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timer.c

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  • intel_guc_loader.c 22.19 KiB
    /*
     * 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.
     *
     * Authors:
     *    Vinit Azad <vinit.azad@intel.com>
     *    Ben Widawsky <ben@bwidawsk.net>
     *    Dave Gordon <david.s.gordon@intel.com>
     *    Alex Dai <yu.dai@intel.com>
     */
    #include <linux/firmware.h>
    #include "i915_drv.h"
    #include "intel_guc.h"
    
    /**
     * DOC: GuC-specific firmware loader
     *
     * intel_guc:
     * Top level structure of guc. It handles firmware loading and manages client
     * pool and doorbells. intel_guc owns a i915_guc_client to replace the legacy
     * ExecList submission.
     *
     * Firmware versioning:
     * The firmware build process will generate a version header file with major and
     * minor version defined. The versions are built into CSS header of firmware.
     * i915 kernel driver set the minimal firmware version required per platform.
     * The firmware installation package will install (symbolic link) proper version
     * of firmware.
     *
     * GuC address space:
     * GuC does not allow any gfx GGTT address that falls into range [0, WOPCM_TOP),
     * which is reserved for Boot ROM, SRAM and WOPCM. Currently this top address is
     * 512K. In order to exclude 0-512K address space from GGTT, all gfx objects
     * used by GuC is pinned with PIN_OFFSET_BIAS along with size of WOPCM.
     *
     * Firmware log:
     * Firmware log is enabled by setting i915.guc_log_level to non-negative level.
     * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
     * i915_guc_load_status will print out firmware loading status and scratch
     * registers value.
     *
     */
    
    #define I915_SKL_GUC_UCODE "i915/skl_guc_ver6_1.bin"
    MODULE_FIRMWARE(I915_SKL_GUC_UCODE);
    
    #define I915_BXT_GUC_UCODE "i915/bxt_guc_ver8_7.bin"
    MODULE_FIRMWARE(I915_BXT_GUC_UCODE);
    
    /* User-friendly representation of an enum */
    const char *intel_guc_fw_status_repr(enum intel_guc_fw_status status)
    {
    	switch (status) {
    	case GUC_FIRMWARE_FAIL:
    		return "FAIL";
    	case GUC_FIRMWARE_NONE:
    		return "NONE";
    	case GUC_FIRMWARE_PENDING:
    		return "PENDING";
    	case GUC_FIRMWARE_SUCCESS:
    		return "SUCCESS";
    	default:
    		return "UNKNOWN!";
    	}
    };
    
    static void direct_interrupts_to_host(struct drm_i915_private *dev_priv)
    {
    	struct intel_engine_cs *engine;
    	int irqs;
    
    	/* tell all command streamers NOT to forward interrupts and vblank to GuC */
    	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_NEVER);
    	irqs |= _MASKED_BIT_DISABLE(GFX_INTERRUPT_STEERING);
    	for_each_engine(engine, dev_priv)
    		I915_WRITE(RING_MODE_GEN7(engine), irqs);
    
    	/* route all GT interrupts to the host */
    	I915_WRITE(GUC_BCS_RCS_IER, 0);
    	I915_WRITE(GUC_VCS2_VCS1_IER, 0);
    	I915_WRITE(GUC_WD_VECS_IER, 0);
    }
    
    static void direct_interrupts_to_guc(struct drm_i915_private *dev_priv)
    {
    	struct intel_engine_cs *engine;
    	int irqs;
    	u32 tmp;
    
    	/* tell all command streamers to forward interrupts and vblank to GuC */
    	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_ALWAYS);
    	irqs |= _MASKED_BIT_ENABLE(GFX_INTERRUPT_STEERING);
    	for_each_engine(engine, dev_priv)
    		I915_WRITE(RING_MODE_GEN7(engine), irqs);
    
    	/* route USER_INTERRUPT to Host, all others are sent to GuC. */
    	irqs = GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
    	       GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT;
    	/* These three registers have the same bit definitions */
    	I915_WRITE(GUC_BCS_RCS_IER, ~irqs);
    	I915_WRITE(GUC_VCS2_VCS1_IER, ~irqs);
    	I915_WRITE(GUC_WD_VECS_IER, ~irqs);
    
