linux/drivers/gpu/drm/i915/gt/uc/intel_guc_fw.c

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2014-2019 Intel Corporation
 *
 * 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 "gt/intel_gt.h"
#include "intel_guc_fw.h"
#include "i915_drv.h"

static void guc_prepare_xfer(struct intel_uncore *uncore)
{
	u32 shim_flags = GUC_DISABLE_SRAM_INIT_TO_ZEROES |
			 GUC_ENABLE_READ_CACHE_LOGIC |
			 GUC_ENABLE_MIA_CACHING |
			 GUC_ENABLE_READ_CACHE_FOR_SRAM_DATA |
			 GUC_ENABLE_READ_CACHE_FOR_WOPCM_DATA |
			 GUC_ENABLE_MIA_CLOCK_GATING;

	/* Must program this register before loading the ucode with DMA */
	intel_uncore_write(uncore, GUC_SHIM_CONTROL, shim_flags);

	if (IS_GEN9_LP(uncore->i915))
		intel_uncore_write(uncore, GEN9LP_GT_PM_CONFIG, GT_DOORBELL_ENABLE);
	else
		intel_uncore_write(uncore, GEN9_GT_PM_CONFIG, GT_DOORBELL_ENABLE);

	if (IS_GEN(uncore->i915, 9)) {
		/* DOP Clock Gating Enable for GuC clocks */
		intel_uncore_rmw(uncore, GEN7_MISCCPCTL,
				 0, GEN8_DOP_CLOCK_GATE_GUC_ENABLE);

		/* allows for 5us (in 10ns units) before GT can go to RC6 */
		intel_uncore_write(uncore, GUC_ARAT_C6DIS, 0x1FF);
	}
}

/* Copy RSA signature from the fw image to HW for verification */
static void guc_xfer_rsa(struct intel_uc_fw *guc_fw,
			 struct intel_uncore *uncore)
{
	u32 rsa[UOS_RSA_SCRATCH_COUNT];
	size_t copied;
	int i;

	copied = intel_uc_fw_copy_rsa(guc_fw, rsa, sizeof(rsa));
	GEM_BUG_ON(copied < sizeof(rsa));

	for (i = 0; i < UOS_RSA_SCRATCH_COUNT; i++)
		intel_uncore_write(uncore, UOS_RSA_SCRATCH(i), rsa[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_ready(struct intel_uncore *uncore, u32 *status)
{
	u32 val = intel_uncore_read(uncore, 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));
}

static int guc_wait_ucode(struct intel_uncore *uncore)
{
	u32 status;
	int ret;

	/*
	 * Wait for 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 may decide to reset the GuC and
	 * attempt the ucode load again if this happens.)
	 */
	ret = wait_for(guc_ready(uncore, &status), 100);
	DRM_DEBUG_DRIVER("GuC status %#x\n", status);

	if ((status & GS_BOOTROM_MASK) == GS_BOOTROM_RSA_FAILED) {
		DRM_ERROR("GuC firmware signature verification failed\n");
		ret = -ENOEXEC;
	}

	if ((status & GS_UKERNEL_MASK) == GS_UKERNEL_EXCEPTION) {
		DRM_ERROR("GuC firmware exception. EIP: %#x\n",
			  intel_uncore_read(uncore, SOFT_SCRATCH(13)));
		ret = -ENXIO;
	}

	return ret;
}

/**
 * intel_guc_fw_upload() - load GuC uCode to device
 * @guc: intel_guc structure
 *
 * Called from intel_uc_init_hw() during driver load, resume from sleep and
 * after a GPU reset.
 *
 * The firmware image should have already been fetched into memory, so only
 * check that fetch succeeded, and then transfer the image to the h/w.
 *
 * Return:	non-zero code on error
 */
int intel_guc_fw_upload(struct intel_guc *guc)
{
	struct intel_gt *gt = guc_to_gt(guc);
	struct intel_uncore *uncore = gt->uncore;
	int ret;

	guc_prepare_xfer(uncore);

	/*
	 * 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.
	 */
	guc_xfer_rsa(&guc->fw, uncore);

	/*
	 * Current uCode expects the code to be loaded at 8k; locations below
	 * this are used for the stack.
	 */
	ret = intel_uc_fw_upload(&guc->fw, 0x2000, UOS_MOVE);
	if (ret)
		goto out;

	ret = guc_wait_ucode(uncore);
	if (ret)
		goto out;

	intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_RUNNING);
	return 0;

out:
	intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_FAIL);
	return ret;
}