drivers/gpu/drm/i915/intel_guc.c - linux - Git at Google

 /*
  * Copyright © 2014-2017 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 "intel_guc.h"
 #include "intel_guc_ads.h"
 #include "intel_guc_submission.h"
 #include "i915_drv.h"

 static void guc_init_ggtt_pin_bias(struct intel_guc *guc);

 static void gen8_guc_raise_irq(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);

 	I915_WRITE(GUC_SEND_INTERRUPT, GUC_SEND_TRIGGER);
 }

 static inline i915_reg_t guc_send_reg(struct intel_guc *guc, u32 i)
 {
 	GEM_BUG_ON(!guc->send_regs.base);
 	GEM_BUG_ON(!guc->send_regs.count);
 	GEM_BUG_ON(i >= guc->send_regs.count);

 	return _MMIO(guc->send_regs.base + 4 * i);
 }

 void intel_guc_init_send_regs(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	enum forcewake_domains fw_domains = 0;
 	unsigned int i;

 	guc->send_regs.base = i915_mmio_reg_offset(SOFT_SCRATCH(0));
 	guc->send_regs.count = SOFT_SCRATCH_COUNT - 1;

 	for (i = 0; i < guc->send_regs.count; i++) {
 		fw_domains |= intel_uncore_forcewake_for_reg(dev_priv,
 					guc_send_reg(guc, i),
 					FW_REG_READ | FW_REG_WRITE);
 	}
 	guc->send_regs.fw_domains = fw_domains;
 }

 void intel_guc_init_early(struct intel_guc *guc)
 {
 	intel_guc_fw_init_early(guc);
 	intel_guc_ct_init_early(&guc->ct);
 	intel_guc_log_init_early(&guc->log);

 	mutex_init(&guc->send_mutex);
 	spin_lock_init(&guc->irq_lock);
 	guc->send = intel_guc_send_nop;
 	guc->handler = intel_guc_to_host_event_handler_nop;
 	guc->notify = gen8_guc_raise_irq;
 }

 static int guc_init_wq(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);

 	/*
 	 * GuC log buffer flush work item has to do register access to
 	 * send the ack to GuC and this work item, if not synced before
 	 * suspend, can potentially get executed after the GFX device is
 	 * suspended.
 	 * By marking the WQ as freezable, we don't have to bother about
 	 * flushing of this work item from the suspend hooks, the pending
 	 * work item if any will be either executed before the suspend
 	 * or scheduled later on resume. This way the handling of work
 	 * item can be kept same between system suspend & rpm suspend.
 	 */
 	guc->log.relay.flush_wq =
 		alloc_ordered_workqueue("i915-guc_log",
 					WQ_HIGHPRI | WQ_FREEZABLE);
 	if (!guc->log.relay.flush_wq) {
 		DRM_ERROR("Couldn't allocate workqueue for GuC log\n");
 		return -ENOMEM;
 	}

 	/*
 	 * Even though both sending GuC action, and adding a new workitem to
 	 * GuC workqueue are serialized (each with its own locking), since
 	 * we're using mutliple engines, it's possible that we're going to
 	 * issue a preempt request with two (or more - each for different
 	 * engine) workitems in GuC queue. In this situation, GuC may submit
 	 * all of them, which will make us very confused.
 	 * Our preemption contexts may even already be complete - before we
 	 * even had the chance to sent the preempt action to GuC!. Rather
 	 * than introducing yet another lock, we can just use ordered workqueue
 	 * to make sure we're always sending a single preemption request with a
 	 * single workitem.
 	 */
 	if (HAS_LOGICAL_RING_PREEMPTION(dev_priv) &&
 	    USES_GUC_SUBMISSION(dev_priv)) {
 		guc->preempt_wq = alloc_ordered_workqueue("i915-guc_preempt",
 							  WQ_HIGHPRI);
 		if (!guc->preempt_wq) {
 			destroy_workqueue(guc->log.relay.flush_wq);
 			DRM_ERROR("Couldn't allocate workqueue for GuC "
 				  "preemption\n");
 			return -ENOMEM;
 		}
 	}

 	return 0;
 }

 static void guc_fini_wq(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);

 	if (HAS_LOGICAL_RING_PREEMPTION(dev_priv) &&
 	    USES_GUC_SUBMISSION(dev_priv))
 		destroy_workqueue(guc->preempt_wq);

 	destroy_workqueue(guc->log.relay.flush_wq);
 }

 int intel_guc_init_misc(struct intel_guc *guc)
 {
 	struct drm_i915_private *i915 = guc_to_i915(guc);
 	int ret;

 	guc_init_ggtt_pin_bias(guc);

 	ret = guc_init_wq(guc);
 	if (ret)
 		return ret;

 	intel_uc_fw_fetch(i915, &guc->fw);

 	return 0;
 }

 void intel_guc_fini_misc(struct intel_guc *guc)
 {
 	intel_uc_fw_fini(&guc->fw);
 	guc_fini_wq(guc);
 }

 static int guc_shared_data_create(struct intel_guc *guc)
 {
 	struct i915_vma *vma;
 	void *vaddr;

 	vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
 	if (IS_ERR(vma))
 		return PTR_ERR(vma);

 	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
 	if (IS_ERR(vaddr)) {
 		i915_vma_unpin_and_release(&vma);
 		return PTR_ERR(vaddr);
 	}

 	guc->shared_data = vma;
 	guc->shared_data_vaddr = vaddr;

 	return 0;
 }

 static void guc_shared_data_destroy(struct intel_guc *guc)
 {
 	i915_gem_object_unpin_map(guc->shared_data->obj);
 	i915_vma_unpin_and_release(&guc->shared_data);
 }

 int intel_guc_init(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	int ret;

 	ret = guc_shared_data_create(guc);
 	if (ret)
 		goto err_fetch;
 	GEM_BUG_ON(!guc->shared_data);

 	ret = intel_guc_log_create(&guc->log);
 	if (ret)
 		goto err_shared;

 	ret = intel_guc_ads_create(guc);
 	if (ret)
 		goto err_log;
 	GEM_BUG_ON(!guc->ads_vma);

