1 /*
2  * Copyright © 2021 Google, Inc.
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 FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  */
23 
24 #include <assert.h>
25 #include <ctype.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sys/mman.h>
31 #include <unistd.h>
32 
33 #include "util/u_math.h"
34 
35 #include "freedreno_pm4.h"
36 
37 #include "emu.h"
38 #include "util.h"
39 
40 #define rotl32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
41 #define rotl64(x,r) (((x) << (r)) | ((x) >> (64 - (r))))
42 
43 /**
44  * AFUC emulator.  Currently only supports a6xx
45  *
46  * TODO to add a5xx it might be easier to compile this multiple times
47  * with conditional compile to deal with differences between generations.
48  */
49 
50 static uint32_t
emu_alu(struct emu * emu,afuc_opc opc,uint32_t src1,uint32_t src2)51 emu_alu(struct emu *emu, afuc_opc opc, uint32_t src1, uint32_t src2)
52 {
53    uint64_t tmp;
54    switch (opc) {
55    case OPC_ADD:
56       tmp = (uint64_t)src1 + (uint64_t)src2;
57       emu->carry = tmp >> 32;
58       return (uint32_t)tmp;
59    case OPC_ADDHI:
60       return src1 + src2 + emu->carry;
61    case OPC_SUB:
62       tmp = (uint64_t)src1 - (uint64_t)src2;
63       emu->carry = tmp >> 32;
64       return (uint32_t)tmp;
65    case OPC_SUBHI:
66       return src1 - src2 + emu->carry;
67    case OPC_AND:
68       return src1 & src2;
69    case OPC_OR:
70       return src1 | src2;
71    case OPC_XOR:
72       return src1 ^ src2;
73    case OPC_NOT:
74       return ~src1;
75    case OPC_SHL:
76       return src1 << src2;
77    case OPC_USHR:
78       return src1 >> src2;
79    case OPC_ISHR:
80       return (int32_t)src1 >> src2;
81    case OPC_ROT:
82       if (src2 & 0x80000000)
83          return rotl64(src1, -*(int32_t *)&src2);
84       else
85          return rotl32(src1, src2);
86    case OPC_MUL8:
87       return (src1 & 0xff) * (src2 & 0xff);
88    case OPC_MIN:
89       return MIN2(src1, src2);
90    case OPC_MAX:
91       return MAX2(src1, src2);
92    case OPC_CMP:
93       if (src1 > src2)
94          return 0x00;
95       else if (src1 == src2)
96          return 0x2b;
97       return 0x1e;
98    case OPC_MSB:
99       if (!src2)
100          return 0;
101       return util_last_bit(src2) - 1;
102    default:
103       printf("unhandled alu opc: 0x%02x\n", opc);
104       exit(1);
105    }
106 }
107 
108 /**
109  * Helper to calculate load/store address based on LOAD_STORE_HI
110  */
111 static uintptr_t
load_store_addr(struct emu * emu,unsigned gpr)112 load_store_addr(struct emu *emu, unsigned gpr)
113 {
114    EMU_CONTROL_REG(LOAD_STORE_HI);
115 
116    uintptr_t addr = emu_get_reg32(emu, &LOAD_STORE_HI);
117    addr <<= 32;
118 
119    return addr + emu_get_gpr_reg(emu, gpr);
120 }
121 
122 static void
emu_instr(struct emu * emu,afuc_instr * instr)123 emu_instr(struct emu *emu, afuc_instr *instr)
124 {
125    uint32_t rem = emu_get_gpr_reg(emu, REG_REM);
126    afuc_opc opc;
127    bool rep;
128 
129    afuc_get_opc(instr, &opc, &rep);
130 
131    switch (opc) {
132    case OPC_NOP:
133       break;
134    case OPC_ADD ... OPC_CMP: {
135       uint32_t val = emu_alu(emu, opc,
136                              emu_get_gpr_reg(emu, instr->alui.src),
137                              instr->alui.uimm);
138       emu_set_gpr_reg(emu, instr->alui.dst, val);
139       break;
140    }
141    case OPC_MOVI: {
142       uint32_t val = instr->movi.uimm << instr->movi.shift;
143       emu_set_gpr_reg(emu, instr->movi.dst, val);
144       break;
145    }
146    case OPC_ALU: {
147       uint32_t val = emu_alu(emu, instr->alu.alu,
148                              emu_get_gpr_reg(emu, instr->alu.src1),
