drm/i915: Prepare for GuC-based command submission

This adds the first of the data structures used to communicate with the
GuC (the pool of guc_context structures).

We create a GuC-specific wrapper round the GEM object allocator as all
GEM objects shared with the GuC must be pinned into GGTT space at an
address that is NOT in the range [0..WOPCM_TOP), as that range of GGTT
addresses is not accessible to the GuC (from the GuC's point of view,
it's permanently reserved for other objects such as the BootROM & SRAM).

Later, we will need to allocate additional GuC-sharable objects for the
submission client(s) and the GuC's debug log.

v2:
    Remove redundant initialisation [Chris Wilson]
    Defer adding struct members until needed [Chris Wilson]
    Local functions should pass dev_priv rather than dev [Chris Wilson]

v5:
    Invalidate GuC TLB after allocating and pinning a new object

v6:
    Rebased

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/Makefile

@@ -41,7 +41,8 @@ i915-y += i915_cmd_parser.o \
 	  intel_uncore.o
 
 # general-purpose microcontroller (GuC) support
-i915-y += intel_guc_loader.o
+i915-y += intel_guc_loader.o \
+	  i915_guc_submission.o
 
 # autogenerated null render state
 i915-y += intel_renderstate_gen6.o \

drivers/gpu/drm/i915/i915_guc_submission.c

@@ -0,0 +1,118 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+#include <linux/firmware.h>
+#include <linux/circ_buf.h>
+#include "i915_drv.h"
+#include "intel_guc.h"
+
+/**
+ * gem_allocate_guc_obj() - Allocate gem object for GuC usage
+ * @dev:	drm device
+ * @size:	size of object
+ *
+ * This is a wrapper to create a gem obj. In order to use it inside GuC, the
+ * object needs to be pinned lifetime. Also we must pin it to gtt space other
+ * than [0, GUC_WOPCM_TOP) because this range is reserved inside GuC.
+ *
+ * Return:	A drm_i915_gem_object if successful, otherwise NULL.
+ */
+static struct drm_i915_gem_object *gem_allocate_guc_obj(struct drm_device *dev,
+							u32 size)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_gem_object *obj;
+
+	obj = i915_gem_alloc_object(dev, size);
+	if (!obj)
+		return NULL;
+
+	if (i915_gem_object_get_pages(obj)) {
+		drm_gem_object_unreference(&obj->base);
+		return NULL;
+	}
+
+	if (i915_gem_obj_ggtt_pin(obj, PAGE_SIZE,
+			PIN_OFFSET_BIAS | GUC_WOPCM_TOP)) {
+		drm_gem_object_unreference(&obj->base);
+		return NULL;
+	}
+
+	/* Invalidate GuC TLB to let GuC take the latest updates to GTT. */
+	I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
+
+	return obj;
+}
+
+/**
+ * gem_release_guc_obj() - Release gem object allocated for GuC usage
+ * @obj:	gem obj to be released
+  */
+static void gem_release_guc_obj(struct drm_i915_gem_object *obj)
+{
+	if (!obj)
+		return;
+
+	if (i915_gem_obj_is_pinned(obj))
+		i915_gem_object_ggtt_unpin(obj);
+
+	drm_gem_object_unreference(&obj->base);
+}
+
+/*
+ * Set up the memory resources to be shared with the GuC.  At this point,
+ * we require just one object that can be mapped through the GGTT.
+ */
+int i915_guc_submission_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	const size_t ctxsize = sizeof(struct guc_context_desc);
+	const size_t poolsize = GUC_MAX_GPU_CONTEXTS * ctxsize;
+	const size_t gemsize = round_up(poolsize, PAGE_SIZE);
+	struct intel_guc *guc = &dev_priv->guc;
+
+	if (!i915.enable_guc_submission)
+		return 0; /* not enabled  */
+
+	if (guc->ctx_pool_obj)
+		return 0; /* already allocated */
+
+	guc->ctx_pool_obj = gem_allocate_guc_obj(dev_priv->dev, gemsize);
+	if (!guc->ctx_pool_obj)
+		return -ENOMEM;
+
+	ida_init(&guc->ctx_ids);
+
+	return 0;
+}
+
+void i915_guc_submission_fini(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+
+	if (guc->ctx_pool_obj)
+		ida_destroy(&guc->ctx_ids);
+	gem_release_guc_obj(guc->ctx_pool_obj);
+	guc->ctx_pool_obj = NULL;
+}

drivers/gpu/drm/i915/intel_guc.h

@@ -56,6 +56,9 @@ struct intel_guc {
 	struct intel_guc_fw guc_fw;
 
 	uint32_t log_flags;
+
+	struct drm_i915_gem_object *ctx_pool_obj;
+	struct ida ctx_ids;
 };
 
 /* intel_guc_loader.c */
@@ -64,4 +67,8 @@ extern int intel_guc_ucode_load(struct drm_device *dev);
 extern void intel_guc_ucode_fini(struct drm_device *dev);
 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);
+void i915_guc_submission_fini(struct drm_device *dev);
+
 #endif

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -128,6 +128,21 @@ static void set_guc_init_params(struct drm_i915_private *dev_priv)
 			i915.guc_log_level << GUC_LOG_VERBOSITY_SHIFT;
 	}
 
+	/* If GuC submission is enabled, set up additional parameters here */
+	if (i915.enable_guc_submission) {
+		u32 pgs = i915_gem_obj_ggtt_offset(dev_priv->guc.ctx_pool_obj);
+		u32 ctx_in_16 = GUC_MAX_GPU_CONTEXTS / 16;
+
+		pgs >>= PAGE_SHIFT;
+		params[GUC_CTL_CTXINFO] = (pgs << GUC_CTL_BASE_ADDR_SHIFT) |
+			(ctx_in_16 << GUC_CTL_CTXNUM_IN16_SHIFT);
+
+		params[GUC_CTL_FEATURE] |= GUC_CTL_KERNEL_SUBMISSIONS;
+
+		/* Unmask this bit to enable the GuC's internal scheduler */
+		params[GUC_CTL_FEATURE] &= ~GUC_CTL_DISABLE_SCHEDULER;
+	}
+
 	I915_WRITE(SOFT_SCRATCH(0), 0);
 
 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
@@ -360,6 +375,10 @@ int intel_guc_ucode_load(struct drm_device *dev)
 		break;
 	}
 
+	err = i915_guc_submission_init(dev);
+	if (err)
+		goto fail;
+
 	err = guc_ucode_xfer(dev_priv);
 	if (err)
 		goto fail;
@@ -521,6 +540,8 @@ void intel_guc_ucode_fini(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
 
+	i915_guc_submission_fini(dev);
+
 	if (guc_fw->guc_fw_obj)
 		drm_gem_object_unreference(&guc_fw->guc_fw_obj->base);
 	guc_fw->guc_fw_obj = NULL;