#define GEN8_CTX_STATUS_COMPLETE (1 << 4)
#define GEN8_CTX_STATUS_LITE_RESTORE (1 << 15)
+#define GEN8_CTX_STATUS_COMPLETED_MASK \
+ (GEN8_CTX_STATUS_ACTIVE_IDLE | \
+ GEN8_CTX_STATUS_PREEMPTED | \
+ GEN8_CTX_STATUS_ELEMENT_SWITCH)
+
#define CTX_LRI_HEADER_0 0x01
#define CTX_CONTEXT_CONTROL 0x02
#define CTX_RING_HEAD 0x04
{
struct drm_i915_private *dev_priv = engine->i915;
- if (IS_GEN8(dev_priv) || IS_GEN9(dev_priv))
- engine->idle_lite_restore_wa = ~0;
-
- engine->disable_lite_restore_wa = (IS_SKL_REVID(dev_priv, 0, SKL_REVID_B0) ||
- IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1)) &&
- (engine->id == VCS || engine->id == VCS2);
+ engine->disable_lite_restore_wa =
+ (IS_SKL_REVID(dev_priv, 0, SKL_REVID_B0) ||
+ IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1)) &&
+ (engine->id == VCS || engine->id == VCS2);
engine->ctx_desc_template = GEN8_CTX_VALID;
if (IS_GEN8(dev_priv))
ASSIGN_CTX_PDP(ppgtt, reg_state, 0);
}
-static void execlists_update_context(struct drm_i915_gem_request *rq)
+static u64 execlists_update_context(struct drm_i915_gem_request *rq)
{
- struct intel_engine_cs *engine = rq->engine;
+ struct intel_context *ce = &rq->ctx->engine[rq->engine->id];
struct i915_hw_ppgtt *ppgtt = rq->ctx->ppgtt;
- uint32_t *reg_state = rq->ctx->engine[engine->id].lrc_reg_state;
+ u32 *reg_state = ce->lrc_reg_state;
reg_state[CTX_RING_TAIL+1] = intel_ring_offset(rq->ring, rq->tail);
*/
if (ppgtt && !USES_FULL_48BIT_PPGTT(ppgtt->base.dev))
execlists_update_context_pdps(ppgtt, reg_state);
+
+ return ce->lrc_desc;
}
-static void execlists_elsp_write(struct drm_i915_gem_request *rq0,
- struct drm_i915_gem_request *rq1)
+static void execlists_submit_ports(struct intel_engine_cs *engine)
{
- struct intel_engine_cs *engine = rq0->engine;
- struct drm_i915_private *dev_priv = rq0->i915;
+ struct drm_i915_private *dev_priv = engine->i915;
+ struct execlist_port *port = engine->execlist_port;
u32 __iomem *elsp =
dev_priv->regs + i915_mmio_reg_offset(RING_ELSP(engine));
u64 desc[2];
- if (rq1) {
- desc[1] = intel_lr_context_descriptor(rq1->ctx, rq1->engine);
- rq1->elsp_submitted++;
+ if (!port[0].count)
+ execlists_context_status_change(port[0].request,
+ INTEL_CONTEXT_SCHEDULE_IN);
+ desc[0] = execlists_update_context(port[0].request);
+ engine->preempt_wa = port[0].count++; /* bdw only? fixed on skl? */
+
+ if (port[1].request) {
+ GEM_BUG_ON(port[1].count);
+ execlists_context_status_change(port[1].request,
+ INTEL_CONTEXT_SCHEDULE_IN);
+ desc[1] = execlists_update_context(port[1].request);
+ port[1].count = 1;
} else {
desc[1] = 0;
}
-
- desc[0] = intel_lr_context_descriptor(rq0->ctx, rq0->engine);
- rq0->elsp_submitted++;
+ GEM_BUG_ON(desc[0] == desc[1]);
/* You must always write both descriptors in the order below. */
writel(upper_32_bits(desc[1]), elsp);
writel(lower_32_bits(desc[0]), elsp);
}
-static void execlists_elsp_submit_contexts(struct drm_i915_gem_request *rq0,
- struct drm_i915_gem_request *rq1)
+static bool ctx_single_port_submission(const struct i915_gem_context *ctx)
{
- struct drm_i915_private *dev_priv = rq0->i915;
- unsigned int fw_domains = rq0->engine->fw_domains;
-
- execlists_update_context(rq0);
-
- if (rq1)
- execlists_update_context(rq1);
+ return (IS_ENABLED(CONFIG_DRM_I915_GVT) &&
+ ctx->execlists_force_single_submission);
+}
- spin_lock_irq(&dev_priv->uncore.lock);
- intel_uncore_forcewake_get__locked(dev_priv, fw_domains);