149                              emu_get_gpr_reg(emu, instr->alu.src2));
150       emu_set_gpr_reg(emu, instr->alu.dst, val);
151 
152       if (instr->alu.xmov) {
153          unsigned m = MIN2(instr->alu.xmov, rem);
154 
155          assert(m <= 3);
156 
157          if (m == 1) {
158             emu_set_gpr_reg(emu, REG_REM, --rem);
159             emu_dump_state_change(emu);
160             emu_set_gpr_reg(emu, REG_DATA,
161                             emu_get_gpr_reg(emu, instr->alu.src2));
162          } else if (m == 2) {
163             emu_set_gpr_reg(emu, REG_REM, --rem);
164             emu_dump_state_change(emu);
165             emu_set_gpr_reg(emu, REG_DATA,
166                             emu_get_gpr_reg(emu, instr->alu.src2));
167             emu_set_gpr_reg(emu, REG_REM, --rem);
168             emu_dump_state_change(emu);
169             emu_set_gpr_reg(emu, REG_DATA,
170                             emu_get_gpr_reg(emu, instr->alu.src2));
171          } else if (m == 3) {
172             emu_set_gpr_reg(emu, REG_REM, --rem);
173             emu_dump_state_change(emu);
174             emu_set_gpr_reg(emu, REG_DATA,
175                             emu_get_gpr_reg(emu, instr->alu.src2));
176             emu_set_gpr_reg(emu, REG_REM, --rem);
177             emu_dump_state_change(emu);
178             emu_set_gpr_reg(emu, instr->alu.dst,
179                             emu_get_gpr_reg(emu, instr->alu.src2));
180             emu_set_gpr_reg(emu, REG_REM, --rem);
181             emu_dump_state_change(emu);
182             emu_set_gpr_reg(emu, REG_DATA,
183                             emu_get_gpr_reg(emu, instr->alu.src2));
184          }
185       }
186       break;
187    }
188    case OPC_CWRITE6: {
189       uint32_t src1 = emu_get_gpr_reg(emu, instr->control.src1);
190       uint32_t src2 = emu_get_gpr_reg(emu, instr->control.src2);
191 
192       if (instr->control.flags == 0x4) {
193          emu_set_gpr_reg(emu, instr->control.src2, src2 + instr->control.uimm);
194       } else if (instr->control.flags && !emu->quiet) {
195          printf("unhandled flags: %x\n", instr->control.flags);
196       }
197 
198       emu_set_control_reg(emu, src2 + instr->control.uimm, src1);
199       break;
200    }
201    case OPC_CREAD6: {
202       uint32_t src2 = emu_get_gpr_reg(emu, instr->control.src2);
203 
204       if (instr->control.flags == 0x4) {
205          emu_set_gpr_reg(emu, instr->control.src2, src2 + instr->control.uimm);
206       } else if (instr->control.flags && !emu->quiet) {
207          printf("unhandled flags: %x\n", instr->control.flags);
208       }
209 
210       emu_set_gpr_reg(emu, instr->control.src1,
211                       emu_get_control_reg(emu, src2 + instr->control.uimm));
212       break;
213    }
214    case OPC_LOAD6: {
215       uintptr_t addr = load_store_addr(emu, instr->control.src2) +
216             instr->control.uimm;
217 
218       if (instr->control.flags == 0x4) {
219          uint32_t src2 = emu_get_gpr_reg(emu, instr->control.src2);
220          emu_set_gpr_reg(emu, instr->control.src2, src2 + instr->control.uimm);
221       } else if (instr->control.flags && !emu->quiet) {
222          printf("unhandled flags: %x\n", instr->control.flags);
223       }
224 
225       uint32_t val = emu_mem_read_dword(emu, addr);
226 
227       emu_set_gpr_reg(emu, instr->control.src1, val);
228 
229       break;
230    }
231    case OPC_STORE6: {
232       uintptr_t addr = load_store_addr(emu, instr->control.src2) +
233             instr->control.uimm;
234 
235       if (instr->control.flags == 0x4) {
236          uint32_t src2 = emu_get_gpr_reg(emu, instr->control.src2);
237          emu_set_gpr_reg(emu, instr->control.src2, src2 + instr->control.uimm);