    	/*
    	 * If GuC has routed PM interrupts to itself, don't keep it.
    	 * and keep other interrupts those are unmasked by GuC.
    	*/
    	tmp = I915_READ(GEN6_PMINTRMSK);
    	if (tmp & GEN8_PMINTR_REDIRECT_TO_NON_DISP) {
    		dev_priv->rps.pm_intr_keep |= ~(tmp & ~GEN8_PMINTR_REDIRECT_TO_NON_DISP);
    		dev_priv->rps.pm_intr_keep &= ~GEN8_PMINTR_REDIRECT_TO_NON_DISP;
    	}
    }
    
    static u32 get_gttype(struct drm_i915_private *dev_priv)
    {
    	/* XXX: GT type based on PCI device ID? field seems unused by fw */
    	return 0;
    }
    
    static u32 get_core_family(struct drm_i915_private *dev_priv)
    {
    	switch (INTEL_INFO(dev_priv)->gen) {
    	case 9:
    		return GFXCORE_FAMILY_GEN9;
    
    	default:
    		DRM_ERROR("GUC: unsupported core family\n");
    		return GFXCORE_FAMILY_UNKNOWN;
    	}
    }
    
    static void set_guc_init_params(struct drm_i915_private *dev_priv)
    {
    	struct intel_guc *guc = &dev_priv->guc;
    	u32 params[GUC_CTL_MAX_DWORDS];
    	int i;
    
    	memset(&params, 0, sizeof(params));
    
    	params[GUC_CTL_DEVICE_INFO] |=
    		(get_gttype(dev_priv) << GUC_CTL_GTTYPE_SHIFT) |
    		(get_core_family(dev_priv) << GUC_CTL_COREFAMILY_SHIFT);
    
    	/*
    	 * 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_DISABLE_SCHEDULER |
    			GUC_CTL_VCS2_ENABLED;
    
    	if (i915.guc_log_level >= 0) {
    		params[GUC_CTL_LOG_PARAMS] = guc->log_flags;
    		params[GUC_CTL_DEBUG] =
    			i915.guc_log_level << GUC_LOG_VERBOSITY_SHIFT;
    	}
    
    	if (guc->ads_obj) {
    		u32 ads = (u32)i915_gem_obj_ggtt_offset(guc->ads_obj)
    				>> PAGE_SHIFT;
    		params[GUC_CTL_DEBUG] |= ads << GUC_ADS_ADDR_SHIFT;
    		params[GUC_CTL_DEBUG] |= GUC_ADS_ENABLED;
    	}
    
    	/* 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++)
    		I915_WRITE(SOFT_SCRATCH(1 + i), params[i]);
    }
    
    /*
     * Read the GuC status register (GUC_STATUS) and store it in the
     * specified location; then return a boolean indicating whether
     * the value matches either of two values representing completion
     * of the GuC boot process.
     *
     * This is used for polling the GuC status in a wait_for()
     * loop below.
     */
    static inline bool guc_ucode_response(struct drm_i915_private *dev_priv,
    				      u32 *status)
    {
    	u32 val = I915_READ(GUC_STATUS);
    	u32 uk_val = val & GS_UKERNEL_MASK;
    	*status = val;
    	return (uk_val == GS_UKERNEL_READY ||
    		((val & GS_MIA_CORE_STATE) && uk_val == GS_UKERNEL_LAPIC_DONE));
    }
    
    /*
     * Transfer the firmware image to RAM for execution by the microcontroller.
     *
     * Architecturally, the DMA engine is bidirectional, and can potentially even
     * transfer between GTT locations. This functionality is left out of the API
     * for now as there is no need for it.
     *
     * Note that GuC needs the CSS header plus uKernel code to be copied by the
     * DMA engine in one operation, whereas the RSA signature is loaded via MMIO.
     */
    static int guc_ucode_xfer_dma(struct drm_i915_private *dev_priv)
    {
    	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
    	struct drm_i915_gem_object *fw_obj = guc_fw->guc_fw_obj;
    	unsigned long offset;
    	struct sg_table *sg = fw_obj->pages;
    	u32 status, rsa[UOS_RSA_SCRATCH_MAX_COUNT];
    	int i, ret = 0;
    
