linux/drivers/gpu/drm/i915/intel_uc.c

/*
 * Copyright © 2016 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 "i915_drv.h"
#include "intel_uc.h"

void intel_uc_init_early(struct drm_i915_private *dev_priv)
{
	mutex_init(&dev_priv->guc.send_mutex);
}

/*
 * Read GuC command/status register (SOFT_SCRATCH_0)
 * Return true if it contains a response rather than a command
 */
static bool intel_guc_recv(struct intel_guc *guc, u32 *status)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	u32 val = I915_READ(SOFT_SCRATCH(0));
	*status = val;
	return INTEL_GUC_RECV_IS_RESPONSE(val);
}

int intel_guc_send(struct intel_guc *guc, const u32 *action, u32 len)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 status;
	int i;
	int ret;

	if (WARN_ON(len < 1 || len > 15))
		return -EINVAL;

	mutex_lock(&guc->send_mutex);
	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

	dev_priv->guc.action_count += 1;
	dev_priv->guc.action_cmd = action[0];

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

	POSTING_READ(SOFT_SCRATCH(i - 1));

	I915_WRITE(GUC_SEND_INTERRUPT, GUC_SEND_TRIGGER);

	/*
	 * Fast commands should complete in less than 10us, so sample quickly
	 * up to that length of time, then switch to a slower sleep-wait loop.
	 * No inte_guc_send command should ever take longer than 10ms.
	 */
	ret = wait_for_us(intel_guc_recv(guc, &status), 10);
	if (ret)
		ret = wait_for(intel_guc_recv(guc, &status), 10);
	if (status != INTEL_GUC_STATUS_SUCCESS) {
		/*
		 * Either the GuC explicitly returned an error (which
		 * we convert to -EIO here) or no response at all was
		 * received within the timeout limit (-ETIMEDOUT)
		 */
		if (ret != -ETIMEDOUT)
			ret = -EIO;

		DRM_WARN("INTEL_GUC_SEND: Action 0x%X failed;"
			 " ret=%d status=0x%08X response=0x%08X\n",
			 action[0], ret, status, I915_READ(SOFT_SCRATCH(15)));

		dev_priv->guc.action_fail += 1;
		dev_priv->guc.action_err = ret;
	}
	dev_priv->guc.action_status = status;

	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
	mutex_unlock(&guc->send_mutex);

	return ret;
}

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,bxt */
	if (!intel_enable_rc6() || 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));
}