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@jlekstrand.net Reviewed-by: Jon Bloomfield jon.bloomfield@intel.com --- 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) { /*