+static bool can_merge_ctx(const struct i915_gem_context *prev,
+ const struct i915_gem_context *next)
+{
+ if (prev != next)
+ return false;
- execlists_elsp_write(rq0, rq1);
+ if (ctx_single_port_submission(prev))
+ return false;
- intel_uncore_forcewake_put__locked(dev_priv, fw_domains);
- spin_unlock_irq(&dev_priv->uncore.lock);
+ return true;
}
-static void execlists_unqueue(struct intel_engine_cs *engine)
+static void execlists_dequeue(struct intel_engine_cs *engine)
{
- struct drm_i915_gem_request *req0 = NULL, *req1 = NULL;
- struct drm_i915_gem_request *cursor, *tmp;
+ struct drm_i915_gem_request *cursor, *last;
+ struct execlist_port *port = engine->execlist_port;
+ bool submit = false;
+
+ last = port->request;
+ if (last)
+ /* WaIdleLiteRestore:bdw,skl
+ * Apply the wa NOOPs to prevent ring:HEAD == req:TAIL
+ * as we resubmit the request. See gen8_emit_request()
+ * for where we prepare the padding after the end of the
+ * request.
+ */
+ last->tail = last->wa_tail;
- assert_spin_locked(&engine->execlist_lock);
+ GEM_BUG_ON(port[1].request);
- /*
- * If irqs are not active generate a warning as batches that finish
- * without the irqs may get lost and a GPU Hang may occur.
+ /* Hardware submission is through 2 ports. Conceptually each port
+ * has a (RING_START, RING_HEAD, RING_TAIL) tuple. RING_START is
+ * static for a context, and unique to each, so we only execute
+ * requests belonging to a single context from each ring. RING_HEAD
+ * is maintained by the CS in the context image, it marks the place
+ * where it got up to last time, and through RING_TAIL we tell the CS
+ * where we want to execute up to this time.
+ *
+ * In this list the requests are in order of execution. Consecutive
+ * requests from the same context are adjacent in the ringbuffer. We
+ * can combine these requests into a single RING_TAIL update:
+ *
+ * RING_HEAD...req1...req2
+ * ^- RING_TAIL
+ * since to execute req2 the CS must first execute req1.
+ *
+ * Our goal then is to point each port to the end of a consecutive
+ * sequence of requests as being the most optimal (fewest wake ups
+ * and context switches) submission.
*/
- WARN_ON(!intel_irqs_enabled(engine->i915));
-
- /* Try to read in pairs */
- list_for_each_entry_safe(cursor, tmp, &engine->execlist_queue,
- execlist_link) {
- if (!req0) {
- req0 = cursor;
- } else if (req0->ctx == cursor->ctx) {
- /* Same ctx: ignore first request, as second request
- * will update tail past first request's workload */
- cursor->elsp_submitted = req0->elsp_submitted;
- list_del(&req0->execlist_link);
- i915_gem_request_put(req0);
- req0 = cursor;
- } else {
- if (IS_ENABLED(CONFIG_DRM_I915_GVT)) {
- /*
- * req0 (after merged) ctx requires single
- * submission, stop picking
- */
- if (req0->ctx->execlists_force_single_submission)
- break;
- /*
- * req0 ctx doesn't require single submission,
- * but next req ctx requires, stop picking
- */
- if (cursor->ctx->execlists_force_single_submission)
- break;
- }
- req1 = cursor;
- WARN_ON(req1->elsp_submitted);
- break;
- }
- }
- if (unlikely(!req0))
- return;
-
- execlists_context_status_change(req0, INTEL_CONTEXT_SCHEDULE_IN);
-
- if (req1)
- execlists_context_status_change(req1,
- INTEL_CONTEXT_SCHEDULE_IN);
-
- if (req0->elsp_submitted & engine->idle_lite_restore_wa) {
- /*
- * WaIdleLiteRestore: make sure we never cause a lite restore
- * with HEAD==TAIL.
