/*
 * Copyright © 2012 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:
 *    Ben Widawsky <ben@bwidawsk.net>
 *
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/stat.h>
#include <linux/sysfs.h>
#include "intel_drv.h"
#include "i915_drv.h"

#define dev_to_drm_minor(d) dev_get_drvdata((d))

#ifdef CONFIG_PM
static u32 calc_residency(struct drm_device *dev, const u32 reg)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	u64 raw_time; /* 32b value may overflow during fixed point math */
	u64 units = 128ULL, div = 100000ULL, bias = 100ULL;
	u32 ret;

	if (!intel_enable_rc6(dev))
		return 0;

	intel_runtime_pm_get(dev_priv);

	/* On VLV and CHV, residency time is in CZ units rather than 1.28us */
	if (IS_VALLEYVIEW(dev)) {
		u32 reg, czcount_30ns;

		if (IS_CHERRYVIEW(dev))
			reg = CHV_CLK_CTL1;
		else
			reg = VLV_CLK_CTL2;

		czcount_30ns = I915_READ(reg) >> CLK_CTL2_CZCOUNT_30NS_SHIFT;

		if (!czcount_30ns) {
			WARN(!czcount_30ns, "bogus CZ count value");
			ret = 0;
			goto out;
		}

		units = 0;
		div = 1000000ULL;

		if (IS_CHERRYVIEW(dev)) {
			/* Special case for 320Mhz */
			if (czcount_30ns == 1) {
				div = 10000000ULL;
				units = 3125ULL;
			} else {
				/* chv counts are one less */
				czcount_30ns += 1;
			}
		}

		if (units == 0)
			units = DIV_ROUND_UP_ULL(30ULL * bias,
						 (u64)czcount_30ns);

		if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH)
			units <<= 8;

		div = div * bias;
	}

	raw_time = I915_READ(reg) * units;
	ret = DIV_ROUND_UP_ULL(raw_time, div);

out:
	intel_runtime_pm_put(dev_priv);
	return ret;
}

static ssize_t
show_rc6_mask(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *dminor = dev_to_drm_minor(kdev);
	return snprintf(buf, PAGE_SIZE, "%x\n", intel_enable_rc6(dminor->dev));
}

static ssize_t
show_rc6_ms(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *dminor = dev_get_drvdata(kdev);
	u32 rc6_residency = calc_residency(dminor->dev, GEN6_GT_GFX_RC6);
	return snprintf(buf, PAGE_SIZE, "%u\n", rc6_residency);
}

static ssize_t
show_rc6p_ms(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *dminor = dev_to_drm_minor(kdev);
	u32 rc6p_residency = calc_residency(dminor->dev, GEN6_GT_GFX_RC6p);
	if (IS_VALLEYVIEW(dminor->dev))
		rc6p_residency = 0;
	return snprintf(buf, PAGE_SIZE, "%u\n", rc6p_residency);
}

static ssize_t
show_rc6pp_ms(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *dminor = dev_to_drm_minor(kdev);
	u32 rc6pp_residency = calc_residency(dminor->dev, GEN6_GT_GFX_RC6pp);
	if (IS_VALLEYVIEW(dminor->dev))
		rc6pp_residency = 0;
	return snprintf(buf, PAGE_SIZE, "%u\n", rc6pp_residency);
}

static DEVICE_ATTR(rc6_enable, S_IRUGO, show_rc6_mask, NULL);
static DEVICE_ATTR(rc6_residency_ms, S_IRUGO, show_rc6_ms, NULL);
static DEVICE_ATTR(rc6p_residency_ms, S_IRUGO, show_rc6p_ms, NULL);
static DEVICE_ATTR(rc6pp_residency_ms, S_IRUGO, show_rc6pp_ms, NULL);

static struct attribute *rc6_attrs[] = {
	&dev_attr_rc6_enable.attr,
	&dev_attr_rc6_residency_ms.attr,
	NULL
};

static struct attribute_group rc6_attr_group = {
	.name = power_group_name,
	.attrs =  rc6_attrs
};

static struct attribute *rc6p_attrs[] = {
	&dev_attr_rc6p_residency_ms.attr,
	&dev_attr_rc6pp_residency_ms.attr,
	NULL
};

static struct attribute_group rc6p_attr_group = {
	.name = power_group_name,
	.attrs =  rc6p_attrs
};
#endif