 	/* We need to notify the guc whenever we change the GGTT */
 	i915_ggtt_enable_guc(dev_priv);

 	return 0;

 err_log:
 	intel_guc_log_destroy(&guc->log);
 err_shared:
 	guc_shared_data_destroy(guc);
 err_fetch:
 	intel_uc_fw_fini(&guc->fw);
 	return ret;
 }

 void intel_guc_fini(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);

 	i915_ggtt_disable_guc(dev_priv);
 	intel_guc_ads_destroy(guc);
 	intel_guc_log_destroy(&guc->log);
 	guc_shared_data_destroy(guc);
 	intel_uc_fw_fini(&guc->fw);
 }

 static u32 guc_ctl_debug_flags(struct intel_guc *guc)
 {
 	u32 level = intel_guc_log_get_level(&guc->log);
 	u32 flags;
 	u32 ads;

 	ads = intel_guc_ggtt_offset(guc, guc->ads_vma) >> PAGE_SHIFT;
 	flags = ads << GUC_ADS_ADDR_SHIFT | GUC_ADS_ENABLED;

 	if (!GUC_LOG_LEVEL_IS_ENABLED(level))
 		flags |= GUC_LOG_DEFAULT_DISABLED;

 	if (!GUC_LOG_LEVEL_IS_VERBOSE(level))
 		flags |= GUC_LOG_DISABLED;
 	else
 		flags |= GUC_LOG_LEVEL_TO_VERBOSITY(level) <<
 			 GUC_LOG_VERBOSITY_SHIFT;

 	return flags;
 }

 static u32 guc_ctl_feature_flags(struct intel_guc *guc)
 {
 	u32 flags = 0;

 	flags |=  GUC_CTL_VCS2_ENABLED;

 	if (USES_GUC_SUBMISSION(guc_to_i915(guc)))
 		flags |= GUC_CTL_KERNEL_SUBMISSIONS;
 	else
 		flags |= GUC_CTL_DISABLE_SCHEDULER;

 	return flags;
 }

 static u32 guc_ctl_ctxinfo_flags(struct intel_guc *guc)
 {
 	u32 flags = 0;

 	if (USES_GUC_SUBMISSION(guc_to_i915(guc))) {
 		u32 ctxnum, base;

 		base = intel_guc_ggtt_offset(guc, guc->stage_desc_pool);
 		ctxnum = GUC_MAX_STAGE_DESCRIPTORS / 16;

 		base >>= PAGE_SHIFT;
 		flags |= (base << GUC_CTL_BASE_ADDR_SHIFT) |
 			(ctxnum << GUC_CTL_CTXNUM_IN16_SHIFT);
 	}
 	return flags;
 }

 static u32 guc_ctl_log_params_flags(struct intel_guc *guc)
 {
 	u32 offset = intel_guc_ggtt_offset(guc, guc->log.vma) >> PAGE_SHIFT;
 	u32 flags;

 	#if (((CRASH_BUFFER_SIZE) % SZ_1M) == 0)
 	#define UNIT SZ_1M
 	#define FLAG GUC_LOG_ALLOC_IN_MEGABYTE
 	#else
 	#define UNIT SZ_4K
 	#define FLAG 0
 	#endif

 	BUILD_BUG_ON(!CRASH_BUFFER_SIZE);
 	BUILD_BUG_ON(!IS_ALIGNED(CRASH_BUFFER_SIZE, UNIT));
 	BUILD_BUG_ON(!DPC_BUFFER_SIZE);
 	BUILD_BUG_ON(!IS_ALIGNED(DPC_BUFFER_SIZE, UNIT));
 	BUILD_BUG_ON(!ISR_BUFFER_SIZE);
 	BUILD_BUG_ON(!IS_ALIGNED(ISR_BUFFER_SIZE, UNIT));

 	BUILD_BUG_ON((CRASH_BUFFER_SIZE / UNIT - 1) >
 			(GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT));
 	BUILD_BUG_ON((DPC_BUFFER_SIZE / UNIT - 1) >
 			(GUC_LOG_DPC_MASK >> GUC_LOG_DPC_SHIFT));
 	BUILD_BUG_ON((ISR_BUFFER_SIZE / UNIT - 1) >
 			(GUC_LOG_ISR_MASK >> GUC_LOG_ISR_SHIFT));

 	flags = GUC_LOG_VALID |
 		GUC_LOG_NOTIFY_ON_HALF_FULL |
 		FLAG |
 		((CRASH_BUFFER_SIZE / UNIT - 1) << GUC_LOG_CRASH_SHIFT) |
 		((DPC_BUFFER_SIZE / UNIT - 1) << GUC_LOG_DPC_SHIFT) |
 		((ISR_BUFFER_SIZE / UNIT - 1) << GUC_LOG_ISR_SHIFT) |
 		(offset << GUC_LOG_BUF_ADDR_SHIFT);

 	#undef UNIT
 	#undef FLAG

 	return flags;
 }

 /*
  * Initialise the GuC parameter block before starting the firmware
  * transfer. These parameters are read by the firmware on startup
  * and cannot be changed thereafter.
  */
 void intel_guc_init_params(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	u32 params[GUC_CTL_MAX_DWORDS];
 	int i;

 	memset(params, 0, sizeof(params));

