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 <lionel.g.landwerlin@intel.com>
Fixes: 1de401c08f ("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 <chris@chris-wilson.co.uk>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180602112946.30803-3-lionel.g.landwerlin@intel.com
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
This commit is contained in:
Lionel Landwerlin 2018-06-02 12:29:46 +01:00
parent 218b500098
commit 61d5676b55
3 changed files with 99 additions and 34 deletions

View File

@ -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;

View File

@ -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
@ -1215,39 +1237,75 @@ 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;
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 drm_i915_private *i915 = stream->dev_priv;
struct intel_context *ce;
int ret;
ret = i915_mutex_lock_interruptible(&dev_priv->drm);
if (ret)
return 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(stream->ctx, engine);
mutex_unlock(&dev_priv->drm.struct_mutex);
ce = oa_pin_context(i915, stream->ctx);
if (IS_ERR(ce))
return PTR_ERR(ce);
dev_priv->perf.oa.pinned_ctx = ce;
switch (INTEL_GEN(i915)) {
case 7: {
/*
* On Haswell we don't do any post processing of the reports
* and don't need to use the mask.
*/
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;
/*
* Explicitly track the ID (instead of calling
* i915_ggtt_offset() on the fly) considering the difference
* with gen8+ and execlists
* GuC uses the top bit to signal proxy submission, so
* ignore that bit.
*/
dev_priv->perf.oa.specific_ctx_id = i915_ggtt_offset(ce->state);
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) {

View File

@ -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;