[Mesa-dev] [PATCH 06/18] i965/cs: Add support for the SEND message that terminates a CS thread.

[Matt Turner]

On Sat, Mar 14, 2015 at 9:54 PM, Jordan Justen
<jordan.l.justen at intel.com> wrote:
> From: Paul Berry <stereotype441 at gmail.com>
>
> This message must be sent to the "thread spawner" unit.
>
> Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>
> ---
>  src/mesa/drivers/dri/i965/brw_eu.h      |  4 +++
>  src/mesa/drivers/dri/i965/brw_eu_emit.c | 46 +++++++++++++++++++++++++++++++++
>  2 files changed, 50 insertions(+)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_eu.h b/src/mesa/drivers/dri/i965/brw_eu.h
> index d9ad5bd..708c216 100644
> --- a/src/mesa/drivers/dri/i965/brw_eu.h
> +++ b/src/mesa/drivers/dri/i965/brw_eu.h
> @@ -349,6 +349,10 @@ brw_jump_scale(const struct brw_context *brw)
>     return 1;
>  }
>
> +void brw_cs_terminate(struct brw_compile *p,
> +                      unsigned msg_reg_nr,
> +                      struct brw_reg src0);
> +
>  /* If/else/endif.  Works by manipulating the execution flags on each
>   * channel.
>   */
> diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
> index 43e5783..9c166a3 100644
> --- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
> +++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
> @@ -2895,3 +2895,49 @@ void brw_shader_time_add(struct brw_compile *p,
>                                       0 /* response length */,
>                                       false /* header present */);
>  }
> +
> +
> +static void
> +brw_set_cs_terminate_message(struct brw_context *brw,
> +                             struct brw_compile *p,
> +                             struct brw_inst *insn)
> +{
> +   /* Terminate a compute shader by sending a message to the thread spawner.
> +    * Note that even though the thread has a URB resource associated with it,
> +    * we set the "do not dereference URB" bit, because the URB resource is
> +    * managed by the fixed-function unit, so it will free it automatically.
> +    */
> +   brw_set_message_descriptor(p, insn, BRW_SFID_THREAD_SPAWNER,
> +                              1 /* msg_length */,
> +                              0 /* response_length */,
> +                              false /* header_present */,
> +                              true /* end_of_thread */);
> +   brw_inst_set_ts_opcode(brw, insn, 0); /* Dereference resource */
> +   brw_inst_set_ts_request_type(brw, insn, 0); /* Root thread */
> +   brw_inst_set_ts_resource_select(brw, insn, 1); /* Do not dereference URB */
> +}
> +
> +
> +/**
> + * Emit the SEND message to terminate a compute shader.
> + */
> +void
> +brw_cs_terminate(struct brw_compile *p,
> +                 unsigned msg_reg_nr,
> +                 struct brw_reg src0)
> +{
> +   struct brw_context *brw = p->brw;
> +   struct brw_inst *insn;
> +
> +   gen6_resolve_implied_move(p, &src0, msg_reg_nr);
> +   insn = next_insn(p, BRW_OPCODE_SEND);
> +   brw_set_dest(p, insn, brw_null_reg());
> +   brw_set_src0(p, insn, src0);
> +   brw_set_src1(p, insn, brw_imm_d(0));
> +
> +   if (brw->gen < 6)
> +      brw_inst_set_cond_modifier(brw, insn, msg_reg_nr);

Presumably gen <= 6 can't do compute shaders, so what's going on here
and in the call to gen6_resolve_implied_move above?

> +
> +   brw_set_cs_terminate_message(brw, p, insn);
> +   brw_inst_set_mask_control(brw, insn, BRW_MASK_DISABLE);
> +}
> --
> 2.1.4
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev