#include "vc4_qpu.h"
#include "vc4_qpu_defines.h"
+#define LIVE_REG_COUNT (32 + 32 + 4)
+
struct vc4_shader_validation_state {
/* Current IP being validated. */
uint32_t ip;
*
* This is used for the validation of direct address memory reads.
*/
- uint32_t live_min_clamp_offsets[32 + 32 + 4];
- bool live_max_clamp_regs[32 + 32 + 4];
+ uint32_t live_min_clamp_offsets[LIVE_REG_COUNT];
+ bool live_max_clamp_regs[LIVE_REG_COUNT];
+ uint32_t live_immediates[LIVE_REG_COUNT];
/* Bitfield of which IPs are used as branch targets.
*
* points and clearing the texturing/clamping state.
*/
unsigned long *branch_targets;
+
+ /* Set when entering a basic block, and cleared when the uniform
+ * address update is found. This is used to make sure that we don't
+ * read uniforms when the address is undefined.
+ */
+ bool needs_uniform_address_update;
+
+ /* Set when we find a backwards branch. If the branch is backwards,
+ * the taraget is probably doing an address reset to read uniforms,
+ * and so we need to be sure that a uniforms address is present in the
+ * stream, even if the shader didn't need to read uniforms in later
+ * basic blocks.
+ */
+ bool needs_uniform_address_for_loop;
};
static uint32_t
/* Since direct uses a RADDR uniform reference, it will get counted in
* check_instruction_reads()
*/
- if (!is_direct)
+ if (!is_direct) {
+ if (validation_state->needs_uniform_address_update) {
+ DRM_ERROR("Texturing with undefined uniform address\n");
+ return false;
+ }
+
validated_shader->uniforms_size += 4;
+ }
if (submit) {
if (!record_texture_sample(validated_shader,
return true;
}
+static bool require_uniform_address_uniform(struct vc4_validated_shader_info *validated_shader)
+{
+ uint32_t o = validated_shader->num_uniform_addr_offsets;
+ uint32_t num_uniforms = validated_shader->uniforms_size / 4;
+
+ validated_shader->uniform_addr_offsets =
+ krealloc(validated_shader->uniform_addr_offsets,
+ (o + 1) *
+ sizeof(*validated_shader->uniform_addr_offsets),
+ GFP_KERNEL);
+ if (!validated_shader->uniform_addr_offsets)
+ return false;
+
+ validated_shader->uniform_addr_offsets[o] = num_uniforms;
+ validated_shader->num_uniform_addr_offsets++;
+
+ return true;
+}
+
+static bool
+validate_uniform_address_write(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state,
+ bool is_mul)
+{
+ uint64_t inst = validation_state->shader[validation_state->ip];
+ u32 add_b = QPU_GET_FIELD(inst, QPU_ADD_B);
+ u32 raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
+ u32 raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
+ u32 add_lri = raddr_add_a_to_live_reg_index(inst);
+ /* We want our reset to be pointing at whatever uniform follows the
+ * uniforms base address.
+ */
+ u32 expected_offset = validated_shader->uniforms_size + 4;
+
+ /* We only support absolute uniform address changes, and we
+ * require that they be in the current basic block before any
+ * of its uniform reads.
+ *
+ * One could potentially emit more efficient QPU code, by
+ * noticing that (say) an if statement does uniform control
+ * flow for all threads and that the if reads the same number
+ * of uniforms on each side. However, this scheme is easy to
+ * validate so it's all we allow for now.
