Avoid a global idle barrier by reconfiguring each context by rewriting
them with MI_STORE_DWORD from the kernel context.
v2: We only need to determine the desired register values once, they are
the same for all contexts.
v3: Don't remove the kernel context from the list of known GEM contexts;
the world is not ready for that yet.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_lrc.c | 7 +-
drivers/gpu/drm/i915/i915_perf.c | 251 +++++++++++++++++++++-------
2 files changed, 197 insertions(+), 61 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 9e0992498087..fc4c77555e06 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1570,9 +1570,12 @@ __execlists_update_reg_state(struct intel_context *ce,
regs[CTX_RING_TAIL + 1] = ring->tail;
/* RPCS */
- if (engine->class == RENDER_CLASS)
+ if (engine->class == RENDER_CLASS) {
regs[CTX_R_PWR_CLK_STATE + 1] =
intel_sseu_make_rpcs(engine->i915, &ce->sseu);
+
+ i915_oa_init_reg_state(engine, ce, regs);
+ }
}
static int
@@ -2992,8 +2995,6 @@ static void execlists_init_reg_state(u32 *regs,
if (rcs) {
regs[CTX_LRI_HEADER_2] = MI_LOAD_REGISTER_IMM(1);
CTX_REG(regs, CTX_R_PWR_CLK_STATE, GEN8_R_PWR_CLK_STATE, 0);
-
- i915_oa_init_reg_state(engine, ce, regs);
}
regs[CTX_END] = MI_BATCH_BUFFER_END;
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 007826ded9b3..78cb9ec8866c 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1636,6 +1636,27 @@ static void hsw_disable_metric_set(struct drm_i915_private *dev_priv)
~GT_NOA_ENABLE));
}
+static u32 oa_config_flex_reg(const struct i915_oa_config *oa_config,
+ i915_reg_t reg)
+{
+ u32 mmio = i915_mmio_reg_offset(reg);
+ int i;
+
+ /*
+ * This arbitrary default will select the 'EU FPU0 Pipeline
+ * Active' event. In the future it's anticipated that there
+ * will be an explicit 'No Event' we can select, but not yet...
+ */
+ if (!oa_config)
+ return 0;
+
+ for (i = 0; i < oa_config->flex_regs_len; i++) {
+ if (i915_mmio_reg_offset(oa_config->flex_regs[i].addr) == mmio)
+ return oa_config->flex_regs[i].value;
+ }
+
+ return 0;
+}
/*
* NB: It must always remain pointer safe to run this even if the OA unit
* has been disabled.
@@ -1669,28 +1690,8 @@ gen8_update_reg_state_unlocked(struct intel_context *ce,
GEN8_OA_COUNTER_RESUME);
for (i = 0; i < ARRAY_SIZE(flex_regs); i++) {
- u32 state_offset = ctx_flexeu0 + i * 2;
- u32 mmio = i915_mmio_reg_offset(flex_regs[i]);
-
- /*
- * This arbitrary default will select the 'EU FPU0 Pipeline
- * Active' event. In the future it's anticipated that there
- * will be an explicit 'No Event' we can select, but not yet...
