2 * Copyright © 2014 Broadcom
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:
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
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
25 * DOC: Shader validator for VC4.
27 * The VC4 has no IOMMU between it and system memory, so a user with
28 * access to execute shaders could escalate privilege by overwriting
29 * system memory (using the VPM write address register in the
30 * general-purpose DMA mode) or reading system memory it shouldn't
31 * (reading it as a texture, or uniform data, or vertex data).
33 * This walks over a shader BO, ensuring that its accesses are
34 * appropriately bounded, and recording how many texture accesses are
35 * made and where so that we can do relocations for them in the
40 #include "vc4_qpu_defines.h"
42 #define LIVE_REG_COUNT (32 + 32 + 4)
44 struct vc4_shader_validation_state
{
45 /* Current IP being validated. */
48 /* IP at the end of the BO, do not read shader[max_ip] */
53 struct vc4_texture_sample_info tmu_setup
[2];
54 int tmu_write_count
[2];
56 /* For registers that were last written to by a MIN instruction with
57 * one argument being a uniform, the address of the uniform.
60 * This is used for the validation of direct address memory reads.
62 uint32_t live_min_clamp_offsets
[LIVE_REG_COUNT
];
63 bool live_max_clamp_regs
[LIVE_REG_COUNT
];
64 uint32_t live_immediates
[LIVE_REG_COUNT
];
66 /* Bitfield of which IPs are used as branch targets.
68 * Used for validation that the uniform stream is updated at the right
69 * points and clearing the texturing/clamping state.
71 unsigned long *branch_targets
;
73 /* Set when entering a basic block, and cleared when the uniform
74 * address update is found. This is used to make sure that we don't
75 * read uniforms when the address is undefined.
77 bool needs_uniform_address_update
;
79 /* Set when we find a backwards branch. If the branch is backwards,
80 * the taraget is probably doing an address reset to read uniforms,
81 * and so we need to be sure that a uniforms address is present in the
82 * stream, even if the shader didn't need to read uniforms in later
85 bool needs_uniform_address_for_loop
;
89 waddr_to_live_reg_index(uint32_t waddr
, bool is_b
)
96 } else if (waddr
<= QPU_W_ACC3
) {
97 return 64 + waddr
- QPU_W_ACC0
;
104 raddr_add_a_to_live_reg_index(uint64_t inst
)
106 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
107 uint32_t add_a
= QPU_GET_FIELD(inst
, QPU_ADD_A
);
108 uint32_t raddr_a
= QPU_GET_FIELD(inst
, QPU_RADDR_A
);
109 uint32_t raddr_b
= QPU_GET_FIELD(inst
, QPU_RADDR_B
);
111 if (add_a
== QPU_MUX_A
)
113 else if (add_a
== QPU_MUX_B
&& sig
!= QPU_SIG_SMALL_IMM
)
115 else if (add_a
<= QPU_MUX_R3
)
122 is_tmu_submit(uint32_t waddr
)
124 return (waddr
== QPU_W_TMU0_S
||
125 waddr
== QPU_W_TMU1_S
);
129 is_tmu_write(uint32_t waddr
)
131 return (waddr
>= QPU_W_TMU0_S
&&
132 waddr
<= QPU_W_TMU1_B
);
136 record_texture_sample(struct vc4_validated_shader_info
*validated_shader
,
137 struct vc4_shader_validation_state
*validation_state
,
140 uint32_t s
= validated_shader
->num_texture_samples
;
142 struct vc4_texture_sample_info
*temp_samples
;
144 temp_samples
= krealloc(validated_shader
->texture_samples
,
145 (s
+ 1) * sizeof(*temp_samples
),
150 memcpy(&temp_samples
[s
],
151 &validation_state
->tmu_setup
[tmu
],
152 sizeof(*temp_samples
));
154 validated_shader
->num_texture_samples
= s
+ 1;
155 validated_shader
->texture_samples
= temp_samples
;
157 for (i
= 0; i
< 4; i
++)
158 validation_state
->tmu_setup
[tmu
].p_offset
[i
] = ~0;
164 check_tmu_write(struct vc4_validated_shader_info
*validated_shader
,
165 struct vc4_shader_validation_state
*validation_state
,
168 uint64_t inst
= validation_state
->shader
[validation_state
->ip
];
169 uint32_t waddr
= (is_mul
?
