drm/i915: Implementation of GuC submission client

A GuC client has its own doorbell and workqueue. It maintains the
doorbell cache line, process description object and work queue item.

A default guc_client is created for the i915 driver to use for
normal-priority in-order submission.

Note that the created client is not yet ready for use; doorbell
allocation will fail as we haven't yet linked the GuC's context
descriptor to the default contexts for each ring (see later patch).

v2:
    Defer adding structure members until needed [Chris Wilson]
    Rationalise type declarations [Chris Wilson]

v5:
    Add GuC per-engine submission & seqno statistics.
    Move wq locking to encompass both get_space() and add_item().
    Take forcewake lock in host2guc_action() [Tom O'Rourke]

v6:
    Fix GuC doorbell cacheline selection code (the
        cacheline-within-page calculation was wrong).
    Rename GuC priorities to make them closer to the names used in
        the GuC firmware source, matching what the autogenerated
        versions will (probably) be.
    Add per-ring statistics to client.

Issue: VIZ-4884
Signed-off-by: Alex Dai <yu.dai@intel.com>
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Tom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_guc.h

@@ -27,6 +27,31 @@
 #include "intel_guc_fwif.h"
 #include "i915_guc_reg.h"
 
+struct i915_guc_client {
+	struct drm_i915_gem_object *client_obj;
+	struct intel_guc *guc;
+	uint32_t priority;
+	uint32_t ctx_index;
+
+	uint32_t proc_desc_offset;
+	uint32_t doorbell_offset;
+	uint32_t cookie;
+	uint16_t doorbell_id;
+	uint16_t padding;		/* Maintain alignment		*/
+
+	uint32_t wq_offset;
+	uint32_t wq_size;
+
+	spinlock_t wq_lock;		/* Protects all data below	*/
+	uint32_t wq_tail;
+
+	/* GuC submission statistics & status */
+	uint64_t submissions[I915_NUM_RINGS];
+	uint32_t q_fail;
+	uint32_t b_fail;
+	int retcode;
+};
+
 enum intel_guc_fw_status {
 	GUC_FIRMWARE_FAIL = -1,
 	GUC_FIRMWARE_NONE = 0,
@@ -60,6 +85,23 @@ struct intel_guc {
 
 	struct drm_i915_gem_object *ctx_pool_obj;
 	struct ida ctx_ids;
+
+	struct i915_guc_client *execbuf_client;
+
+	spinlock_t host2guc_lock;	/* Protects all data below	*/
+
+	DECLARE_BITMAP(doorbell_bitmap, GUC_MAX_DOORBELLS);
+	uint32_t db_cacheline;		/* Cyclic counter mod pagesize	*/
+
+	/* Action status & statistics */
+	uint64_t action_count;		/* Total commands issued	*/
+	uint32_t action_cmd;		/* Last command word		*/
+	uint32_t action_status;		/* Last return status		*/
+	uint32_t action_fail;		/* Total number of failures	*/
+	int32_t action_err;		/* Last error code		*/
+
+	uint64_t submissions[I915_NUM_RINGS];
+	uint32_t last_seqno[I915_NUM_RINGS];
 };
 
 /* intel_guc_loader.c */
@@ -70,6 +112,10 @@ extern const char *intel_guc_fw_status_repr(enum intel_guc_fw_status status);
 
 /* i915_guc_submission.c */
 int i915_guc_submission_init(struct drm_device *dev);
+int i915_guc_submission_enable(struct drm_device *dev);
+int i915_guc_submit(struct i915_guc_client *client,
+		    struct drm_i915_gem_request *rq);
+void i915_guc_submission_disable(struct drm_device *dev);
 void i915_guc_submission_fini(struct drm_device *dev);
 
 #endif

drivers/gpu/drm/i915/intel_guc_fwif.h

@@ -35,10 +35,10 @@
 #define GFXCORE_FAMILY_GEN9		12
 #define GFXCORE_FAMILY_UNKNOWN		0x7fffffff
 
-#define GUC_CTX_PRIORITY_CRITICAL	0
+#define GUC_CTX_PRIORITY_KMD_HIGH	0
 #define GUC_CTX_PRIORITY_HIGH		1
-#define GUC_CTX_PRIORITY_NORMAL		2
-#define GUC_CTX_PRIORITY_LOW		3
+#define GUC_CTX_PRIORITY_KMD_NORMAL	2
+#define GUC_CTX_PRIORITY_NORMAL		3
 
 #define GUC_MAX_GPU_CONTEXTS		1024
 #define	GUC_INVALID_CTX_ID		(GUC_MAX_GPU_CONTEXTS + 1)

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -342,6 +342,8 @@ int intel_guc_ucode_load(struct drm_device *dev)
 		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status),
 		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
 
+	i915_guc_submission_disable(dev);
+
 	if (guc_fw->guc_fw_fetch_status == GUC_FIRMWARE_NONE)
 		return 0;
 
@@ -389,12 +391,20 @@ int intel_guc_ucode_load(struct drm_device *dev)
 		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status),
 		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
 
+	if (i915.enable_guc_submission) {
+		err = i915_guc_submission_enable(dev);
+		if (err)
+			goto fail;
+	}
+
 	return 0;
 
 fail:
 	if (guc_fw->guc_fw_load_status == GUC_FIRMWARE_PENDING)
 		guc_fw->guc_fw_load_status = GUC_FIRMWARE_FAIL;
 
+	i915_guc_submission_disable(dev);
+
 	return err;
 }