static int l3_access_valid(struct drm_device *dev, loff_t offset)
{
	if (!HAS_L3_DPF(dev))
		return -EPERM;

	if (offset % 4 != 0)
		return -EINVAL;

	if (offset >= GEN7_L3LOG_SIZE)
		return -ENXIO;

	return 0;
}

static ssize_t
i915_l3_read(struct file *filp, struct kobject *kobj,
	     struct bin_attribute *attr, char *buf,
	     loff_t offset, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct drm_minor *dminor = dev_to_drm_minor(dev);
	struct drm_device *drm_dev = dminor->dev;
	struct drm_i915_private *dev_priv = drm_dev->dev_private;
	int slice = (int)(uintptr_t)attr->private;
	int ret;

	count = round_down(count, 4);

	ret = l3_access_valid(drm_dev, offset);
	if (ret)
		return ret;

	count = min_t(size_t, GEN7_L3LOG_SIZE - offset, count);

	ret = i915_mutex_lock_interruptible(drm_dev);
	if (ret)
		return ret;

	if (dev_priv->l3_parity.remap_info[slice])
		memcpy(buf,
		       dev_priv->l3_parity.remap_info[slice] + (offset/4),
		       count);
	else
		memset(buf, 0, count);

	mutex_unlock(&drm_dev->struct_mutex);

	return count;
}

static ssize_t
i915_l3_write(struct file *filp, struct kobject *kobj,
	      struct bin_attribute *attr, char *buf,
	      loff_t offset, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct drm_minor *dminor = dev_to_drm_minor(dev);
	struct drm_device *drm_dev = dminor->dev;
	struct drm_i915_private *dev_priv = drm_dev->dev_private;
	struct intel_context *ctx;
	u32 *temp = NULL; /* Just here to make handling failures easy */
	int slice = (int)(uintptr_t)attr->private;
	int ret;

	if (!HAS_HW_CONTEXTS(drm_dev))
		return -ENXIO;

	ret = l3_access_valid(drm_dev, offset);
	if (ret)
		return ret;

	ret = i915_mutex_lock_interruptible(drm_dev);
	if (ret)
		return ret;

	if (!dev_priv->l3_parity.remap_info[slice]) {
		temp = kzalloc(GEN7_L3LOG_SIZE, GFP_KERNEL);
		if (!temp) {
			mutex_unlock(&drm_dev->struct_mutex);
			return -ENOMEM;
		}
	}

	ret = i915_gpu_idle(drm_dev);
	if (ret) {
		kfree(temp);
		mutex_unlock(&drm_dev->struct_mutex);
		return ret;
	}

	/* TODO: Ideally we really want a GPU reset here to make sure errors
	 * aren't propagated. Since I cannot find a stable way to reset the GPU
	 * at this point it is left as a TODO.
	*/
	if (temp)
		dev_priv->l3_parity.remap_info[slice] = temp;

	memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count);

	/* NB: We defer the remapping until we switch to the context */
	list_for_each_entry(ctx, &dev_priv->context_list, link)
		ctx->remap_slice |= (1<<slice);

	mutex_unlock(&drm_dev->struct_mutex);

	return count;
}

static struct bin_attribute dpf_attrs = {
	.attr = {.name = "l3_parity", .mode = (S_IRUSR | S_IWUSR)},
	.size = GEN7_L3LOG_SIZE,
	.read = i915_l3_read,
	.write = i915_l3_write,
	.mmap = NULL,
	.private = (void *)0
};

static struct bin_attribute dpf_attrs_1 = {
	.attr = {.name = "l3_parity_slice_1", .mode = (S_IRUSR | S_IWUSR)},
	.size = GEN7_L3LOG_SIZE,
	.read = i915_l3_read,
	.write = i915_l3_write,
	.mmap = NULL,
	.private = (void *)1
};

static ssize_t gt_cur_freq_mhz_show(struct device *kdev,
				    struct device_attribute *attr, char *buf)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	int ret;

	flush_delayed_work(&dev_priv->rps.delayed_resume_work);

	intel_runtime_pm_get(dev_priv);