170 QPU_GET_FIELD(inst
, QPU_WADDR_MUL
) :
171 QPU_GET_FIELD(inst
, QPU_WADDR_ADD
));
172 uint32_t raddr_a
= QPU_GET_FIELD(inst
, QPU_RADDR_A
);
173 uint32_t raddr_b
= QPU_GET_FIELD(inst
, QPU_RADDR_B
);
174 int tmu
= waddr
> QPU_W_TMU0_B
;
175 bool submit
= is_tmu_submit(waddr
);
176 bool is_direct
= submit
&& validation_state
->tmu_write_count
[tmu
] == 0;
177 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
180 uint32_t add_b
= QPU_GET_FIELD(inst
, QPU_ADD_B
);
181 uint32_t clamp_reg
, clamp_offset
;
183 if (sig
== QPU_SIG_SMALL_IMM
) {
184 DRM_ERROR("direct TMU read used small immediate\n");
188 /* Make sure that this texture load is an add of the base
189 * address of the UBO to a clamped offset within the UBO.
192 QPU_GET_FIELD(inst
, QPU_OP_ADD
) != QPU_A_ADD
) {
193 DRM_ERROR("direct TMU load wasn't an add\n");
197 /* We assert that the clamped address is the first
198 * argument, and the UBO base address is the second argument.
199 * This is arbitrary, but simpler than supporting flipping the
202 clamp_reg
= raddr_add_a_to_live_reg_index(inst
);
203 if (clamp_reg
== ~0) {
204 DRM_ERROR("direct TMU load wasn't clamped\n");
208 clamp_offset
= validation_state
->live_min_clamp_offsets
[clamp_reg
];
209 if (clamp_offset
== ~0) {
210 DRM_ERROR("direct TMU load wasn't clamped\n");
214 /* Store the clamp value's offset in p1 (see reloc_tex() in
217 validation_state
->tmu_setup
[tmu
].p_offset
[1] =
220 if (!(add_b
== QPU_MUX_A
&& raddr_a
== QPU_R_UNIF
) &&
221 !(add_b
== QPU_MUX_B
&& raddr_b
== QPU_R_UNIF
)) {
222 DRM_ERROR("direct TMU load didn't add to a uniform\n");
226 validation_state
->tmu_setup
[tmu
].is_direct
= true;
228 if (raddr_a
== QPU_R_UNIF
|| (sig
!= QPU_SIG_SMALL_IMM
&&
229 raddr_b
== QPU_R_UNIF
)) {
230 DRM_ERROR("uniform read in the same instruction as "
236 if (validation_state
->tmu_write_count
[tmu
] >= 4) {
237 DRM_ERROR("TMU%d got too many parameters before dispatch\n",
241 validation_state
->tmu_setup
[tmu
].p_offset
[validation_state
->tmu_write_count
[tmu
]] =
242 validated_shader
->uniforms_size
;
243 validation_state
->tmu_write_count
[tmu
]++;
244 /* Since direct uses a RADDR uniform reference, it will get counted in
245 * check_instruction_reads()
248 if (validation_state
->needs_uniform_address_update
) {
249 DRM_ERROR("Texturing with undefined uniform address\n");
253 validated_shader
->uniforms_size
+= 4;
257 if (!record_texture_sample(validated_shader
,
258 validation_state
, tmu
)) {
262 validation_state
->tmu_write_count
[tmu
] = 0;
268 static bool require_uniform_address_uniform(struct vc4_validated_shader_info
*validated_shader
)
270 uint32_t o
= validated_shader
->num_uniform_addr_offsets
;
271 uint32_t num_uniforms
= validated_shader
->uniforms_size
/ 4;
273 validated_shader
->uniform_addr_offsets
=
274 krealloc(validated_shader
->uniform_addr_offsets
,
276 sizeof(*validated_shader
->uniform_addr_offsets
),
278 if (!validated_shader
->uniform_addr_offsets
)
281 validated_shader
->uniform_addr_offsets
[o
] = num_uniforms
;
282 validated_shader
->num_uniform_addr_offsets
++;
288 validate_uniform_address_write(struct vc4_validated_shader_info
*validated_shader
,
289 struct vc4_shader_validation_state
*validation_state
,
292 uint64_t inst
= validation_state
->shader
[validation_state
->ip
];
293 u32 add_b
= QPU_GET_FIELD(inst
, QPU_ADD_B
);
294 u32 raddr_a
= QPU_GET_FIELD(inst
, QPU_RADDR_A
);
295 u32 raddr_b
= QPU_GET_FIELD(inst
, QPU_RADDR_B
);
296 u32 add_lri
= raddr_add_a_to_live_reg_index(inst
);
297 /* We want our reset to be pointing at whatever uniform follows the
298 * uniforms base address.
