1 /* Author(s):
2  *   Connor Abbott
3  *   Alyssa Rosenzweig
4  *
5  * Copyright (c) 2013 Connor Abbott (connor@abbott.cx)
6  * Copyright (c) 2018 Alyssa Rosenzweig (alyssa@rosenzweig.io)
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #ifndef __midgard_h__
28 #define __midgard_h__
29 
30 #include <stdint.h>
31 #include <stdbool.h>
32 #include "panfrost-job.h"
33 
34 #define MIDGARD_DBG_MSGS		0x0001
35 #define MIDGARD_DBG_SHADERS		0x0002
36 #define MIDGARD_DBG_SHADERDB            0x0004
37 
38 extern int midgard_debug;
39 
40 typedef enum {
41         midgard_word_type_alu,
42         midgard_word_type_load_store,
43         midgard_word_type_texture,
44         midgard_word_type_unknown
45 } midgard_word_type;
46 
47 typedef enum {
48         midgard_alu_vmul,
49         midgard_alu_sadd,
50         midgard_alu_smul,
51         midgard_alu_vadd,
52         midgard_alu_lut
53 } midgard_alu;
54 
55 enum {
56         TAG_INVALID = 0x0,
57         TAG_BREAK = 0x1,
58         TAG_TEXTURE_4_VTX = 0x2,
59         TAG_TEXTURE_4 = 0x3,
60         TAG_TEXTURE_4_BARRIER = 0x4,
61         TAG_LOAD_STORE_4 = 0x5,
62         TAG_UNKNOWN_1 = 0x6,
63         TAG_UNKNOWN_2 = 0x7,
64         TAG_ALU_4 = 0x8,
65         TAG_ALU_8 = 0x9,
66         TAG_ALU_12 = 0xA,
67         TAG_ALU_16 = 0xB,
68         TAG_ALU_4_WRITEOUT = 0xC,
69         TAG_ALU_8_WRITEOUT = 0xD,
70         TAG_ALU_12_WRITEOUT = 0xE,
71         TAG_ALU_16_WRITEOUT = 0xF
72 };
73 
74 /*
75  * ALU words
76  */
77 
78 typedef enum {
79         midgard_alu_op_fadd       = 0x10,
80         midgard_alu_op_fmul       = 0x14,
81 
82         midgard_alu_op_fmin       = 0x28,
83         midgard_alu_op_fmax       = 0x2C,
84 
85         midgard_alu_op_fmov       = 0x30, /* fmov_rte */
86         midgard_alu_op_fmov_rtz   = 0x31,
87         midgard_alu_op_fmov_rtn   = 0x32,
88         midgard_alu_op_fmov_rtp   = 0x33,
89         midgard_alu_op_froundeven = 0x34,
90         midgard_alu_op_ftrunc     = 0x35,
91         midgard_alu_op_ffloor     = 0x36,
92         midgard_alu_op_fceil      = 0x37,
93         midgard_alu_op_ffma       = 0x38,
94         midgard_alu_op_fdot3      = 0x3C,
95         midgard_alu_op_fdot3r     = 0x3D,
96         midgard_alu_op_fdot4      = 0x3E,
97         midgard_alu_op_freduce    = 0x3F,
98 
99         midgard_alu_op_iadd       = 0x40,
100         midgard_alu_op_ishladd    = 0x41, /* a + (b<<1) */
101         midgard_alu_op_isub       = 0x46,
102         midgard_alu_op_iaddsat    = 0x48,
103         midgard_alu_op_uaddsat    = 0x49,
104         midgard_alu_op_isubsat    = 0x4E,
105         midgard_alu_op_usubsat    = 0x4F,
106 
107         midgard_alu_op_imul       = 0x58,
108 
109         midgard_alu_op_imin       = 0x60,
110         midgard_alu_op_umin       = 0x61,
111         midgard_alu_op_imax       = 0x62,
112         midgard_alu_op_umax       = 0x63,
113         midgard_alu_op_ihadd      = 0x64,
114         midgard_alu_op_uhadd      = 0x65,
115         midgard_alu_op_irhadd     = 0x66,
116         midgard_alu_op_urhadd     = 0x67,
117         midgard_alu_op_iasr       = 0x68,
118         midgard_alu_op_ilsr       = 0x69,
119         midgard_alu_op_ishl       = 0x6E,
120 
121         midgard_alu_op_iand       = 0x70,
122         midgard_alu_op_ior        = 0x71,
123         midgard_alu_op_inand      = 0x72, /* ~(a & b), for inot let a = b */
124         midgard_alu_op_inor       = 0x73, /* ~(a | b) */
125         midgard_alu_op_iandnot    = 0x74, /* (a & ~b), used for not/b2f */