 	/*
 	 * GuC ARAT increment is 10 ns. GuC default scheduler quantum is one
 	 * second. This ARAR is calculated by:
 	 * Scheduler-Quantum-in-ns / ARAT-increment-in-ns = 1000000000 / 10
 	 */
 	params[GUC_CTL_ARAT_HIGH] = 0;
 	params[GUC_CTL_ARAT_LOW] = 100000000;

 	params[GUC_CTL_WA] |= GUC_CTL_WA_UK_BY_DRIVER;

 	params[GUC_CTL_FEATURE] = guc_ctl_feature_flags(guc);
 	params[GUC_CTL_LOG_PARAMS]  = guc_ctl_log_params_flags(guc);
 	params[GUC_CTL_DEBUG] = guc_ctl_debug_flags(guc);
 	params[GUC_CTL_CTXINFO] = guc_ctl_ctxinfo_flags(guc);

 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
 		DRM_DEBUG_DRIVER("param[%2d] = %#x\n", i, params[i]);

 	/*
 	 * All SOFT_SCRATCH registers are in FORCEWAKE_BLITTER domain and
 	 * they are power context saved so it's ok to release forcewake
 	 * when we are done here and take it again at xfer time.
 	 */
 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_BLITTER);

 	I915_WRITE(SOFT_SCRATCH(0), 0);

 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
 		I915_WRITE(SOFT_SCRATCH(1 + i), params[i]);

 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_BLITTER);
 }

 int intel_guc_send_nop(struct intel_guc *guc, const u32 *action, u32 len,
 		       u32 *response_buf, u32 response_buf_size)
 {
 	WARN(1, "Unexpected send: action=%#x\n", *action);
 	return -ENODEV;
 }

 void intel_guc_to_host_event_handler_nop(struct intel_guc *guc)
 {
 	WARN(1, "Unexpected event: no suitable handler\n");
 }

 /*
  * This function implements the MMIO based host to GuC interface.
  */
 int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len,
 			u32 *response_buf, u32 response_buf_size)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	u32 status;
 	int i;
 	int ret;

 	GEM_BUG_ON(!len);
 	GEM_BUG_ON(len > guc->send_regs.count);

 	/* We expect only action code */
 	GEM_BUG_ON(*action & ~INTEL_GUC_MSG_CODE_MASK);

 	/* If CT is available, we expect to use MMIO only during init/fini */
 	GEM_BUG_ON(HAS_GUC_CT(dev_priv) &&
 		*action != INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER &&
 		*action != INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER);

 	mutex_lock(&guc->send_mutex);
 	intel_uncore_forcewake_get(dev_priv, guc->send_regs.fw_domains);

 	for (i = 0; i < len; i++)
 		I915_WRITE(guc_send_reg(guc, i), action[i]);

 	POSTING_READ(guc_send_reg(guc, i - 1));

 	intel_guc_notify(guc);

 	/*
 	 * No GuC command should ever take longer than 10ms.
 	 * Fast commands should still complete in 10us.
 	 */
 	ret = __intel_wait_for_register_fw(dev_priv,
 					   guc_send_reg(guc, 0),
 					   INTEL_GUC_MSG_TYPE_MASK,
 					   INTEL_GUC_MSG_TYPE_RESPONSE <<
 					   INTEL_GUC_MSG_TYPE_SHIFT,
 					   10, 10, &status);
 	/* If GuC explicitly returned an error, convert it to -EIO */
 	if (!ret && !INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(status))
 		ret = -EIO;

 	if (ret) {
 		DRM_ERROR("MMIO: GuC action %#x failed with error %d %#x\n",
 			  action[0], ret, status);
 		goto out;
 	}

 	if (response_buf) {
 		int count = min(response_buf_size, guc->send_regs.count - 1);

 		for (i = 0; i < count; i++)
 			response_buf[i] = I915_READ(guc_send_reg(guc, i + 1));
 	}

 	/* Use data from the GuC response as our return value */
 	ret = INTEL_GUC_MSG_TO_DATA(status);

 out:
 	intel_uncore_forcewake_put(dev_priv, guc->send_regs.fw_domains);
 	mutex_unlock(&guc->send_mutex);

 	return ret;
 }

 void intel_guc_to_host_event_handler_mmio(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	u32 msg, val;

 	/*
 	 * Sample the log buffer flush related bits & clear them out now
 	 * itself from the message identity register to minimize the
 	 * probability of losing a flush interrupt, when there are back
 	 * to back flush interrupts.
 	 * There can be a new flush interrupt, for different log buffer
 	 * type (like for ISR), whilst Host is handling one (for DPC).
 	 * Since same bit is used in message register for ISR & DPC, it
 	 * could happen that GuC sets the bit for 2nd interrupt but Host
 	 * clears out the bit on handling the 1st interrupt.
 	 */
 	disable_rpm_wakeref_asserts(dev_priv);
 	spin_lock(&guc->irq_lock);
 	val = I915_READ(SOFT_SCRATCH(15));
 	msg = val & guc->msg_enabled_mask;
 	I915_WRITE(SOFT_SCRATCH(15), val & ~msg);
 	spin_unlock(&guc->irq_lock);
 	enable_rpm_wakeref_asserts(dev_priv);

 	intel_guc_to_host_process_recv_msg(guc, msg);
 }

 void intel_guc_to_host_process_recv_msg(struct intel_guc *guc, u32 msg)
 {
 	/* Make sure to handle only enabled messages */
 	msg &= guc->msg_enabled_mask;

 	if (msg & (INTEL_GUC_RECV_MSG_FLUSH_LOG_BUFFER |
 		   INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED))
 		intel_guc_log_handle_flush_event(&guc->log);
 }

 int intel_guc_sample_forcewake(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	u32 action[2];

 	action[0] = INTEL_GUC_ACTION_SAMPLE_FORCEWAKE;
 	/* WaRsDisableCoarsePowerGating:skl,cnl */
 	if (!HAS_RC6(dev_priv) || NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
 		action[1] = 0;
 	else
 		/* bit 0 and 1 are for Render and Media domain separately */
 		action[1] = GUC_FORCEWAKE_RENDER | GUC_FORCEWAKE_MEDIA;

