src/panfrost/bifrost/bifrost.h

   1 /*
   2  * Copyright (C) 2019 Connor Abbott <cwabbott0@gmail.com>
   3  * Copyright (C) 2019 Lyude Paul <thatslyude@gmail.com>
   4  * Copyright (C) 2019 Ryan Houdek <Sonicadvance1@gmail.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #ifndef __bifrost_h__
  27 #define __bifrost_h__
  28
  29 #include <stdint.h>
  30 #include <stdbool.h>
  31
  32 struct bifrost_header {
  33         unsigned unk0 : 7;
  34         // If true, convert any infinite result of any floating-point operation to
  35         // the biggest representable number.
  36         unsigned suppress_inf: 1;
  37         // Convert any NaN results to 0.
  38         unsigned suppress_nan : 1;
  39         unsigned unk1 : 2;
  40         // true if the execution mask of the next clause is the same as the mask of
  41         // the current clause.
  42         unsigned back_to_back : 1;
  43         unsigned no_end_of_shader: 1;
  44         unsigned unk2 : 2;
  45         // Set to true for fragment shaders, to implement this bit of spec text
  46         // from section 7.1.5 of the GLSL ES spec:
  47         //
  48         // "Stores to image and buffer variables performed by helper invocations
  49         // have no effect on the underlying image or buffer memory."
  50         //
  51         // Helper invocations are threads (invocations) corresponding to pixels in
  52         // a quad that aren't actually part of the triangle, but are included to
  53         // make derivatives work correctly. They're usually turned on, but they
  54         // need to be masked off for GLSL-level stores. This bit seems to be the
  55         // only bit that's actually different between fragment shaders and other
  56         // shaders, so this is probably what it's doing.
  57         unsigned elide_writes : 1;
  58         // If backToBack is off:
  59         // - true for conditional branches and fallthrough
  60         // - false for unconditional branches
  61         // The blob seems to always set it to true if back-to-back is on.
  62         unsigned branch_cond : 1;
  63         // This bit is set when the next clause writes to the data register of some
  64         // previous clause.
  65         unsigned datareg_writebarrier: 1;
  66         unsigned datareg : 6;
  67         unsigned scoreboard_deps: 8;
  68         unsigned scoreboard_index: 3;
  69         unsigned clause_type: 4;
  70         unsigned unk3 : 1; // part of clauseType?
  71         unsigned next_clause_type: 4;
  72         unsigned unk4 : 1; // part of nextClauseType?
  73 } __attribute__((packed));
  74
  75 struct bifrost_fma_inst {
  76         unsigned src0 : 3;
  77         unsigned op   : 20;
  78 } __attribute__((packed));
  79
  80 struct bifrost_add_inst {
  81         unsigned src0 : 3;
  82         unsigned op   : 17;
  83 } __attribute__((packed));
  84
  85 enum bifrost_outmod {
  86         BIFROST_NONE = 0x0,
  87         BIFROST_POS = 0x1,
  88         BIFROST_SAT_SIGNED = 0x2,
  89         BIFROST_SAT = 0x3,
  90 };
  91
  92 enum bifrost_roundmode {
  93         BIFROST_RTE = 0x0, /* round to even */
  94         BIFROST_RTP = 0x1, /* round to positive */
  95         BIFROST_RTN = 0x2, /* round to negative */
  96         BIFROST_RTZ = 0x3 /* round to zero */
  97 };
  98
  99 /* NONE: Same as fmax() and fmin() -- return the other
 100  * number if any number is NaN.  Also always return +0 if
 101  * one argument is +0 and the other is -0.
 102  *
 103  * NAN_WINS: Instead of never returning a NaN, always return
 104  * one. The "greater"/"lesser" NaN is always returned, first
 105  * by checking the sign and then the mantissa bits.
 106  *
 107  * SRC1_WINS: For max, implement src0 > src1 ? src0 : src1.
 108  * For min, implement src0 < src1 ? src0 : src1.  This
 109  * includes handling NaN's and signedness of 0 differently
 110  * from above, since +0 and -0 compare equal and comparisons
 111  * always return false for NaN's. As a result, this mode is
 112  * *not* commutative.
