[Mesa-dev] [PATCH 2/2] etnaviv: Set shader instruction area correctly for GC3000

[Wladimir J. van der Laan]

- Use the same instruction area on GC3000 as the Vivante driver.
  This allows the same number of instructions on GC3000 as GC2000
  instead of half.

- Makes sure that the "PE to FE" stall before updating the shader code
  or constants is hit (which is conditional on vs_offset > 0x4000). This
  is necessary on GC3000 too, it increases stability.
---
 src/gallium/drivers/etnaviv/etnaviv_screen.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/etnaviv/etnaviv_screen.c b/src/gallium/drivers/etnaviv/etnaviv_screen.c
index 8c66f79..1507967 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_screen.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_screen.c
@@ -626,14 +626,30 @@ etna_get_specs(struct etna_screen *screen)
    screen->specs.has_new_sin_cos =
       VIV_FEATURE(screen, chipMinorFeatures3, HAS_FAST_TRANSCENDENTALS);
 
-   if (instruction_count > 256) { /* unified instruction memory? */
+   if (VIV_FEATURE(screen, chipMinorFeatures3, INSTRUCTION_CACHE)) {
+      /* GC3000 - this core is capable of loading shaders from
+       * memory. It can also run shaders from registers, as a fallback, but
+       * "max_instructions" does not have the correct value. It has place for
+       * 2*256 instructions just like GC2000, but the offsets are slightly
+       * different.
+       */
       screen->specs.vs_offset = 0xC000;
-      screen->specs.ps_offset = 0xD000; /* like vivante driver */
+      /* State 08000-0C000 mirrors 0C000-0E000, and the Vivante driver uses
+       * this mirror for writing PS instructions, probably safest to do the
+       * same.
+       */
+      screen->specs.ps_offset = 0x8000 + 0x1000;
       screen->specs.max_instructions = 256;
    } else {
-      screen->specs.vs_offset = 0x4000;
-      screen->specs.ps_offset = 0x6000;
-      screen->specs.max_instructions = instruction_count / 2;
+      if (instruction_count > 256) { /* unified instruction memory? */
+         screen->specs.vs_offset = 0xC000;
+         screen->specs.ps_offset = 0xD000; /* like vivante driver */
+         screen->specs.max_instructions = 256;
+      } else {
+         screen->specs.vs_offset = 0x4000;
+         screen->specs.ps_offset = 0x6000;
+         screen->specs.max_instructions = instruction_count / 2;
+      }
    }
 
    if (VIV_FEATURE(screen, chipMinorFeatures1, HALTI0)) {
-- 
2.7.4