 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
 }

 /**
  * intel_guc_auth_huc() - Send action to GuC to authenticate HuC ucode
  * @guc: intel_guc structure
  * @rsa_offset: rsa offset w.r.t ggtt base of huc vma
  *
  * Triggers a HuC firmware authentication request to the GuC via intel_guc_send
  * INTEL_GUC_ACTION_AUTHENTICATE_HUC interface. This function is invoked by
  * intel_huc_auth().
  *
  * Return:	non-zero code on error
  */
 int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset)
 {
 	u32 action[] = {
 		INTEL_GUC_ACTION_AUTHENTICATE_HUC,
 		rsa_offset
 	};

 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
 }

 /**
  * intel_guc_suspend() - notify GuC entering suspend state
  * @guc:	the guc
  */
 int intel_guc_suspend(struct intel_guc *guc)
 {
 	u32 data[] = {
 		INTEL_GUC_ACTION_ENTER_S_STATE,
 		GUC_POWER_D1, /* any value greater than GUC_POWER_D0 */
 		intel_guc_ggtt_offset(guc, guc->shared_data)
 	};

 	return intel_guc_send(guc, data, ARRAY_SIZE(data));
 }

 /**
  * intel_guc_reset_engine() - ask GuC to reset an engine
  * @guc:	intel_guc structure
  * @engine:	engine to be reset
  */
 int intel_guc_reset_engine(struct intel_guc *guc,
 			   struct intel_engine_cs *engine)
 {
 	u32 data[7];

 	GEM_BUG_ON(!guc->execbuf_client);

 	data[0] = INTEL_GUC_ACTION_REQUEST_ENGINE_RESET;
 	data[1] = engine->guc_id;
 	data[2] = 0;
 	data[3] = 0;
 	data[4] = 0;
 	data[5] = guc->execbuf_client->stage_id;
 	data[6] = intel_guc_ggtt_offset(guc, guc->shared_data);

 	return intel_guc_send(guc, data, ARRAY_SIZE(data));
 }

 /**
  * intel_guc_resume() - notify GuC resuming from suspend state
  * @guc:	the guc
  */
 int intel_guc_resume(struct intel_guc *guc)
 {
 	u32 data[] = {
 		INTEL_GUC_ACTION_EXIT_S_STATE,
 		GUC_POWER_D0,
 		intel_guc_ggtt_offset(guc, guc->shared_data)
 	};

 	return intel_guc_send(guc, data, ARRAY_SIZE(data));
 }

 /**
  * DOC: GuC Address Space
  *
  * The layout of GuC address space is shown below:
  *
  * ::
  *
  *     +==============> +====================+ <== GUC_GGTT_TOP
  *     ^                |                    |
  *     |                |                    |
  *     |                |        DRAM        |
  *     |                |       Memory       |
  *     |                |                    |
  *    GuC               |                    |
  *  Address  +========> +====================+ <== WOPCM Top
  *   Space   ^          |   HW contexts RSVD |
  *     |     |          |        WOPCM       |
  *     |     |     +==> +--------------------+ <== GuC WOPCM Top
  *     |    GuC    ^    |                    |
  *     |    GGTT   |    |                    |
  *     |    Pin   GuC   |        GuC         |
  *     |    Bias WOPCM  |       WOPCM        |
  *     |     |    Size  |                    |
  *     |     |     |    |                    |
  *     v     v     v    |                    |
  *     +=====+=====+==> +====================+ <== GuC WOPCM Base
  *                      |   Non-GuC WOPCM    |
  *                      |   (HuC/Reserved)   |
  *                      +====================+ <== WOPCM Base
  *
  * The lower part of GuC Address Space [0, ggtt_pin_bias) is mapped to WOPCM
  * while upper part of GuC Address Space [ggtt_pin_bias, GUC_GGTT_TOP) is mapped
  * to DRAM. The value of the GuC ggtt_pin_bias is determined by WOPCM size and
  * actual GuC WOPCM size.
  */

 /**
  * guc_init_ggtt_pin_bias() - Initialize the GuC ggtt_pin_bias value.
  * @guc: intel_guc structure.
  *
  * This function will calculate and initialize the ggtt_pin_bias value based on
  * overall WOPCM size and GuC WOPCM size.
  */
 static void guc_init_ggtt_pin_bias(struct intel_guc *guc)
 {
 	struct drm_i915_private *i915 = guc_to_i915(guc);

 	GEM_BUG_ON(!i915->wopcm.size);
 	GEM_BUG_ON(i915->wopcm.size < i915->wopcm.guc.base);

 	guc->ggtt_pin_bias = i915->wopcm.size - i915->wopcm.guc.base;
 }

 /**
  * intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
  * @guc:	the guc
  * @size:	size of area to allocate (both virtual space and memory)
  *
  * This is a wrapper to create an object for use with the GuC. In order to
  * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
  * both some backing storage and a range inside the Global GTT. We must pin
  * it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that
  * range is reserved inside GuC.
  *
  * Return:	A i915_vma if successful, otherwise an ERR_PTR.
  */
 struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 	int ret;

 	obj = i915_gem_object_create(dev_priv, size);
 	if (IS_ERR(obj))
 		return ERR_CAST(obj);

 	vma = i915_vma_instance(obj, &dev_priv->ggtt.vm, NULL);
 	if (IS_ERR(vma))
 		goto err;