300 u32 expected_offset
= validated_shader
->uniforms_size
+ 4;
302 /* We only support absolute uniform address changes, and we
303 * require that they be in the current basic block before any
304 * of its uniform reads.
306 * One could potentially emit more efficient QPU code, by
307 * noticing that (say) an if statement does uniform control
308 * flow for all threads and that the if reads the same number
309 * of uniforms on each side. However, this scheme is easy to
310 * validate so it's all we allow for now.
312 switch (QPU_GET_FIELD(inst
, QPU_SIG
)) {
314 case QPU_SIG_SCOREBOARD_UNLOCK
:
315 case QPU_SIG_COLOR_LOAD
:
316 case QPU_SIG_LOAD_TMU0
:
317 case QPU_SIG_LOAD_TMU1
:
320 DRM_ERROR("uniforms address change must be "
325 if (is_mul
|| QPU_GET_FIELD(inst
, QPU_OP_ADD
) != QPU_A_ADD
) {
326 DRM_ERROR("Uniform address reset must be an ADD.\n");
330 if (QPU_GET_FIELD(inst
, QPU_COND_ADD
) != QPU_COND_ALWAYS
) {
331 DRM_ERROR("Uniform address reset must be unconditional.\n");
335 if (QPU_GET_FIELD(inst
, QPU_PACK
) != QPU_PACK_A_NOP
&&
337 DRM_ERROR("No packing allowed on uniforms reset\n");
342 DRM_ERROR("First argument of uniform address write must be "
343 "an immediate value.\n");
347 if (validation_state
->live_immediates
[add_lri
] != expected_offset
) {
348 DRM_ERROR("Resetting uniforms with offset %db instead of %db\n",
349 validation_state
->live_immediates
[add_lri
],
354 if (!(add_b
== QPU_MUX_A
&& raddr_a
== QPU_R_UNIF
) &&
355 !(add_b
== QPU_MUX_B
&& raddr_b
== QPU_R_UNIF
)) {
356 DRM_ERROR("Second argument of uniform address write must be "
361 validation_state
->needs_uniform_address_update
= false;
362 validation_state
->needs_uniform_address_for_loop
= false;
363 return require_uniform_address_uniform(validated_shader
);
367 check_reg_write(struct vc4_validated_shader_info
*validated_shader
,
368 struct vc4_shader_validation_state
*validation_state
,
371 uint64_t inst
= validation_state
->shader
[validation_state
->ip
];
372 uint32_t waddr
= (is_mul
?