- */
- u32 value = 0;
-
- if (oa_config) {
- u32 j;
-
- for (j = 0; j < oa_config->flex_regs_len; j++) {
- if (i915_mmio_reg_offset(oa_config->flex_regs[j].addr) == mmio) {
- value = oa_config->flex_regs[j].value;
- break;
- }
- }
- }
-
- CTX_REG(reg_state, state_offset, flex_regs[i], value);
+ CTX_REG(reg_state, ctx_flexeu0 + i * 2, flex_regs[i],
+ oa_config_flex_reg(oa_config, flex_regs[i]));
}
CTX_REG(reg_state,
@@ -1698,6 +1699,107 @@ gen8_update_reg_state_unlocked(struct intel_context *ce,
intel_sseu_make_rpcs(i915, &ce->sseu));
}
+struct flex {
+ i915_reg_t reg;
+ u32 offset;
+ u32 value;
+};
+
+static int
+gen8_store_flex(struct i915_request *rq,
+ struct intel_context *ce,
+ const struct flex *flex, unsigned int count)
+{
+ u32 offset;
+ u32 *cs;
+
+ cs = intel_ring_begin(rq, 4 * count);
+ if (IS_ERR(cs))
+ return PTR_ERR(cs);
+
+ offset = i915_ggtt_offset(ce->state) + LRC_STATE_PN * PAGE_SIZE;
+ do {
+ *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
+ *cs++ = offset + (flex->offset + 1) * sizeof(u32);
+ *cs++ = 0;
+ *cs++ = flex->value;
+ } while (flex++, --count);
+
+ intel_ring_advance(rq, cs);
+
+ return 0;
+}
+
+static int
+gen8_load_flex(struct i915_request *rq,
+ struct intel_context *ce,
+ const struct flex *flex, unsigned int count)
+{
+ u32 *cs;
+
+ GEM_BUG_ON(!count || count > 63);
+
+ cs = intel_ring_begin(rq, 2 * count + 2);
+ if (IS_ERR(cs))
+ return PTR_ERR(cs);
+
+ *cs++ = MI_LOAD_REGISTER_IMM(count);
+ do {
+ *cs++ = i915_mmio_reg_offset(flex->reg);
+ *cs++ = flex->value;
+ } while (flex++, --count);
+ *cs++ = MI_NOOP;
+
+ intel_ring_advance(rq, cs);
+
+ return 0;
+}
+
+static int gen8_modify_context(struct intel_context *ce,
+ const struct flex *flex, unsigned int count)
+{
+ struct i915_request *rq;
+ int err;
+
+ lockdep_assert_held(&ce->pin_mutex);
+
+ rq = i915_request_create(ce->engine->kernel_context);
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
+
+ /* Serialise with the remote context */
+ err = i915_active_request_set(&ce->ring->timeline->last_request, rq);
+ if (err)
+ goto out_add;
+
+ /* Keep the remote context alive until after we finish editing */
+ err = i915_active_ref(&ce->active, rq->fence.context, rq);
+ if (err)
+ goto out_add;
+
+ err = gen8_store_flex(rq, ce, flex, count);
+
+out_add:
+ i915_request_add(rq);
+ return err;
+}
+
+static int gen8_modify_self(struct intel_context *ce,
+ const struct flex *flex, unsigned int count)
+{
+ struct i915_request *rq;
+ int err;
+
+ rq = i915_request_create(ce);
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
+
+ err = gen8_load_flex(rq, ce, flex, count);
+
+ i915_request_add(rq);
+ return err;
+}
+
/*
* Manages updating the per-context aspects of the OA stream
* configuration across all contexts.
@@ -1722,15 +1824,43 @@ gen8_update_reg_state_unlocked(struct intel_context *ce,
*
* Note: it's only the RCS/Render context that has any OA state.
*/
-static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv,
+static int gen8_configure_all_contexts(struct drm_i915_private *i915,
const struct i915_oa_config *oa_config)
{
- unsigned int map_type = i915_coherent_map_type(dev_priv);
+ /* The MMIO offsets for Flex EU registers aren't contiguous */
+ const u32 ctx_flexeu0 = i915->perf.oa.ctx_flexeu0_offset;
+#define ctx_flexeuN(N) (ctx_flexeu0 + 2 * (N))
+ struct flex regs[] = {
+ {
+ GEN8_R_PWR_CLK_STATE,
+ CTX_R_PWR_CLK_STATE,
+ },
+ {
+ GEN8_OACTXCONTROL,
+ i915->perf.oa.ctx_oactxctrl_offset,
+ ((i915->perf.oa.period_exponent << GEN8_OA_TIMER_PERIOD_SHIFT) |
+ (i915->perf.oa.periodic ? GEN8_OA_TIMER_ENABLE : 0) |
+ GEN8_OA_COUNTER_RESUME)
+ },
+ { EU_PERF_CNTL0, ctx_flexeuN(0) },
+ { EU_PERF_CNTL1, ctx_flexeuN(1) },
+ { EU_PERF_CNTL2, ctx_flexeuN(2) },
+ { EU_PERF_CNTL3, ctx_flexeuN(3) },
+ { EU_PERF_CNTL4, ctx_flexeuN(4) },
+ { EU_PERF_CNTL5, ctx_flexeuN(5) },
+ { EU_PERF_CNTL6, ctx_flexeuN(6) },
+ };
+#undef ctx_flexeuN
+ struct intel_engine_cs *engine;
struct i915_gem_context *ctx;
- struct i915_request *rq;
- int ret;
+ enum intel_engine_id id;
+ int err;
+ int i;
- lockdep_assert_held(&dev_priv->drm.struct_mutex);
+ for (i = 2; i < ARRAY_SIZE(regs); i++)
+ regs[i].value = oa_config_flex_reg(oa_config, regs[i].reg);
+
+ lockdep_assert_held(&i915->drm.struct_mutex);
/*
* The OA register config is setup through the context image. This image
@@ -1742,58 +1872,63 @@ static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv,
* this might leave small interval of time where the OA unit is
* configured at an invalid sampling period.