	mutex_lock(&dev_priv->rps.hw_lock);
	if (IS_VALLEYVIEW(dev_priv->dev)) {
		u32 freq;
		freq = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS);
		ret = vlv_gpu_freq(dev_priv, (freq >> 8) & 0xff);
	} else {
		ret = dev_priv->rps.cur_freq * GT_FREQUENCY_MULTIPLIER;
	}
	mutex_unlock(&dev_priv->rps.hw_lock);

	intel_runtime_pm_put(dev_priv);

	return snprintf(buf, PAGE_SIZE, "%d\n", ret);
}

static ssize_t vlv_rpe_freq_mhz_show(struct device *kdev,
				     struct device_attribute *attr, char *buf)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;

	return snprintf(buf, PAGE_SIZE, "%d\n",
			vlv_gpu_freq(dev_priv, dev_priv->rps.efficient_freq));
}

static ssize_t gt_max_freq_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	int ret;

	flush_delayed_work(&dev_priv->rps.delayed_resume_work);

	mutex_lock(&dev_priv->rps.hw_lock);
	if (IS_VALLEYVIEW(dev_priv->dev))
		ret = vlv_gpu_freq(dev_priv, dev_priv->rps.max_freq_softlimit);
	else
		ret = dev_priv->rps.max_freq_softlimit * GT_FREQUENCY_MULTIPLIER;
	mutex_unlock(&dev_priv->rps.hw_lock);

	return snprintf(buf, PAGE_SIZE, "%d\n", ret);
}

static ssize_t gt_max_freq_mhz_store(struct device *kdev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 val;
	ssize_t ret;

	ret = kstrtou32(buf, 0, &val);
	if (ret)
		return ret;

	flush_delayed_work(&dev_priv->rps.delayed_resume_work);

	mutex_lock(&dev_priv->rps.hw_lock);

	if (IS_VALLEYVIEW(dev_priv->dev))
		val = vlv_freq_opcode(dev_priv, val);
	else
		val /= GT_FREQUENCY_MULTIPLIER;

	if (val < dev_priv->rps.min_freq ||
	    val > dev_priv->rps.max_freq ||
	    val < dev_priv->rps.min_freq_softlimit) {
		mutex_unlock(&dev_priv->rps.hw_lock);
		return -EINVAL;
	}

	if (val > dev_priv->rps.rp0_freq)
		DRM_DEBUG("User requested overclocking to %d\n",
			  val * GT_FREQUENCY_MULTIPLIER);

	dev_priv->rps.max_freq_softlimit = val;

	if (dev_priv->rps.cur_freq > val) {
		if (IS_VALLEYVIEW(dev))
			valleyview_set_rps(dev, val);
		else
			gen6_set_rps(dev, val);
	} else if (!IS_VALLEYVIEW(dev)) {
		/* We still need gen6_set_rps to process the new max_delay and
		 * update the interrupt limits even though frequency request is
		 * unchanged. */
		gen6_set_rps(dev, dev_priv->rps.cur_freq);
	}

	mutex_unlock(&dev_priv->rps.hw_lock);

	return count;
}

static ssize_t gt_min_freq_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	int ret;

	flush_delayed_work(&dev_priv->rps.delayed_resume_work);

	mutex_lock(&dev_priv->rps.hw_lock);
	if (IS_VALLEYVIEW(dev_priv->dev))
		ret = vlv_gpu_freq(dev_priv, dev_priv->rps.min_freq_softlimit);
	else
		ret = dev_priv->rps.min_freq_softlimit * GT_FREQUENCY_MULTIPLIER;
	mutex_unlock(&dev_priv->rps.hw_lock);

	return snprintf(buf, PAGE_SIZE, "%d\n", ret);
}

static ssize_t gt_min_freq_mhz_store(struct device *kdev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 val;
	ssize_t ret;

	ret = kstrtou32(buf, 0, &val);
	if (ret)
		return ret;

	flush_delayed_work(&dev_priv->rps.delayed_resume_work);

	mutex_lock(&dev_priv->rps.hw_lock);

	if (IS_VALLEYVIEW(dev))
		val = vlv_freq_opcode(dev_priv, val);
	else
		val /= GT_FREQUENCY_MULTIPLIER;

	if (val < dev_priv->rps.min_freq ||
	    val > dev_priv->rps.max_freq ||
	    val > dev_priv->rps.max_freq_softlimit) {
		mutex_unlock(&dev_priv->rps.hw_lock);
		return -EINVAL;
	}