373 QPU_GET_FIELD(inst
, QPU_WADDR_MUL
) :
374 QPU_GET_FIELD(inst
, QPU_WADDR_ADD
));
375 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
376 bool ws
= inst
& QPU_WS
;
377 bool is_b
= is_mul
^ ws
;
378 u32 lri
= waddr_to_live_reg_index(waddr
, is_b
);
381 uint32_t cond_add
= QPU_GET_FIELD(inst
, QPU_COND_ADD
);
382 uint32_t cond_mul
= QPU_GET_FIELD(inst
, QPU_COND_MUL
);
384 if (sig
== QPU_SIG_LOAD_IMM
&&
385 QPU_GET_FIELD(inst
, QPU_PACK
) == QPU_PACK_A_NOP
&&
386 ((is_mul
&& cond_mul
== QPU_COND_ALWAYS
) ||
387 (!is_mul
&& cond_add
== QPU_COND_ALWAYS
))) {
388 validation_state
->live_immediates
[lri
] =
389 QPU_GET_FIELD(inst
, QPU_LOAD_IMM
);
391 validation_state
->live_immediates
[lri
] = ~0;
396 case QPU_W_UNIFORMS_ADDRESS
:
398 DRM_ERROR("relative uniforms address change "
403 return validate_uniform_address_write(validated_shader
,
407 case QPU_W_TLB_COLOR_MS
:
408 case QPU_W_TLB_COLOR_ALL
:
410 /* These only interact with the tile buffer, not main memory,
423 return check_tmu_write(validated_shader
, validation_state
,
427 case QPU_W_TMU_NOSWAP
:
428 case QPU_W_TLB_ALPHA_MASK
:
429 case QPU_W_MUTEX_RELEASE
:
430 /* XXX: I haven't thought about these, so don't support them
433 DRM_ERROR("Unsupported waddr %d\n", waddr
);
437 DRM_ERROR("General VPM DMA unsupported\n");
441 case QPU_W_VPMVCD_SETUP
:
442 /* We allow VPM setup in general, even including VPM DMA
443 * configuration setup, because the (unsafe) DMA can only be
444 * triggered by QPU_W_VPM_ADDR writes.
448 case QPU_W_TLB_STENCIL_SETUP
:
456 track_live_clamps(struct vc4_validated_shader_info
*validated_shader
,
457 struct vc4_shader_validation_state
*validation_state
)
459 uint64_t inst
= validation_state
->shader
[validation_state
->ip
];
460 uint32_t op_add
= QPU_GET_FIELD(inst
, QPU_OP_ADD
);
461 uint32_t waddr_add
= QPU_GET_FIELD(inst
, QPU_WADDR_ADD
);
462 uint32_t waddr_mul
= QPU_GET_FIELD(inst
, QPU_WADDR_MUL
);
463 uint32_t cond_add
= QPU_GET_FIELD(inst
, QPU_COND_ADD
);
464 uint32_t add_a
= QPU_GET_FIELD(inst
, QPU_ADD_A
);
465 uint32_t add_b
= QPU_GET_FIELD(inst
, QPU_ADD_B
);
466 uint32_t raddr_a
= QPU_GET_FIELD(inst
, QPU_RADDR_A
);
467 uint32_t raddr_b
= QPU_GET_FIELD(inst
, QPU_RADDR_B
);
468 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
469 bool ws
= inst
& QPU_WS
;
470 uint32_t lri_add_a
, lri_add
, lri_mul
;
473 /* Check whether OP_ADD's A argumennt comes from a live MAX(x, 0),
474 * before we clear previous live state.
476 lri_add_a
= raddr_add_a_to_live_reg_index(inst
);
477 add_a_is_min_0
= (lri_add_a
!= ~0 &&
478 validation_state
->live_max_clamp_regs
[lri_add_a
]);
480 /* Clear live state for registers written by our instruction. */
481 lri_add
= waddr_to_live_reg_index(waddr_add
, ws
);
482 lri_mul
= waddr_to_live_reg_index(waddr_mul
, !ws
);
484 validation_state
->live_max_clamp_regs
[lri_mul
] = false;
485 validation_state
->live_min_clamp_offsets
[lri_mul
] = ~0;
488 validation_state
->live_max_clamp_regs
[lri_add
] = false;
489 validation_state
->live_min_clamp_offsets
[lri_add
] = ~0;
491 /* Nothing further to do for live tracking, since only ADDs
492 * generate new live clamp registers.