+ */
+
+ if (QPU_GET_FIELD(inst, QPU_SIG) != QPU_SIG_NONE) {
+ DRM_ERROR("uniforms address change must be "
+ "normal math\n");
+ return false;
+ }
+
+ if (is_mul || QPU_GET_FIELD(inst, QPU_OP_ADD) != QPU_A_ADD) {
+ DRM_ERROR("Uniform address reset must be an ADD.\n");
+ return false;
+ }
+
+ if (QPU_GET_FIELD(inst, QPU_COND_ADD) != QPU_COND_ALWAYS) {
+ DRM_ERROR("Uniform address reset must be unconditional.\n");
+ return false;
+ }
+
+ if (QPU_GET_FIELD(inst, QPU_PACK) != QPU_PACK_A_NOP &&
+ !(inst & QPU_PM)) {
+ DRM_ERROR("No packing allowed on uniforms reset\n");
+ return false;
+ }
+
+ if (add_lri == -1) {
+ DRM_ERROR("First argument of uniform address write must be "
+ "an immediate value.\n");
+ return false;
+ }
+
+ if (validation_state->live_immediates[add_lri] != expected_offset) {
+ DRM_ERROR("Resetting uniforms with offset %db instead of %db\n",
+ validation_state->live_immediates[add_lri],
+ expected_offset);
+ return false;
+ }
+
+ if (!(add_b == QPU_MUX_A && raddr_a == QPU_R_UNIF) &&
+ !(add_b == QPU_MUX_B && raddr_b == QPU_R_UNIF)) {
+ DRM_ERROR("Second argument of uniform address write must be "
+ "a uniform.\n");
+ return false;
+ }
+
+ validation_state->needs_uniform_address_update = false;
+ validation_state->needs_uniform_address_for_loop = false;
+ return require_uniform_address_uniform(validated_shader);
+}
+
static bool
check_reg_write(struct vc4_validated_shader_info *validated_shader,
struct vc4_shader_validation_state *validation_state,
uint32_t waddr = (is_mul ?
QPU_GET_FIELD(inst, QPU_WADDR_MUL) :
QPU_GET_FIELD(inst, QPU_WADDR_ADD));
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+ bool ws = inst & QPU_WS;
+ bool is_b = is_mul ^ ws;
+ u32 lri = waddr_to_live_reg_index(waddr, is_b);
+
+ if (lri != -1) {
+ uint32_t cond_add = QPU_GET_FIELD(inst, QPU_COND_ADD);
+ uint32_t cond_mul = QPU_GET_FIELD(inst, QPU_COND_MUL);
+
+ if (sig == QPU_SIG_LOAD_IMM &&
+ QPU_GET_FIELD(inst, QPU_PACK) == QPU_PACK_A_NOP &&
+ ((is_mul && cond_mul == QPU_COND_ALWAYS) ||
+ (!is_mul && cond_add == QPU_COND_ALWAYS))) {
+ validation_state->live_immediates[lri] =
+ QPU_GET_FIELD(inst, QPU_LOAD_IMM);
+ } else {
+ validation_state->live_immediates[lri] = ~0;
+ }
+ }
switch (waddr) {
case QPU_W_UNIFORMS_ADDRESS:
- /* XXX: We'll probably need to support this for reladdr, but
- * it's definitely a security-related one.
- */
- DRM_ERROR("uniforms address load unsupported\n");
- return false;
+ if (is_b) {
+ DRM_ERROR("relative uniforms address change "
+ "unsupported\n");
+ return false;
+ }
+
+ return validate_uniform_address_write(validated_shader,
+ validation_state,
+ is_mul);
case QPU_W_TLB_COLOR_MS:
case QPU_W_TLB_COLOR_ALL:
}
static bool
-check_instruction_reads(uint64_t inst,
- struct vc4_validated_shader_info *validated_shader)
+check_branch(uint64_t inst,
+ struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state,
+ int ip)
+{
+ int32_t branch_imm = QPU_GET_FIELD(inst, QPU_BRANCH_TARGET);
+ uint32_t waddr_add = QPU_GET_FIELD(inst, QPU_WADDR_ADD);
+ uint32_t waddr_mul = QPU_GET_FIELD(inst, QPU_WADDR_MUL);
+
+ if ((int)branch_imm < 0)
+ validation_state->needs_uniform_address_for_loop = true;
+
+ /* We don't want to have to worry about validation of this, and
+ * there's no need for it.
+ */
+ if (waddr_add != QPU_W_NOP || waddr_mul != QPU_W_NOP) {
+ DRM_ERROR("branch instruction at %d wrote a register.\n",
+ validation_state->ip);
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+check_instruction_reads(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state)
{
+ uint64_t inst = validation_state->shader[validation_state->ip];
uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
* already be OOM.
*/
validated_shader->uniforms_size += 4;
+
+ if (validation_state->needs_uniform_address_update) {
+ DRM_ERROR("Uniform read with undefined uniform "
+ "address\n");
+ return false;
+ }
}
return true;
return true;
}
+/* Resets any known state for the shader, used when we may be branched to from
+ * multiple locations in the program (or at shader start).
