1/* 2 * Copyright (c) 2015 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 */ 23 24#include "common/gen_l3_config.h" 25 26#include "brw_context.h" 27#include "brw_defines.h" 28#include "brw_state.h" 29#include "intel_batchbuffer.h" 30 31/** 32 * Calculate the desired L3 partitioning based on the current state of the 33 * pipeline. For now this simply returns the conservative defaults calculated 34 * by get_default_l3_weights(), but we could probably do better by gathering 35 * more statistics from the pipeline state (e.g. guess of expected URB usage 36 * and bound surfaces), or by using feed-back from performance counters. 37 */ 38static struct gen_l3_weights 39get_pipeline_state_l3_weights(const struct brw_context *brw) 40{ 41 const struct brw_stage_state *stage_states[] = { 42 [MESA_SHADER_VERTEX] = &brw->vs.base, 43 [MESA_SHADER_TESS_CTRL] = &brw->tcs.base, 44 [MESA_SHADER_TESS_EVAL] = &brw->tes.base, 45 [MESA_SHADER_GEOMETRY] = &brw->gs.base, 46 [MESA_SHADER_FRAGMENT] = &brw->wm.base, 47 [MESA_SHADER_COMPUTE] = &brw->cs.base 48 }; 49 bool needs_dc = false, needs_slm = false; 50 51 for (unsigned i = 0; i < ARRAY_SIZE(stage_states); i++) { 52 const struct gl_program *prog = 53 brw->ctx._Shader->CurrentProgram[stage_states[i]->stage]; 54 const struct brw_stage_prog_data *prog_data = stage_states[i]->prog_data; 55 56 needs_dc |= (prog && (prog->sh.data->NumAtomicBuffers || 57 prog->sh.data->NumShaderStorageBlocks || 58 prog->info.num_images)) || 59 (prog_data && prog_data->total_scratch); 60 needs_slm |= prog_data && prog_data->total_shared; 61 } 62 63 return gen_get_default_l3_weights(&brw->screen->devinfo, 64 needs_dc, needs_slm); 65} 66 67/** 68 * Program the hardware to use the specified L3 configuration. 69 */ 70static void 71setup_l3_config(struct brw_context *brw, const struct gen_l3_config *cfg) 72{ 73 const struct gen_device_info *devinfo = &brw->screen->devinfo; 74 const bool has_dc = cfg->n[GEN_L3P_DC] || cfg->n[GEN_L3P_ALL]; 75 const bool has_is = cfg->n[GEN_L3P_IS] || cfg->n[GEN_L3P_RO] || 76 cfg->n[GEN_L3P_ALL]; 77 const bool has_c = cfg->n[GEN_L3P_C] || cfg->n[GEN_L3P_RO] || 78 cfg->n[GEN_L3P_ALL]; 79 const bool has_t = cfg->n[GEN_L3P_T] || cfg->n[GEN_L3P_RO] || 80 cfg->n[GEN_L3P_ALL]; 81 const bool has_slm = cfg->n[GEN_L3P_SLM]; 82 83 /* According to the hardware docs, the L3 partitioning can only be changed 84 * while the pipeline is completely drained and the caches are flushed, 85 * which involves a first PIPE_CONTROL flush which stalls the pipeline... 86 */ 87 brw_emit_pipe_control_flush(brw, 88 PIPE_CONTROL_DATA_CACHE_FLUSH | 89 PIPE_CONTROL_CS_STALL); 90 91 /* ...followed by a second pipelined PIPE_CONTROL that initiates 92 * invalidation of the relevant caches. Note that because RO invalidation 93 * happens at the top of the pipeline (i.e. right away as the PIPE_CONTROL 94 * command is processed by the CS) we cannot combine it with the previous 95 * stalling flush as the hardware documentation suggests, because that 96 * would cause the CS to stall on previous