497 /* Now, handle remaining live clamp tracking for the ADD operation. */
499 if (cond_add
!= QPU_COND_ALWAYS
)
502 if (op_add
== QPU_A_MAX
) {
503 /* Track live clamps of a value to a minimum of 0 (in either
506 if (sig
!= QPU_SIG_SMALL_IMM
|| raddr_b
!= 0 ||
507 (add_a
!= QPU_MUX_B
&& add_b
!= QPU_MUX_B
)) {
511 validation_state
->live_max_clamp_regs
[lri_add
] = true;
512 } else if (op_add
== QPU_A_MIN
) {
513 /* Track live clamps of a value clamped to a minimum of 0 and
514 * a maximum of some uniform's offset.
519 if (!(add_b
== QPU_MUX_A
&& raddr_a
== QPU_R_UNIF
) &&
520 !(add_b
== QPU_MUX_B
&& raddr_b
== QPU_R_UNIF
&&
521 sig
!= QPU_SIG_SMALL_IMM
)) {
525 validation_state
->live_min_clamp_offsets
[lri_add
] =
526 validated_shader
->uniforms_size
;
531 check_instruction_writes(struct vc4_validated_shader_info
*validated_shader
,
532 struct vc4_shader_validation_state
*validation_state
)
534 uint64_t inst
= validation_state
->shader
[validation_state
->ip
];
535 uint32_t waddr_add
= QPU_GET_FIELD(inst
, QPU_WADDR_ADD
);
536 uint32_t waddr_mul
= QPU_GET_FIELD(inst
, QPU_WADDR_MUL
);
539 if (is_tmu_write(waddr_add
) && is_tmu_write(waddr_mul
)) {
540 DRM_ERROR("ADD and MUL both set up textures\n");
544 ok
= (check_reg_write(validated_shader
, validation_state
, false) &&
545 check_reg_write(validated_shader
, validation_state
, true));
547 track_live_clamps(validated_shader
, validation_state
);
553 check_branch(uint64_t inst
,
554 struct vc4_validated_shader_info
*validated_shader
,
555 struct vc4_shader_validation_state
*validation_state
,
558 int32_t branch_imm
= QPU_GET_FIELD(inst
, QPU_BRANCH_TARGET
);
559 uint32_t waddr_add
= QPU_GET_FIELD(inst
, QPU_WADDR_ADD
);
560 uint32_t waddr_mul
= QPU_GET_FIELD(inst
, QPU_WADDR_MUL
);
562 if ((int)branch_imm
< 0)
563 validation_state
->needs_uniform_address_for_loop
= true;
565 /* We don't want to have to worry about validation of this, and
566 * there's no need for it.
568 if (waddr_add
!= QPU_W_NOP
|| waddr_mul
!= QPU_W_NOP
) {
569 DRM_ERROR("branch instruction at %d wrote a register.\n",
570 validation_state
->ip
);
578 check_instruction_reads(struct vc4_validated_shader_info
*validated_shader
,
579 struct vc4_shader_validation_state
*validation_state
)
581 uint64_t inst
= validation_state
->shader
[validation_state
->ip
];
582 uint32_t raddr_a
= QPU_GET_FIELD(inst
, QPU_RADDR_A
);
583 uint32_t raddr_b
= QPU_GET_FIELD(inst
, QPU_RADDR_B
);
584 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
586 if (raddr_a
== QPU_R_UNIF
||
587 (raddr_b
== QPU_R_UNIF
&& sig
!= QPU_SIG_SMALL_IMM
)) {
588 /* This can't overflow the uint32_t, because we're reading 8
589 * bytes of instruction to increment by 4 here, so we'd
592 validated_shader
->uniforms_size
+= 4;
594 if (validation_state
->needs_uniform_address_update
) {
595 DRM_ERROR("Uniform read with undefined uniform "
604 /* Make sure that all branches are absolute and point within the shader, and
605 * note their targets for later.
