1 files changed, 88 insertions, 130 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 6043062ffce7..d72db15afa02 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -96,9 +96,6 @@
 #define GEN6_CONTEXT_ALIGN (64<<10)
 #define GEN7_CONTEXT_ALIGN 4096
 
-static int do_switch(struct intel_ring_buffer *ring,
-                     struct i915_hw_context *to);
-
 static void do_ppgtt_cleanup(struct i915_hw_ppgtt *ppgtt)
 {
         struct drm_device *dev = ppgtt->base.dev;
@@ -185,13 +182,15 @@ void i915_gem_context_free(struct kref *ctx_ref)
                                                    typeof(*ctx), ref);
         struct i915_hw_ppgtt *ppgtt = NULL;
 
-        /* We refcount even the aliasing PPGTT to keep the code symmetric */
-        if (USES_PPGTT(ctx->obj->base.dev))
-                ppgtt = ctx_to_ppgtt(ctx);
+        if (ctx->obj) {
+                /* We refcount even the aliasing PPGTT to keep the code symmetric */
+                if (USES_PPGTT(ctx->obj->base.dev))
+                        ppgtt = ctx_to_ppgtt(ctx);
 
-        /* XXX: Free up the object before tearing down the address space, in
-         * case we're bound in the PPGTT */
-        drm_gem_object_unreference(&ctx->obj->base);
+                /* XXX: Free up the object before tearing down the address space, in
+                 * case we're bound in the PPGTT */
+                drm_gem_object_unreference(&ctx->obj->base);
+        }
 
         if (ppgtt)
                 kref_put(&ppgtt->ref, ppgtt_release);
@@ -232,32 +231,32 @@ __create_hw_context(struct drm_device *dev,
                 return ERR_PTR(-ENOMEM);
 
         kref_init(&ctx->ref);
-        ctx->obj = i915_gem_alloc_object(dev, dev_priv->hw_context_size);
-        INIT_LIST_HEAD(&ctx->link);
-        if (ctx->obj == NULL) {
-                kfree(ctx);
-                DRM_DEBUG_DRIVER("Context object allocated failed\n");
-                return ERR_PTR(-ENOMEM);
-        }
+        list_add_tail(&ctx->link, &dev_priv->context_list);
 
-        if (INTEL_INFO(dev)->gen >= 7) {
-                ret = i915_gem_object_set_cache_level(ctx->obj,
-                                                      I915_CACHE_L3_LLC);
-                /* Failure shouldn't ever happen this early */
-                if (WARN_ON(ret))
+        if (dev_priv->hw_context_size) {
+                ctx->obj = i915_gem_alloc_object(dev, dev_priv->hw_context_size);
+                if (ctx->obj == NULL) {
+                        ret = -ENOMEM;
                         goto err_out;
-        }
+                }
 
-        list_add_tail(&ctx->link, &dev_priv->context_list);
+                if (INTEL_INFO(dev)->gen >= 7) {
+                        ret = i915_gem_object_set_cache_level(ctx->obj,
+                                                              I915_CACHE_L3_LLC);
+                        /* Failure shouldn't ever happen this early */
+                        if (WARN_ON(ret))
+                                goto err_out;
+                }
+        }
 
         /* Default context will never have a file_priv */
-        if (file_priv == NULL)
-                return ctx;
-
-        ret = idr_alloc(&file_priv->context_idr, ctx, DEFAULT_CONTEXT_ID, 0,
-                        GFP_KERNEL);
-        if (ret < 0)
-                goto err_out;
+        if (file_priv != NULL) {
+                ret = idr_alloc(&file_priv->context_idr, ctx,
+                                DEFAULT_CONTEXT_ID, 0, GFP_KERNEL);
+                if (ret < 0)
+                        goto err_out;
+        } else
+                ret = DEFAULT_CONTEXT_ID;
 
         ctx->file_priv = file_priv;
         ctx->id = ret;
@@ -294,7 +293,7 @@ i915_gem_create_context(struct drm_device *dev,
         if (IS_ERR(ctx))
                 return ctx;
 
