
        lockdep_assert_held(&ctx->i915->drm.struct_mutex);
        GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
-       GEM_BUG_ON(!list_empty(&ctx->active_engines));
 
        release_hw_id(ctx);
        i915_ppgtt_put(ctx->ppgtt);
@@ -416,7 +415,6 @@ __create_context(struct drm_i915_private *dev_priv)
        list_add_tail(&ctx->link, &dev_priv->contexts.list);
        ctx->i915 = dev_priv;
        ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL);
-       INIT_LIST_HEAD(&ctx->active_engines);
        mutex_init(&ctx->mutex);
 
        mutex_init(&ctx->engines_mutex);

diff --git a/drivers/gpu/drm/i915/i915_gem_context_types.h b/drivers/gpu/drm/i915/i915_gem_context_types.h
index 5f84618cf7dbbf18b1eeb16da404d3c189165984..d5cb4f121aad23ad3110557b6cf7352c8c9c8dc3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/i915_gem_context_types.h
@@ -165,7 +165,6 @@ struct i915_gem_context {
        atomic_t hw_id_pin_count;
        struct list_head hw_id_link;
 
-       struct list_head active_engines;
        struct mutex mutex;
 
        struct i915_sched_attr sched;

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
index 7fd224a4ca4c6eb0b73af13d13499d365978dba9..deedd1898fe538033b971d06342feaf4b4151e70 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
@@ -1675,7 +1675,6 @@ static int mock_context_barrier(void *arg)
                goto out;
        }
        i915_request_add(rq);
-       GEM_BUG_ON(list_empty(&ctx->active_engines));
 
        counter = 0;
        context_barrier_inject_fault = BIT(RCS0);

diff --git a/drivers/gpu/drm/i915/selftests/mock_context.c b/drivers/gpu/drm/i915/selftests/mock_context.c
index 71c7506935858388ce58105dd6351b1015f7849a..10e67c931ed147eb2cfbc284db6106d1427d2903 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/selftests/mock_context.c
@@ -50,7 +50,6 @@ mock_context(struct drm_i915_private *i915,
        INIT_RADIX_TREE(&ctx->handles_vma, GFP_KERNEL);
        INIT_LIST_HEAD(&ctx->handles_list);
        INIT_LIST_HEAD(&ctx->hw_id_link);
-       INIT_LIST_HEAD(&ctx->active_engines);
        mutex_init(&ctx->mutex);
 
        ret = i915_gem_context_pin_hw_id(ctx);