    	/* where RSA signature starts */
    	offset = guc_fw->rsa_offset;
    
    	/* Copy RSA signature from the fw image to HW for verification */
    	sg_pcopy_to_buffer(sg->sgl, sg->nents, rsa, sizeof(rsa), offset);
    	for (i = 0; i < UOS_RSA_SCRATCH_MAX_COUNT; i++)
    		I915_WRITE(UOS_RSA_SCRATCH(i), rsa[i]);
    
    	/* The header plus uCode will be copied to WOPCM via DMA, excluding any
    	 * other components */
    	I915_WRITE(DMA_COPY_SIZE, guc_fw->header_size + guc_fw->ucode_size);
    
    	/* Set the source address for the new blob */
    	offset = i915_gem_obj_ggtt_offset(fw_obj) + guc_fw->header_offset;
    	I915_WRITE(DMA_ADDR_0_LOW, lower_32_bits(offset));
    	I915_WRITE(DMA_ADDR_0_HIGH, upper_32_bits(offset) & 0xFFFF);
    
    	/*
    	 * Set the DMA destination. Current uCode expects the code to be
    	 * loaded at 8k; locations below this are used for the stack.
    	 */
    	I915_WRITE(DMA_ADDR_1_LOW, 0x2000);
    	I915_WRITE(DMA_ADDR_1_HIGH, DMA_ADDRESS_SPACE_WOPCM);
    
    	/* Finally start the DMA */
    	I915_WRITE(DMA_CTRL, _MASKED_BIT_ENABLE(UOS_MOVE | START_DMA));
    
    	/*
    	 * Wait for the DMA to complete & the GuC to start up.
    	 * NB: Docs recommend not using the interrupt for completion.
    	 * Measurements indicate this should take no more than 20ms, so a
    	 * timeout here indicates that the GuC has failed and is unusable.
    	 * (Higher levels of the driver will attempt to fall back to
    	 * execlist mode if this happens.)
    	 */
    	ret = wait_for(guc_ucode_response(dev_priv, &status), 100);
    
    	DRM_DEBUG_DRIVER("DMA status 0x%x, GuC status 0x%x\n",
    			I915_READ(DMA_CTRL), status);
    
    	if ((status & GS_BOOTROM_MASK) == GS_BOOTROM_RSA_FAILED) {
    		DRM_ERROR("GuC firmware signature verification failed\n");
    		ret = -ENOEXEC;
    	}
    
    	DRM_DEBUG_DRIVER("returning %d\n", ret);
    
    	return ret;
    }
    
    static u32 guc_wopcm_size(struct drm_i915_private *dev_priv)
    {
    	u32 wopcm_size = GUC_WOPCM_TOP;
    
    	/* On BXT, the top of WOPCM is reserved for RC6 context */
    	if (IS_BROXTON(dev_priv))
    		wopcm_size -= BXT_GUC_WOPCM_RC6_RESERVED;
    
    	return wopcm_size;
    }
    
    /*
     * Load the GuC firmware blob into the MinuteIA.
     */
    static int guc_ucode_xfer(struct drm_i915_private *dev_priv)
    {
    	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
    	struct drm_device *dev = dev_priv->dev;
    	int ret;
    
    	ret = i915_gem_object_set_to_gtt_domain(guc_fw->guc_fw_obj, false);
    	if (ret) {
    		DRM_DEBUG_DRIVER("set-domain failed %d\n", ret);
    		return ret;
    	}
    
    	ret = i915_gem_obj_ggtt_pin(guc_fw->guc_fw_obj, 0, 0);
    	if (ret) {
    		DRM_DEBUG_DRIVER("pin failed %d\n", ret);
    		return ret;
    	}
    
    	/* Invalidate GuC TLB to let GuC take the latest updates to GTT. */
    	I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
    