-        if (is_global_default_ctx) {
+        if (is_global_default_ctx && ctx->obj) {
                 /* We may need to do things with the shrinker which
                  * require us to immediately switch back to the default
                  * context. This can cause a problem as pinning the
@@ -342,7 +341,7 @@ i915_gem_create_context(struct drm_device *dev,
         return ctx;
 
 err_unpin:
-        if (is_global_default_ctx)
+        if (is_global_default_ctx && ctx->obj)
                 i915_gem_object_ggtt_unpin(ctx->obj);
 err_destroy:
         i915_gem_context_unreference(ctx);
@@ -352,32 +351,22 @@ err_destroy:
 void i915_gem_context_reset(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
-        struct intel_ring_buffer *ring;
         int i;
 
-        if (!HAS_HW_CONTEXTS(dev))
-                return;
-
         /* Prevent the hardware from restoring the last context (which hung) on
          * the next switch */
         for (i = 0; i < I915_NUM_RINGS; i++) {
-                struct i915_hw_context *dctx;
-                if (!(INTEL_INFO(dev)->ring_mask & (1<<i)))
-                        continue;
+                struct intel_ring_buffer *ring = &dev_priv->ring[i];
+                struct i915_hw_context *dctx = ring->default_context;
 
                 /* Do a fake switch to the default context */
-                ring = &dev_priv->ring[i];
-                dctx = ring->default_context;
-                if (WARN_ON(!dctx))
+                if (ring->last_context == dctx)
                         continue;
 
                 if (!ring->last_context)
                         continue;
 
-                if (ring->last_context == dctx)
-                        continue;
-
-                if (i == RCS) {
+                if (dctx->obj && i == RCS) {
                         WARN_ON(i915_gem_obj_ggtt_pin(dctx->obj,
                                                       get_context_alignment(dev), 0));
                         /* Fake a finish/inactive */
@@ -394,44 +383,35 @@ void i915_gem_context_reset(struct drm_device *dev)
 int i915_gem_context_init(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
-        struct intel_ring_buffer *ring;
+        struct i915_hw_context *ctx;
         int i;
 
-        if (!HAS_HW_CONTEXTS(dev))
-                return 0;
-
         /* Init should only be called once per module load. Eventually the
          * restriction on the context_disabled check can be loosened. */
         if (WARN_ON(dev_priv->ring[RCS].default_context))
                 return 0;
 
-        dev_priv->hw_context_size = round_up(get_context_size(dev), 4096);
-
-        if (dev_priv->hw_context_size > (1<<20)) {
-                DRM_DEBUG_DRIVER("Disabling HW Contexts; invalid size\n");
-                return -E2BIG;
+        if (HAS_HW_CONTEXTS(dev)) {
+                dev_priv->hw_context_size = round_up(get_context_size(dev), 4096);
+                if (dev_priv->hw_context_size > (1<<20)) {
+                        DRM_DEBUG_DRIVER("Disabling HW Contexts; invalid size %d\n",
+                                         dev_priv->hw_context_size);
+                        dev_priv->hw_context_size = 0;
+                }
         }
 
-        dev_priv->ring[RCS].default_context =
-                i915_gem_create_context(dev, NULL, USES_PPGTT(dev));
-
-        if (IS_ERR_OR_NULL(dev_priv->ring[RCS].default_context)) {
-                DRM_DEBUG_DRIVER("Disabling HW Contexts; create failed %ld\n",
-                                 PTR_ERR(dev_priv->ring[RCS].default_context));
-                return PTR_ERR(dev_priv->ring[RCS].default_context);
+        ctx = i915_gem_create_context(dev, NULL, USES_PPGTT(dev));
+        if (IS_ERR(ctx)) {
+                DRM_ERROR("Failed to create default global context (error %ld)\n",
+                          PTR_ERR(ctx));
+                return PTR_ERR(ctx);
         }
 