rendering *after* RO 97 * invalidation and wouldn't prevent the RO caches from being polluted by 98 * concurrent rendering before the stall completes. This intentionally 99 * doesn't implement the SKL+ hardware workaround suggesting to enable CS 100 * stall on PIPE_CONTROLs with the texture cache invalidation bit set for 101 * GPGPU workloads because the previous and subsequent PIPE_CONTROLs 102 * already guarantee that there is no concurrent GPGPU kernel execution 103 * (see SKL HSD 2132585). 104 */ 105 brw_emit_pipe_control_flush(brw, 106 PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE | 107 PIPE_CONTROL_CONST_CACHE_INVALIDATE | 108 PIPE_CONTROL_INSTRUCTION_INVALIDATE | 109 PIPE_CONTROL_STATE_CACHE_INVALIDATE); 110 111 /* Now send a third stalling flush to make sure that invalidation is 112 * complete when the L3 configuration registers are modified. 113 */ 114 brw_emit_pipe_control_flush(brw, 115 PIPE_CONTROL_DATA_CACHE_FLUSH | 116 PIPE_CONTROL_CS_STALL); 117 118 if (devinfo->gen >= 8) { 119 assert(!cfg->n[GEN_L3P_IS] && !cfg->n[GEN_L3P_C] && !cfg->n[GEN_L3P_T]); 120 121 const unsigned imm_data = ((has_slm ? GEN8_L3CNTLREG_SLM_ENABLE : 0) | 122 (devinfo->gen == 11 ? GEN11_L3CNTLREG_USE_FULL_WAYS : 0) | 123 SET_FIELD(cfg->n[GEN_L3P_URB], GEN8_L3CNTLREG_URB_ALLOC) | 124 SET_FIELD(cfg->n[GEN_L3P_RO], GEN8_L3CNTLREG_RO_ALLOC) | 125 SET_FIELD(cfg->n[GEN_L3P_DC], GEN8_L3CNTLREG_DC_ALLOC) | 126 SET_FIELD(cfg->n[GEN_L3P_ALL], GEN8_L3CNTLREG_ALL_ALLOC)); 127 128 /* Set up the L3 partitioning. */ 129 brw_load_register_imm32(brw, GEN8_L3CNTLREG, imm_data); 130 } else { 131 assert(!cfg->n[GEN_L3P_ALL]); 132 133 /* When enabled SLM only uses a portion of the L3 on half of the banks, 134 * the matching space on the remaining banks has to be allocated to a 135 * client (URB for all validated configurations) set to the 136 * lower-bandwidth 2-bank address hashing mode. 137 */ 138 const bool urb_low_bw = has_slm && !devinfo->is_baytrail; 139 assert(!urb_low_bw || cfg->n[GEN_L3P_URB] == cfg->n[GEN_L3P_SLM]); 140 141 /* Minimum number of ways that can be allocated to the URB. */ 142 const unsigned n0_urb = (devinfo->is_baytrail ? 32 : 0); 143 assert(cfg->n[GEN_L3P_URB] >= n0_urb); 144 145 BEGIN_BATCH(7); 146 OUT_BATCH(MI_LOAD_REGISTER_IMM | (7 - 2)); 147 148 /* Demote any clients with no ways assigned to LLC. */ 149 OUT_BATCH(GEN7_L3SQCREG1); 150 OUT_BATCH((devinfo->is_haswell ? HSW_L3SQCREG1_SQGHPCI_DEFAULT : 151 devinfo->is_baytrail ? VLV_L3SQCREG1_SQGHPCI_DEFAULT : 152 IVB_L3SQCREG1_SQGHPCI_DEFAULT) | 153 (has_dc ? 0 : GEN7_L3SQCREG1_CONV_DC_UC) | 154 (has_is ? 0 : GEN7_L3SQCREG1_CONV_IS_UC) | 155 (has_c ? 0 : GEN7_L3SQCREG1_CONV_C_UC) | 156 (has_t ? 