    	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
    
    	/* init WOPCM */
    	I915_WRITE(GUC_WOPCM_SIZE, guc_wopcm_size(dev_priv));
    	I915_WRITE(DMA_GUC_WOPCM_OFFSET, GUC_WOPCM_OFFSET_VALUE);
    
    	/* Enable MIA caching. GuC clock gating is disabled. */
    	I915_WRITE(GUC_SHIM_CONTROL, GUC_SHIM_CONTROL_VALUE);
    
    	/* WaDisableMinuteIaClockGating:skl,bxt */
    	if (IS_SKL_REVID(dev, 0, SKL_REVID_B0) ||
    	    IS_BXT_REVID(dev, 0, BXT_REVID_A1)) {
    		I915_WRITE(GUC_SHIM_CONTROL, (I915_READ(GUC_SHIM_CONTROL) &
    					      ~GUC_ENABLE_MIA_CLOCK_GATING));
    	}
    
    	/* WaC6DisallowByGfxPause*/
    	I915_WRITE(GEN6_GFXPAUSE, 0x30FFF);
    
    	if (IS_BROXTON(dev))
    		I915_WRITE(GEN9LP_GT_PM_CONFIG, GT_DOORBELL_ENABLE);
    	else
    		I915_WRITE(GEN9_GT_PM_CONFIG, GT_DOORBELL_ENABLE);
    
    	if (IS_GEN9(dev)) {
    		/* DOP Clock Gating Enable for GuC clocks */
    		I915_WRITE(GEN7_MISCCPCTL, (GEN8_DOP_CLOCK_GATE_GUC_ENABLE |
    					    I915_READ(GEN7_MISCCPCTL)));
    
    		/* allows for 5us before GT can go to RC6 */
    		I915_WRITE(GUC_ARAT_C6DIS, 0x1FF);
    	}
    
    	set_guc_init_params(dev_priv);
    
    	ret = guc_ucode_xfer_dma(dev_priv);
    
    	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
    
    	/*
    	 * We keep the object pages for reuse during resume. But we can unpin it
    	 * now that DMA has completed, so it doesn't continue to take up space.
    	 */
    	i915_gem_object_ggtt_unpin(guc_fw->guc_fw_obj);
    
    	return ret;
    }
    
    static int i915_reset_guc(struct drm_i915_private *dev_priv)
    {
    	int ret;
    	u32 guc_status;
    
    	ret = intel_guc_reset(dev_priv);
    	if (ret) {
    		DRM_ERROR("GuC reset failed, ret = %d\n", ret);
    		return ret;
    	}
    
    	guc_status = I915_READ(GUC_STATUS);
    	WARN(!(guc_status & GS_MIA_IN_RESET),
    	     "GuC status: 0x%x, MIA core expected to be in reset\n", guc_status);
    
    	return ret;
    }
    
    /**
     * intel_guc_setup() - finish preparing the GuC for activity
     * @dev:	drm device
     *
     * Called from gem_init_hw() during driver loading and also after a GPU reset.
     *
     * The main action required here it to load the GuC uCode into the device.
     * The firmware image should have already been fetched into memory by the
     * earlier call to intel_guc_init(), so here we need only check that worked,
     * and then transfer the image to the h/w.
     *
     * Return:	non-zero code on error
     */
    int intel_guc_setup(struct drm_device *dev)
    {
    	struct drm_i915_private *dev_priv = dev->dev_private;
    	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
    	const char *fw_path = guc_fw->guc_fw_path;
    	int retries, ret, err;
    
    	DRM_DEBUG_DRIVER("GuC fw status: path %s, fetch %s, load %s\n",
    		fw_path,
    		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status),
    		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
    
    	/* Loading forbidden, or no firmware to load? */
    	if (!i915.enable_guc_loading) {
    		err = 0;
    		goto fail;
    	} else if (fw_path == NULL) {
    		/* Device is known to have no uCode (e.g. no GuC) */
    		err = -ENXIO;
    		goto fail;
    	} else if (*fw_path == '\0') {
    		/* Device has a GuC but we don't know what f/w to load? */
    		DRM_INFO("No GuC firmware known for this platform\n");
    		err = -ENODEV;
    		goto fail;
    	}
    