608 vc4_validate_branches(struct vc4_shader_validation_state
*validation_state
)
610 uint32_t max_branch_target
= 0;
611 bool found_shader_end
= false;
613 int shader_end_ip
= 0;
614 int last_branch
= -2;
616 for (ip
= 0; ip
< validation_state
->max_ip
; ip
++) {
617 uint64_t inst
= validation_state
->shader
[ip
];
618 int32_t branch_imm
= QPU_GET_FIELD(inst
, QPU_BRANCH_TARGET
);
619 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
620 uint32_t after_delay_ip
= ip
+ 4;
621 uint32_t branch_target_ip
;
623 if (sig
== QPU_SIG_PROG_END
) {
625 found_shader_end
= true;
629 if (sig
!= QPU_SIG_BRANCH
)
632 if (ip
- last_branch
< 4) {
633 DRM_ERROR("Branch at %d during delay slots\n", ip
);
638 if (inst
& QPU_BRANCH_REG
) {
639 DRM_ERROR("branching from register relative "
644 if (!(inst
& QPU_BRANCH_REL
)) {
645 DRM_ERROR("relative branching required\n");
649 /* The actual branch target is the instruction after the delay
650 * slots, plus whatever byte offset is in the low 32 bits of
651 * the instruction. Make sure we're not branching beyond the
652 * end of the shader object.
654 if (branch_imm
% sizeof(inst
) != 0) {
655 DRM_ERROR("branch target not aligned\n");
659 branch_target_ip
= after_delay_ip
+ (branch_imm
>> 3);
660 if (branch_target_ip
>= validation_state
->max_ip
) {
661 DRM_ERROR("Branch at %d outside of shader (ip %d/%d)\n",
662 ip
, branch_target_ip
,
663 validation_state
->max_ip
);
666 set_bit(branch_target_ip
, validation_state
->branch_targets
);
668 /* Make sure that the non-branching path is also not outside
671 if (after_delay_ip
>= validation_state
->max_ip
) {
672 DRM_ERROR("Branch at %d continues past shader end "
674 ip
, after_delay_ip
, validation_state
->max_ip
);
677 set_bit(after_delay_ip
, validation_state
->branch_targets
);
678 max_branch_target
= max(max_branch_target
, after_delay_ip
);
680 /* There are two delay slots after program end is signaled
681 * that are still executed, then we're finished.
683 if (found_shader_end
&& ip
== shader_end_ip
+ 2)
687 if (max_branch_target
> shader_end_ip
) {
688 DRM_ERROR("Branch landed after QPU_SIG_PROG_END");
695 /* Resets any known state for the shader, used when we may be branched to from
696 * multiple locations in the program (or at shader start).
699 reset_validation_state(struct vc4_shader_validation_state
*validation_state
)
703 for (i
= 0; i
< 8; i
++)
704 validation_state
->tmu_setup
[i
/ 4].p_offset
[i
% 4] = ~0;
706 for (i
= 0; i
< LIVE_REG_COUNT
; i
++) {
707 validation_state
->live_min_clamp_offsets
[i
] = ~0;
708 validation_state
->live_max_clamp_regs
[i
] = false;
709 validation_state
->live_immediates
[i
] = ~0;
714 texturing_in_progress(struct vc4_shader_validation_state
*validation_state
)
716 return (validation_state
->tmu_write_count
[0] != 0 ||
717 validation_state
->tmu_write_count
[1] != 0);
721 vc4_handle_branch_target(struct vc4_shader_validation_state
*validation_state
)
723 uint32_t ip
= validation_state
->ip
;
725 if (!test_bit(ip
, validation_state
->branch_targets
))
728 if (texturing_in_progress(validation_state
)) {
729 DRM_ERROR("Branch target landed during TMU setup\n");
733 /* Reset our live values tracking, since this instruction may have
734 * multiple predecessors.
736 * One could potentially do analysis to determine that, for
737 * example, all predecessors have a live max clamp in the same
738 * register, but we don't bother with that.
740 reset_validation_state(validation_state
);
742 /* Since we've entered a basic block from potentially multiple
743 * predecessors, we need the uniforms address to be updated before any
744 * unforms are read. We require that after any branch point, the next
745 * uniform to be loaded is a uniform address offset. That uniform's
746 * offset will be marked by the uniform address register write
747 * validation, or a one-off the end-of-program check.