+ spin_lock(&engine->execlist_lock);
+ list_for_each_entry(cursor, &engine->execlist_queue, execlist_link) {
+ /* Can we combine this request with the current port? It has to
+ * be the same context/ringbuffer and not have any exceptions
+ * (e.g. GVT saying never to combine contexts).
*
- * Apply the wa NOOPS to prevent ring:HEAD == req:TAIL as we
- * resubmit the request. See gen8_emit_request() for where we
- * prepare the padding after the end of the request.
+ * If we can combine the requests, we can execute both by
+ * updating the RING_TAIL to point to the end of the second
+ * request, and so we never need to tell the hardware about
+ * the first.
*/
- req0->tail = req0->wa_tail;
+ if (last && !can_merge_ctx(cursor->ctx, last->ctx)) {
+ /* If we are on the second port and cannot combine
+ * this request with the last, then we are done.
+ */
+ if (port != engine->execlist_port)
+ break;
+
+ /* If GVT overrides us we only ever submit port[0],
+ * leaving port[1] empty. Note that we also have
+ * to be careful that we don't queue the same
+ * context (even though a different request) to
+ * the second port.
+ */
+ if (ctx_single_port_submission(cursor->ctx))
+ break;
+
+ GEM_BUG_ON(last->ctx == cursor->ctx);
+
+ i915_gem_request_assign(&port->request, last);
+ port++;
+ }
+ last = cursor;
+ submit = true;
+ }
+ if (submit) {
+ /* Decouple all the requests submitted from the queue */
+ engine->execlist_queue.next = &cursor->execlist_link;
+ cursor->execlist_link.prev = &engine->execlist_queue;
+
+ i915_gem_request_assign(&port->request, last);
}
+ spin_unlock(&engine->execlist_lock);
- execlists_elsp_submit_contexts(req0, req1);
+ if (submit)
+ execlists_submit_ports(engine);
}
-static unsigned int
-execlists_check_remove_request(struct intel_engine_cs *engine, u32 ctx_id)
+static bool execlists_elsp_idle(struct intel_engine_cs *engine)
{
- struct drm_i915_gem_request *head_req;
-
- assert_spin_locked(&engine->execlist_lock);
-
- head_req = list_first_entry_or_null(&engine->execlist_queue,
- struct drm_i915_gem_request,
- execlist_link);
-
- if (WARN_ON(!head_req || (head_req->ctx_hw_id != ctx_id)))
- return 0;
-
- WARN(head_req->elsp_submitted == 0, "Never submitted head request\n");
-
- if (--head_req->elsp_submitted > 0)
- return 0;
-
- execlists_context_status_change(head_req, INTEL_CONTEXT_SCHEDULE_OUT);
-
- list_del(&head_req->execlist_link);
- i915_gem_request_put(head_req);
-
- return 1;
+ return !engine->execlist_port[0].request;
}
-static u32
-get_context_status(struct intel_engine_cs *engine, unsigned int read_pointer,
- u32 *context_id)
+static bool execlists_elsp_ready(struct intel_engine_cs *engine)
{
- struct drm_i915_private *dev_priv = engine->i915;
- u32 status;
-
- read_pointer %= GEN8_CSB_ENTRIES;
-
- status = I915_READ_FW(RING_CONTEXT_STATUS_BUF_LO(engine, read_pointer));
-
- if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
- return 0;
+ int port;
- *context_id = I915_READ_FW(RING_CONTEXT_STATUS_BUF_HI(engine,
- read_pointer));
+ port = 1; /* wait for a free slot */