238       } else if (instr->control.flags && !emu->quiet) {
239          printf("unhandled flags: %x\n", instr->control.flags);
240       }
241 
242       uint32_t val = emu_get_gpr_reg(emu, instr->control.src1);
243 
244       emu_mem_write_dword(emu, addr, val);
245 
246       break;
247    }
248    case OPC_BRNEI ... OPC_BREQB: {
249       uint32_t off = emu->gpr_regs.pc + instr->br.ioff;
250       uint32_t src = emu_get_gpr_reg(emu, instr->br.src);
251 
252       if (opc == OPC_BRNEI) {
253          if (src != instr->br.bit_or_imm)
254             emu->branch_target = off;
255       } else if (opc == OPC_BREQI) {
256          if (src == instr->br.bit_or_imm)
257             emu->branch_target = off;
258       } else if (opc == OPC_BRNEB) {
259          if (!(src & (1 << instr->br.bit_or_imm)))
260             emu->branch_target = off;
261       } else if (opc == OPC_BREQB) {
262          if (src & (1 << instr->br.bit_or_imm))
263             emu->branch_target = off;
264       } else {
265          assert(0);
266       }
267       break;
268    }
269    case OPC_RET: {
270       assert(emu->call_stack_idx > 0);
271 
272       /* counter-part to 'call' instruction, also has a delay slot: */
273       emu->branch_target = emu->call_stack[--emu->call_stack_idx];
274 
275       break;
276    }
277    case OPC_CALL: {
278       assert(emu->call_stack_idx < ARRAY_SIZE(emu->call_stack));
279 
280       /* call looks to have same delay-slot behavior as branch/etc, so
281        * presumably the return PC is two instructions later:
282        */
283       emu->call_stack[emu->call_stack_idx++] = emu->gpr_regs.pc + 2;
284       emu->branch_target = instr->call.uoff;
285 
286       break;
287    }
288    case OPC_WIN: {
289       assert(!emu->branch_target);
290       emu->run_mode = false;
291       emu->waitin = true;
292       break;
293    }
294    /* OPC_PREEMPTLEAVE6 */
295    case OPC_SETSECURE: {
296       // TODO this acts like a conditional branch, but in which case
297       // does it branch?
298       break;
299    }
300    default:
301       printf("unhandled opc: 0x%02x\n", opc);
302       exit(1);
303    }
304 
305    if (rep) {
306       assert(rem > 0);
307       emu_set_gpr_reg(emu, REG_REM, --rem);
308    }
309 }
310 
311 void
emu_step(struct emu * emu)312 emu_step(struct emu *emu)
313 {
314    afuc_instr *instr = (void *)&emu->instrs[emu->gpr_regs.pc];
315    afuc_opc opc;
316    bool rep;
317 
318    emu_main_prompt(emu);
319 
320    uint32_t branch_target = emu->branch_target;
321    emu->branch_target = 0;
322 
323    bool waitin = emu->waitin;
324    emu->waitin = false;
325 
326    afuc_get_opc(instr, &opc, &rep);
327 
328    if (rep) {
329       do {
330          if (!emu_get_gpr_reg(emu, REG_REM))
331             break;
332 
333          emu_clear_state_change(emu);
334          emu_instr(emu, instr);
335 
336          /* defer last state-change dump until after any
337           * post-delay-slot handling below:
338           */
339          if (emu_get_gpr_reg(emu, REG_REM))
340             emu_dump_state_change(emu);
341       } while (true);
342    } else {
343       emu_clear_state_change(emu);
344       emu_instr(emu, instr);
345    }
346 
347    emu->gpr_regs.pc++;
348 
349    if (branch_target) {
350       emu->gpr_regs.pc = branch_target;
351    }
352 
353    if (waitin) {
354       uint32_t hdr = emu_get_gpr_reg(emu, 1);
355       uint32_t id, count;
356 
357       if (pkt_is_type4(hdr)) {
358          id = afuc_pm4_id("PKT4");
359          count = type4_pkt_size(hdr);
360 
361          /* Possibly a hack, not sure what the hw actually
362           * does here, but we want to mask out the pkt
363           * type field from the hdr, so that PKT4 handler