 	ret = i915_vma_pin(vma, 0, PAGE_SIZE,
 			   PIN_GLOBAL | PIN_OFFSET_BIAS | guc->ggtt_pin_bias);
 	if (ret) {
 		vma = ERR_PTR(ret);
 		goto err;
 	}

 	return vma;

 err:
 	i915_gem_object_put(obj);
 	return vma;
 }
	/*
	* Copyright © 2014-2017 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 "intel_guc.h"
	#include "intel_guc_ads.h"
	#include "intel_guc_submission.h"
	#include "i915_drv.h"

	static void guc_init_ggtt_pin_bias(struct intel_guc *guc);

	static void gen8_guc_raise_irq(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	I915_WRITE(GUC_SEND_INTERRUPT, GUC_SEND_TRIGGER);
	}

	static inline i915_reg_t guc_send_reg(struct intel_guc *guc, u32 i)
	{
	GEM_BUG_ON(!guc->send_regs.base);
	GEM_BUG_ON(!guc->send_regs.count);
	GEM_BUG_ON(i >= guc->send_regs.count);

	return _MMIO(guc->send_regs.base + 4 * i);
	}

	void intel_guc_init_send_regs(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	enum forcewake_domains fw_domains = 0;
	unsigned int i;

	guc->send_regs.base = i915_mmio_reg_offset(SOFT_SCRATCH(0));
	guc->send_regs.count = SOFT_SCRATCH_COUNT - 1;

	for (i = 0; i < guc->send_regs.count; i++) {
	fw_domains \|= intel_uncore_forcewake_for_reg(dev_priv,
	guc_send_reg(guc, i),
	FW_REG_READ \| FW_REG_WRITE);
	}
	guc->send_regs.fw_domains = fw_domains;
	}

	void intel_guc_init_early(struct intel_guc *guc)
	{
	intel_guc_fw_init_early(guc);
	intel_guc_ct_init_early(&guc->ct);
	intel_guc_log_init_early(&guc->log);

	mutex_init(&guc->send_mutex);
	spin_lock_init(&guc->irq_lock);
	guc->send = intel_guc_send_nop;
	guc->handler = intel_guc_to_host_event_handler_nop;
	guc->notify = gen8_guc_raise_irq;
	}

	static int guc_init_wq(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	/*
	* GuC log buffer flush work item has to do register access to
	* send the ack to GuC and this work item, if not synced before
	* suspend, can potentially get executed after the GFX device is
	* suspended.
	* By marking the WQ as freezable, we don't have to bother about
	* flushing of this work item from the suspend hooks, the pending
	* work item if any will be either executed before the suspend
	* or scheduled later on resume. This way the handling of work
	* item can be kept same between system suspend & rpm suspend.
	*/
	guc->log.relay.flush_wq =
	alloc_ordered_workqueue("i915-guc_log",
	WQ_HIGHPRI \| WQ_FREEZABLE);
	if (!guc->log.relay.flush_wq) {
	DRM_ERROR("Couldn't allocate workqueue for GuC log\n");
	return -ENOMEM;
	}

	/*
	* Even though both sending GuC action, and adding a new workitem to
	* GuC workqueue are serialized (each with its own locking), since
	* we're using mutliple engines, it's possible that we're going to
	* issue a preempt request with two (or more - each for different
	* engine) workitems in GuC queue. In this situation, GuC may submit
	* all of them, which will make us very confused.
	* Our preemption contexts may even already be complete - before we
	* even had the chance to sent the preempt action to GuC!. Rather
	* than introducing yet another lock, we can just use ordered workqueue
	* to make sure we're always sending a single preemption request with a
	* single workitem.
	*/
	if (HAS_LOGICAL_RING_PREEMPTION(dev_priv) &&
	USES_GUC_SUBMISSION(dev_priv)) {
	guc->preempt_wq = alloc_ordered_workqueue("i915-guc_preempt",
	WQ_HIGHPRI);
	if (!guc->preempt_wq) {
	destroy_workqueue(guc->log.relay.flush_wq);
	DRM_ERROR("Couldn't allocate workqueue for GuC "
	"preemption\n");
	return -ENOMEM;
	}
	}

	return 0;
	}

	static void guc_fini_wq(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	if (HAS_LOGICAL_RING_PREEMPTION(dev_priv) &&
	USES_GUC_SUBMISSION(dev_priv))
	destroy_workqueue(guc->preempt_wq);

	destroy_workqueue(guc->log.relay.flush_wq);
	}

	int intel_guc_init_misc(struct intel_guc *guc)
	{
	struct drm_i915_private *i915 = guc_to_i915(guc);
	int ret;

	guc_init_ggtt_pin_bias(guc);

	ret = guc_init_wq(guc);
	if (ret)
	return ret;

	intel_uc_fw_fetch(i915, &guc->fw);

	return 0;
	}

	void intel_guc_fini_misc(struct intel_guc *guc)
	{
	intel_uc_fw_fini(&guc->fw);
	guc_fini_wq(guc);
	}

	static int guc_shared_data_create(struct intel_guc *guc)
	{
	struct i915_vma *vma;
	void *vaddr;

	vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
	if (IS_ERR(vma))
	return PTR_ERR(vma);

	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
	if (IS_ERR(vaddr)) {
	i915_vma_unpin_and_release(&vma);
	return PTR_ERR(vaddr);
	}

	guc->shared_data = vma;
	guc->shared_data_vaddr = vaddr;

	return 0;
	}

	static void guc_shared_data_destroy(struct intel_guc *guc)
	{
	i915_gem_object_unpin_map(guc->shared_data->obj);
	i915_vma_unpin_and_release(&guc->shared_data);
	}

	int intel_guc_init(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	int ret;

	ret = guc_shared_data_create(guc);
	if (ret)
	goto err_fetch;
	GEM_BUG_ON(!guc->shared_data);

	ret = intel_guc_log_create(&guc->log);
	if (ret)
	goto err_shared;

	ret = intel_guc_ads_create(guc);
	if (ret)
	goto err_log;
	GEM_BUG_ON(!guc->ads_vma);

