This reverts a6c5e2aea704 ("drm/i915: Skip over MI_NOOP when parsing").
It complicates the batch parsing code a bit and increases indentation
for no reason other than fast-skipping a command that userspace uses
only rarely. Sure, there may be IGT tests that fill batches with NOOPs
but that's not a case we should optimize for in the kernel. We should
optimize for code clarity instead.
Signed-off-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
Reviewed-by: Jon Bloomfield <jon.bloomfield@xxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/i915/i915_cmd_parser.c | 67 +++++++++++++-------------
1 file changed, 34 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 056a233f443b4..8d34f05d22b75 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -1470,42 +1470,43 @@ 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);
- 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;
- }
+ do {
+ u32 length;
- if (desc->flags & CMD_DESC_FIXED)
- length = desc->length.fixed;
- else
- length = (*cmd & desc->length.mask) + LENGTH_BIAS;
+ if (*cmd == MI_BATCH_BUFFER_END)
+ 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;
- }
+ desc = find_cmd(engine, *cmd, desc, &default_desc);
+ if (!desc) {
+ DRM_DEBUG("CMD: Unrecognized command: 0x%08X\n", *cmd);
+ ret = -EINVAL;
+ break;
+ }
- if (!check_cmd(engine, desc, cmd, length)) {
- ret = -EACCES;
- break;
- }
+ if (desc->flags & CMD_DESC_FIXED)
+ length = desc->length.fixed;
+ else
+ length = (*cmd & desc->length.mask) + LENGTH_BIAS;
- 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 ((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 (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))
@@ -1518,7 +1519,7 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
ret = -EINVAL;
break;
}
- }
+ } while (1);
if (trampoline) {
/*
--
2.31.1
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