From 61d5676b5561d61e3fdd9e88fc2b549b9b4df08f Mon Sep 17 00:00:00 2001 From: Lionel Landwerlin Date: Sat, 2 Jun 2018 12:29:46 +0100 Subject: [PATCH] drm/i915/perf: fix ctx_id read with GuC & ICL One thing we didn't really understand about the OA report is that the ContextID field (dword 2) is copy of the context descriptor (dword 1). On Gen8->10 and without using GuC we didn't notice the issue because we only checked the 21bits of the ContextID field in the OA reports which matches exactly the hw_id stored into the context descriptor. When using GuC submission we have an issue of a non matching hw_id because GuC uses bit 20 of the hw_id to signal proxy submission. This change introduces a mask to compare only the relevant bits. On ICL the context descriptor format has changed and we failed to address this. On top of using a mask we also need to shift the bits properly. v2: Reuse lrc_desc rather than recomputing part of it (Chris/Michel) v3: Always pin the context we're filtering with (Chris) Signed-off-by: Lionel Landwerlin Fixes: 1de401c08fa805 ("drm/i915/perf: enable perf support on ICL") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104252 BSpec: 1237 Testcase: igt/perf/gen8-unprivileged-single-ctx-counters Acked-by: Chris Wilson Reviewed-by: Michel Thierry Link: https://patchwork.freedesktop.org/patch/msgid/20180602112946.30803-3-lionel.g.landwerlin@intel.com Cc: Lionel Landwerlin Cc: Matthew Auld Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: intel-gfx@lists.freedesktop.org --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_perf.c | 127 ++++++++++++++++++++++--------- drivers/gpu/drm/i915/intel_lrc.c | 5 ++ 3 files changed, 99 insertions(+), 34 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index b5b09c8a327f..06ecac4c3253 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1951,6 +1951,7 @@ struct drm_i915_private { struct intel_context *pinned_ctx; u32 specific_ctx_id; + u32 specific_ctx_id_mask; struct hrtimer poll_check_timer; wait_queue_head_t poll_wq; diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 4f0eb84b3c00..a6c8d61add0c 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -737,12 +737,7 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream, continue; } - /* - * XXX: Just keep the lower 21 bits for now since I'm not - * entirely sure if the HW touches any of the higher bits in - * this field - */ - ctx_id = report32[2] & 0x1fffff; + ctx_id = report32[2] & dev_priv->perf.oa.specific_ctx_id_mask; /* * Squash whatever is in the CTX_ID field if it's marked as @@ -1203,6 +1198,33 @@ static int i915_oa_read(struct i915_perf_stream *stream, return dev_priv->perf.oa.ops.read(stream, buf, count, offset); } +static struct intel_context *oa_pin_context(struct drm_i915_private *i915, + struct i915_gem_context *ctx) +{ + struct intel_engine_cs *engine = i915->engine[RCS]; + struct intel_context *ce; + int ret; + + ret = i915_mutex_lock_interruptible(&i915->drm); + if (ret) + return ERR_PTR(ret); + + /* + * As the ID is the gtt offset of the context's vma we + * pin the vma to ensure the ID remains fixed. + * + * NB: implied RCS engine... + */ + ce = intel_context_pin(ctx, engine); + mutex_unlock(&i915->drm.struct_mutex); + if (IS_ERR(ce)) + return ce; + + i915->perf.oa.pinned_ctx = ce; + + return ce; +} + /** * oa_get_render_ctx_id - determine and hold ctx hw id * @stream: An i915-perf stream opened for OA metrics @@ -1215,40 +1237,76 @@ static int i915_oa_read(struct i915_perf_stream *stream, */ static int oa_get_render_ctx_id(struct i915_perf_stream *stream) { - struct drm_i915_private *dev_priv = stream->dev_priv; + struct drm_i915_private *i915 = stream->dev_priv; + struct