	/* We need to notify the guc whenever we change the GGTT */
	i915_ggtt_enable_guc(dev_priv);

	return 0;

	err_log:
	intel_guc_log_destroy(&guc->log);
	err_shared:
	guc_shared_data_destroy(guc);
	err_fetch:
	intel_uc_fw_fini(&guc->fw);
	return ret;
	}

	void intel_guc_fini(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	i915_ggtt_disable_guc(dev_priv);
	intel_guc_ads_destroy(guc);
	intel_guc_log_destroy(&guc->log);
	guc_shared_data_destroy(guc);
	intel_uc_fw_fini(&guc->fw);
	}

	static u32 guc_ctl_debug_flags(struct intel_guc *guc)
	{
	u32 level = intel_guc_log_get_level(&guc->log);
	u32 flags;
	u32 ads;

	ads = intel_guc_ggtt_offset(guc, guc->ads_vma) >> PAGE_SHIFT;
	flags = ads << GUC_ADS_ADDR_SHIFT \| GUC_ADS_ENABLED;

	if (!GUC_LOG_LEVEL_IS_ENABLED(level))
	flags \|= GUC_LOG_DEFAULT_DISABLED;

	if (!GUC_LOG_LEVEL_IS_VERBOSE(level))
	flags \|= GUC_LOG_DISABLED;
	else
	flags \|= GUC_LOG_LEVEL_TO_VERBOSITY(level) <<
	GUC_LOG_VERBOSITY_SHIFT;

	return flags;
	}

	static u32 guc_ctl_feature_flags(struct intel_guc *guc)
	{
	u32 flags = 0;

	flags \|= GUC_CTL_VCS2_ENABLED;

	if (USES_GUC_SUBMISSION(guc_to_i915(guc)))
	flags \|= GUC_CTL_KERNEL_SUBMISSIONS;
	else
	flags \|= GUC_CTL_DISABLE_SCHEDULER;

	return flags;
	}

	static u32 guc_ctl_ctxinfo_flags(struct intel_guc *guc)
	{
	u32 flags = 0;

	if (USES_GUC_SUBMISSION(guc_to_i915(guc))) {
	u32 ctxnum, base;

	base = intel_guc_ggtt_offset(guc, guc->stage_desc_pool);
	ctxnum = GUC_MAX_STAGE_DESCRIPTORS / 16;

	base >>= PAGE_SHIFT;
	flags \|= (base << GUC_CTL_BASE_ADDR_SHIFT) \|
	(ctxnum << GUC_CTL_CTXNUM_IN16_SHIFT);
	}
	return flags;
	}

	static u32 guc_ctl_log_params_flags(struct intel_guc *guc)
	{
	u32 offset = intel_guc_ggtt_offset(guc, guc->log.vma) >> PAGE_SHIFT;
	u32 flags;

	#if (((CRASH_BUFFER_SIZE) % SZ_1M) == 0)
	#define UNIT SZ_1M
	#define FLAG GUC_LOG_ALLOC_IN_MEGABYTE
	#else
	#define UNIT SZ_4K
	#define FLAG 0
	#endif

	BUILD_BUG_ON(!CRASH_BUFFER_SIZE);
	BUILD_BUG_ON(!IS_ALIGNED(CRASH_BUFFER_SIZE, UNIT));
	BUILD_BUG_ON(!DPC_BUFFER_SIZE);
	BUILD_BUG_ON(!IS_ALIGNED(DPC_BUFFER_SIZE, UNIT));
	BUILD_BUG_ON(!ISR_BUFFER_SIZE);
	BUILD_BUG_ON(!IS_ALIGNED(ISR_BUFFER_SIZE, UNIT));

	BUILD_BUG_ON((CRASH_BUFFER_SIZE / UNIT - 1) >
	(GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT));
	BUILD_BUG_ON((DPC_BUFFER_SIZE / UNIT - 1) >
	(GUC_LOG_DPC_MASK >> GUC_LOG_DPC_SHIFT));
	BUILD_BUG_ON((ISR_BUFFER_SIZE / UNIT - 1) >
	(GUC_LOG_ISR_MASK >> GUC_LOG_ISR_SHIFT));

	flags = GUC_LOG_VALID \|
	GUC_LOG_NOTIFY_ON_HALF_FULL \|
	FLAG \|
	((CRASH_BUFFER_SIZE / UNIT - 1) << GUC_LOG_CRASH_SHIFT) \|
	((DPC_BUFFER_SIZE / UNIT - 1) << GUC_LOG_DPC_SHIFT) \|
	((ISR_BUFFER_SIZE / UNIT - 1) << GUC_LOG_ISR_SHIFT) \|
	(offset << GUC_LOG_BUF_ADDR_SHIFT);

	#undef UNIT
	#undef FLAG

	return flags;
	}

	/*
	* Initialise the GuC parameter block before starting the firmware
	* transfer. These parameters are read by the firmware on startup
	* and cannot be changed thereafter.
	*/
	void intel_guc_init_params(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 params[GUC_CTL_MAX_DWORDS];
	int i;

	memset(params, 0, sizeof(params));