0 : GEN7_L3SQCREG1_CONV_T_UC)); 157 158 /* Set up the L3 partitioning. */ 159 OUT_BATCH(GEN7_L3CNTLREG2); 160 OUT_BATCH((has_slm ? GEN7_L3CNTLREG2_SLM_ENABLE : 0) | 161 SET_FIELD(cfg->n[GEN_L3P_URB] - n0_urb, GEN7_L3CNTLREG2_URB_ALLOC) | 162 (urb_low_bw ? GEN7_L3CNTLREG2_URB_LOW_BW : 0) | 163 SET_FIELD(cfg->n[GEN_L3P_ALL], GEN7_L3CNTLREG2_ALL_ALLOC) | 164 SET_FIELD(cfg->n[GEN_L3P_RO], GEN7_L3CNTLREG2_RO_ALLOC) | 165 SET_FIELD(cfg->n[GEN_L3P_DC], GEN7_L3CNTLREG2_DC_ALLOC)); 166 OUT_BATCH(GEN7_L3CNTLREG3); 167 OUT_BATCH(SET_FIELD(cfg->n[GEN_L3P_IS], GEN7_L3CNTLREG3_IS_ALLOC) | 168 SET_FIELD(cfg->n[GEN_L3P_C], GEN7_L3CNTLREG3_C_ALLOC) | 169 SET_FIELD(cfg->n[GEN_L3P_T], GEN7_L3CNTLREG3_T_ALLOC)); 170 171 ADVANCE_BATCH(); 172 173 if (can_do_hsw_l3_atomics(brw->screen)) { 174 /* Enable L3 atomics on HSW if we have a DC partition, otherwise keep 175 * them disabled to avoid crashing the system hard. 176 */ 177 BEGIN_BATCH(5); 178 OUT_BATCH(MI_LOAD_REGISTER_IMM | (5 - 2)); 179 OUT_BATCH(HSW_SCRATCH1); 180 OUT_BATCH(has_dc ? 0 : HSW_SCRATCH1_L3_ATOMIC_DISABLE); 181 OUT_BATCH(HSW_ROW_CHICKEN3); 182 OUT_BATCH(REG_MASK(HSW_ROW_CHICKEN3_L3_ATOMIC_DISABLE) | 183 (has_dc ? 0 : HSW_ROW_CHICKEN3_L3_ATOMIC_DISABLE)); 184 ADVANCE_BATCH(); 185 } 186 } 187} 188 189/** 190 * Update the URB size in the context state for the specified L3 191 * configuration. 192 */ 193static void 194update_urb_size(struct brw_context *brw, const struct gen_l3_config *cfg) 195{ 196 const struct gen_device_info *devinfo = &brw->screen->devinfo; 197 const unsigned sz = gen_get_l3_config_urb_size(devinfo, cfg); 198 199 if (brw->urb.size != sz) { 200 brw->urb.size = sz; 201 brw->ctx.NewDriverState |= BRW_NEW_URB_SIZE; 202 203 /* If we change the total URB size, reset the individual stage sizes to 204 * zero so that, even if there is no URB size change, gen7_upload_urb 205 * still re-emits 3DSTATE_URB_*. 206 */ 207 brw->urb.vsize = 0; 208 brw->urb.gsize = 0; 209 brw->urb.hsize = 0; 210 brw->urb.dsize = 0; 211 } 212} 213 214static void 215emit_l3_state(struct brw_context *brw) 216{ 217 const struct gen_l3_weights w = get_pipeline_state_l3_weights(brw); 218 const float dw = gen_diff_l3_weights(w, gen_get_l3_config_weights(brw->l3.config)); 219 /* The distance between any two compatible weight vectors cannot exceed two 220 * due to the triangle inequality. 221 */ 222 const float large_dw_threshold = 2.0; 223 /* Somewhat arbitrary, simply makes sure that there will be no repeated 224 * transitions to the same L3 configuration, could probably do better here. 225 */ 226 const float small_dw_threshold = 0.5; 227 /* If we're emitting a new batch the caches should already be clean and the 228 * transition should be relatively cheap, so it shouldn't hurt much to use 229 * the smaller threshold. Otherwise use the larger threshold so that we 230 * only reprogram the L3 mid-batch if the most recently programmed 231 * configuration is incompatible with the current pipeline state. 232 */ 233 const float dw_threshold = (brw->ctx.NewDriverState & BRW_NEW_BATCH ? 