From 3abc3ce3b52a4bd4de4e7e21f05e60c1bd576b6a Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 16 Apr 2015 20:59:16 +0100
Subject: [PATCH] sna/gen8: reduce CHV VS URB entries to 640
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According to BSpec the max number of VS URB entries for CHV is 640.

Based on a patch by Ville Syrjälä.

v2: Start using a GT info block like earlier generations.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> [v1]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 src/sna/gen8_render.c | 38 ++++++++++++++++++++++++++++++++++++--
 src/sna/sna_render.h  |  2 +-
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/sna/gen8_render.c b/src/sna/gen8_render.c
index ebabb2e5..c0fe9f9c 100644
--- a/src/sna/gen8_render.c
+++ b/src/sna/gen8_render.c
@@ -205,6 +205,33 @@ static const struct blendinfo {
 #define OUT_VERTEX(x,y) vertex_emit_2s(sna, x,y)
 #define OUT_VERTEX_F(v) vertex_emit(sna, v)
 
+struct gt_info {
+	const char *name;
+	struct {
+		int max_vs_entries;
+	} urb;
+};
+
+static const struct gt_info bdw_gt_info = {
+	.name = "Broadwell (gen8)",
+	.urb = { .max_vs_entries = 960 },
+};
+
+static bool is_bdw(struct sna *sna)
+{
+	return sna->kgem.gen == 0100;
+}
+
+static const struct gt_info chv_gt_info = {
+	.name = "Cherryview (gen8)",
+	.urb = { .max_vs_entries = 640 },
+};
+
+static bool is_chv(struct sna *sna)
+{
+	return sna->kgem.gen == 0101;
+}
+
 static inline bool too_large(int width, int height)
 {
 	return width > GEN8_MAX_SIZE || height > GEN8_MAX_SIZE;
@@ -462,7 +489,7 @@ gen8_emit_urb(struct sna *sna)
 {
 	/* num of VS entries must be divisible by 8 if size < 9 */
 	OUT_BATCH(GEN8_3DSTATE_URB_VS | (2 - 2));
-	OUT_BATCH(960 << URB_ENTRY_NUMBER_SHIFT |
+	OUT_BATCH(sna->render_state.gen8.info->urb.max_vs_entries << URB_ENTRY_NUMBER_SHIFT |
 		  (2 - 1) << URB_ENTRY_SIZE_SHIFT |
 		  4 << URB_STARTING_ADDRESS_SHIFT);
 
@@ -3915,6 +3942,13 @@ static bool gen8_render_setup(struct sna *sna)
 		state->gt = ((devid >> 4) & 0xf) + 1;
 	DBG(("%s: gt=%d\n", __FUNCTION__, state->gt));
 
+	if (is_bdw(sna))
+		state->info = &bdw_gt_info;
+	else if (is_chv(sna))
+		state->info = &chv_gt_info;
+	else
+		return false;
+
 	sna_static_stream_init(&general);
 
 	/* Zero pad the start. If you see an offset of 0x0 in the batchbuffer
@@ -4026,5 +4060,5 @@ const char *gen8_render_init(struct sna *sna, const char *backend)
 
 	sna->render.max_3d_size = GEN8_MAX_SIZE;
 	sna->render.max_3d_pitch = 1 << 18;
-	return "Broadwell";
+	return sna->render_state.gen8.info->name;
 }
diff --git a/src/sna/sna_render.h b/src/sna/sna_render.h
index f59a9283..723de80b 100644
--- a/src/sna/sna_render.h
+++ b/src/sna/sna_render.h
@@ -540,7 +540,7 @@ enum {
 
 struct gen8_render_state {
 	unsigned gt;
-
+	const struct gt_info *info;
 	struct kgem_bo *general_bo;
 
 	uint32_t vs_state;