intel_context *ce; - if (HAS_LOGICAL_RING_CONTEXTS(dev_priv)) { - dev_priv->perf.oa.specific_ctx_id = stream->ctx->hw_id; - } else { - struct intel_engine_cs *engine = dev_priv->engine[RCS]; - struct intel_context *ce; - int ret; - - ret = i915_mutex_lock_interruptible(&dev_priv->drm); - if (ret) - return ret; + ce = oa_pin_context(i915, stream->ctx); + if (IS_ERR(ce)) + return PTR_ERR(ce); + switch (INTEL_GEN(i915)) { + case 7: { /* - * As the ID is the gtt offset of the context's vma we - * pin the vma to ensure the ID remains fixed. - * - * NB: implied RCS engine... + * On Haswell we don't do any post processing of the reports + * and don't need to use the mask. */ - ce = intel_context_pin(stream->ctx, engine); - mutex_unlock(&dev_priv->drm.struct_mutex); - if (IS_ERR(ce)) - return PTR_ERR(ce); - - dev_priv->perf.oa.pinned_ctx = ce; - - /* - * Explicitly track the ID (instead of calling - * i915_ggtt_offset() on the fly) considering the difference - * with gen8+ and execlists - */ - dev_priv->perf.oa.specific_ctx_id = i915_ggtt_offset(ce->state); + i915->perf.oa.specific_ctx_id = i915_ggtt_offset(ce->state); + i915->perf.oa.specific_ctx_id_mask = 0; + break; } + case 8: + case 9: + case 10: + if (USES_GUC_SUBMISSION(i915)) { + /* + * When using GuC, the context descriptor we write in + * i915 is read by GuC and rewritten before it's + * actually written into the hardware. The LRCA is + * what is put into the context id field of the + * context descriptor by GuC. Because it's aligned to + * a page, the lower 12bits are always at 0 and + * dropped by GuC. They won't be part of the context + * ID in the OA reports, so squash those lower bits. + */ + i915->perf.oa.specific_ctx_id = + lower_32_bits(ce->lrc_desc) >> 12; + + /* + * GuC uses the top bit to signal proxy submission, so + * ignore that bit. + */ + i915->perf.oa.specific_ctx_id_mask = + (1U << (GEN8_CTX_ID_WIDTH - 1)) - 1; + } else { + i915->perf.oa.specific_ctx_id = stream->ctx->hw_id; + i915->perf.oa.specific_ctx_id_mask = + (1U << GEN8_CTX_ID_WIDTH) - 1; + } + break; + + case 11: { + struct intel_engine_cs *engine = i915->engine[RCS]; + + i915->perf.oa.specific_ctx_id = + stream->ctx->hw_id << (GEN11_SW_CTX_ID_SHIFT - 32) | + engine->instance << (GEN11_ENGINE_INSTANCE_SHIFT - 32) | + engine->class << (GEN11_ENGINE_INSTANCE_SHIFT - 32); + i915->perf.oa.specific_ctx_id_mask = + ((1U << GEN11_SW_CTX_ID_WIDTH) - 1) << (GEN11_SW_CTX_ID_SHIFT - 32) | + ((1U << GEN11_ENGINE_INSTANCE_WIDTH) - 1) << (GEN11_ENGINE_INSTANCE_SHIFT - 32) | + ((1 << GEN11_ENGINE_CLASS_WIDTH) - 1) << (GEN11_ENGINE_CLASS_SHIFT - 32); + break; + } + + default: + MISSING_CASE(INTEL_GEN(i915)); + } + + DRM_DEBUG_DRIVER("filtering on ctx_id=0x%x ctx_id_mask=0x%x\n", + i915->perf.oa.specific_ctx_id, + i915->perf.oa.specific_ctx_id_mask); + return 0; } @@ -1265,6 +1323,7 @@ static void oa_put_render_ctx_id(struct i915_perf_stream *stream) struct intel_context *ce; dev_priv->perf.oa.specific_ctx_id = INVALID_CTX_ID; + dev_priv->perf.oa.specific_ctx_id_mask = 0; ce = fetch_and_zero(&dev_priv->perf.oa.pinned_ctx); if (ce) { diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index cbc2a8d4dc9c..f6f09f808f74 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -233,6 +233,11 @@ intel_lr_context_descriptor_update(struct i915_gem_context *ctx, /* bits 12-31 */ GEM_BUG_ON(desc & GENMASK_ULL(63, 32)); + /* + * The following 32bits are copied into the OA reports (dword 2). + * Consider updating oa_get_render_ctx_id in i915_perf.c when changing + * anything below. + */ if (INTEL_GEN(ctx->i915) >= 11) { GEM_BUG_ON(ctx->hw_id >= BIT(GEN11_SW_CTX_ID_WIDTH)); desc |= (u64)ctx->hw_id << GEN11_SW_CTX_ID_SHIFT;