gma500: allow non stolen page backed framebuffer

For Moorestown at least we may not have stolen RAM with which to back the
initial framebuffer. Allow a GEM backing.

At this point we should have all the bits in place needed to make it work once
it has been debugged.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/gma500/psb_fb.c

@@ -335,6 +335,38 @@ err:
 	return NULL;
 }
 
+/**
+ *	psbfb_alloc		-	allocate frame buffer memory
+ *	@dev: the DRM device
+ *	@aligned_size: space needed
+ *
+ *	Allocate the frame buffer. In the usual case we get a GTT range that
+ *	is stolen memory backed and life is simple. If there isn't sufficient
+ *	stolen memory or the system has no stolen memory we allocate a range
+ *	and back it with a GEM object.
+ *
+ *	In this case the GEM object has no handle. 
+ */
+static struct gtt_range *psbfb_alloc(struct drm_device *dev, int aligned_size)
+{
+	struct gtt_range *backing;
+	/* Begin by trying to use stolen memory backing */
+	backing = psb_gtt_alloc_range(dev, aligned_size, "fb", 1);
+	if (backing)
+		return backing;
+	/* Next try using GEM host memory */
+	backing = psb_gtt_alloc_range(dev, aligned_size, "fb(gem)", 0);
+	if (backing == NULL)
+		return NULL;
+
+	/* Now back it with an object */
+	if (drm_gem_object_init(dev, &backing->gem, aligned_size) != 0) {
+		psb_gtt_free_range(dev, backing);
+		return NULL;
+	}
+	return backing;
+}
+	
 /**
  *	psbfb_create		-	create a framebuffer
  *	@fbdev: the framebuffer device
@@ -368,7 +400,7 @@ static int psbfb_create(struct psb_fbdev *fbdev,
 	aligned_size = ALIGN(size, PAGE_SIZE);
 
 	/* Allocate the framebuffer in the GTT with stolen page backing */
-	backing = psb_gtt_alloc_range(dev, aligned_size, "fb", 1);
+	backing = psbfb_alloc(dev, aligned_size);
 	if (backing == NULL)
 	        return -ENOMEM;
 
@@ -523,7 +555,13 @@ int psb_fbdev_destroy(struct drm_device *dev, struct psb_fbdev *fbdev)
 
 	if (fbdev->psb_fb_helper.fbdev) {
 		info = fbdev->psb_fb_helper.fbdev;
+		/* FIXME: this is a bit more inside knowledge than I'd like
+		   but I don't see how to make a fake GEM object of the
+		   stolen space nicely */
+		if (psbfb->gtt->stolen)
 			psb_gtt_free_range(dev, psbfb->gtt);
+		else
+			drm_gem_object_unreference(&psbfb->gtt->gem);
 		unregister_framebuffer(info);
 		iounmap(info->screen_base);
 		framebuffer_release(info);
@@ -571,7 +609,6 @@ void psb_fbdev_fini(struct drm_device *dev)
 	dev_priv->fbdev = NULL;
 }
 
-
 static void psbfb_output_poll_changed(struct drm_device *dev)
 {
 	struct drm_psb_private *dev_priv = dev->dev_private;

drivers/staging/gma500/psb_gem.c

@@ -39,6 +39,8 @@ int psb_gem_init_object(struct drm_gem_object *obj)
 
 void psb_gem_free_object(struct drm_gem_object *obj)
 {
+	struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
+	psb_gtt_free_range(obj->dev, gtt);
 	drm_gem_object_release(obj);
 }
 

drivers/staging/gma500/psb_gtt.c

@@ -298,7 +298,6 @@ struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
 	return NULL;
 }
 
-
 static void psb_gtt_destroy(struct kref *kref)
 {
 	struct gtt_range *gt = container_of(kref, struct gtt_range, kref);

drivers/staging/gma500/psb_intel_display.c

@@ -361,7 +361,13 @@ int psb_intel_pipe_set_base(struct drm_crtc *crtc,
 	if (!gma_power_begin(dev, true))
 		return 0;
 
+	/* We are displaying this buffer, make sure it is actually loaded
+	   into the GTT */
+	ret = psb_gtt_pin(dev, psbfb->gtt);
+	if (ret < 0)
+		goto psb_intel_pipe_set_base_exit;
 	start = psbfb->gtt->offset;
+
 	offset = y * crtc->fb->pitch + x * (crtc->fb->bits_per_pixel / 8);
 
 	REG_WRITE(dspstride, crtc->fb->pitch);
@@ -386,10 +392,12 @@ int psb_intel_pipe_set_base(struct drm_crtc *crtc,
 	default:
 		DRM_ERROR("Unknown color depth\n");
 		ret = -EINVAL;
+		psb_gtt_unpin(dev, psbfb->gtt);
 		goto psb_intel_pipe_set_base_exit;
 	}
 	REG_WRITE(dspcntr_reg, dspcntr);
 
+
 	DRM_DEBUG("Writing base %08lX %08lX %d %d\n", start, offset, x, y);
 	if (0 /* FIXMEAC - check what PSB needs */) {
 		REG_WRITE(dspbase, offset);
@@ -401,10 +409,12 @@ int psb_intel_pipe_set_base(struct drm_crtc *crtc,
 		REG_READ(dspbase);
 	}
 
+	/* If there was a previous display we can now unpin it */
+	if (old_fb)
+		psb_gtt_unpin(dev, to_psb_fb(old_fb)->gtt);
+
 psb_intel_pipe_set_base_exit:
-
 	gma_power_end(dev);
-
 	return ret;
 }