drm/i915/gt: Split logical ring contexts from execlist submission

Split the definition, construction and updating of the Logical Ring
Context from the execlist submission interface. The LRC is used by the
HW, irrespective of our different submission backends.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201219020343.22681-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/Makefile

@@ -104,6 +104,7 @@ gt-y += \
 	gt/intel_gt_requests.o \
 	gt/intel_gtt.o \
 	gt/intel_llc.o \
+	gt/intel_lrc.o \
 	gt/intel_mocs.o \
 	gt/intel_ppgtt.o \
 	gt/intel_rc6.o \

drivers/gpu/drm/i915/gt/gen8_engine_cs.c

@@ -5,7 +5,7 @@
 
 #include "gen8_engine_cs.h"
 #include "i915_drv.h"
-#include "intel_execlists_submission.h" /* XXX */
+#include "intel_lrc.h"
 #include "intel_gpu_commands.h"
 #include "intel_ring.h"
 

drivers/gpu/drm/i915/gt/intel_context_sseu.c

@@ -8,8 +8,7 @@
 #include "intel_context.h"
 #include "intel_engine_pm.h"
 #include "intel_gpu_commands.h"
-#include "intel_execlists_submission.h"
-#include "intel_lrc_reg.h"
+#include "intel_lrc.h"
 #include "intel_ring.h"
 #include "intel_sseu.h"
 

drivers/gpu/drm/i915/gt/intel_execlists_submission.h

@@ -22,25 +22,8 @@ enum {
 
 int intel_execlists_submission_setup(struct intel_engine_cs *engine);
 
-/* Logical Ring Contexts */
-/* At the start of the context image is its per-process HWS page */
-#define LRC_PPHWSP_PN	(0)
-#define LRC_PPHWSP_SZ	(1)
-/* After the PPHWSP we have the logical state for the context */
-#define LRC_STATE_PN	(LRC_PPHWSP_PN + LRC_PPHWSP_SZ)
-#define LRC_STATE_OFFSET (LRC_STATE_PN * PAGE_SIZE)
-
-/* Space within PPHWSP reserved to be used as scratch */
-#define LRC_PPHWSP_SCRATCH		0x34
-#define LRC_PPHWSP_SCRATCH_ADDR		(LRC_PPHWSP_SCRATCH * sizeof(u32))
-
 void intel_execlists_set_default_submission(struct intel_engine_cs *engine);
 
-void intel_lr_context_reset(struct intel_engine_cs *engine,
-			    struct intel_context *ce,
-			    u32 head,
-			    bool scrub);
-
 void intel_execlists_show_requests(struct intel_engine_cs *engine,
 				   struct drm_printer *m,
 				   void (*show_request)(struct drm_printer *m,

drivers/gpu/drm/i915/gt/intel_lrc.h

@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2014 Intel Corporation
+ */
+
+#ifndef __INTEL_LRC_H__
+#define __INTEL_LRC_H__
+
+#include <linux/types.h>
+
+#include "intel_context.h"
+#include "intel_lrc_reg.h"
+
+struct drm_i915_gem_object;
+struct intel_engine_cs;
+struct intel_ring;
+
+/* At the start of the context image is its per-process HWS page */
+#define LRC_PPHWSP_PN	(0)
+#define LRC_PPHWSP_SZ	(1)
+/* After the PPHWSP we have the logical state for the context */
+#define LRC_STATE_PN	(LRC_PPHWSP_PN + LRC_PPHWSP_SZ)
+#define LRC_STATE_OFFSET (LRC_STATE_PN * PAGE_SIZE)
+
+/* Space within PPHWSP reserved to be used as scratch */
+#define LRC_PPHWSP_SCRATCH		0x34
+#define LRC_PPHWSP_SCRATCH_ADDR		(LRC_PPHWSP_SCRATCH * sizeof(u32))
+
+int lrc_init_wa_ctx(struct intel_engine_cs *engine);
+void lrc_fini_wa_ctx(struct intel_engine_cs *engine);
+
+int lrc_alloc(struct intel_context *ce,
+	      struct intel_engine_cs *engine);
+void lrc_reset(struct intel_context *ce);
+void lrc_fini(struct intel_context *ce);
+void lrc_destroy(struct kref *kref);
+
+int
+lrc_pre_pin(struct intel_context *ce,
+	    struct intel_engine_cs *engine,
+	    struct i915_gem_ww_ctx *ww,
+	    void **vaddr);
+int
+lrc_pin(struct intel_context *ce,
+	struct intel_engine_cs *engine,
+	void *vaddr);
+void lrc_unpin(struct intel_context *ce);
+void lrc_post_unpin(struct intel_context *ce);
+
+void lrc_init_state(struct intel_context *ce,
+		    struct intel_engine_cs *engine,
+		    void *state);
+
+void lrc_init_regs(const struct intel_context *ce,
+		   const struct intel_engine_cs *engine,
+		   bool clear);
+void lrc_reset_regs(const struct intel_context *ce,
+		    const struct intel_engine_cs *engine);
+
+u32 lrc_update_regs(const struct intel_context *ce,
+		    const struct intel_engine_cs *engine,
+		    u32 head);
+void lrc_update_offsets(struct intel_context *ce,
+			struct intel_engine_cs *engine);
+
+void lrc_check_regs(const struct intel_context *ce,
+		    const struct intel_engine_cs *engine,
+		    const char *when);
+
+void lrc_update_runtime(struct intel_context *ce);
+static inline u32 lrc_get_runtime(const struct intel_context *ce)
+{
+	/*
+	 * We can use either ppHWSP[16] which is recorded before the context
+	 * switch (and so excludes the cost of context switches) or use the
+	 * value from the context image itself, which is saved/restored earlier
+	 * and so includes the cost of the save.
+	 */
+	return READ_ONCE(ce->lrc_reg_state[CTX_TIMESTAMP]);
+}
+
+#endif /* __INTEL_LRC_H__ */