364           * doesn't see it and interpret it as part as the
365           * register offset:
366           */
367          emu->gpr_regs.val[1] &= 0x0fffffff;
368       } else if (pkt_is_type7(hdr)) {
369          id = cp_type7_opcode(hdr);
370          count = type7_pkt_size(hdr);
371       } else {
372          printf("Invalid opcode: 0x%08x\n", hdr);
373          exit(1);  /* GPU goes *boom* */
374       }
375 
376       assert(id < ARRAY_SIZE(emu->jmptbl));
377 
378       emu_set_gpr_reg(emu, REG_REM, count);
379       emu->gpr_regs.pc = emu->jmptbl[id];
380    }
381 
382    emu_dump_state_change(emu);
383 }
384 
385 void
emu_run_bootstrap(struct emu * emu)386 emu_run_bootstrap(struct emu *emu)
387 {
388    EMU_CONTROL_REG(PACKET_TABLE_WRITE_ADDR);
389 
390    emu->quiet = true;
391    emu->run_mode = true;
392 
393    while (emu_get_reg32(emu, &PACKET_TABLE_WRITE_ADDR) < 0x80) {
394       emu_step(emu);
395    }
396 }
397 
398 
399 static void
check_access(struct emu * emu,uintptr_t gpuaddr,unsigned sz)400 check_access(struct emu *emu, uintptr_t gpuaddr, unsigned sz)
401 {
402    if ((gpuaddr % sz) != 0) {
403       printf("unaligned access fault: %p\n", (void *)gpuaddr);
404       exit(1);
405    }
406 
407    if ((gpuaddr + sz) >= EMU_MEMORY_SIZE) {
408       printf("iova fault: %p\n", (void *)gpuaddr);
409       exit(1);
410    }
411 }
412 
413 uint32_t
emu_mem_read_dword(struct emu * emu,uintptr_t gpuaddr)414 emu_mem_read_dword(struct emu *emu, uintptr_t gpuaddr)
415 {
416    check_access(emu, gpuaddr, 4);
417    return *(uint32_t *)(emu->gpumem + gpuaddr);
418 }
419 
420 static void
mem_write_dword(struct emu * emu,uintptr_t gpuaddr,uint32_t val)421 mem_write_dword(struct emu *emu, uintptr_t gpuaddr, uint32_t val)
422 {
423    check_access(emu, gpuaddr, 4);
424    *(uint32_t *)(emu->gpumem + gpuaddr) = val;
425 }
426 
427 void
emu_mem_write_dword(struct emu * emu,uintptr_t gpuaddr,uint32_t val)428 emu_mem_write_dword(struct emu *emu, uintptr_t gpuaddr, uint32_t val)
429 {
430    mem_write_dword(emu, gpuaddr, val);
431    assert(emu->gpumem_written == ~0);
432    emu->gpumem_written = gpuaddr;
433 }
434 
435 void
emu_init(struct emu * emu)436 emu_init(struct emu *emu)
437 {
438    emu->gpumem = mmap(NULL, EMU_MEMORY_SIZE,
439                       PROT_READ | PROT_WRITE,
440                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
441                       0, 0);
442    if (emu->gpumem == MAP_FAILED) {
443       printf("Could not allocate GPU memory: %s\n", strerror(errno));
444       exit(1);
445    }
446 
447    /* Copy the instructions into GPU memory: */
448    for (unsigned i = 0; i < emu->sizedwords; i++) {
449       mem_write_dword(emu, EMU_INSTR_BASE + (4 * i), emu->instrs[i]);
450    }
451 
452    EMU_GPU_REG(CP_SQE_INSTR_BASE);
453    EMU_GPU_REG(CP_LPAC_SQE_INSTR_BASE);
454 
455    /* Setup the address of the SQE fw, just use the normal CPU ptr address: */
456    if (emu->lpac) {
457       emu_set_reg64(emu, &CP_LPAC_SQE_INSTR_BASE, EMU_INSTR_BASE);
458    } else {
459       emu_set_reg64(emu, &CP_SQE_INSTR_BASE, EMU_INSTR_BASE);
460    }
461 
462    if (emu->gpu_id == 660) {
463       emu_set_control_reg(emu, 0, 3 << 28);
464    } else if (emu->gpu_id == 650) {
465       emu_set_control_reg(emu, 0, 1 << 28);
466    }
467 }
468 
469 void
emu_fini(struct emu * emu)470 emu_fini(struct emu *emu)
471 {
472    uint32_t *instrs = emu->instrs;
473    unsigned sizedwords = emu->sizedwords;
474    unsigned gpu_id = emu->gpu_id;
475 
476    munmap(emu->gpumem, EMU_MEMORY_SIZE);
477    memset(emu, 0, sizeof(*emu));
478 
479    emu->instrs = instrs;
480    emu->sizedwords = sizedwords;
481    emu->gpu_id = gpu_id;
482 }
483