126         midgard_alu_op_iornot     = 0x75, /* (a | ~b) */
127         midgard_alu_op_ixor       = 0x76,
128         midgard_alu_op_inxor      = 0x77, /* ~(a & b) */
129         midgard_alu_op_iclz       = 0x78, /* Number of zeroes on left */
130         midgard_alu_op_ibitcount8 = 0x7A, /* Counts bits in 8-bit increments */
131         midgard_alu_op_imov       = 0x7B,
132         midgard_alu_op_iabsdiff   = 0x7C,
133         midgard_alu_op_uabsdiff   = 0x7D,
134         midgard_alu_op_ichoose    = 0x7E, /* vector, component number - dupe for shuffle() */
135 
136         midgard_alu_op_feq        = 0x80,
137         midgard_alu_op_fne        = 0x81,
138         midgard_alu_op_flt        = 0x82,
139         midgard_alu_op_fle        = 0x83,
140         midgard_alu_op_fball_eq   = 0x88,
141         midgard_alu_op_fball_neq  = 0x89,
142         midgard_alu_op_fball_lt   = 0x8A, /* all(lessThan(.., ..)) */
143         midgard_alu_op_fball_lte  = 0x8B, /* all(lessThanEqual(.., ..)) */
144 
145         midgard_alu_op_fbany_eq   = 0x90,
146         midgard_alu_op_fbany_neq  = 0x91,
147         midgard_alu_op_fbany_lt   = 0x92, /* any(lessThan(.., ..)) */
148         midgard_alu_op_fbany_lte  = 0x93, /* any(lessThanEqual(.., ..)) */
149 
150         midgard_alu_op_f2i_rte    = 0x98,
151         midgard_alu_op_f2i_rtz    = 0x99,
152         midgard_alu_op_f2i_rtn    = 0x9A,
153         midgard_alu_op_f2i_rtp    = 0x9B,
154         midgard_alu_op_f2u_rte    = 0x9C,
155         midgard_alu_op_f2u_rtz    = 0x9D,
156         midgard_alu_op_f2u_rtn    = 0x9E,
157         midgard_alu_op_f2u_rtp    = 0x9F,
158 
159         midgard_alu_op_ieq        = 0xA0,
160         midgard_alu_op_ine        = 0xA1,
161         midgard_alu_op_ult        = 0xA2,
162         midgard_alu_op_ule        = 0xA3,
163         midgard_alu_op_ilt        = 0xA4,
164         midgard_alu_op_ile        = 0xA5,
165         midgard_alu_op_iball_eq   = 0xA8,
166         midgard_alu_op_iball_neq  = 0xA9,
167         midgard_alu_op_uball_lt   = 0xAA,
168         midgard_alu_op_uball_lte  = 0xAB,
169         midgard_alu_op_iball_lt   = 0xAC,
170         midgard_alu_op_iball_lte  = 0xAD,
171 
172         midgard_alu_op_ibany_eq   = 0xB0,
173         midgard_alu_op_ibany_neq  = 0xB1,
174         midgard_alu_op_ubany_lt   = 0xB2,
175         midgard_alu_op_ubany_lte  = 0xB3,
176         midgard_alu_op_ibany_lt   = 0xB4, /* any(lessThan(.., ..)) */
177         midgard_alu_op_ibany_lte  = 0xB5, /* any(lessThanEqual(.., ..)) */
178         midgard_alu_op_i2f_rte    = 0xB8,
179         midgard_alu_op_i2f_rtz    = 0xB9,
180         midgard_alu_op_i2f_rtn    = 0xBA,
181         midgard_alu_op_i2f_rtp    = 0xBB,
182         midgard_alu_op_u2f_rte    = 0xBC,
183         midgard_alu_op_u2f_rtz    = 0xBD,
184         midgard_alu_op_u2f_rtn    = 0xBE,
185         midgard_alu_op_u2f_rtp    = 0xBF,
186 
187         midgard_alu_op_icsel_v    = 0xC0, /* condition code r31 */
188         midgard_alu_op_icsel      = 0xC1, /* condition code r31.w */
189         midgard_alu_op_fcsel_v    = 0xC4,
190         midgard_alu_op_fcsel      = 0xC5,
191         midgard_alu_op_fround     = 0xC6,
192 
193         midgard_alu_op_fatan_pt2  = 0xE8,
194         midgard_alu_op_fpow_pt1   = 0xEC,
195         midgard_alu_op_fpown_pt1  = 0xED,
196         midgard_alu_op_fpowr_pt1  = 0xEE,
197 
198         midgard_alu_op_frcp       = 0xF0,
199         midgard_alu_op_frsqrt     = 0xF2,
200         midgard_alu_op_fsqrt      = 0xF3,
201         midgard_alu_op_fexp2      = 0xF4,
