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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-10-01 11:26:32 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-10-06 10:41:11 +0100 |
| commit | a6c5e2aea70451f6f1012734a606721c75c57276 (patch) | |
| tree | 894fdabca3bf5c5ba0914a46ec9e921c89a8bc4d /drivers/gpu/drm/i915/i915_cmd_parser.c | |
| parent | b05734720de982a40676a14ddfdca5f87b4aab5e (diff) | |
| download | lwn-a6c5e2aea70451f6f1012734a606721c75c57276.tar.gz lwn-a6c5e2aea70451f6f1012734a606721c75c57276.zip | |
drm/i915: Skip over MI_NOOP when parsing
Though less likely in practice, igt uses MI_NOOP frequently to pad out
its batch buffers. The lookup and valiation of so many MI_NOOP command
descriptions is noticeable, though the side-effect of poisoning the
last-validated-command cache is more likely to impact upon real CS.
Testcase: igt/gen9_exec_parse/bb-large
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201001102632.18789-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_cmd_parser.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_cmd_parser.c | 67 |
1 files changed, 33 insertions, 34 deletions
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index e88970256e8e..93265951fdbb 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -1452,43 +1452,42 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine, * space. Parsing should be faster in some cases this way. */ batch_end = cmd + batch_length / sizeof(*batch_end); - do { - u32 length; - - if (*cmd == MI_BATCH_BUFFER_END) - break; - - desc = find_cmd(engine, *cmd, desc, &default_desc); - if (!desc) { - DRM_DEBUG("CMD: Unrecognized command: 0x%08X\n", *cmd); - ret = -EINVAL; - break; - } + while (*cmd != MI_BATCH_BUFFER_END) { + u32 length = 1; + + if (*cmd != MI_NOOP) { /* MI_NOOP == 0 */ + desc = find_cmd(engine, *cmd, desc, &default_desc); + if (!desc) { + DRM_DEBUG("CMD: Unrecognized command: 0x%08X\n", *cmd); + ret = -EINVAL; + break; + } - if (desc->flags & CMD_DESC_FIXED) - length = desc->length.fixed; - else - length = (*cmd & desc->length.mask) + LENGTH_BIAS; + if (desc->flags & CMD_DESC_FIXED) + length = desc->length.fixed; + else + length = (*cmd & desc->length.mask) + LENGTH_BIAS; - if ((batch_end - cmd) < length) { - DRM_DEBUG("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n", - *cmd, - length, - batch_end - cmd); - ret = -EINVAL; - break; - } + if ((batch_end - cmd) < length) { + DRM_DEBUG("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n", + *cmd, + length, + batch_end - cmd); + ret = -EINVAL; + break; + } - if (!check_cmd(engine, desc, cmd, length)) { - ret = -EACCES; - break; - } + if (!check_cmd(engine, desc, cmd, length)) { + ret = -EACCES; + break; + } - if (cmd_desc_is(desc, MI_BATCH_BUFFER_START)) { - ret = check_bbstart(cmd, offset, length, batch_length, - batch_addr, shadow_addr, - jump_whitelist); - break; + if (cmd_desc_is(desc, MI_BATCH_BUFFER_START)) { + ret = check_bbstart(cmd, offset, length, batch_length, + batch_addr, shadow_addr, + jump_whitelist); + break; + } } if (!IS_ERR_OR_NULL(jump_whitelist)) @@ -1501,7 +1500,7 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine, ret = -EINVAL; break; } - } while (1); + } if (trampoline) { /* |