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authorChris Wilson <chris@chris-wilson.co.uk>2020-10-01 13:26:32 +0300
committerChris Wilson <chris@chris-wilson.co.uk>2020-10-06 12:41:11 +0300
commita6c5e2aea70451f6f1012734a606721c75c57276 (patch)
tree894fdabca3bf5c5ba0914a46ec9e921c89a8bc4d /drivers/gpu/drm/i915/i915_cmd_parser.c
parentb05734720de982a40676a14ddfdca5f87b4aab5e (diff)
downloadlinux-a6c5e2aea70451f6f1012734a606721c75c57276.tar.xz
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.c67
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) {
/*