202         midgard_alu_op_flog2      = 0xF5,
203         midgard_alu_op_fsin       = 0xF6,
204         midgard_alu_op_fcos       = 0xF7,
205         midgard_alu_op_fatan2_pt1 = 0xF9,
206 } midgard_alu_op;
207 
208 typedef enum {
209         midgard_outmod_none = 0,
210         midgard_outmod_pos  = 1, /* max(x, 0.0) */
211         midgard_outmod_sat_signed  = 2, /* clamp(x, -1.0, 1.0) */
212         midgard_outmod_sat  = 3 /* clamp(x, 0.0, 1.0) */
213 } midgard_outmod_float;
214 
215 typedef enum {
216         midgard_outmod_int_saturate = 0,
217         midgard_outmod_uint_saturate = 1,
218         midgard_outmod_int_wrap = 2,
219         midgard_outmod_int_high = 3, /* Overflowed portion */
220 } midgard_outmod_int;
221 
222 typedef enum {
223         midgard_reg_mode_8 = 0,
224         midgard_reg_mode_16 = 1,
225         midgard_reg_mode_32 = 2,
226         midgard_reg_mode_64 = 3
227 } midgard_reg_mode;
228 
229 typedef enum {
230         midgard_dest_override_lower = 0,
231         midgard_dest_override_upper = 1,
232         midgard_dest_override_none = 2
233 } midgard_dest_override;
234 
235 typedef enum {
236         midgard_int_sign_extend = 0,
237         midgard_int_zero_extend = 1,
238         midgard_int_normal = 2,
239         midgard_int_shift = 3
240 } midgard_int_mod;
241 
242 #define MIDGARD_FLOAT_MOD_ABS (1 << 0)
243 #define MIDGARD_FLOAT_MOD_NEG (1 << 1)
244 
245 typedef struct
246 __attribute__((__packed__))
247 {
248         /* Either midgard_int_mod or from midgard_float_mod_*, depending on the
249          * type of op */
250         unsigned mod : 2;
251 
252         /* replicate lower half if dest = half, or low/high half selection if
253          * dest = full
254          */
255         bool rep_low     : 1;
256         bool rep_high    : 1; /* unused if dest = full */
257         bool half        : 1; /* only matters if dest = full */
258         unsigned swizzle : 8;
259 }
260 midgard_vector_alu_src;
261 
262 typedef struct
263 __attribute__((__packed__))
264 {
265         midgard_alu_op op               :  8;
266         midgard_reg_mode reg_mode   :  2;
267         unsigned src1 : 13;
268         unsigned src2 : 13;
269         midgard_dest_override dest_override : 2;
270         unsigned outmod               : 2;
271         unsigned mask                           : 8;
272 }
273 midgard_vector_alu;
274 
275 typedef struct
276 __attribute__((__packed__))
277 {
278         unsigned mod       : 2;
279         bool full          : 1; /* 0 = half, 1 = full */
280         unsigned component : 3;
281 }
282 midgard_scalar_alu_src;
283 
284 typedef struct
285 __attribute__((__packed__))
286 {
287         midgard_alu_op op         :  8;
288         unsigned src1             :  6;
289         unsigned src2             : 11;
290         unsigned unknown          :  1;
291         unsigned outmod :  2;
292         bool output_full          :  1;
293         unsigned output_component :  3;
294 }
295 midgard_scalar_alu;
296 
297 typedef struct
298 __attribute__((__packed__))
299 {
300         unsigned src1_reg : 5;
301         unsigned src2_reg : 5;
302         unsigned out_reg  : 5;
303         bool src2_imm     : 1;
304 }
305 midgard_reg_info;
306 
307 /* In addition to conditional branches and jumps (unconditional branches),
308  * Midgard implements a bit of fixed function functionality used in fragment
309  * shaders via specially crafted branches. These have special branch opcodes,
310  * which perform a fixed-function operation and/or use the results of a