    	/* Fetch failed, or already fetched but failed to load? */
    	if (guc_fw->guc_fw_fetch_status != GUC_FIRMWARE_SUCCESS) {
    		err = -EIO;
    		goto fail;
    	} else if (guc_fw->guc_fw_load_status == GUC_FIRMWARE_FAIL) {
    		err = -ENOEXEC;
    		goto fail;
    	}
    
    	direct_interrupts_to_host(dev_priv);
    
    	guc_fw->guc_fw_load_status = GUC_FIRMWARE_PENDING;
    
    	DRM_DEBUG_DRIVER("GuC fw status: fetch %s, load %s\n",
    		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status),
    		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
    
    	err = i915_guc_submission_init(dev);
    	if (err)
    		goto fail;
    
    	/*
    	 * WaEnableuKernelHeaderValidFix:skl,bxt
    	 * For BXT, this is only upto B0 but below WA is required for later
    	 * steppings also so this is extended as well.
    	 */
    	/* WaEnableGuCBootHashCheckNotSet:skl,bxt */
    	for (retries = 3; ; ) {
    		/*
    		 * Always reset the GuC just before (re)loading, so
    		 * that the state and timing are fairly predictable
    		 */
    		err = i915_reset_guc(dev_priv);
    		if (err) {
    			DRM_ERROR("GuC reset failed: %d\n", err);
    			goto fail;
    		}
    
    		err = guc_ucode_xfer(dev_priv);
    		if (!err)
    			break;
    
    		if (--retries == 0)
    			goto fail;
    
    		DRM_INFO("GuC fw load failed: %d; will reset and "
    			 "retry %d more time(s)\n", err, retries);
    	}
    
    	guc_fw->guc_fw_load_status = GUC_FIRMWARE_SUCCESS;
    
    	DRM_DEBUG_DRIVER("GuC fw status: fetch %s, load %s\n",
    		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;
    		direct_interrupts_to_guc(dev_priv);
    	}
    
    	return 0;
    
    fail:
    	if (guc_fw->guc_fw_load_status == GUC_FIRMWARE_PENDING)
    		guc_fw->guc_fw_load_status = GUC_FIRMWARE_FAIL;
    
    	direct_interrupts_to_host(dev_priv);
    	i915_guc_submission_disable(dev);
    	i915_guc_submission_fini(dev);
    
    	/*
    	 * We've failed to load the firmware :(
    	 *
    	 * Decide whether to disable GuC submission and fall back to
    	 * execlist mode, and whether to hide the error by returning
    	 * zero or to return -EIO, which the caller will treat as a
    	 * nonfatal error (i.e. it doesn't prevent driver load, but
    	 * marks the GPU as wedged until reset).
    	 */
    	if (i915.enable_guc_loading > 1) {
    		ret = -EIO;
    	} else if (i915.enable_guc_submission > 1) {
    		ret = -EIO;
    	} else {
    		ret = 0;
    	}
    
    	if (err == 0 && !HAS_GUC_UCODE(dev))
    		;	/* Don't mention the GuC! */
    	else if (err == 0)
    		DRM_INFO("GuC firmware load skipped\n");
    	else if (ret != -EIO)
    		DRM_INFO("GuC firmware load failed: %d\n", err);
    	else
    		DRM_ERROR("GuC firmware load failed: %d\n", err);
    
    	if (i915.enable_guc_submission) {
    		if (fw_path == NULL)
    			DRM_INFO("GuC submission without firmware not supported\n");
    		if (ret == 0)
    			DRM_INFO("Falling back from GuC submission to execlist mode\n");
    		else
    			DRM_ERROR("GuC init failed: %d\n", ret);
    	}
    	i915.enable_guc_submission = 0;
    
    	return ret;
    }
    
    static void guc_fw_fetch(struct drm_device *dev, struct intel_guc_fw *guc_fw)
    {
    	struct drm_i915_gem_object *obj;
    	const struct firmware *fw;
    	struct guc_css_header *css;
    	size_t size;
    	int err;
    