	/*
	* GuC ARAT increment is 10 ns. GuC default scheduler quantum is one
	* second. This ARAR is calculated by:
	* Scheduler-Quantum-in-ns / ARAT-increment-in-ns = 1000000000 / 10
	*/
	params[GUC_CTL_ARAT_HIGH] = 0;
	params[GUC_CTL_ARAT_LOW] = 100000000;

	params[GUC_CTL_WA] \|= GUC_CTL_WA_UK_BY_DRIVER;

	params[GUC_CTL_FEATURE] = guc_ctl_feature_flags(guc);
	params[GUC_CTL_LOG_PARAMS] = guc_ctl_log_params_flags(guc);
	params[GUC_CTL_DEBUG] = guc_ctl_debug_flags(guc);
	params[GUC_CTL_CTXINFO] = guc_ctl_ctxinfo_flags(guc);

	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
	DRM_DEBUG_DRIVER("param[%2d] = %#x\n", i, params[i]);

	/*
	* All SOFT_SCRATCH registers are in FORCEWAKE_BLITTER domain and
	* they are power context saved so it's ok to release forcewake
	* when we are done here and take it again at xfer time.
	*/
	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_BLITTER);

	I915_WRITE(SOFT_SCRATCH(0), 0);

	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
	I915_WRITE(SOFT_SCRATCH(1 + i), params[i]);

	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_BLITTER);
	}

	int intel_guc_send_nop(struct intel_guc guc, const u32 action, u32 len,
	u32 *response_buf, u32 response_buf_size)
	{
	WARN(1, "Unexpected send: action=%#x\n", *action);
	return -ENODEV;
	}

	void intel_guc_to_host_event_handler_nop(struct intel_guc *guc)
	{
	WARN(1, "Unexpected event: no suitable handler\n");
	}

	/*
	* This function implements the MMIO based host to GuC interface.
	*/
	int intel_guc_send_mmio(struct intel_guc guc, const u32 action, u32 len,
	u32 *response_buf, u32 response_buf_size)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 status;
	int i;
	int ret;

	GEM_BUG_ON(!len);
	GEM_BUG_ON(len > guc->send_regs.count);

	/* We expect only action code */
	GEM_BUG_ON(*action & ~INTEL_GUC_MSG_CODE_MASK);

	/* If CT is available, we expect to use MMIO only during init/fini */
	GEM_BUG_ON(HAS_GUC_CT(dev_priv) &&
	*action != INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER &&
	*action != INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER);

	mutex_lock(&guc->send_mutex);
	intel_uncore_forcewake_get(dev_priv, guc->send_regs.fw_domains);

	for (i = 0; i < len; i++)
	I915_WRITE(guc_send_reg(guc, i), action[i]);

	POSTING_READ(guc_send_reg(guc, i - 1));

	intel_guc_notify(guc);

	/*
	* No GuC command should ever take longer than 10ms.
	* Fast commands should still complete in 10us.
	*/
	ret = __intel_wait_for_register_fw(dev_priv,
	guc_send_reg(guc, 0),
	INTEL_GUC_MSG_TYPE_MASK,
	INTEL_GUC_MSG_TYPE_RESPONSE <<
	INTEL_GUC_MSG_TYPE_SHIFT,
	10, 10, &status);
	/* If GuC explicitly returned an error, convert it to -EIO */
	if (!ret && !INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(status))
	ret = -EIO;

	if (ret) {
	DRM_ERROR("MMIO: GuC action %#x failed with error %d %#x\n",
	action[0], ret, status);
	goto out;
	}

	if (response_buf) {
	int count = min(response_buf_size, guc->send_regs.count - 1);

	for (i = 0; i < count; i++)
	response_buf[i] = I915_READ(guc_send_reg(guc, i + 1));
	}

	/* Use data from the GuC response as our return value */
	ret = INTEL_GUC_MSG_TO_DATA(status);

	out:
	intel_uncore_forcewake_put(dev_priv, guc->send_regs.fw_domains);
	mutex_unlock(&guc->send_mutex);

	return ret;
	}

	void intel_guc_to_host_event_handler_mmio(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 msg, val;

	/*
	* Sample the log buffer flush related bits & clear them out now
	* itself from the message identity register to minimize the
	* probability of losing a flush interrupt, when there are back
	* to back flush interrupts.
	* There can be a new flush interrupt, for different log buffer
	* type (like for ISR), whilst Host is handling one (for DPC).
	* Since same bit is used in message register for ISR & DPC, it
	* could happen that GuC sets the bit for 2nd interrupt but Host
	* clears out the bit on handling the 1st interrupt.
	*/
	disable_rpm_wakeref_asserts(dev_priv);
	spin_lock(&guc->irq_lock);
	val = I915_READ(SOFT_SCRATCH(15));
	msg = val & guc->msg_enabled_mask;
	I915_WRITE(SOFT_SCRATCH(15), val & ~msg);
	spin_unlock(&guc->irq_lock);
	enable_rpm_wakeref_asserts(dev_priv);

	intel_guc_to_host_process_recv_msg(guc, msg);
	}

	void intel_guc_to_host_process_recv_msg(struct intel_guc *guc, u32 msg)
	{
	/* Make sure to handle only enabled messages */
	msg &= guc->msg_enabled_mask;

	if (msg & (INTEL_GUC_RECV_MSG_FLUSH_LOG_BUFFER \|
	INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED))
	intel_guc_log_handle_flush_event(&guc->log);
	}

	int intel_guc_sample_forcewake(struct intel_guc *guc)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 action[2];

	action[0] = INTEL_GUC_ACTION_SAMPLE_FORCEWAKE;
	/* WaRsDisableCoarsePowerGating:skl,cnl */
	if (!HAS_RC6(dev_priv) \|\| NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
	action[1] = 0;
	else
	/* bit 0 and 1 are for Render and Media domain separately */
	action[1] = GUC_FORCEWAKE_RENDER \| GUC_FORCEWAKE_MEDIA;