311  * fixed-function operation as the branch condition.  */
312 
313 typedef enum {
314         /* Regular branches */
315         midgard_jmp_writeout_op_branch_uncond = 1,
316         midgard_jmp_writeout_op_branch_cond = 2,
317 
318         /* In a fragment shader, execute a discard_if instruction, with the
319          * corresponding condition code. Terminates the shader, so generally
320          * set the branch target to out of the shader */
321         midgard_jmp_writeout_op_discard = 4,
322 
323         /* Branch if the tilebuffer is not yet ready. At the beginning of a
324          * fragment shader that reads from the tile buffer, for instance via
325          * ARM_shader_framebuffer_fetch or EXT_pixel_local_storage, this branch
326          * operation should be used as a loop. An instruction like
327          * "br.tilebuffer.always -1" does the trick, corresponding to
328          * "while(!is_tilebuffer_ready) */
329         midgard_jmp_writeout_op_tilebuffer_pending = 6,
330 
331         /* In a fragment shader, try to write out the value pushed to r0 to the
332          * tilebuffer, subject to unknown state in r1.z and r1.w. If this
333          * succeeds, the shader terminates. If it fails, it branches to the
334          * specified branch target. Generally, this should be used in a loop to
335          * itself, acting as "do { write(r0); } while(!write_successful);" */
336         midgard_jmp_writeout_op_writeout = 7,
337 } midgard_jmp_writeout_op;
338 
339 typedef enum {
340         midgard_condition_write0 = 0,
341 
342         /* These condition codes denote a conditional branch on FALSE and on
343          * TRUE respectively */
344         midgard_condition_false = 1,
345         midgard_condition_true = 2,
346 
347         /* This condition code always branches. For a pure branch, the
348          * unconditional branch coding should be used instead, but for
349          * fixed-function branch opcodes, this is still useful */
350         midgard_condition_always = 3,
351 } midgard_condition;
352 
353 typedef struct
354 __attribute__((__packed__))
355 {
356         midgard_jmp_writeout_op op : 3; /* == branch_uncond */
357         unsigned dest_tag : 4; /* tag of branch destination */
358         unsigned unknown : 2;
359         int offset : 7;
360 }
361 midgard_branch_uncond;
362 
363 typedef struct
364 __attribute__((__packed__))
365 {
366         midgard_jmp_writeout_op op : 3; /* == branch_cond */
367         unsigned dest_tag : 4; /* tag of branch destination */
368         int offset : 7;
369         midgard_condition cond : 2;
370 }
371 midgard_branch_cond;
372 
373 typedef struct
374 __attribute__((__packed__))
375 {
376         midgard_jmp_writeout_op op : 3; /* == branch_cond */
377         unsigned dest_tag : 4; /* tag of branch destination */
378         unsigned unknown : 2;
379         signed offset : 23;
380 
381         /* Extended branches permit inputting up to 4 conditions loaded into
382          * r31 (two in r31.w and two in r31.x). In the most general case, we
383          * specify a function f(A, B, C, D) mapping 4 1-bit conditions to a
384          * single 1-bit branch criteria. Note that the domain of f has 2^(2^4)
385          * elements, each mapping to 1-bit of output, so we can trivially
386          * construct a Godel numbering of f as a (2^4)=16-bit integer. This
387          * 16-bit integer serves as a lookup table to compute f, subject to
388          * some swaps for ordering.