    	DRM_DEBUG_DRIVER("before requesting firmware: GuC fw fetch status %s\n",
    		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status));
    
    	err = request_firmware(&fw, guc_fw->guc_fw_path, &dev->pdev->dev);
    	if (err)
    		goto fail;
    	if (!fw)
    		goto fail;
    
    	DRM_DEBUG_DRIVER("fetch GuC fw from %s succeeded, fw %p\n",
    		guc_fw->guc_fw_path, fw);
    
    	/* Check the size of the blob before examining buffer contents */
    	if (fw->size < sizeof(struct guc_css_header)) {
    		DRM_ERROR("Firmware header is missing\n");
    		goto fail;
    	}
    
    	css = (struct guc_css_header *)fw->data;
    
    	/* Firmware bits always start from header */
    	guc_fw->header_offset = 0;
    	guc_fw->header_size = (css->header_size_dw - css->modulus_size_dw -
    		css->key_size_dw - css->exponent_size_dw) * sizeof(u32);
    
    	if (guc_fw->header_size != sizeof(struct guc_css_header)) {
    		DRM_ERROR("CSS header definition mismatch\n");
    		goto fail;
    	}
    
    	/* then, uCode */
    	guc_fw->ucode_offset = guc_fw->header_offset + guc_fw->header_size;
    	guc_fw->ucode_size = (css->size_dw - css->header_size_dw) * sizeof(u32);
    
    	/* now RSA */
    	if (css->key_size_dw != UOS_RSA_SCRATCH_MAX_COUNT) {
    		DRM_ERROR("RSA key size is bad\n");
    		goto fail;
    	}
    	guc_fw->rsa_offset = guc_fw->ucode_offset + guc_fw->ucode_size;
    	guc_fw->rsa_size = css->key_size_dw * sizeof(u32);
    
    	/* At least, it should have header, uCode and RSA. Size of all three. */
    	size = guc_fw->header_size + guc_fw->ucode_size + guc_fw->rsa_size;
    	if (fw->size < size) {
    		DRM_ERROR("Missing firmware components\n");
    		goto fail;
    	}
    
    	/* Header and uCode will be loaded to WOPCM. Size of the two. */
    	size = guc_fw->header_size + guc_fw->ucode_size;
    	if (size > guc_wopcm_size(dev->dev_private)) {
    		DRM_ERROR("Firmware is too large to fit in WOPCM\n");
    		goto fail;
    	}
    
    	/*
    	 * The GuC firmware image has the version number embedded at a well-known
    	 * offset within the firmware blob; note that major / minor version are
    	 * TWO bytes each (i.e. u16), although all pointers and offsets are defined
    	 * in terms of bytes (u8).
    	 */
    	guc_fw->guc_fw_major_found = css->guc_sw_version >> 16;
    	guc_fw->guc_fw_minor_found = css->guc_sw_version & 0xFFFF;
    
    	if (guc_fw->guc_fw_major_found != guc_fw->guc_fw_major_wanted ||
    	    guc_fw->guc_fw_minor_found < guc_fw->guc_fw_minor_wanted) {
    		DRM_ERROR("GuC firmware version %d.%d, required %d.%d\n",
    			guc_fw->guc_fw_major_found, guc_fw->guc_fw_minor_found,
    			guc_fw->guc_fw_major_wanted, guc_fw->guc_fw_minor_wanted);
    		err = -ENOEXEC;
    		goto fail;
    	}
    
    	DRM_DEBUG_DRIVER("firmware version %d.%d OK (minimum %d.%d)\n",
    			guc_fw->guc_fw_major_found, guc_fw->guc_fw_minor_found,
    			guc_fw->guc_fw_major_wanted, guc_fw->guc_fw_minor_wanted);
    
    	mutex_lock(&dev->struct_mutex);
    	obj = i915_gem_object_create_from_data(dev, fw->data, fw->size);
    	mutex_unlock(&dev->struct_mutex);
    	if (IS_ERR_OR_NULL(obj)) {
    		err = obj ? PTR_ERR(obj) : -ENOMEM;
    		goto fail;
    	}
    
    	guc_fw->guc_fw_obj = obj;
    	guc_fw->guc_fw_size = fw->size;
    
