Mesa (10.1): nv50: only over-allocate by a page for code

[Ian Romanick]

Module: Mesa
Branch: 10.1
Commit: 31911f8d37fe149626c4810ef264730dab204598
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=31911f8d37fe149626c4810ef264730dab204598

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Tue Feb  4 02:30:18 2014 -0500

nv50: only over-allocate by a page for code

The pre-fetching doesn't go too far. Tested with over-allocating by only
a page, and didn't see any errors in dmesg. Saves ~512KB of VRAM.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: 10.1 <mesa-stable at lists.freedesktop.org>
Reviewed-by: Christoph Bumiller <e0425955 at student.tuwien.ac.at>
(cherry picked from commit f76c7ad5b14f5646a56ca3518f0c2e739811f223)

---

 src/gallium/drivers/nouveau/nv50/nv50_screen.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/gallium/drivers/nouveau/nv50/nv50_screen.c b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
index 5bb341d..b219a3b 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
@@ -741,12 +741,13 @@ nv50_screen_create(struct nouveau_device *dev)
       goto fail;
    }
 
-   /* This over-allocates by a whole code BO. The GP, which would execute at
-    * the end of the last page, would trigger faults. The going theory is that
-    * it prefetches up to a certain amount. This avoids dmesg spam.
+   /* This over-allocates by a page. The GP, which would execute at the end of
+    * the last page, would trigger faults. The going theory is that it
+    * prefetches up to a certain amount.
     */
    ret = nouveau_bo_new(dev, NOUVEAU_BO_VRAM, 1 << 16,
-                        4 << NV50_CODE_BO_SIZE_LOG2, NULL, &screen->code);
+                        (3 << NV50_CODE_BO_SIZE_LOG2) + 0x1000,
+                        NULL, &screen->code);
    if (ret) {
       NOUVEAU_ERR("Failed to allocate code bo: %d\n", ret);
       goto fail;