389          *
390          * Interesting, the standard 2-bit condition codes are also a LUT with
391          * the same format (2^1-bit), but it's usually easier to use enums. */
392 
393         unsigned cond : 16;
394 }
395 midgard_branch_extended;
396 
397 typedef struct
398 __attribute__((__packed__))
399 {
400         midgard_jmp_writeout_op op : 3; /* == writeout */
401         unsigned unknown : 13;
402 }
403 midgard_writeout;
404 
405 /*
406  * Load/store words
407  */
408 
409 typedef enum {
410         midgard_op_ld_st_noop   = 0x03,
411 
412         /* Unpack a colour from a native format to fp16 */
413         midgard_op_unpack_colour = 0x05,
414 
415         /* Packs a colour from fp16 to a native format */
416         midgard_op_pack_colour   = 0x09,
417 
418         /* Likewise packs from fp32 */
419         midgard_op_pack_colour_32 = 0x0A,
420 
421         /* Unclear why this is on the L/S unit, but moves fp32 cube map
422          * coordinates in r27 to its cube map texture coordinate destination
423          * (e.g r29). */
424 
425         midgard_op_ld_cubemap_coords = 0x0E,
426 
427         /* Loads a global/local/group ID, depending on arguments */
428         midgard_op_ld_compute_id = 0x10,
429 
430         /* The L/S unit can do perspective division a clock faster than the ALU
431          * if you're lucky. Put the vec4 in r27, and call with 0x24 as the
432          * unknown state; the output will be <x/w, y/w, z/w, 1>. Replace w with
433          * z for the z version */
434         midgard_op_ldst_perspective_division_z = 0x12,
435         midgard_op_ldst_perspective_division_w = 0x13,
436 
437         /* val in r27.y, address embedded, outputs result to argument. Invert val for sub. Let val = +-1 for inc/dec. */
438         midgard_op_atomic_add = 0x40,
439         midgard_op_atomic_add64 = 0x41,
440 
441         midgard_op_atomic_and = 0x44,
442         midgard_op_atomic_and64 = 0x45,
443         midgard_op_atomic_or = 0x48,
444         midgard_op_atomic_or64 = 0x49,
445         midgard_op_atomic_xor = 0x4C,
446         midgard_op_atomic_xor64 = 0x4D,
447 
448         midgard_op_atomic_imin = 0x50,
449         midgard_op_atomic_imin64 = 0x51,
450         midgard_op_atomic_umin = 0x54,
451         midgard_op_atomic_umin64 = 0x55,
452         midgard_op_atomic_imax = 0x58,
453         midgard_op_atomic_imax64 = 0x59,
454         midgard_op_atomic_umax = 0x5C,
455         midgard_op_atomic_umax64 = 0x5D,
456 
457         midgard_op_atomic_xchg = 0x60,
458         midgard_op_atomic_xchg64 = 0x61,
459 
460         /* Used for compute shader's __global arguments, __local variables (or
461          * for register spilling) */
462 
463         midgard_op_ld_uchar = 0x80, /* zero extends */
464         midgard_op_ld_char = 0x81, /* sign extends */
465         midgard_op_ld_ushort = 0x84, /* zero extends */
466         midgard_op_ld_short = 0x85, /* sign extends */
467         midgard_op_ld_char4 = 0x88, /* short2, int, float */
468         midgard_op_ld_short4 = 0x8C, /* int2, float2, long */
469         midgard_op_ld_int4 = 0x90, /* float4, long2 */
470 
471         midgard_op_ld_attr_32 = 0x94,
472         midgard_op_ld_attr_16 = 0x95,
473         midgard_op_ld_attr_32u = 0x96,
474         midgard_op_ld_attr_32i = 0x97,
475         midgard_op_ld_vary_32 = 0x98,
476         midgard_op_ld_vary_16 = 0x99,
477         midgard_op_ld_vary_32u = 0x9A,
478         midgard_op_ld_vary_32i = 0x9B,
479 
480         /* Old version of midgard_op_ld_color_buffer_as_fp16, for T720 */