 113  *
 114  * SRC0_WINS: For max, implement src0 < src1 ? src1 : src0
 115  * For min, implement src0 > src1 ? src1 : src0
 116  */
 117
 118
 119 enum bifrost_minmax_mode {
 120         BIFROST_MINMAX_NONE = 0x0,
 121         BIFROST_NAN_WINS    = 0x1,
 122         BIFROST_SRC1_WINS   = 0x2,
 123         BIFROST_SRC0_WINS   = 0x3,
 124 };
 125
 126 struct bifrost_fma_add {
 127         unsigned src0 : 3;
 128         unsigned src1 : 3;
 129         unsigned src1_abs : 1;
 130         unsigned src0_neg : 1;
 131         unsigned src1_neg : 1;
 132         unsigned unk : 3;
 133         unsigned src0_abs : 1;
 134         enum bifrost_outmod outmod : 2;
 135         enum bifrost_roundmode roundmode : 2;
 136         unsigned op : 6;
 137 } __attribute__((packed));
 138
 139 enum bifrost_csel_cond {
 140         BIFROST_FEQ_F = 0x0,
 141         BIFROST_FGT_F = 0x1,
 142         BIFROST_FGE_F = 0x2,
 143         BIFROST_IEQ_F = 0x3,
 144         BIFROST_IGT_I = 0x4,
 145         BIFROST_IGE_I = 0x5,
 146         BIFROST_UGT_I = 0x6,
 147         BIFROST_UGE_I = 0x7
 148 };
 149
 150 struct bifrost_csel4 {
 151         unsigned src0 : 3;
 152         unsigned src1 : 3;
 153         unsigned src2 : 3;
 154         unsigned src3 : 3;
 155         enum bifrost_csel_cond cond : 3;
 156         unsigned op   : 8;
 157 } __attribute__((packed));
 158
 159 struct bifrost_shift_fma {
 160         unsigned src0 : 3;
 161         unsigned src1 : 3;
 162         unsigned src2 : 3;
 163         unsigned half : 3; /* 000 for i32, 100 for i8, 111 for v2i16 */
 164         unsigned unk  : 1; /* always set? */
 165         unsigned invert_1 : 1; /* Inverts sources to combining op */
 166         /* For XOR, switches RSHIFT to LSHIFT since only one invert needed */
 167         unsigned invert_2 : 1;
 168         unsigned op : 8;
 169 } __attribute__((packed));
 170
 171 struct bifrost_shift_add {
 172         unsigned src0 : 3;
 173         unsigned src1 : 3;
 174         unsigned src2 : 3;
 175         unsigned zero : 2;
 176
 177         unsigned invert_1 : 1;
 178         unsigned invert_2 : 1;
 179
 180         unsigned op : 7;
 181 } __attribute__((packed));
 182
 183 enum bifrost_ldst_type {
 184         BIFROST_LDST_F16 = 0,
 185         BIFROST_LDST_F32 = 1,
 186         BIFROST_LDST_I32 = 2,
 187         BIFROST_LDST_U32 = 3
 188 };
 189
 190 struct bifrost_ld_var_addr {
 191         unsigned src0 : 3;
 192         unsigned src1 : 3;
 193         unsigned location : 5;
 194         enum bifrost_ldst_type type : 2;
 195         unsigned op : 7;
 196 } __attribute__((packed));
 197
 198 struct bifrost_ld_attr {
 199         unsigned src0 : 3;
 200         unsigned src1 : 3;
 201         unsigned location : 5;
 202         unsigned channels : 2; /* MALI_POSITIVE */
 203         enum bifrost_ldst_type type : 2;
 204         unsigned op : 5;
 205 } __attribute__((packed));
 206
 207 enum bifrost_interp_mode {
 208         BIFROST_INTERP_PER_FRAG = 0x0,
 209         BIFROST_INTERP_CENTROID = 0x1,
 210         BIFROST_INTERP_DEFAULT  = 0x2,
 211         BIFROST_INTERP_EXPLICIT = 0x3
 212 };
 213
 214 struct bifrost_ld_var {
 215         unsigned src0 : 3;
 216
 217         /* If top two bits set, indirect with src in bottom three */
 218         unsigned addr : 5;
 219
 220         unsigned channels : 2; /* MALI_POSITIVE */
 221         enum bifrost_interp_mode interp_mode : 2;
 222         unsigned reuse : 1;
 223         unsigned flat : 1;
 224         unsigned op : 6;
 225 } __attribute__((packed));
 226
 227 struct bifrost_tex_ctrl {
 228         unsigned sampler_index : 4; // also used to signal indirects
 229         unsigned tex_index : 7;
 230         bool no_merge_index : 1; // whether to merge (direct) sampler & texture indices
 231         bool filter : 1; // use the usual filtering pipeline (0 for texelFetch & textureGather)
 232         unsigned unk0 : 2;
 233         bool texel_offset : 1; // *Offset()
 234         bool is_shadow : 1;
 235         bool is_array : 1;
 236         unsigned tex_type : 2; // 2D, 3D, Cube, Buffer
 237         bool compute_lod : 1; // 0 for *Lod()
 238         bool not_supply_lod : 1; // 0 for *Lod() or when a bias is applied
 239         bool calc_gradients : 1; // 0 for *Grad()
 240         unsigned unk1 : 1;
 241         unsigned result_type : 4; // integer, unsigned, float TODO: why is this 4 bits?
