From efdfd91f9b234638705d79a2b2f0a6ac8a5f99e8 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 18 Aug 2016 17:17:15 +0100 Subject: [PATCH] drm/i915/cmdparser: Compare against the previous command descriptor On the blitter (and in test code), we see long sequences of repeated commands, e.g. XY_PIXEL_BLT, XY_SCANLINE_BLT, or XY_SRC_COPY. For these, we can skip the hashtable lookup by remembering the previous command descriptor and doing a straightforward compare of the command header. The corollary is that we need to do one extra comparison before lookup up new commands. v2: Less magic mask (ok, it is still magic, but now you cannot see!) Signed-off-by: Chris Wilson Reviewed-by: Matthew Auld Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-36-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_cmd_parser.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 54aeab3..558077a 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -90,6 +90,7 @@ #define STD_3D_OPCODE_SHIFT (32 - 16) #define STD_2D_OPCODE_SHIFT (32 - 10) #define STD_MFX_OPCODE_SHIFT (32 - 16) +#define MIN_OPCODE_SHIFT 16 #define CMD(op, opm, f, lm, fl, ...) \ { \ @@ -350,6 +351,9 @@ static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = { CMD( MI_LOAD_SCAN_LINES_EXCL, SMI, !F, 0x3F, R ), }; +static const struct drm_i915_cmd_descriptor noop_desc = + CMD(MI_NOOP, SMI, F, 1, S); + #undef CMD #undef SMI #undef S3D @@ -893,11 +897,14 @@ find_cmd_in_table(struct intel_engine_cs *engine, static const struct drm_i915_cmd_descriptor* find_cmd(struct intel_engine_cs *engine, u32 cmd_header, + const struct drm_i915_cmd_descriptor *desc, struct drm_i915_cmd_descriptor *default_desc) { - const struct drm_i915_cmd_descriptor *desc; u32 mask; + if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0) + return desc; + desc = find_cmd_in_table(engine, cmd_header); if (desc) return desc; @@ -906,10 +913,10 @@ find_cmd(struct intel_engine_cs *engine, if (!mask) return NULL; - BUG_ON(!default_desc); - default_desc->flags = CMD_DESC_SKIP; + default_desc->cmd.value = cmd_header; + default_desc->cmd.mask = ~0u << MIN_OPCODE_SHIFT; default_desc->length.mask = mask; - + default_desc->flags = CMD_DESC_SKIP; return default_desc; } @@ -1188,7 +1195,8 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine, bool is_master) { u32 *cmd, *batch_end; - struct drm_i915_cmd_descriptor default_desc = { 0 }; + struct drm_i915_cmd_descriptor default_desc = noop_desc; + const struct drm_i915_cmd_descriptor *desc = &default_desc; bool oacontrol_set = false; /* OACONTROL tracking. See check_cmd() */ bool needs_clflush_after = false; int ret = 0; @@ -1208,13 +1216,12 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine, */ batch_end = cmd + (batch_len / sizeof(*batch_end)); while (cmd < batch_end) { - const struct drm_i915_cmd_descriptor *desc; u32 length; if (*cmd == MI_BATCH_BUFFER_END) break; - desc = find_cmd(engine, *cmd, &default_desc); + desc = find_cmd(engine, *cmd, desc, &default_desc); if (!desc) { DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n", *cmd); -- 2.7.4