749 validation_state
->needs_uniform_address_update
= true;
754 struct vc4_validated_shader_info
*
755 vc4_validate_shader(struct drm_gem_cma_object
*shader_obj
)
757 bool found_shader_end
= false;
758 int shader_end_ip
= 0;
760 struct vc4_validated_shader_info
*validated_shader
= NULL
;
761 struct vc4_shader_validation_state validation_state
;
763 memset(&validation_state
, 0, sizeof(validation_state
));
764 validation_state
.shader
= shader_obj
->vaddr
;
765 validation_state
.max_ip
= shader_obj
->base
.size
/ sizeof(uint64_t);
767 reset_validation_state(&validation_state
);
769 validation_state
.branch_targets
=
770 kcalloc(BITS_TO_LONGS(validation_state
.max_ip
),
771 sizeof(unsigned long), GFP_KERNEL
);
772 if (!validation_state
.branch_targets
)
775 validated_shader
= kcalloc(1, sizeof(*validated_shader
), GFP_KERNEL
);
776 if (!validated_shader
)
779 if (!vc4_validate_branches(&validation_state
))
782 for (ip
= 0; ip
< validation_state
.max_ip
; ip
++) {
783 uint64_t inst
= validation_state
.shader
[ip
];
784 uint32_t sig
= QPU_GET_FIELD(inst
, QPU_SIG
);
786 validation_state
.ip
= ip
;
788 if (!vc4_handle_branch_target(&validation_state
))
793 case QPU_SIG_WAIT_FOR_SCOREBOARD
:
794 case QPU_SIG_SCOREBOARD_UNLOCK
:
795 case QPU_SIG_COLOR_LOAD
:
796 case QPU_SIG_LOAD_TMU0
:
797 case QPU_SIG_LOAD_TMU1
:
798 case QPU_SIG_PROG_END
:
799 case QPU_SIG_SMALL_IMM
:
800 if (!check_instruction_writes(validated_shader
,
801 &validation_state
)) {
802 DRM_ERROR("Bad write at ip %d\n", ip
);
806 if (!check_instruction_reads(validated_shader
,
810 if (sig
== QPU_SIG_PROG_END
) {
811 found_shader_end
= true;
817 case QPU_SIG_LOAD_IMM
:
818 if (!check_instruction_writes(validated_shader
,
819 &validation_state
)) {
820 DRM_ERROR("Bad LOAD_IMM write at ip %d\n", ip
);
826 if (!check_branch(inst
, validated_shader
,
827 &validation_state
, ip
))
831 DRM_ERROR("Unsupported QPU signal %d at "
832 "instruction %d\n", sig
, ip
);
836 /* There are two delay slots after program end is signaled
837 * that are still executed, then we're finished.
839 if (found_shader_end
&& ip
== shader_end_ip
+ 2)
843 if (ip
== validation_state
.max_ip
) {
844 DRM_ERROR("shader failed to terminate before "
845 "shader BO end at %zd\n",
846 shader_obj
->base
.size
);
850 /* If we did a backwards branch and we haven't emitted a uniforms
851 * reset since then, we still need the uniforms stream to have the
852 * uniforms address available so that the backwards branch can do its
855 * We could potentially prove that the backwards branch doesn't
856 * contain any uses of uniforms until program exit, but that doesn't
857 * seem to be worth the trouble.
859 if (validation_state
.needs_uniform_address_for_loop
) {
860 if (!require_uniform_address_uniform(validated_shader
))
862 validated_shader
->uniforms_size
+= 4;
865 /* Again, no chance of integer overflow here because the worst case
866 * scenario is 8 bytes of uniforms plus handles per 8-byte
869 validated_shader
->uniforms_src_size
=
870 (validated_shader
->uniforms_size
+
871 4 * validated_shader
->num_texture_samples
);
873 kfree(validation_state
.branch_targets
);
875 return validated_shader
;
878 kfree(validation_state
.branch_targets
);
879 if (validated_shader
) {
880 kfree(validated_shader
->texture_samples
);
881 kfree(validated_shader
);