drivers/gpu/drm/i915/gt/intel_lrc_reg.h

@@ -9,6 +9,8 @@
 
 #include <linux/types.h>
 
+#define CTX_DESC_FORCE_RESTORE BIT_ULL(2)
+
 /* GEN8 to GEN12 Reg State Context */
 #define CTX_CONTEXT_CONTROL		(0x02 + 1)
 #define CTX_RING_HEAD			(0x04 + 1)

drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c

@@ -3,8 +3,8 @@
  * Copyright © 2014-2019 Intel Corporation
  */
 
-#include "gt/intel_execlists_submission.h" /* lrc layout */
 #include "gt/intel_gt.h"
+#include "gt/intel_lrc.h"
 #include "intel_guc_ads.h"
 #include "intel_uc.h"
 #include "i915_drv.h"

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -11,7 +11,7 @@
 #include "gt/intel_execlists_submission.h" /* XXX */
 #include "gt/intel_gt.h"
 #include "gt/intel_gt_pm.h"
-#include "gt/intel_lrc_reg.h"
+#include "gt/intel_lrc.h"
 #include "gt/intel_ring.h"
 
 #include "intel_guc_submission.h"
@@ -402,6 +402,28 @@ cancel_port_requests(struct intel_engine_execlists * const execlists)
 		memset(execlists->inflight, 0, sizeof(execlists->inflight));
 }
 
+static void guc_reset_state(struct intel_context *ce,
+			    struct intel_engine_cs *engine,
+			    u32 head,
+			    bool scrub)
+{
+	GEM_BUG_ON(!intel_context_is_pinned(ce));
+
+	/*
+	 * We want a simple context + ring to execute the breadcrumb update.
+	 * We cannot rely on the context being intact across the GPU hang,
+	 * so clear it and rebuild just what we need for the breadcrumb.
+	 * All pending requests for this context will be zapped, and any
+	 * future request will be after userspace has had the opportunity
+	 * to recreate its own state.
+	 */
+	if (scrub)
+		lrc_init_regs(ce, engine, true);
+
+	/* Rerun the request; its payload has been neutered (if guilty). */
+	lrc_update_regs(ce, engine, head);
+}
+
 static void guc_reset_rewind(struct intel_engine_cs *engine, bool stalled)
 {
 	struct intel_engine_execlists * const execlists = &engine->execlists;
@@ -421,7 +443,7 @@ static void guc_reset_rewind(struct intel_engine_cs *engine, bool stalled)
 		stalled = false;
 
 	__i915_request_reset(rq, stalled);
-	intel_lr_context_reset(engine, rq->context, rq->head, stalled);
+	guc_reset_state(rq->context, engine, rq->head, stalled);
 
 out_unlock:
 	spin_unlock_irqrestore(&engine->active.lock, flags);

drivers/gpu/drm/i915/gvt/scheduler.c

@@ -38,6 +38,7 @@
 #include "gem/i915_gem_pm.h"
 #include "gt/intel_context.h"
 #include "gt/intel_execlists_submission.h"
+#include "gt/intel_lrc.h"
 #include "gt/intel_ring.h"
 
 #include "i915_drv.h"

drivers/gpu/drm/i915/i915_perf.c

@@ -201,7 +201,7 @@
 #include "gt/intel_execlists_submission.h"
 #include "gt/intel_gpu_commands.h"
 #include "gt/intel_gt.h"
-#include "gt/intel_lrc_reg.h"
+#include "gt/intel_lrc.h"
 #include "gt/intel_ring.h"
 
 #include "i915_drv.h"