drm/i915/guc: Implement GuC context operations for new inteface

Implement GuC context operations which includes GuC specific operations
alloc, pin, unpin, and destroy.

v2:
 (Daniel Vetter)
  - Use msleep_interruptible rather than cond_resched in busy loop
 (Michal)
  - Remove C++ style comment
v3:
 (Matthew Brost)
  - Drop GUC_ID_START
 (John Harrison)
  - Fix a bunch of typos
  - Use drm_err rather than drm_dbg for G2H errors
 (Daniele)
  - Fix ;; typo
  - Clean up sched state functions
  - Add lockdep for guc_id functions
  - Don't call __release_guc_id when guc_id is invalid
  - Use MISSING_CASE
  - Add comment in guc_context_pin
  - Use shorter path to rpm
 (Daniele / CI)
  - Don't call release_guc_id on an invalid guc_id in destroy
v4:
 (Daniel Vetter)
  - Add FIXME comment

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721215101.139794-7-matthew.brost@intel.com

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

@@ -384,6 +384,11 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
 
 	mutex_init(&ce->pin_mutex);
 
+	spin_lock_init(&ce->guc_state.lock);
+
+	ce->guc_id = GUC_INVALID_LRC_ID;
+	INIT_LIST_HEAD(&ce->guc_id_link);
+
 	i915_active_init(&ce->active,
 			 __intel_context_active, __intel_context_retire, 0);
 }

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

@@ -96,6 +96,7 @@ struct intel_context {
 #define CONTEXT_BANNED			6
 #define CONTEXT_FORCE_SINGLE_SUBMISSION	7
 #define CONTEXT_NOPREEMPT		8
+#define CONTEXT_LRCA_DIRTY		9
 
 	struct {
 		u64 timeout_us;
@@ -138,14 +139,29 @@ struct intel_context {
 
 	u8 wa_bb_page; /* if set, page num reserved for context workarounds */
 
+	struct {
+		/** lock: protects everything in guc_state */
+		spinlock_t lock;
+		/**
+		 * sched_state: scheduling state of this context using GuC
+		 * submission
+		 */
+		u8 sched_state;
+	} guc_state;
+
 	/* GuC scheduling state flags that do not require a lock. */
 	atomic_t guc_sched_state_no_lock;
 
+	/* GuC LRC descriptor ID */
+	u16 guc_id;
+
+	/* GuC LRC descriptor reference count */
+	atomic_t guc_id_ref;
+
 	/*
-	 * GuC LRC descriptor ID - Not assigned in this patch but future patches
-	 * in the series will.
+	 * GuC ID link - in list when unpinned but guc_id still valid in GuC
 	 */
-	u16 guc_id;
+	struct list_head guc_id_link;
 };
 
 #endif /* __INTEL_CONTEXT_TYPES__ */

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

@@ -87,7 +87,6 @@
 #define GEN11_CSB_WRITE_PTR_MASK	(GEN11_CSB_PTR_MASK << 0)
 
 #define MAX_CONTEXT_HW_ID	(1 << 21) /* exclusive */
-#define MAX_GUC_CONTEXT_HW_ID	(1 << 20) /* exclusive */
 #define GEN11_MAX_CONTEXT_HW_ID	(1 << 11) /* exclusive */
 /* in Gen12 ID 0x7FF is reserved to indicate idle */
 #define GEN12_MAX_CONTEXT_HW_ID	(GEN11_MAX_CONTEXT_HW_ID - 1)

drivers/gpu/drm/i915/gt/uc/intel_guc.h

@@ -7,6 +7,7 @@
 #define _INTEL_GUC_H_
 
 #include <linux/xarray.h>
+#include <linux/delay.h>
 
 #include "intel_uncore.h"
 #include "intel_guc_fw.h"
@@ -44,6 +45,14 @@ struct intel_guc {
 		void (*disable)(struct intel_guc *guc);
 	} interrupts;
 
+	/*
+	 * contexts_lock protects the pool of free guc ids and a linked list of
+	 * guc ids available to be stolen
+	 */
+	spinlock_t contexts_lock;
+	struct ida guc_ids;
+	struct list_head guc_id_list;
+
 	bool submission_selected;
 
 	struct i915_vma *ads_vma;
@@ -101,6 +110,41 @@ intel_guc_send_and_receive(struct intel_guc *guc, const u32 *action, u32 len,
 				 response_buf, response_buf_size, 0);
 }
 
+static inline int intel_guc_send_busy_loop(struct intel_guc *guc,
+					   const u32 *action,
+					   u32 len,
+					   bool loop)
+{
+	int err;
+	unsigned int sleep_period_ms = 1;
+	bool not_atomic = !in_atomic() && !irqs_disabled();
+
+	/*
+	 * FIXME: Have caller pass in if we are in an atomic context to avoid
+	 * using in_atomic(). It is likely safe here as we check for irqs
+	 * disabled which basically all the spin locks in the i915 do but
+	 * regardless this should be cleaned up.
+	 */
+
+	/* No sleeping with spin locks, just busy loop */
+	might_sleep_if(loop && not_atomic);
+
+retry:
+	err = intel_guc_send_nb(guc, action, len);
+	if (unlikely(err == -EBUSY && loop)) {
+		if (likely(not_atomic)) {
+			if (msleep_interruptible(sleep_period_ms))
+				return -EINTR;
+			sleep_period_ms = sleep_period_ms << 1;
+		} else {
+			cpu_relax();
+		}
+		goto retry;
+	}
+
+	return err;
+}
+
 static inline void intel_guc_to_host_event_handler(struct intel_guc *guc)
 {
 	intel_guc_ct_event_handler(&guc->ct);
@@ -202,6 +246,9 @@ static inline void intel_guc_disable_msg(struct intel_guc *guc, u32 mask)
 int intel_guc_reset_engine(struct intel_guc *guc,
 			   struct intel_engine_cs *engine);
 
+int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
+					  const u32 *msg, u32 len);
+
 void intel_guc_load_status(struct intel_guc *guc, struct drm_printer *p);
 
 #endif

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

@@ -928,6 +928,10 @@ static int ct_process_request(struct intel_guc_ct *ct, struct ct_incoming_msg *r
 	case INTEL_GUC_ACTION_DEFAULT:
 		ret = intel_guc_to_host_process_recv_msg(guc, payload, len);
 		break;
+	case INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE:
+		ret = intel_guc_deregister_done_process_msg(guc, payload,
+							    len);
+		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;