-        for (i = RCS + 1; i < I915_NUM_RINGS; i++) {
-                if (!(INTEL_INFO(dev)->ring_mask & (1<<i)))
-                        continue;
-
-                ring = &dev_priv->ring[i];
+        /* NB: RCS will hold a ref for all rings */
+        for (i = 0; i < I915_NUM_RINGS; i++)
+                dev_priv->ring[i].default_context = ctx;
 
-                /* NB: RCS will hold a ref for all rings */
-                ring->default_context = dev_priv->ring[RCS].default_context;
-        }
-
-        DRM_DEBUG_DRIVER("HW context support initialized\n");
+        DRM_DEBUG_DRIVER("%s context support initialized\n", dev_priv->hw_context_size ? "HW" : "fake");
         return 0;
 }
 
@@ -441,33 +421,30 @@ void i915_gem_context_fini(struct drm_device *dev)
         struct i915_hw_context *dctx = dev_priv->ring[RCS].default_context;
         int i;
 
-        if (!HAS_HW_CONTEXTS(dev))
-                return;
-
-        /* The only known way to stop the gpu from accessing the hw context is
-         * to reset it. Do this as the very last operation to avoid confusing
-         * other code, leading to spurious errors. */
-        intel_gpu_reset(dev);
-
-        /* When default context is created and switched to, base object refcount
-         * will be 2 (+1 from object creation and +1 from do_switch()).
-         * i915_gem_context_fini() will be called after gpu_idle() has switched
-         * to default context. So we need to unreference the base object once
-         * to offset the do_switch part, so that i915_gem_context_unreference()
-         * can then free the base object correctly. */
-        WARN_ON(!dev_priv->ring[RCS].last_context);
-        if (dev_priv->ring[RCS].last_context == dctx) {
-                /* Fake switch to NULL context */
-                WARN_ON(dctx->obj->active);
-                i915_gem_object_ggtt_unpin(dctx->obj);
-                i915_gem_context_unreference(dctx);
-                dev_priv->ring[RCS].last_context = NULL;
+        if (dctx->obj) {
+                /* The only known way to stop the gpu from accessing the hw context is
+                 * to reset it. Do this as the very last operation to avoid confusing
+                 * other code, leading to spurious errors. */
+                intel_gpu_reset(dev);
+
+                /* When default context is created and switched to, base object refcount
+                 * will be 2 (+1 from object creation and +1 from do_switch()).
+                 * i915_gem_context_fini() will be called after gpu_idle() has switched
+                 * to default context. So we need to unreference the base object once
+                 * to offset the do_switch part, so that i915_gem_context_unreference()
+                 * can then free the base object correctly. */
+                WARN_ON(!dev_priv->ring[RCS].last_context);
+                if (dev_priv->ring[RCS].last_context == dctx) {
+                        /* Fake switch to NULL context */
+                        WARN_ON(dctx->obj->active);
+                        i915_gem_object_ggtt_unpin(dctx->obj);
+                        i915_gem_context_unreference(dctx);
+                        dev_priv->ring[RCS].last_context = NULL;
+                }
         }
 
         for (i = 0; i < I915_NUM_RINGS; i++) {
                 struct intel_ring_buffer *ring = &dev_priv->ring[i];
-                if (!(INTEL_INFO(dev)->ring_mask & (1<<i)))
-                        continue;
 
                 if (ring->last_context)
                         i915_gem_context_unreference(ring->last_context);
@@ -478,7 +455,6 @@ void i915_gem_context_fini(struct drm_device *dev)
 
         i915_gem_object_ggtt_unpin(dctx->obj);
         i915_gem_context_unreference(dctx);
-        dev_priv->mm.aliasing_ppgtt = NULL;
 }
 
 int i915_gem_context_enable(struct drm_i915_private *dev_priv)
@@ -486,9 +462,6 @@ int i915_gem_context_enable(struct drm_i915_private *dev_priv)
         struct intel_ring_buffer *ring;
         int ret, i;
 