+ */
+static void
+reset_validation_state(struct vc4_shader_validation_state *validation_state)
+{
+ int i;
+
+ for (i = 0; i < 8; i++)
+ validation_state->tmu_setup[i / 4].p_offset[i % 4] = ~0;
+
+ for (i = 0; i < LIVE_REG_COUNT; i++) {
+ validation_state->live_min_clamp_offsets[i] = ~0;
+ validation_state->live_max_clamp_regs[i] = false;
+ validation_state->live_immediates[i] = ~0;
+ }
+}
+
+static bool
+texturing_in_progress(struct vc4_shader_validation_state *validation_state)
+{
+ return (validation_state->tmu_write_count[0] != 0 ||
+ validation_state->tmu_write_count[1] != 0);
+}
+
+static bool
+vc4_handle_branch_target(struct vc4_shader_validation_state *validation_state)
+{
+ uint32_t ip = validation_state->ip;
+
+ if (!test_bit(ip, validation_state->branch_targets))
+ return true;
+
+ if (texturing_in_progress(validation_state)) {
+ DRM_ERROR("Branch target landed during TMU setup\n");
+ return false;
+ }
+
+ /* Reset our live values tracking, since this instruction may have
+ * multiple predecessors.
+ *
+ * One could potentially do analysis to determine that, for
+ * example, all predecessors have a live max clamp in the same
+ * register, but we don't bother with that.
+ */
+ reset_validation_state(validation_state);
+
+ /* Since we've entered a basic block from potentially multiple
+ * predecessors, we need the uniforms address to be updated before any
+ * unforms are read. We require that after any branch point, the next
+ * uniform to be loaded is a uniform address offset. That uniform's
+ * offset will be marked by the uniform address register write
+ * validation, or a one-off the end-of-program check.
+ */
+ validation_state->needs_uniform_address_update = true;
+
+ return true;
+}
+
struct vc4_validated_shader_info *
vc4_validate_shader(struct drm_gem_cma_object *shader_obj)
{
uint32_t ip;
struct vc4_validated_shader_info *validated_shader = NULL;
struct vc4_shader_validation_state validation_state;
- int i;
memset(&validation_state, 0, sizeof(validation_state));
validation_state.shader = shader_obj->vaddr;
validation_state.max_ip = shader_obj->base.size / sizeof(uint64_t);
- for (i = 0; i < 8; i++)
- validation_state.tmu_setup[i / 4].p_offset[i % 4] = ~0;
- for (i = 0; i < ARRAY_SIZE(validation_state.live_min_clamp_offsets); i++)
- validation_state.live_min_clamp_offsets[i] = ~0;
+ reset_validation_state(&validation_state);
validation_state.branch_targets =
kcalloc(BITS_TO_LONGS(validation_state.max_ip),
validation_state.ip = ip;
+ if (!vc4_handle_branch_target(&validation_state))
+ goto fail;
+
switch (sig) {
case QPU_SIG_NONE:
case QPU_SIG_WAIT_FOR_SCOREBOARD:
goto fail;
}
- if (!check_instruction_reads(inst, validated_shader))
+ if (!check_instruction_reads(validated_shader,
+ &validation_state))
goto fail;
if (sig == QPU_SIG_PROG_END) {
}
break;
+ case QPU_SIG_BRANCH:
+ if (!check_branch(inst, validated_shader,
+ &validation_state, ip))
+ goto fail;
+ break;
default:
DRM_ERROR("Unsupported QPU signal %d at "
"instruction %d\n", sig, ip);
goto fail;
}
+ /* If we did a backwards branch and we haven't emitted a uniforms
+ * reset since then, we still need the uniforms stream to have the
+ * uniforms address available so that the backwards branch can do its
+ * uniforms reset.
+ *
+ * We could potentially prove that the backwards branch doesn't
+ * contain any uses of uniforms until program exit, but that doesn't
+ * seem to be worth the trouble.
+ */
+ if (validation_state.needs_uniform_address_for_loop) {
+ if (!require_uniform_address_uniform(validated_shader))
+ goto fail;
+ validated_shader->uniforms_size += 4;
+ }
+
/* Again, no chance of integer overflow here because the worst case
* scenario is 8 bytes of uniforms plus handles per 8-byte
* instruction.
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