leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

drm/i915/cmdparser: Compare against the previous command descriptor

Browse Source 
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 <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-36-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2016-08-18 17:17:15 +01:00
parent d6a4ead7a3
commit efdfd91f9b
1 changed files with 14 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/gpu/drm/i915/i915_cmd_parser.c
View File

@ -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);