-        if (!HAS_HW_CONTEXTS(dev_priv->dev))
-                return 0;
-
         /* This is the only place the aliasing PPGTT gets enabled, which means
          * it has to happen before we bail on reset */
         if (dev_priv->mm.aliasing_ppgtt) {
@@ -503,7 +476,7 @@ int i915_gem_context_enable(struct drm_i915_private *dev_priv)
         BUG_ON(!dev_priv->ring[RCS].default_context);
 
         for_each_ring(ring, dev_priv, i) {
-                ret = do_switch(ring, ring->default_context);
+                ret = i915_switch_context(ring, ring->default_context);
                 if (ret)
                         return ret;
         }
@@ -526,19 +499,6 @@ static int context_idr_cleanup(int id, void *p, void *data)
 int i915_gem_context_open(struct drm_device *dev, struct drm_file *file)
 {
         struct drm_i915_file_private *file_priv = file->driver_priv;
-        struct drm_i915_private *dev_priv = dev->dev_private;
-
-        if (!HAS_HW_CONTEXTS(dev)) {
-                /* Cheat for hang stats */
-                file_priv->private_default_ctx =
-                        kzalloc(sizeof(struct i915_hw_context), GFP_KERNEL);
-
-                if (file_priv->private_default_ctx == NULL)
-                        return -ENOMEM;
-
-                file_priv->private_default_ctx->vm = &dev_priv->gtt.base;
-                return 0;
-        }
 
         idr_init(&file_priv->context_idr);
 
@@ -559,14 +519,10 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
 {
         struct drm_i915_file_private *file_priv = file->driver_priv;
 
-        if (!HAS_HW_CONTEXTS(dev)) {
-                kfree(file_priv->private_default_ctx);
-                return;
-        }
-
         idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL);
-        i915_gem_context_unreference(file_priv->private_default_ctx);
         idr_destroy(&file_priv->context_idr);
+
+        i915_gem_context_unreference(file_priv->private_default_ctx);
 }
 
 struct i915_hw_context *
@@ -574,9 +530,6 @@ i915_gem_context_get(struct drm_i915_file_private *file_priv, u32 id)
 {
         struct i915_hw_context *ctx;
 
-        if (!HAS_HW_CONTEXTS(file_priv->dev_priv->dev))
-                return file_priv->private_default_ctx;
-
         ctx = (struct i915_hw_context *)idr_find(&file_priv->context_idr, id);
         if (!ctx)
                 return ERR_PTR(-ENOENT);
@@ -758,7 +711,6 @@ unpin_out:
 /**
  * i915_switch_context() - perform a GPU context switch.
  * @ring: ring for which we'll execute the context switch
- * @file_priv: file_priv associated with the context, may be NULL
  * @to: the context to switch to
  *
  * The context life cycle is simple. The context refcount is incremented and
@@ -767,24 +719,30 @@ unpin_out:
  * object while letting the normal object tracking destroy the backing BO.
  */
 int i915_switch_context(struct intel_ring_buffer *ring,
-                        struct drm_file *file,
                         struct i915_hw_context *to)
 {
         struct drm_i915_private *dev_priv = ring->dev->dev_private;
 
         WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
 
-        BUG_ON(file && to == NULL);
-
-        /* We have the fake context */
-        if (!HAS_HW_CONTEXTS(ring->dev)) {
-                ring->last_context = to;
+        if (to->obj == NULL) { /* We have the fake context */
+                if (to != ring->last_context) {
+                        i915_gem_context_reference(to);
+                        if (ring->last_context)
+                                i915_gem_context_unreference(ring->last_context);
+                        ring->last_context = to;
+                }
                 return 0;
         }
 
         return do_switch(ring, to);
 }
 
+static bool hw_context_enabled(struct drm_device *dev)
+{
+        return to_i915(dev)->hw_context_size;
+}
+
 int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
                                   struct drm_file *file)
 {
@@ -793,7 +751,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
         struct i915_hw_context *ctx;
         int ret;
 
-        if (!HAS_HW_CONTEXTS(dev))
+        if (!hw_context_enabled(dev))
                 return -ENODEV;
 
         ret = i915_mutex_lock_interruptible(dev);