	dev_priv->rps.min_freq_softlimit = val;

	if (dev_priv->rps.cur_freq < val) {
		if (IS_VALLEYVIEW(dev))
			valleyview_set_rps(dev, val);
		else
			gen6_set_rps(dev, val);
	} else if (!IS_VALLEYVIEW(dev)) {
		/* We still need gen6_set_rps to process the new min_delay and
		 * update the interrupt limits even though frequency request is
		 * unchanged. */
		gen6_set_rps(dev, dev_priv->rps.cur_freq);
	}

	mutex_unlock(&dev_priv->rps.hw_lock);

	return count;

}

static DEVICE_ATTR(gt_cur_freq_mhz, S_IRUGO, gt_cur_freq_mhz_show, NULL);
static DEVICE_ATTR(gt_max_freq_mhz, S_IRUGO | S_IWUSR, gt_max_freq_mhz_show, gt_max_freq_mhz_store);
static DEVICE_ATTR(gt_min_freq_mhz, S_IRUGO | S_IWUSR, gt_min_freq_mhz_show, gt_min_freq_mhz_store);

static DEVICE_ATTR(vlv_rpe_freq_mhz, S_IRUGO, vlv_rpe_freq_mhz_show, NULL);

static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf);
static DEVICE_ATTR(gt_RP0_freq_mhz, S_IRUGO, gt_rp_mhz_show, NULL);
static DEVICE_ATTR(gt_RP1_freq_mhz, S_IRUGO, gt_rp_mhz_show, NULL);
static DEVICE_ATTR(gt_RPn_freq_mhz, S_IRUGO, gt_rp_mhz_show, NULL);

/* For now we have a static number of RP states */
static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf)
{
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 val, rp_state_cap;
	ssize_t ret;

	ret = mutex_lock_interruptible(&dev->struct_mutex);
	if (ret)
		return ret;
	intel_runtime_pm_get(dev_priv);
	rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
	intel_runtime_pm_put(dev_priv);
	mutex_unlock(&dev->struct_mutex);

	if (attr == &dev_attr_gt_RP0_freq_mhz) {
		if (IS_VALLEYVIEW(dev))
			val = vlv_gpu_freq(dev_priv, dev_priv->rps.rp0_freq);
		else
			val = ((rp_state_cap & 0x0000ff) >> 0) * GT_FREQUENCY_MULTIPLIER;
	} else if (attr == &dev_attr_gt_RP1_freq_mhz) {
		if (IS_VALLEYVIEW(dev))
			val = vlv_gpu_freq(dev_priv, dev_priv->rps.rp1_freq);
		else
			val = ((rp_state_cap & 0x00ff00) >> 8) * GT_FREQUENCY_MULTIPLIER;
	} else if (attr == &dev_attr_gt_RPn_freq_mhz) {
		if (IS_VALLEYVIEW(dev))
			val = vlv_gpu_freq(dev_priv, dev_priv->rps.min_freq);
		else
			val = ((rp_state_cap & 0xff0000) >> 16) * GT_FREQUENCY_MULTIPLIER;
	} else {
		BUG();
	}
	return snprintf(buf, PAGE_SIZE, "%d\n", val);
}

static const struct attribute *gen6_attrs[] = {
	&dev_attr_gt_cur_freq_mhz.attr,
	&dev_attr_gt_max_freq_mhz.attr,
	&dev_attr_gt_min_freq_mhz.attr,
	&dev_attr_gt_RP0_freq_mhz.attr,
	&dev_attr_gt_RP1_freq_mhz.attr,
	&dev_attr_gt_RPn_freq_mhz.attr,
	NULL,
};

static const struct attribute *vlv_attrs[] = {
	&dev_attr_gt_cur_freq_mhz.attr,
	&dev_attr_gt_max_freq_mhz.attr,
	&dev_attr_gt_min_freq_mhz.attr,
	&dev_attr_gt_RP0_freq_mhz.attr,
	&dev_attr_gt_RP1_freq_mhz.attr,
	&dev_attr_gt_RPn_freq_mhz.attr,
	&dev_attr_vlv_rpe_freq_mhz.attr,
	NULL,
};

static ssize_t error_state_read(struct file *filp, struct kobject *kobj,
				struct bin_attribute *attr, char *buf,
				loff_t off, size_t count)
{