*
- * So far the best way to work around this issue seems to be draining
- * the GPU from any submitted work.
+ * Note that since we emit all requests from a single ring, there
+ * is still an implicit global barrier here that may cause a high
+ * priority context to wait for an otherwise independent low priority
+ * context. Contexts idle at the time of reconfiguration are not
+ * trapped behind the barrier.
*/
- ret = i915_gem_wait_for_idle(dev_priv,
- I915_WAIT_LOCKED,
- MAX_SCHEDULE_TIMEOUT);
- if (ret)
- return ret;
-
- /* Update all contexts now that we've stalled the submission. */
- list_for_each_entry(ctx, &dev_priv->contexts.list, link) {
+ list_for_each_entry(ctx, &i915->contexts.list, link) {
struct i915_gem_engines_iter it;
struct intel_context *ce;
+ if (ctx == i915->kernel_context)
+ continue;
+
for_each_gem_engine(ce,
i915_gem_context_lock_engines(ctx),
it) {
- u32 *regs;
+ GEM_BUG_ON(ce == ce->engine->kernel_context);
if (ce->engine->class != RENDER_CLASS)
continue;
- /* OA settings will be set upon first use */
- if (!ce->state)
- continue;
-
- regs = i915_gem_object_pin_map(ce->state->obj,
- map_type);
- if (IS_ERR(regs)) {
- i915_gem_context_unlock_engines(ctx);
- return PTR_ERR(regs);
- }
+ err = intel_context_lock_pinned(ce);
+ if (err)
+ break;
- ce->state->obj->mm.dirty = true;
- regs += LRC_STATE_PN * PAGE_SIZE / sizeof(*regs);
+ regs[0].value = intel_sseu_make_rpcs(i915, &ce->sseu);
- gen8_update_reg_state_unlocked(ce, regs, oa_config);
+ /* Otherwise OA settings will be set upon first use */
+ if (intel_context_is_pinned(ce))
+ err = gen8_modify_context(ce, regs, ARRAY_SIZE(regs));
- i915_gem_object_unpin_map(ce->state->obj);
+ intel_context_unlock_pinned(ce);
+ if (err)
+ break;
}
i915_gem_context_unlock_engines(ctx);
+ if (err)
+ return err;
}
/*
- * Apply the configuration by doing one context restore of the edited
- * context image.
+ * After updating all other contexts, we need to modify ourselves.
+ * If we don't modify the kernel_context, we do not get events while
+ * idle.
*/
- rq = i915_request_create(dev_priv->engine[RCS0]->kernel_context);
- if (IS_ERR(rq))
- return PTR_ERR(rq);
+ for_each_engine(engine, i915, id) {
+ struct intel_context *ce = engine->kernel_context;
- i915_request_add(rq);
+ if (engine->class != RENDER_CLASS)
+ continue;
+
+ regs[0].value = intel_sseu_make_rpcs(i915, &ce->sseu);
+
+ err = gen8_modify_self(ce, regs, ARRAY_SIZE(regs));
+ if (err)
+ return err;
+ }
return 0;
}
--
2.22.0
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