From 8ec5a4e4a4a32f4de351c5fc2bf0eb615b6eef1b Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Thu, 14 Aug 2014 22:36:45 -0700 Subject: [PATCH] i965: Switch to absolute addressing for constant buffer 0. By default, 3DSTATE_CONSTANT_* Constant Buffer 0 is relative to dynamic state base address. This makes it unusable for pushing UBOs. I'd like to be able to use all four push buffers. There is a bit in the INSTPM register (or CS_DEBUG_MODE2 on Skylake) which controls whether buffer 0 is relative to dynamic state base address, or simply a normal pointer. Setting that gives us full flexibility. We can't currently write this on Haswell and earlier, and will need to update the kernel command parser, and then do the whole version checking song and dance. Reviewed-by: Matt Turner --- src/intel/compiler/brw_compiler.h | 6 +++++ src/mesa/drivers/dri/i965/brw_defines.h | 6 +++++ src/mesa/drivers/dri/i965/brw_state_upload.c | 24 ++++++++++++++++++++ src/mesa/drivers/dri/i965/intel_screen.c | 1 + 4 files changed, 37 insertions(+) diff --git a/src/intel/compiler/brw_compiler.h b/src/intel/compiler/brw_compiler.h index 3f383403883..e4c22e31177 100644 --- a/src/intel/compiler/brw_compiler.h +++ b/src/intel/compiler/brw_compiler.h @@ -100,6 +100,12 @@ struct brw_compiler { * This can negatively impact performance. */ bool precise_trig; + + /** + * Is 3DSTATE_CONSTANT_*'s Constant Buffer 0 relative to Dynamic State + * Base Address? (If not, it's a normal GPU address.) + */ + bool constant_buffer_0_is_relative; }; diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h index a4794c6a1d2..2a8dbf8cb9a 100644 --- a/src/mesa/drivers/dri/i965/brw_defines.h +++ b/src/mesa/drivers/dri/i965/brw_defines.h @@ -1680,4 +1680,10 @@ enum brw_pixel_shader_coverage_mask_mode { # define GEN8_L3CNTLREG_ALL_ALLOC_SHIFT 25 # define GEN8_L3CNTLREG_ALL_ALLOC_MASK INTEL_MASK(31, 25) +#define INSTPM 0x20c0 +# define INSTPM_CONSTANT_BUFFER_ADDRESS_OFFSET_DISABLE (1 << 6) + +#define CS_DEBUG_MODE2 0x20d8 /* Gen9+ */ +# define CSDBG2_CONSTANT_BUFFER_ADDRESS_OFFSET_DISABLE (1 << 4) + #endif diff --git a/src/mesa/drivers/dri/i965/brw_state_upload.c b/src/mesa/drivers/dri/i965/brw_state_upload.c index 5e82c1b4ce8..e14ed02e2e1 100644 --- a/src/mesa/drivers/dri/i965/brw_state_upload.c +++ b/src/mesa/drivers/dri/i965/brw_state_upload.c @@ -90,6 +90,30 @@ brw_upload_initial_gpu_state(struct brw_context *brw) OUT_BATCH(0); ADVANCE_BATCH(); } + + /* Set the "CONSTANT_BUFFER Address Offset Disable" bit, so + * 3DSTATE_CONSTANT_XS buffer 0 is an absolute address. + * + * On Gen6-7.5, we use an execbuf parameter to do this for us. + * However, the kernel ignores that when execlists are in use. + * Fortunately, we can just write the registers from userspace + * on Gen8+, and they're context saved/restored. + */ + if (brw->gen >= 9) { + BEGIN_BATCH(3); + OUT_BATCH(MI_LOAD_REGISTER_IMM | (3 - 2)); + OUT_BATCH(CS_DEBUG_MODE2); + OUT_BATCH(REG_MASK(CSDBG2_CONSTANT_BUFFER_ADDRESS_OFFSET_DISABLE) | + CSDBG2_CONSTANT_BUFFER_ADDRESS_OFFSET_DISABLE); + ADVANCE_BATCH(); + } else if (brw->gen == 8) { + BEGIN_BATCH(3); + OUT_BATCH(MI_LOAD_REGISTER_IMM | (3 - 2)); + OUT_BATCH(INSTPM); + OUT_BATCH(REG_MASK(INSTPM_CONSTANT_BUFFER_ADDRESS_OFFSET_DISABLE) | + INSTPM_CONSTANT_BUFFER_ADDRESS_OFFSET_DISABLE); + ADVANCE_BATCH(); + } } static inline const struct brw_tracked_state * diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c index 6d0588e9cfa..641edb7e72b 100644 --- a/src/mesa/drivers/dri/i965/intel_screen.c +++ b/src/mesa/drivers/dri/i965/intel_screen.c @@ -2327,6 +2327,7 @@ __DRIconfig **intelInitScreen2(__DRIscreen *dri_screen) screen->compiler = brw_compiler_create(screen, devinfo); screen->compiler->shader_debug_log = shader_debug_log_mesa; screen->compiler->shader_perf_log = shader_perf_log_mesa; + screen->compiler->constant_buffer_0_is_relative = devinfo->gen < 8; screen->program_id = 1; screen->has_exec_fence = -- 2.30.2