481         midgard_op_ld_color_buffer_as_fp32_old = 0x9C,
482         midgard_op_ld_color_buffer_as_fp16_old = 0x9D,
483         midgard_op_ld_color_buffer_32u_old = 0x9E,
484 
485         /* The distinction between these ops is the alignment requirement /
486          * accompanying shift. Thus, the offset to ld_ubo_int4 is in 16-byte
487          * units and can load 128-bit. The offset to ld_ubo_short4 is in 8-byte
488          * units; ld_ubo_char4 in 4-byte units. ld_ubo_char/ld_ubo_char2 are
489          * purely theoretical (never seen in the wild) since int8/int16/fp16
490          * UBOs don't really exist. The ops are still listed to maintain
491          * symmetry with generic I/O ops. */
492 
493         midgard_op_ld_ubo_char   = 0xA0, /* theoretical */
494         midgard_op_ld_ubo_char2  = 0xA4, /* theoretical */
495         midgard_op_ld_ubo_char4  = 0xA8,
496         midgard_op_ld_ubo_short4 = 0xAC,
497         midgard_op_ld_ubo_int4   = 0xB0,
498 
499         /* New-style blending ops. Works on T760/T860 */
500         midgard_op_ld_color_buffer_as_fp32 = 0xB8,
501         midgard_op_ld_color_buffer_as_fp16 = 0xB9,
502         midgard_op_ld_color_buffer_32u = 0xBA,
503 
504         midgard_op_st_char = 0xC0,
505         midgard_op_st_char2 = 0xC4, /* short */
506         midgard_op_st_char4 = 0xC8, /* short2, int, float */
507         midgard_op_st_short4 = 0xCC, /* int2, float2, long */
508         midgard_op_st_int4 = 0xD0, /* float4, long2 */
509 
510         midgard_op_st_vary_32 = 0xD4,
511         midgard_op_st_vary_16 = 0xD5,
512         midgard_op_st_vary_32u = 0xD6,
513         midgard_op_st_vary_32i = 0xD7,
514 
515         /* Value to st in r27, location r26.w as short2 */
516         midgard_op_st_image_f = 0xD8,
517         midgard_op_st_image_ui = 0xDA,
518         midgard_op_st_image_i = 0xDB,
519 } midgard_load_store_op;
520 
521 typedef enum {
522         midgard_interp_sample = 0,
523         midgard_interp_centroid = 1,
524         midgard_interp_default = 2
525 } midgard_interpolation;
526 
527 typedef enum {
528         midgard_varying_mod_none = 0,
529 
530         /* Other values unknown */
531 
532         /* Take the would-be result and divide all components by its z/w
533          * (perspective division baked in with the load)  */
534         midgard_varying_mod_perspective_z = 2,
535         midgard_varying_mod_perspective_w = 3,
536 } midgard_varying_modifier;
537 
538 typedef struct
539 __attribute__((__packed__))
540 {
541         unsigned zero0 : 1; /* Always zero */
542 
543         midgard_varying_modifier modifier : 2;
544 
545         unsigned zero1: 1; /* Always zero */
546 
547         /* Varying qualifiers, zero if not a varying */
548         unsigned flat    : 1;
549         unsigned is_varying : 1; /* Always one for varying, but maybe something else? */
550         midgard_interpolation interpolation : 2;
551 
552         unsigned zero2 : 2; /* Always zero */
553 }
554 midgard_varying_parameter;
555 
556 /* 8-bit register/etc selector for load/store ops */
557 typedef struct
558 __attribute__((__packed__))
559 {
560         /* Indexes into the register */
561         unsigned component : 2;
562 
563         /* Register select between r26/r27 */
564         unsigned select : 1;
565 
566         unsigned unknown : 2;
567 
568         /* Like any good Arm instruction set, load/store arguments can be
569          * implicitly left-shifted... but only the second argument. Zero for no
570          * shifting, up to <<7 possible though. This is useful for indexing.
