The predicate source registers are needed to implement conditional rendering without stalling. The two source registers are used to load the previous values of the PS_DEPTH_COUNT register saved from PIPE_CONTROL commands. These can then be compared and used to set the predicate enable bit via the MI_PREDICATE command. The command parser version number is increased to 2 to make it easier to detect the new functionality in user space. Signed-off-by: Neil Roberts <neil@xxxxxxxxxxxxxxx> --- Here is a v2 of the patch that also updates the command parser version to make it easier to detect whether we can use the register in Mesa. I have posted a second version of the Mesa patch which uses this here: http://lists.freedesktop.org/archives/mesa-dev/2014-November/070362.html This was suggested by Glenn Kennard. drivers/gpu/drm/i915/i915_cmd_parser.c | 6 +++++- drivers/gpu/drm/i915/i915_reg.h | 2 ++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 4c35e2a..3eb421e 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -408,6 +408,8 @@ static const u32 gen7_render_regs[] = { REG64(PS_INVOCATION_COUNT), REG64(PS_DEPTH_COUNT), OACONTROL, /* Only allowed for LRI and SRM. See below. */ + REG64(MI_PREDICATE_SRC0), + REG64(MI_PREDICATE_SRC1), GEN7_3DPRIM_END_OFFSET, GEN7_3DPRIM_START_VERTEX, GEN7_3DPRIM_VERTEX_COUNT, @@ -1054,6 +1056,8 @@ int i915_cmd_parser_get_version(void) * * 1. Initial version. Checks batches and reports violations, but leaves * hardware parsing enabled (so does not allow new use cases). + * 2. Allow access to the MI_PREDICATE_SRC0 and + * MI_PREDICATE_SRC1 registers. */ - return 1; + return 2; } diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index ea84e1e..9275d41 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -314,6 +314,8 @@ #define MI_BATCH_GTT (2<<6) /* aliased with (1<<7) on gen4 */ #define MI_BATCH_BUFFER_START_GEN8 MI_INSTR(0x31, 1) +#define MI_PREDICATE_SRC0 (0x2400) +#define MI_PREDICATE_SRC1 (0x2408) #define MI_PREDICATE_RESULT_2 (0x2214) #define LOWER_SLICE_ENABLED (1<<0) -- 1.9.3 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