	return intel_guc_send(guc, action, ARRAY_SIZE(action));
	}

	/**
	* intel_guc_auth_huc() - Send action to GuC to authenticate HuC ucode
	* @guc: intel_guc structure
	* @rsa_offset: rsa offset w.r.t ggtt base of huc vma
	*
	* Triggers a HuC firmware authentication request to the GuC via intel_guc_send
	* INTEL_GUC_ACTION_AUTHENTICATE_HUC interface. This function is invoked by
	* intel_huc_auth().
	*
	* Return: non-zero code on error
	*/
	int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset)
	{
	u32 action[] = {
	INTEL_GUC_ACTION_AUTHENTICATE_HUC,
	rsa_offset
	};

	return intel_guc_send(guc, action, ARRAY_SIZE(action));
	}

	/**
	* intel_guc_suspend() - notify GuC entering suspend state
	* @guc: the guc
	*/
	int intel_guc_suspend(struct intel_guc *guc)
	{
	u32 data[] = {
	INTEL_GUC_ACTION_ENTER_S_STATE,
	GUC_POWER_D1, /* any value greater than GUC_POWER_D0 */
	intel_guc_ggtt_offset(guc, guc->shared_data)
	};

	return intel_guc_send(guc, data, ARRAY_SIZE(data));
	}

	/**
	* intel_guc_reset_engine() - ask GuC to reset an engine
	* @guc: intel_guc structure
	* @engine: engine to be reset
	*/
	int intel_guc_reset_engine(struct intel_guc *guc,
	struct intel_engine_cs *engine)
	{
	u32 data[7];

	GEM_BUG_ON(!guc->execbuf_client);

	data[0] = INTEL_GUC_ACTION_REQUEST_ENGINE_RESET;
	data[1] = engine->guc_id;
	data[2] = 0;
	data[3] = 0;
	data[4] = 0;
	data[5] = guc->execbuf_client->stage_id;
	data[6] = intel_guc_ggtt_offset(guc, guc->shared_data);

	return intel_guc_send(guc, data, ARRAY_SIZE(data));
	}

	/**
	* intel_guc_resume() - notify GuC resuming from suspend state
	* @guc: the guc
	*/
	int intel_guc_resume(struct intel_guc *guc)
	{
	u32 data[] = {
	INTEL_GUC_ACTION_EXIT_S_STATE,
	GUC_POWER_D0,
	intel_guc_ggtt_offset(guc, guc->shared_data)
	};

	return intel_guc_send(guc, data, ARRAY_SIZE(data));
	}

	/**
	* DOC: GuC Address Space
	*
	* The layout of GuC address space is shown below:
	*
	* ::
	*
	* +==============> +====================+ <== GUC_GGTT_TOP
	* ^ \| \|
	* \| \| \|
	* \| \| DRAM \|
	* \| \| Memory \|
	* \| \| \|
	* GuC \| \|
	* Address +========> +====================+ <== WOPCM Top
	* Space ^ \| HW contexts RSVD \|
	* \| \| \| WOPCM \|
	* \| \| +==> +--------------------+ <== GuC WOPCM Top
	* \| GuC ^ \| \|
	* \| GGTT \| \| \|
	* \| Pin GuC \| GuC \|
	* \| Bias WOPCM \| WOPCM \|
	* \| \| Size \| \|
	* \| \| \| \| \|
	* v v v \| \|
	* +=====+=====+==> +====================+ <== GuC WOPCM Base
	* \| Non-GuC WOPCM \|
	* \| (HuC/Reserved) \|
	* +====================+ <== WOPCM Base
	*
	* The lower part of GuC Address Space [0, ggtt_pin_bias) is mapped to WOPCM
	* while upper part of GuC Address Space [ggtt_pin_bias, GUC_GGTT_TOP) is mapped
	* to DRAM. The value of the GuC ggtt_pin_bias is determined by WOPCM size and
	* actual GuC WOPCM size.
	*/

	/**
	* guc_init_ggtt_pin_bias() - Initialize the GuC ggtt_pin_bias value.
	* @guc: intel_guc structure.
	*
	* This function will calculate and initialize the ggtt_pin_bias value based on
	* overall WOPCM size and GuC WOPCM size.
	*/
	static void guc_init_ggtt_pin_bias(struct intel_guc *guc)
	{
	struct drm_i915_private *i915 = guc_to_i915(guc);

	GEM_BUG_ON(!i915->wopcm.size);
	GEM_BUG_ON(i915->wopcm.size < i915->wopcm.guc.base);

	guc->ggtt_pin_bias = i915->wopcm.size - i915->wopcm.guc.base;
	}

	/**
	* intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
	* @guc: the guc
	* @size: size of area to allocate (both virtual space and memory)
	*
	* This is a wrapper to create an object for use with the GuC. In order to
	* use it inside the GuC, an object needs to be pinned lifetime, so we allocate
	* both some backing storage and a range inside the Global GTT. We must pin
	* it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that
	* range is reserved inside GuC.
	*
	* Return: A i915_vma if successful, otherwise an ERR_PTR.
	*/
	struct i915_vma intel_guc_allocate_vma(struct intel_guc guc, u32 size)
	{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct drm_i915_gem_object *obj;
	struct i915_vma *vma;
	int ret;

	obj = i915_gem_object_create(dev_priv, size);
	if (IS_ERR(obj))
	return ERR_CAST(obj);

	vma = i915_vma_instance(obj, &dev_priv->ggtt.vm, NULL);
	if (IS_ERR(vma))
	goto err;

	ret = i915_vma_pin(vma, 0, PAGE_SIZE,
	PIN_GLOBAL \| PIN_OFFSET_BIAS \| guc->ggtt_pin_bias);
	if (ret) {
	vma = ERR_PTR(ret);
	goto err;
	}

	return vma;

	err:
	i915_gem_object_put(obj);
	return vma;
	}