571          *
572          * For the first argument, it's unknown what these bits mean */
573         unsigned shift : 3;
574 }
575 midgard_ldst_register_select;
576 
577 typedef struct
578 __attribute__((__packed__))
579 {
580         midgard_load_store_op op : 8;
581         unsigned reg     : 5;
582         unsigned mask    : 4;
583         unsigned swizzle : 8;
584 
585         /* Load/store ops can take two additional registers as arguments, but
586          * these are limited to load/store registers with only a few supported
587          * mask/swizzle combinations. The tradeoff is these are much more
588          * compact, requiring 8-bits each rather than 17-bits for a full
589          * reg/mask/swizzle. Usually (?) encoded as
590          * midgard_ldst_register_select. */
591         unsigned arg_1   : 8;
592         unsigned arg_2   : 8;
593 
594         unsigned varying_parameters : 10;
595 
596         unsigned address : 9;
597 }
598 midgard_load_store_word;
599 
600 typedef struct
601 __attribute__((__packed__))
602 {
603         unsigned type      : 4;
604         unsigned next_type : 4;
605         uint64_t word1     : 60;
606         uint64_t word2     : 60;
607 }
608 midgard_load_store;
609 
610 /* 8-bit register selector used in texture ops to select a bias/LOD/gradient
611  * register, shoved into the `bias` field */
612 
613 typedef struct
614 __attribute__((__packed__))
615 {
616         /* 32-bit register, clear for half-register */
617         unsigned full : 1;
618 
619         /* Register select between r28/r29 */
620         unsigned select : 1;
621 
622         /* For a half-register, selects the upper half */
623         unsigned upper : 1;
624 
625         /* Indexes into the register */
626         unsigned component : 2;
627 
628         /* Padding to make this 8-bit */
629         unsigned zero : 3;
630 }
631 midgard_tex_register_select;
632 
633 /* Texture pipeline results are in r28-r29 */
634 #define REG_TEX_BASE 28
635 
636 /* Texture opcodes... maybe? */
637 #define TEXTURE_OP_NORMAL 0x11          /* texture */
638 #define TEXTURE_OP_LOD 0x12             /* textureLod */
639 #define TEXTURE_OP_TEXEL_FETCH 0x14     /* texelFetch */
640 
641 /* Implements barrier() */
642 #define TEXTURE_OP_BARRIER 0x0B
643 
644 /* Computes horizontal and vertical derivatives respectively. Use with a float
645  * sampler and a "2D" texture.  Leave texture/sampler IDs as zero; they ought
646  * to be ignored. Only works for fp32 on 64-bit at a time, so derivatives of a
647  * vec4 require 2 texture ops.  For some reason, the blob computes both X and Y
648  * derivatives at the same time and just throws out whichever is unused; it's
649  * not known if this is a quirk of the hardware or just of the blob. */
650 
651 #define TEXTURE_OP_DFDX 0x0D
652 #define TEXTURE_OP_DFDY 0x1D
653 
654 enum mali_sampler_type {
655         MALI_SAMPLER_UNK        = 0x0,
656         MALI_SAMPLER_FLOAT      = 0x1, /* sampler */
657         MALI_SAMPLER_UNSIGNED   = 0x2, /* usampler */
658         MALI_SAMPLER_SIGNED     = 0x3, /* isampler */
659 };
660 
661 #define MIDGARD_BARRIER_BUFFER (1 << 0)
662 #define MIDGARD_BARRIER_SHARED (1 << 1)
663 
664 typedef struct
665 __attribute__((__packed__))
666 {
667         unsigned type      : 4;
668         unsigned next_type : 4;
669 
670         unsigned op  : 6;
671         unsigned shadow    : 1;
672         unsigned is_gather  : 1;
673 
674         /* A little obscure, but last is set for the last texture operation in
675          * a shader. cont appears to just be last's opposite (?). Yeah, I know,
676          * kind of funky.. BiOpen thinks it could do with memory hinting, or
677          * tile locking? */
678 
679         unsigned cont  : 1;
680         unsigned last  : 1;
681 
682         enum mali_texture_type format : 2;
683 
684         /* Are sampler_handle/texture_handler respectively set by registers? If
685          * true, the lower 8-bits of the respective field is a register word.