    	DRM_DEBUG_DRIVER("GuC fw fetch status SUCCESS, obj %p\n",
    			guc_fw->guc_fw_obj);
    
    	release_firmware(fw);
    	guc_fw->guc_fw_fetch_status = GUC_FIRMWARE_SUCCESS;
    	return;
    
    fail:
    	DRM_DEBUG_DRIVER("GuC fw fetch status FAIL; err %d, fw %p, obj %p\n",
    		err, fw, guc_fw->guc_fw_obj);
    	DRM_ERROR("Failed to fetch GuC firmware from %s (error %d)\n",
    		  guc_fw->guc_fw_path, err);
    
    	mutex_lock(&dev->struct_mutex);
    	obj = guc_fw->guc_fw_obj;
    	if (obj)
    		drm_gem_object_unreference(&obj->base);
    	guc_fw->guc_fw_obj = NULL;
    	mutex_unlock(&dev->struct_mutex);
    
    	release_firmware(fw);		/* OK even if fw is NULL */
    	guc_fw->guc_fw_fetch_status = GUC_FIRMWARE_FAIL;
    }
    
    /**
     * intel_guc_init() - define parameters and fetch firmware
     * @dev:	drm device
     *
     * Called early during driver load, but after GEM is initialised.
     *
     * The firmware will be transferred to the GuC's memory later,
     * when intel_guc_setup() is called.
     */
    void intel_guc_init(struct drm_device *dev)
    {
    	struct drm_i915_private *dev_priv = dev->dev_private;
    	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
    	const char *fw_path;
    
    	/* A negative value means "use platform default" */
    	if (i915.enable_guc_loading < 0)
    		i915.enable_guc_loading = HAS_GUC_UCODE(dev);
    	if (i915.enable_guc_submission < 0)
    		i915.enable_guc_submission = HAS_GUC_SCHED(dev);
    
    	if (!HAS_GUC_UCODE(dev)) {
    		fw_path = NULL;
    	} else if (IS_SKYLAKE(dev)) {
    		fw_path = I915_SKL_GUC_UCODE;
    		guc_fw->guc_fw_major_wanted = 6;
    		guc_fw->guc_fw_minor_wanted = 1;
    	} else if (IS_BROXTON(dev)) {
    		fw_path = I915_BXT_GUC_UCODE;
    		guc_fw->guc_fw_major_wanted = 8;
    		guc_fw->guc_fw_minor_wanted = 7;
    	} else {
    		fw_path = "";	/* unknown device */
    	}
    
    	guc_fw->guc_dev = dev;
    	guc_fw->guc_fw_path = fw_path;
    	guc_fw->guc_fw_fetch_status = GUC_FIRMWARE_NONE;
    	guc_fw->guc_fw_load_status = GUC_FIRMWARE_NONE;
    
    	/* Early (and silent) return if GuC loading is disabled */
    	if (!i915.enable_guc_loading)
    		return;
    	if (fw_path == NULL)
    		return;
    	if (*fw_path == '\0')
    		return;
    
    	guc_fw->guc_fw_fetch_status = GUC_FIRMWARE_PENDING;
    	DRM_DEBUG_DRIVER("GuC firmware pending, path %s\n", fw_path);
    	guc_fw_fetch(dev, guc_fw);
    	/* status must now be FAIL or SUCCESS */
    }
    
    /**
     * intel_guc_fini() - clean up all allocated resources
     * @dev:	drm device
     */
    void intel_guc_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;
    
    	mutex_lock(&dev->struct_mutex);
    	direct_interrupts_to_host(dev_priv);
    	i915_guc_submission_disable(dev);
    	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;
    	mutex_unlock(&dev->struct_mutex);
    
    	guc_fw->guc_fw_fetch_status = GUC_FIRMWARE_NONE;
    }