+ if (engine->disable_lite_restore_wa || engine->preempt_wa)
+ port = 0; /* wait for GPU to be idle before continuing */
- return status;
+ return !engine->execlist_port[port].request;
}
/*
static void intel_lrc_irq_handler(unsigned long data)
{
struct intel_engine_cs *engine = (struct intel_engine_cs *)data;
+ struct execlist_port *port = engine->execlist_port;
struct drm_i915_private *dev_priv = engine->i915;
- u32 status_pointer;
- unsigned int read_pointer, write_pointer;
- u32 csb[GEN8_CSB_ENTRIES][2];
- unsigned int csb_read = 0, i;
- unsigned int submit_contexts = 0;
intel_uncore_forcewake_get(dev_priv, engine->fw_domains);
- status_pointer = I915_READ_FW(RING_CONTEXT_STATUS_PTR(engine));
-
- read_pointer = engine->next_context_status_buffer;
- write_pointer = GEN8_CSB_WRITE_PTR(status_pointer);
- if (read_pointer > write_pointer)
- write_pointer += GEN8_CSB_ENTRIES;
-
- while (read_pointer < write_pointer) {
- if (WARN_ON_ONCE(csb_read == GEN8_CSB_ENTRIES))
- break;
- csb[csb_read][0] = get_context_status(engine, ++read_pointer,
- &csb[csb_read][1]);
- csb_read++;
- }
-
- engine->next_context_status_buffer = write_pointer % GEN8_CSB_ENTRIES;
-
- /* Update the read pointer to the old write pointer. Manual ringbuffer
- * management ftw </sarcasm> */
- I915_WRITE_FW(RING_CONTEXT_STATUS_PTR(engine),
- _MASKED_FIELD(GEN8_CSB_READ_PTR_MASK,
- engine->next_context_status_buffer << 8));
-
- intel_uncore_forcewake_put(dev_priv, engine->fw_domains);
-
- spin_lock(&engine->execlist_lock);
+ if (!execlists_elsp_idle(engine)) {
+ u32 __iomem *csb_mmio =
+ dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine));
+ u32 __iomem *buf =
+ dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0));
+ unsigned int csb, head, tail;
+
+ csb = readl(csb_mmio);
+ head = GEN8_CSB_READ_PTR(csb);
+ tail = GEN8_CSB_WRITE_PTR(csb);
+ if (tail < head)
+ tail += GEN8_CSB_ENTRIES;
+ while (head < tail) {
+ unsigned int idx = ++head % GEN8_CSB_ENTRIES;
+ unsigned int status = readl(buf + 2 * idx);
+
+ if (!(status & GEN8_CTX_STATUS_COMPLETED_MASK))
+ continue;
+
+ GEM_BUG_ON(port[0].count == 0);
+ if (--port[0].count == 0) {
+ GEM_BUG_ON(status & GEN8_CTX_STATUS_PREEMPTED);
+ execlists_context_status_change(port[0].request,
+ INTEL_CONTEXT_SCHEDULE_OUT);
+
+ i915_gem_request_put(port[0].request);
+ port[0] = port[1];
+ memset(&port[1], 0, sizeof(port[1]));
+
+ engine->preempt_wa = false;
+ }
- for (i = 0; i < csb_read; i++) {
- if (unlikely(csb[i][0] & GEN8_CTX_STATUS_PREEMPTED)) {
- if (csb[i][0] & GEN8_CTX_STATUS_LITE_RESTORE) {
- if (execlists_check_remove_request(engine, csb[i][1]))
- WARN(1, "Lite Restored request removed from queue\n");
- } else
- WARN(1, "Preemption without Lite Restore\n");
+ GEM_BUG_ON(port[0].count == 0 &&
+ !(status & GEN8_CTX_STATUS_ACTIVE_IDLE));
}
- if (csb[i][0] & (GEN8_CTX_STATUS_ACTIVE_IDLE |
- GEN8_CTX_STATUS_ELEMENT_SWITCH))
- submit_contexts +=
- execlists_check_remove_request(engine, csb[i][1]);
+ writel(_MASKED_FIELD(GEN8_CSB_READ_PTR_MASK,
+ GEN8_CSB_WRITE_PTR(csb) << 8),
+ csb_mmio);
}
- if (submit_contexts) {
- if (!engine->disable_lite_restore_wa ||
