4 files changed, 41 insertions, 27 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index ada095023dad..80bed69fe5b7 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -145,6 +145,13 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
                 seq_printf(m, " (%s)", obj->ring->name);
 }
 
+static void describe_ctx(struct seq_file *m, struct i915_hw_context *ctx)
+{
+        seq_putc(m, ctx->is_initialized ? 'I' : 'i');
+        seq_putc(m, ctx->remap_slice ? 'R' : 'r');
+        seq_putc(m, ' ');
+}
+
 static int i915_gem_object_list_info(struct seq_file *m, void *data)
 {
         struct drm_info_node *node = (struct drm_info_node *) m->private;
@@ -1463,6 +1470,7 @@ static int i915_context_status(struct seq_file *m, void *unused)
 
         list_for_each_entry(ctx, &dev_priv->context_list, link) {
                 seq_puts(m, "HW context ");
+                describe_ctx(m, ctx);
                 for_each_ring(ring, dev_priv, i)
                         if (ring->default_context == ctx)
                                 seq_printf(m, "(default context %s) ", ring->name);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 179592762537..015df5264dcc 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -601,6 +601,7 @@ struct i915_hw_context {
         struct kref ref;
         int id;
         bool is_initialized;
+        uint8_t remap_slice;
         struct drm_i915_file_private *file_priv;
         struct intel_ring_buffer *ring;
         struct drm_i915_gem_object *obj;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 2bbdce821ac3..9af3fe7e42b0 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -181,6 +181,10 @@ create_hw_context(struct drm_device *dev,
 
         ctx->file_priv = file_priv;
         ctx->id = ret;
+        /* NB: Mark all slices as needing a remap so that when the context first
+         * loads it will restore whatever remap state already exists. If there
+         * is no remap info, it will be a NOP. */
+        ctx->remap_slice = (1 << NUM_L3_SLICES(dev)) - 1;
 
         return ctx;
 
@@ -396,11 +400,11 @@ static int do_switch(struct i915_hw_context *to)
         struct intel_ring_buffer *ring = to->ring;
         struct i915_hw_context *from = ring->last_context;
         u32 hw_flags = 0;
-        int ret;
+        int ret, i;
 
         BUG_ON(from != NULL && from->obj != NULL && from->obj->pin_count == 0);
 
-        if (from == to)
+        if (from == to && !to->remap_slice)
                 return 0;
 
         ret = i915_gem_obj_ggtt_pin(to->obj, CONTEXT_ALIGN, false, false);
@@ -423,8 +427,6 @@ static int do_switch(struct i915_hw_context *to)
 
         if (!to->is_initialized || is_default_context(to))
                 hw_flags |= MI_RESTORE_INHIBIT;
-        else if (WARN_ON_ONCE(from == to)) /* not yet expected */
-                hw_flags |= MI_FORCE_RESTORE;
 
         ret = mi_set_context(ring, to, hw_flags);
         if (ret) {
@@ -432,6 +434,18 @@ static int do_switch(struct i915_hw_context *to)
                 return ret;
         }
 
+        for (i = 0; i < MAX_L3_SLICES; i++) {
+                if (!(to->remap_slice & (1<<i)))
+                        continue;
+
+                ret = i915_gem_l3_remap(ring, i);
+                /* If it failed, try again next round */
+                if (ret)
+                        DRM_DEBUG_DRIVER("L3 remapping failed\n");
+                else
+                        to->remap_slice &= ~(1<<i);
+        }
+
         /* The backing object for the context is done after switching to the
          * *next* context. Therefore we cannot retire the previous context until
          * the next context has already started running. In fact, the below code
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index b07bdfb8892d..deb8787308d6 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -118,9 +118,8 @@ i915_l3_read(struct file *filp, struct kobject *kobj,
         struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev);
         struct drm_device *drm_dev = dminor->dev;
         struct drm_i915_private *dev_priv = drm_dev->dev_private;
-        uint32_t misccpctl;
         int slice = (int)(uintptr_t)attr->private;
-        int i, ret;
+        int ret;
 
         count = round_down(count, 4);
 
@@ -134,26 +133,13 @@ i915_l3_read(struct file *filp, struct kobject *kobj,
         if (ret)
                 return ret;
 
-        if (IS_HASWELL(drm_dev)) {
-                if (dev_priv->l3_parity.remap_info[slice])
-                        memcpy(buf,
-                               dev_priv->l3_parity.remap_info[slice] + (offset/4),
-                               count);
-                else
-                        memset(buf, 0, count);
-
-                goto out;
-        }
-
-        misccpctl = I915_READ(GEN7_MISCCPCTL);
-        I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
-
-        for (i = 0; i < count; i += 4)
-                *((uint32_t *)(&buf[i])) = I915_READ(GEN7_L3LOG_BASE + offset + i);
-
-        I915_WRITE(GEN7_MISCCPCTL, misccpctl);
+        if (dev_priv->l3_parity.remap_info[slice])
+                memcpy(buf,
+                       dev_priv->l3_parity.remap_info[slice] + (offset/4),
+                       count);
+        else
+                memset(buf, 0, count);
 
-out:
         mutex_unlock(&drm_dev->struct_mutex);
 
         return count;
@@ -168,6 +154,7 @@ i915_l3_write(struct file *filp, struct kobject *kobj,
         struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev);
         struct drm_device *drm_dev = dminor->dev;
         struct drm_i915_private *dev_priv = drm_dev->dev_private;
+        struct i915_hw_context *ctx;
         u32 *temp = NULL; /* Just here to make handling failures easy */
         int slice = (int)(uintptr_t)attr->private;
         int ret;
@@ -176,6 +163,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj,
         if (ret)
                 return ret;
 
+        if (dev_priv->hw_contexts_disabled)
+                return -ENXIO;
+
         ret = i915_mutex_lock_interruptible(drm_dev);
         if (ret)
                 return ret;
@@ -204,8 +194,9 @@ i915_l3_write(struct file *filp, struct kobject *kobj,
 
         memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count);
 
-        if (i915_gem_l3_remap(&dev_priv->ring[RCS], slice))
-                count = 0;
+        /* NB: We defer the remapping until we switch to the context */
+        list_for_each_entry(ctx, &dev_priv->context_list, link)
+                ctx->remap_slice |= (1<<slice);
 
         mutex_unlock(&drm_dev->struct_mutex);