686          * If false, they are an immediate */
687 
688         unsigned sampler_register : 1;
689         unsigned texture_register : 1;
690 
691         /* Is a register used to specify the
692          * LOD/bias/offset? If set, use the `bias` field as
693          * a register index. If clear, use the `bias` field
694          * as an immediate. */
695         unsigned lod_register : 1;
696 
697         /* Is a register used to specify an offset? If set, use the
698          * offset_reg_* fields to encode this, duplicated for each of the
699          * components. If clear, there is implcitly always an immediate offst
700          * specificed in offset_imm_* */
701         unsigned offset_register : 1;
702 
703         unsigned in_reg_full  : 1;
704         unsigned in_reg_select : 1;
705         unsigned in_reg_upper  : 1;
706         unsigned in_reg_swizzle : 8;
707 
708         unsigned unknown8  : 2;
709 
710         unsigned out_full  : 1;
711 
712         enum mali_sampler_type sampler_type : 2;
713 
714         unsigned out_reg_select : 1;
715         unsigned out_upper : 1;
716 
717         unsigned mask : 4;
718 
719         /* Intriguingly, textures can take an outmod just like alu ops. Int
720          * outmods are not supported as far as I can tell, so this is only
721          * meaningful for float samplers */
722         midgard_outmod_float outmod  : 2;
723 
724         unsigned swizzle  : 8;
725 
726         /* For barriers, control barriers are implied regardless, but these
727          * bits also enable memory barriers of various types. For regular
728          * textures, these indicate how many bundles after this texture op may
729          * be executed in parallel with this op. We may execute only ALU and
730          * ld/st in parallel (not other textures), and obviously there cannot
731          * be any dependency (the blob appears to forbid even accessing other
732          * channels of a given texture register). */
733 
734         unsigned out_of_order   : 2;
735         unsigned unknown4  : 10;
736 
737         /* In immediate mode, each offset field is an immediate range [0, 7].
738          *
739          * In register mode, offset_x becomes a register (full, select, upper)
740          * triplet followed by a vec3 swizzle is splattered across
741          * offset_y/offset_z in a genuinely bizarre way.
742          *
743          * For texel fetches in immediate mode, the range is the full [-8, 7],
744          * but for normal texturing the top bit must be zero and a register
745          * used instead. It's not clear where this limitation is from.
746          *
747          * union {
748          *      struct {
749          *              signed offset_x  : 4;
750          *              signed offset_y  : 4;
751          *              signed offset_z  : 4;
752          *      } immediate;
753          *      struct {
754          *              bool full        : 1;
755          *              bool select      : 1;
756          *              bool upper       : 1;
757          *              unsigned swizzle : 8;
758          *              unsigned zero    : 1;
759          *      } register;
760          * }
761          */
762 
763         unsigned offset : 12;
764 
765         /* In immediate bias mode, for a normal texture op, this is
766          * texture bias, computed as int(2^8 * frac(biasf)), with
767          * bias_int = floor(bias). For a textureLod, it's that, but
768          * s/bias/lod. For a texel fetch, this is the LOD as-is.
769          *
770          * In register mode, this is a midgard_tex_register_select
771          * structure and bias_int is zero */
772 
773         unsigned bias : 8;
774         signed bias_int  : 8;
775 
776         /* If sampler/texture_register is set, the bottom 8-bits are
777          * midgard_tex_register_select and the top 8-bits are zero. If they are
778          * clear, they are immediate texture indices */
779 
780         unsigned sampler_handle : 16;
781         unsigned texture_handle : 16;
782 }
783 midgard_texture_word;
784 
785 /* Technically barriers are texture instructions but it's less work to add them
786  * as an explicitly zeroed special case, since most fields are forced to go to
787  * zero */
788 
789 typedef struct
790 __attribute__((__packed__))
791 {
792         unsigned type      : 4;
793         unsigned next_type : 4;
794 
795         /* op = TEXTURE_OP_BARRIER */
796         unsigned op  : 6;
797         unsigned zero1    : 2;
798 
799         /* Since helper invocations don't make any sense, these are forced to one */
800         unsigned cont  : 1;
801         unsigned last  : 1;
802         unsigned zero2 : 14;
803 
804         unsigned zero3 : 24;
805         unsigned buffer : 1;
806         unsigned shared : 1;
807         unsigned stack  : 1;
808         unsigned zero4 : 5;
809 
810         uint64_t zero5;
811 } midgard_texture_barrier_word;
812 
813 typedef union midgard_constants {
814         double f64[2];
815         uint64_t u64[2];
816         int64_t i64[2];
817         float f32[4];
818         uint32_t u32[4];
819         int32_t i32[4];
820         uint16_t f16[8];
821         uint16_t u16[8];
822         int16_t i16[8];
823         uint8_t u8[16];
824         int8_t i8[16];
825 }
826 midgard_constants;
827 
828 enum midgard_roundmode {
829         MIDGARD_RTE = 0x0, /* round to even */
830         MIDGARD_RTZ = 0x1, /* round to zero */
831         MIDGARD_RTN = 0x2, /* round to negative */
832         MIDGARD_RTP = 0x3, /* round to positive */
833 };
834 
835 #endif
836