Mesa (master): i965: Update URB partitioning code for Haswell's GT3 variant .

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: eca2251f42f0234584d94268c29bddede3ff6451
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=eca2251f42f0234584d94268c29bddede3ff6451

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Sat Sep 24 00:12:58 2011 -0700

i965: Update URB partitioning code for Haswell's GT3 variant.

Haswell's GT3 variant offers 32kB of URB space for push constants, while
GT1 and GT2 match Ivybridge, providing 16kB.  Update the code to reserve
the full 32kB on GT3.

v2: Specify push constant size correctly.  I thought GT3 reinterpreted
    the value as multiples of 2kB, but it doesn't.  You simply have to
    program an even number.

NOTE: This is a candidate for stable branches.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/gen7_urb.c |   25 +++++++++++++++++--------
 1 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen7_urb.c b/src/mesa/drivers/dri/i965/gen7_urb.c
index bdcf164..b9726b5 100644
--- a/src/mesa/drivers/dri/i965/gen7_urb.c
+++ b/src/mesa/drivers/dri/i965/gen7_urb.c
@@ -39,29 +39,37 @@
  * +-------------------------------------------------------------+
  *
  * Notably, push constants must be stored at the beginning of the URB
- * space, while entries can be stored anywhere.  Ivybridge has a maximum
- * constant buffer size of 16kB.
+ * space, while entries can be stored anywhere.  Ivybridge and Haswell
+ * GT1/GT2 have a maximum constant buffer size of 16kB, while Haswell GT3
+ * doubles this (32kB).
  *
  * Currently we split the constant buffer space evenly between VS and FS.
  * This is probably not ideal, but simple.
  *
- * Ivybridge GT1 has 128kB of URB space.
- * Ivybridge GT2 has 256kB of URB space.
+ * Ivybridge GT1 and Haswell GT1 have 128kB of URB space.
+ * Ivybridge GT2 and Haswell GT2 have 256kB of URB space.
+ * Haswell GT3 has 512kB of URB space.
  *
- * See "Volume 2a: 3D Pipeline," section 1.8.
+ * See "Volume 2a: 3D Pipeline," section 1.8, "Volume 1b: Configurations",
+ * and the documentation for 3DSTATE_PUSH_CONSTANT_ALLOC_xS.
  */
 void
 gen7_allocate_push_constants(struct brw_context *brw)
 {
    struct intel_context *intel = &brw->intel;
+
+   unsigned size = 8;
+   if (intel->is_haswell && intel->gt == 3)
+      size = 16;
+
    BEGIN_BATCH(2);
    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_VS << 16 | (2 - 2));
-   OUT_BATCH(8);
+   OUT_BATCH(size);
    ADVANCE_BATCH();
 
    BEGIN_BATCH(2);
    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_PS << 16 | (2 - 2));
-   OUT_BATCH(8 | 8 << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
+   OUT_BATCH(size | size << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
    ADVANCE_BATCH();
 }
 
@@ -78,7 +86,8 @@ static void
 gen7_upload_urb(struct brw_context *brw)
 {
    struct intel_context *intel = &brw->intel;
-   const int push_size_kB = 16;
+   const int push_size_kB = intel->is_haswell && intel->gt == 3 ? 32 : 16;
+
    /* Total space for entries is URB size - 16kB for push constants */
    int handle_region_size = (brw->urb.size - push_size_kB) * 1024; /* bytes */