	struct device *kdev = container_of(kobj, struct device, kobj);
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	struct i915_error_state_file_priv error_priv;
	struct drm_i915_error_state_buf error_str;
	ssize_t ret_count = 0;
	int ret;

	memset(&error_priv, 0, sizeof(error_priv));

	ret = i915_error_state_buf_init(&error_str, to_i915(dev), count, off);
	if (ret)
		return ret;

	error_priv.dev = dev;
	i915_error_state_get(dev, &error_priv);

	ret = i915_error_state_to_str(&error_str, &error_priv);
	if (ret)
		goto out;

	ret_count = count < error_str.bytes ? count : error_str.bytes;

	memcpy(buf, error_str.buf, ret_count);
out:
	i915_error_state_put(&error_priv);
	i915_error_state_buf_release(&error_str);

	return ret ?: ret_count;
}

static ssize_t error_state_write(struct file *file, struct kobject *kobj,
				 struct bin_attribute *attr, char *buf,
				 loff_t off, size_t count)
{
	struct device *kdev = container_of(kobj, struct device, kobj);
	struct drm_minor *minor = dev_to_drm_minor(kdev);
	struct drm_device *dev = minor->dev;
	int ret;

	DRM_DEBUG_DRIVER("Resetting error state\n");

	ret = mutex_lock_interruptible(&dev->struct_mutex);
	if (ret)
		return ret;

	i915_destroy_error_state(dev);
	mutex_unlock(&dev->struct_mutex);

	return count;
}

static struct bin_attribute error_state_attr = {
	.attr.name = "error",
	.attr.mode = S_IRUSR | S_IWUSR,
	.size = 0,
	.read = error_state_read,
	.write = error_state_write,
};

void i915_setup_sysfs(struct drm_device *dev)
{
	int ret;

#ifdef CONFIG_PM
	if (HAS_RC6(dev)) {
		ret = sysfs_merge_group(&dev->primary->kdev->kobj,
					&rc6_attr_group);
		if (ret)
			DRM_ERROR("RC6 residency sysfs setup failed\n");
	}
	if (HAS_RC6p(dev)) {
		ret = sysfs_merge_group(&dev->primary->kdev->kobj,
					&rc6p_attr_group);
		if (ret)
			DRM_ERROR("RC6p residency sysfs setup failed\n");
	}
#endif
	if (HAS_L3_DPF(dev)) {
		ret = device_create_bin_file(dev->primary->kdev, &dpf_attrs);
		if (ret)
			DRM_ERROR("l3 parity sysfs setup failed\n");

		if (NUM_L3_SLICES(dev) > 1) {
			ret = device_create_bin_file(dev->primary->kdev,
						     &dpf_attrs_1);
			if (ret)
				DRM_ERROR("l3 parity slice 1 setup failed\n");
		}
	}

	ret = 0;
	if (IS_VALLEYVIEW(dev))
		ret = sysfs_create_files(&dev->primary->kdev->kobj, vlv_attrs);
	else if (INTEL_INFO(dev)->gen >= 6)
		ret = sysfs_create_files(&dev->primary->kdev->kobj, gen6_attrs);
	if (ret)
		DRM_ERROR("RPS sysfs setup failed\n");

	ret = sysfs_create_bin_file(&dev->primary->kdev->kobj,
				    &error_state_attr);
	if (ret)
		DRM_ERROR("error_state sysfs setup failed\n");
}

void i915_teardown_sysfs(struct drm_device *dev)
{
	sysfs_remove_bin_file(&dev->primary->kdev->kobj, &error_state_attr);
	if (IS_VALLEYVIEW(dev))
		sysfs_remove_files(&dev->primary->kdev->kobj, vlv_attrs);
	else
		sysfs_remove_files(&dev->primary->kdev->kobj, gen6_attrs);
	device_remove_bin_file(dev->primary->kdev,  &dpf_attrs_1);
	device_remove_bin_file(dev->primary->kdev,  &dpf_attrs);
#ifdef CONFIG_PM
	sysfs_unmerge_group(&dev->primary->kdev->kobj, &rc6_attr_group);
	sysfs_unmerge_group(&dev->primary->kdev->kobj, &rc6p_attr_group);
#endif
}