drm/i915: initialization/teardown for the aliasing ppgtt

This just adds the setup and teardown code for the ppgtt PDE and the
last-level pagetables, which are fixed for the entire lifetime, at
least for the moment.

v2: Kill the stray debug printk noted by and improve the pte
definitions as suggested by Chris Wilson.

v3: Clean up the aperture stealing code as noted by Ben Widawsky.

v4: Paint the init code in a more pleasing colour as suggest by Chris
Wilson.

v5: Explain the magic numbers noticed by Ben Widawsky.

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 30 insertions, 11 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index dfef9569f2a1..039fbf4fae10 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1196,22 +1196,39 @@ static int i915_load_gem_init(struct drm_device *dev)
         /* Basic memrange allocator for stolen space */
         drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size);
 
-        /* Let GEM Manage all of the aperture.
-         *
-         * However, leave one page at the end still bound to the scratch page.
-         * There are a number of places where the hardware apparently
-         * prefetches past the end of the object, and we've seen multiple
-         * hangs with the GPU head pointer stuck in a batchbuffer bound
-         * at the last page of the aperture.  One page should be enough to
-         * keep any prefetching inside of the aperture.
-         */
-        i915_gem_do_init(dev, 0, mappable_size, gtt_size - PAGE_SIZE);
+        if (HAS_ALIASING_PPGTT(dev)) {
+                /* PPGTT pdes are stolen from global gtt ptes, so shrink the
+                 * aperture accordingly when using aliasing ppgtt. */
+                gtt_size -= I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
+                /* For paranoia keep the guard page in between. */
+                gtt_size -= PAGE_SIZE;
+
+                i915_gem_do_init(dev, 0, mappable_size, gtt_size);
+
+                ret = i915_gem_init_aliasing_ppgtt(dev);
+                if (ret)
+                        return ret;
+        } else {
+                /* Let GEM Manage all of the aperture.
+                 *
+                 * However, leave one page at the end still bound to the scratch
+                 * page.  There are a number of places where the hardware
+                 * apparently prefetches past the end of the object, and we've
+                 * seen multiple hangs with the GPU head pointer stuck in a
+                 * batchbuffer bound at the last page of the aperture.  One page
+                 * should be enough to keep any prefetching inside of the
+                 * aperture.
+                 */
+                i915_gem_do_init(dev, 0, mappable_size, gtt_size - PAGE_SIZE);
+        }
 
         mutex_lock(&dev->struct_mutex);
         ret = i915_gem_init_hw(dev);
         mutex_unlock(&dev->struct_mutex);
-        if (ret)
+        if (ret) {
+                i915_gem_cleanup_aliasing_ppgtt(dev);
                 return ret;
+        }
 
         /* Try to set up FBC with a reasonable compressed buffer size */
         if (I915_HAS_FBC(dev) && i915_powersave) {
@@ -1298,6 +1315,7 @@ cleanup_gem:
         mutex_lock(&dev->struct_mutex);
         i915_gem_cleanup_ringbuffer(dev);
         mutex_unlock(&dev->struct_mutex);
+        i915_gem_cleanup_aliasing_ppgtt(dev);
 cleanup_vga_switcheroo:
         vga_switcheroo_unregister_client(dev->pdev);
 cleanup_vga_client:
@@ -2184,6 +2202,7 @@ int i915_driver_unload(struct drm_device *dev)
                 i915_gem_free_all_phys_object(dev);
                 i915_gem_cleanup_ringbuffer(dev);
                 mutex_unlock(&dev->struct_mutex);
+                i915_gem_cleanup_aliasing_ppgtt(dev);
                 if (I915_HAS_FBC(dev) && i915_powersave)
                         i915_cleanup_compression(dev);
                 drm_mm_takedown(&dev_priv->mm.stolen);