drm/i915: Split idling from forcing context switch

We only need to force a switch to the kernel context placeholder during
eviction. All other uses of i915_gpu_idle() just want to wait until
existing work on the GPU is idle. Rename i915_gpu_idle() to
i915_gem_wait_for_idle() to avoid any implications about "parking" the
context first.

v2: Tweak an error message if the wait fails for the ilk vtd w/a

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466776558-21516-6-git-send-email-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index a8e0eb7..f664884 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -4947,7 +4947,7 @@ i915_drop_caches_set(void *data, u64 val)
                return ret;
 
        if (val & DROP_ACTIVE) {
-               ret = i915_gpu_idle(dev);
+               ret = i915_gem_wait_for_idle(dev_priv);
                if (ret)
                        goto unlock;
        }

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2b01bbc..9ef4919 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3336,7 +3336,7 @@ int i915_gem_init_engines(struct drm_device *dev);
 int __must_check i915_gem_init_hw(struct drm_device *dev);
 void i915_gem_init_swizzling(struct drm_device *dev);
 void i915_gem_cleanup_engines(struct drm_device *dev);
-int __must_check i915_gpu_idle(struct drm_device *dev);
+int __must_check i915_gem_wait_for_idle(struct drm_i915_private *dev_priv);
 int __must_check i915_gem_suspend(struct drm_device *dev);
 void __i915_add_request(struct drm_i915_gem_request *req,
                        struct drm_i915_gem_object *batch_obj,

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a0533ca..51191b8 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3671,29 +3671,17 @@ int __i915_vma_unbind_no_wait(struct i915_vma *vma)
        return __i915_vma_unbind(vma, false);
 }
 
-int i915_gpu_idle(struct drm_device *dev)
+int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv)
 {
-       struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_engine_cs *engine;
        int ret;
 
+       lockdep_assert_held(&dev_priv->dev->struct_mutex);
+
        for_each_engine(engine, dev_priv) {
                if (engine->last_context == NULL)
                        continue;
 
-               if (!i915.enable_execlists) {
-                       struct drm_i915_gem_request *req;
-
-                       req = i915_gem_request_alloc(engine, NULL);
-                       if (IS_ERR(req))
-                               return PTR_ERR(req);
-
-                       ret = i915_switch_context(req);
-                       i915_add_request_no_flush(req);
-                       if (ret)
-                               return ret;
-               }
-
                ret = intel_engine_idle(engine);
                if (ret)
                        return ret;
@@ -4963,7 +4951,7 @@ i915_gem_suspend(struct drm_device *dev)
        int ret = 0;
 
        mutex_lock(&dev->struct_mutex);
-       ret = i915_gpu_idle(dev);
+       ret = i915_gem_wait_for_idle(dev_priv);
        if (ret)
                goto err;
 

diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index b144c3f..5741b58 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -33,6 +33,37 @@
 #include "intel_drv.h"
 #include "i915_trace.h"
 
+static int switch_to_pinned_context(struct drm_i915_private *dev_priv)
+{
+       struct intel_engine_cs *engine;
+
+       if (i915.enable_execlists)
+               return 0;
+
+       for_each_engine(engine, dev_priv) {
+               struct drm_i915_gem_request *req;
+               int ret;
+
+               if (engine->last_context == NULL)
+                       continue;
+
+               if (engine->last_context == dev_priv->kernel_context)
+                       continue;
+
+               req = i915_gem_request_alloc(engine, dev_priv->kernel_context);
+               if (IS_ERR(req))
+                       return PTR_ERR(req);
+
+               ret = i915_switch_context(req);
+               i915_add_request_no_flush(req);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
+
 static bool
 mark_free(struct i915_vma *vma, struct list_head *unwind)
 {
@@ -150,11 +181,17 @@ none:
 
        /* Only idle the GPU and repeat the search once */
        if (pass++ == 0) {
-               ret = i915_gpu_idle(dev);
+               struct drm_i915_private *dev_priv = to_i915(dev);
+
+               ret = switch_to_pinned_context(dev_priv);
                if (ret)
                        return ret;
 
-               i915_gem_retire_requests(to_i915(dev));
+               ret = i915_gem_wait_for_idle(dev_priv);
+               if (ret)
+                       return ret;
+
+               i915_gem_retire_requests(dev_priv);
                goto search_again;
        }
 
@@ -261,11 +298,17 @@ int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
        trace_i915_gem_evict_vm(vm);
 
        if (do_idle) {
-               ret = i915_gpu_idle(vm->dev);
+               struct drm_i915_private *dev_priv = to_i915(vm->dev);
+
+               ret = switch_to_pinned_context(dev_priv);
+               if (ret)
+                       return ret;
+
+               ret = i915_gem_wait_for_idle(dev_priv);
                if (ret)
                        return ret;
 
-               i915_gem_retire_requests(to_i915(vm->dev));
+               i915_gem_retire_requests(dev_priv);
 
                WARN_ON(!list_empty(&vm->active_list));
        }

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 5890017..6b06971 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2261,8 +2261,8 @@ static bool do_idling(struct drm_i915_private *dev_priv)
 
        if (unlikely(ggtt->do_idle_maps)) {
                dev_priv->mm.interruptible = false;
-               if (i915_gpu_idle(dev_priv->dev)) {
-                       DRM_ERROR("Couldn't idle GPU\n");
+               if (i915_gem_wait_for_idle(dev_priv)) {
+                       DRM_ERROR("Failed to wait for idle; VT'd may hang.\n");
                        /* Wait a bit, in hopes it avoids the hang */
                        udelay(10);
                }

diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index 538c304..886a879 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -408,7 +408,7 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr
                return NOTIFY_DONE;
 
        /* Force everything onto the inactive lists */
-       ret = i915_gpu_idle(dev_priv->dev);
+       ret = i915_gem_wait_for_idle(dev_priv);
        if (ret)
                goto out;