234 small_dw_threshold : large_dw_threshold); 235 236 if (dw > dw_threshold && can_do_pipelined_register_writes(brw->screen)) { 237 const struct gen_l3_config *const cfg = 238 gen_get_l3_config(&brw->screen->devinfo, w); 239 240 setup_l3_config(brw, cfg); 241 update_urb_size(brw, cfg); 242 brw->l3.config = cfg; 243 244 if (unlikely(INTEL_DEBUG & DEBUG_L3)) { 245 fprintf(stderr, "L3 config transition (%f > %f): ", dw, dw_threshold); 246 gen_dump_l3_config(cfg, stderr); 247 } 248 } 249} 250 251const struct brw_tracked_state gen7_l3_state = { 252 .dirty = { 253 .mesa = 0, 254 .brw = BRW_NEW_BATCH | 255 BRW_NEW_BLORP | 256 BRW_NEW_CS_PROG_DATA | 257 BRW_NEW_FS_PROG_DATA | 258 BRW_NEW_GS_PROG_DATA | 259 BRW_NEW_TCS_PROG_DATA | 260 BRW_NEW_TES_PROG_DATA | 261 BRW_NEW_VS_PROG_DATA, 262 }, 263 .emit = emit_l3_state 264}; 265 266/** 267 * Hack to restore the default L3 configuration. 268 * 269 * This will be called at the end of every batch in order to reset the L3 270 * configuration to the default values for the time being until the kernel is 271 * fixed. Until kernel commit 6702cf16e0ba8b0129f5aa1b6609d4e9c70bc13b 272 * (included in v4.1) we would set the MI_RESTORE_INHIBIT bit when submitting 273 * batch buffers for the default context used by the DDX, which meant that any 274 * context state changed by the GL would leak into the DDX, the assumption 275 * being that the DDX would initialize any state it cares about manually. The 276 * DDX is however not careful enough to program an L3 configuration 277 * explicitly, and it makes assumptions about it (URB size) which won't hold 278 * and cause it to misrender if we let our L3 set-up to leak into the DDX. 279 * 280 * Since v4.1 of the Linux kernel the default context is saved and restored 281 * normally, so it's far less likely for our L3 programming to interfere with 282 * other contexts -- In fact restoring the default L3 configuration at the end 283 * of the batch will be redundant most of the time. A kind of state leak is 284 * still possible though if the context making assumptions about L3 state is 285 * created immediately after our context was active (e.g. without the DDX 286 * default context being scheduled in between) because at present the DRM 287 * doesn't fully initialize the contents of newly created contexts and instead 288 * sets the MI_RESTORE_INHIBIT flag causing it to inherit the state from the 289 * last active context. 290 * 291 * It's possible to realize such a scenario if, say, an X server (or a GL 292 * application using an outdated non-L3-aware Mesa version) is started while 293 * another GL application is running and happens to have modified the L3 294 * configuration, or if no X server is running at all and a GL application 295 * using a non-L3-aware Mesa version is started after another GL application 296 * ran and modified the L3 configuration -- The latter situation can actually 297 * be reproduced easily on IVB in our CI system. 298 */ 299void 300gen7_restore_default_l3_config(struct brw_context *brw) 301{ 302 const struct gen_device_info *devinfo = &brw->screen->devinfo; 303 const struct gen_l3_config *const cfg = gen_get_default_l3_config(devinfo); 304 305 if (cfg != brw->l3.config && 306 can_do_pipelined_register_writes(brw->screen)) { 307 setup_l3_config(brw, cfg); 308 update_urb_size(brw, cfg); 309 brw->l3.config = cfg; 310 } 311} 312