- (csb[i][0] & GEN8_CTX_STATUS_ACTIVE_IDLE))
- execlists_unqueue(engine);
- }
+ if (execlists_elsp_ready(engine))
+ execlists_dequeue(engine);
- spin_unlock(&engine->execlist_lock);
-
- if (unlikely(submit_contexts > 2))
- DRM_ERROR("More than two context complete events?\n");
+ intel_uncore_forcewake_put(dev_priv, engine->fw_domains);
}
static void execlists_submit_request(struct drm_i915_gem_request *request)
spin_lock_bh(&engine->execlist_lock);
- i915_gem_request_get(request);
- request->ctx_hw_id = request->ctx->hw_id;
-
- if (list_empty(&engine->execlist_queue))
- tasklet_hi_schedule(&engine->irq_tasklet);
list_add_tail(&request->execlist_link, &engine->execlist_queue);
+ if (execlists_elsp_idle(engine))
+ tasklet_hi_schedule(&engine->irq_tasklet);
spin_unlock_bh(&engine->execlist_lock);
}
return 0;
}
-void intel_execlists_cancel_requests(struct intel_engine_cs *engine)
-{
- struct drm_i915_gem_request *req, *tmp;
- LIST_HEAD(cancel_list);
-
- WARN_ON(!mutex_is_locked(&engine->i915->drm.struct_mutex));
-
- spin_lock_bh(&engine->execlist_lock);
- list_replace_init(&engine->execlist_queue, &cancel_list);
- spin_unlock_bh(&engine->execlist_lock);
-
- list_for_each_entry_safe(req, tmp, &cancel_list, execlist_link) {
- list_del(&req->execlist_link);
- i915_gem_request_put(req);
- }
-}
-
static int intel_lr_context_pin(struct i915_gem_context *ctx,
struct intel_engine_cs *engine)
{
static int gen8_init_common_ring(struct intel_engine_cs *engine)
{
struct drm_i915_private *dev_priv = engine->i915;
- unsigned int next_context_status_buffer_hw;
lrc_init_hws(engine);
I915_WRITE(RING_MODE_GEN7(engine),
_MASKED_BIT_DISABLE(GFX_REPLAY_MODE) |
_MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE));
- POSTING_READ(RING_MODE_GEN7(engine));
-
- /*
- * Instead of resetting the Context Status Buffer (CSB) read pointer to
- * zero, we need to read the write pointer from hardware and use its
- * value because "this register is power context save restored".
- * Effectively, these states have been observed:
- *
- * | Suspend-to-idle (freeze) | Suspend-to-RAM (mem) |
- * BDW | CSB regs not reset | CSB regs reset |
- * CHT | CSB regs not reset | CSB regs not reset |
- * SKL | ? | ? |
- * BXT | ? | ? |
- */
- next_context_status_buffer_hw =
- GEN8_CSB_WRITE_PTR(I915_READ(RING_CONTEXT_STATUS_PTR(engine)));
- /*
- * When the CSB registers are reset (also after power-up / gpu reset),
- * CSB write pointer is set to all 1's, which is not valid, use '5' in
- * this special case, so the first element read is CSB[0].
- */
- if (next_context_status_buffer_hw == GEN8_CSB_PTR_MASK)
- next_context_status_buffer_hw = (GEN8_CSB_ENTRIES - 1);
-
- engine->next_context_status_buffer = next_context_status_buffer_hw;
DRM_DEBUG_DRIVER("Execlists enabled for %s\n", engine->name);
intel_engine_init_hangcheck(engine);
}
intel_lr_context_unpin(dev_priv->kernel_context, engine);
- engine->idle_lite_restore_wa = 0;
- engine->disable_lite_restore_wa = false;
- engine->ctx_desc_template = 0;
-
lrc_destroy_wa_ctx_obj(engine);
engine->i915 = NULL;
}