 242         unsigned unk2 : 4;
 243 } __attribute__((packed));
 244
 245 struct bifrost_dual_tex_ctrl {
 246         unsigned sampler_index0 : 2;
 247         unsigned unk0 : 2;
 248         unsigned tex_index0 : 2;
 249         unsigned sampler_index1 : 2;
 250         unsigned tex_index1 : 2;
 251         unsigned unk1 : 22;
 252 } __attribute__((packed));
 253
 254 enum branch_bit_size {
 255         BR_SIZE_32 = 0,
 256         BR_SIZE_16XX = 1,
 257         BR_SIZE_16YY = 2,
 258         // For the above combinations of bitsize and location, an extra bit is
 259         // encoded via comparing the sources. The only possible source of ambiguity
 260         // would be if the sources were the same, but then the branch condition
 261         // would be always true or always false anyways, so we can ignore it. But
 262         // this no longer works when comparing the y component to the x component,
 263         // since it's valid to compare the y component of a source against its own
 264         // x component. Instead, the extra bit is encoded via an extra bitsize.
 265         BR_SIZE_16YX0 = 3,
 266         BR_SIZE_16YX1 = 4,
 267         BR_SIZE_32_AND_16X = 5,
 268         BR_SIZE_32_AND_16Y = 6,
 269         // Used for comparisons with zero and always-true, see below. I think this
 270         // only works for integer comparisons.
 271         BR_SIZE_ZERO = 7,
 272 };
 273
 274 enum bifrost_reg_write_unit {
 275         REG_WRITE_NONE = 0, // don't write
 276         REG_WRITE_TWO, // write using reg2
 277         REG_WRITE_THREE, // write using reg3
 278 };
 279
 280 struct bifrost_regs {
 281         unsigned uniform_const : 8;
 282         unsigned reg2 : 6;
 283         unsigned reg3 : 6;
 284         unsigned reg0 : 5;
 285         unsigned reg1 : 6;
 286         unsigned ctrl : 4;
 287 } __attribute__((packed));
 288
 289 enum bifrost_branch_cond {
 290         BR_COND_LT = 0,
 291         BR_COND_LE = 1,
 292         BR_COND_GE = 2,
 293         BR_COND_GT = 3,
 294         // Equal vs. not-equal determined by src0/src1 comparison
 295         BR_COND_EQ = 4,
 296         // floating-point comparisons
 297         // Becomes UNE when you flip the arguments
 298         BR_COND_OEQ = 5,
 299         // TODO what happens when you flip the arguments?
 300         BR_COND_OGT = 6,
 301         BR_COND_OLT = 7,
 302 };
 303
 304 enum bifrost_branch_code {
 305         BR_ALWAYS = 63,
 306 };
 307
 308 struct bifrost_branch {
 309         unsigned src0 : 3;
 310
 311         /* For BR_SIZE_ZERO, upper two bits become ctrl */
 312         unsigned src1 : 3;
 313
 314         /* Offset source -- always uniform/const but
 315          * theoretically could support indirect jumps? */
 316         unsigned src2 : 3;
 317
 318         enum bifrost_branch_cond cond : 3;
 319         enum branch_bit_size size : 3;
 320
 321         unsigned op : 5;
 322 };
 323
 324 /* Clause packing */
 325
 326 #define BIFROST_FMA_NOP (0x701960)
 327 #define BIFROST_ADD_NOP (0x3D960)
 328
 329 struct bifrost_fmt1 {
 330         unsigned ins_0 : 3;
 331         unsigned tag : 5;
 332         uint64_t ins_1 : 64;
 333         unsigned ins_2 : 11;
 334         uint64_t header : 45;
 335 } __attribute__((packed));
 336
 337 #define BIFROST_FMT1_INSTRUCTIONS    0b00101
 338 #define BIFROST_FMT1_FINAL           0b01001
 339 #define BIFROST_FMT1_CONSTANTS       0b00001
 340
 341 enum bifrost_reg_control {
 342         BIFROST_WRITE_FMA_P2         = 1,
 343         BIFROST_WRITE_FMA_P2_READ_P3 = 2,
 344         BIFROST_WRITE_FMA_P2_READ_P3_ALT = 3,
 345         BIFROST_READ_P3              = 4,
 346         BIFROST_WRITE_ADD_P2         = 5,
 347         BIFROST_WRITE_ADD_P2_READ_P3 = 6,
 348         BIFROST_WRITE_ADD_P2_FMA_P3  = 7,
 349
 350         BIFROST_FIRST_NONE           = 8,
 351         BIFROST_FIRST_WRITE_FMA_P2   = 9,
 352         BIFROST_REG_NONE             = 11,
 353         BIFROST_FIRST_READ_P3        = 12,
 354         BIFROST_FIRST_WRITE_ADD_P2   = 13,
 355         BIFROST_FIRST_WRITE_ADD_P2_READ_P3 = 14,
 356         BIFROST_FIRST_WRITE_ADD_P2_FMA_P3  = 15
 357 };
 358
 359 #endif