From 504ae4024131c5a01c3ce8382d49b801375e039c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 10 Mar 2017 11:55:18 +0000 Subject: [PATCH] drm/i915/cmdparser: Limit clflush to active cachelines We only need to clflush those cachelines that we have validated to be read by the GPU. Userspace typically fills the batch length in correctly, the exceptions tend to be explicit tests within igt. v2: Use ptr_mask_bits() to make Mika happy v3: cmd is not advanced on MI_BBE, so make sure to include an extra dword in the clflush. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Link: http://patchwork.freedesktop.org/patch/msgid/20170310115518.13832-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_cmd_parser.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 21b1cd917d81..7af100f84410 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -1279,11 +1279,17 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine, * space. Parsing should be faster in some cases this way. */ batch_end = cmd + (batch_len / sizeof(*batch_end)); - while (cmd < batch_end) { + do { u32 length; - if (*cmd == MI_BATCH_BUFFER_END) + if (*cmd == MI_BATCH_BUFFER_END) { + if (needs_clflush_after) { + void *ptr = ptr_mask_bits(shadow_batch_obj->mm.mapping); + drm_clflush_virt_range(ptr, + (void *)(cmd + 1) - ptr); + } break; + } desc = find_cmd(engine, *cmd, desc, &default_desc); if (!desc) { @@ -1323,17 +1329,14 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine, } cmd += length; - } + if (cmd >= batch_end) { + DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n"); + ret = -EINVAL; + break; + } + } while (1); - if (cmd >= batch_end) { - DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n"); - ret = -EINVAL; - } - - if (ret == 0 && needs_clflush_after) - drm_clflush_virt_range(shadow_batch_obj->mm.mapping, batch_len); i915_gem_object_unpin_map(shadow_batch_obj); - return ret; }