From 9c92e82b324291b56e701d6ad265ec73b21a654f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Ol=C5=A1=C3=A1k?= Date: Fri, 25 Aug 2017 01:48:50 +0200 Subject: [PATCH] radeonsi: rewrite late alloc VS limit computation This is still very simple, but it's better than before. Loosely ported from Vulkan. --- src/gallium/drivers/radeonsi/si_state.c | 37 +++++++++++++++++-------- 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c index 4772df25d1f..41b08f8de4f 100644 --- a/src/gallium/drivers/radeonsi/si_state.c +++ b/src/gallium/drivers/radeonsi/si_state.c @@ -4639,26 +4639,39 @@ static void si_init_config(struct si_context *sctx) } si_pm4_set_reg(pm4, R_00B21C_SPI_SHADER_PGM_RSRC3_GS, S_00B21C_CU_EN(0xffff)); - if (sscreen->b.info.num_good_compute_units / - (sscreen->b.info.max_se * sscreen->b.info.max_sh_per_se) <= 4) { + /* Compute LATE_ALLOC_VS.LIMIT. */ + unsigned num_cu_per_sh = sscreen->b.info.num_good_compute_units / + (sscreen->b.info.max_se * + sscreen->b.info.max_sh_per_se); + unsigned late_alloc_limit; /* The limit is per SH. */ + + if (sctx->b.family == CHIP_KABINI) { + late_alloc_limit = 0; /* Potential hang on Kabini. */ + } else if (num_cu_per_sh <= 4) { /* Too few available compute units per SH. Disallowing - * VS to run on CU0 could hurt us more than late VS + * VS to run on one CU could hurt us more than late VS * allocation would help. * - * LATE_ALLOC_VS = 2 is the highest safe number. + * 2 is the highest safe number that allows us to keep + * all CUs enabled. */ - si_pm4_set_reg(pm4, R_00B118_SPI_SHADER_PGM_RSRC3_VS, S_00B118_CU_EN(0xffff)); - si_pm4_set_reg(pm4, R_00B11C_SPI_SHADER_LATE_ALLOC_VS, S_00B11C_LIMIT(2)); + late_alloc_limit = 2; } else { - /* Set LATE_ALLOC_VS == 31. It should be less than - * the number of scratch waves. Limitations: - * - VS can't execute on CU0. - * - If HS writes outputs to LDS, LS can't execute on CU0. + /* This is a good initial value, allowing 1 late_alloc + * wave per SIMD on num_cu - 2. */ - si_pm4_set_reg(pm4, R_00B118_SPI_SHADER_PGM_RSRC3_VS, S_00B118_CU_EN(0xfffe)); - si_pm4_set_reg(pm4, R_00B11C_SPI_SHADER_LATE_ALLOC_VS, S_00B11C_LIMIT(31)); + late_alloc_limit = (num_cu_per_sh - 2) * 4; + + /* The limit is 0-based, so 0 means 1. */ + assert(late_alloc_limit > 0 && late_alloc_limit <= 64); + late_alloc_limit -= 1; } + /* VS can't execute on one CU if the limit is > 2. */ + si_pm4_set_reg(pm4, R_00B118_SPI_SHADER_PGM_RSRC3_VS, + S_00B118_CU_EN(late_alloc_limit > 2 ? 0xfffe : 0xffff)); + si_pm4_set_reg(pm4, R_00B11C_SPI_SHADER_LATE_ALLOC_VS, + S_00B11C_LIMIT(late_alloc_limit)); si_pm4_set_reg(pm4, R_00B01C_SPI_SHADER_PGM_RSRC3_PS, S_00B01C_CU_EN(0xffff)); } -- 2.30.2