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Commit 9270388e authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm/i915: fix up ilk drps/ips locking 



We change the drps/ips sw/hw state from different callers: Our own irq
handler, the external intel-ips module and from process context. Most
of these callers don't take any lock at all.

Protect everything by making the mchdev_lock irqsave and grabbing it in
all relevant callsites. Note that we have to convert a few sleeps in the
drps enable/disable code to delays, but alas, I'm not volunteering to
restructure the code around a few work items.

For paranoia add a spin_locked assert to ironlake_set_drps, too.

v2: Move one access inside the lock protection. Caught by the
dev_priv->ips mass-rename ...

v3: Resolve rebase conflict.

Reviewed-by: default avatarDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 73edd18f

drivers/gpu/drm/i915/i915_irq.c

+11 −1
Original line number Diff line number Diff line
@@ -296,14 +296,22 @@ static void i915_hotplug_work_func(struct work_struct *work) 
	drm_helper_hpd_irq_event(dev);

}



/* defined intel_pm.c */

extern spinlock_t mchdev_lock;



static void ironlake_handle_rps_change(struct drm_device *dev)

{

	drm_i915_private_t *dev_priv = dev->dev_private;

	u32 busy_up, busy_down, max_avg, min_avg;

	u8 new_delay = dev_priv->cur_delay;

	u8 new_delay;

	unsigned long flags;



	spin_lock_irqsave(&mchdev_lock, flags);



	I915_WRITE16(MEMINTRSTS, I915_READ(MEMINTRSTS));



	new_delay = dev_priv->cur_delay;



	I915_WRITE16(MEMINTRSTS, MEMINT_EVAL_CHG);

	busy_up = I915_READ(RCPREVBSYTUPAVG);

	busy_down = I915_READ(RCPREVBSYTDNAVG);
@@ -326,6 +334,8 @@ static void ironlake_handle_rps_change(struct drm_device *dev) 
	if (ironlake_set_drps(dev, new_delay))

		dev_priv->cur_delay = new_delay;



	spin_unlock_irqrestore(&mchdev_lock, flags);



	return;

}

drivers/gpu/drm/i915/intel_pm.c

+47 −36
Original line number Diff line number Diff line
@@ -2160,11 +2160,28 @@ err_unref: 
	return NULL;

}



/**

 * Lock protecting IPS related data structures

 *   - i915_mch_dev

 *   - dev_priv->max_delay

 *   - dev_priv->min_delay

 *   - dev_priv->fmax

 *   - dev_priv->gpu_busy

 *   - dev_priv->gfx_power

 */

DEFINE_SPINLOCK(mchdev_lock);



/* Global for IPS driver to get at the current i915 device. Protected by

 * mchdev_lock. */

static struct drm_i915_private *i915_mch_dev;



bool ironlake_set_drps(struct drm_device *dev, u8 val)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	u16 rgvswctl;



	assert_spin_locked(&mchdev_lock);



	rgvswctl = I915_READ16(MEMSWCTL);

	if (rgvswctl & MEMCTL_CMD_STS) {

		DRM_DEBUG("gpu busy, RCS change rejected\n");
@@ -2188,6 +2205,8 @@ static void ironlake_enable_drps(struct drm_device *dev) 
	u32 rgvmodectl = I915_READ(MEMMODECTL);

	u8 fmax, fmin, fstart, vstart;



	spin_lock_irq(&mchdev_lock);



	/* Enable temp reporting */

	I915_WRITE16(PMMISC, I915_READ(PMMISC) | MCPPCE_EN);

	I915_WRITE16(TSC1, I915_READ(TSC1) | TSE);
@@ -2233,9 +2252,9 @@ static void ironlake_enable_drps(struct drm_device *dev) 
	rgvmodectl |= MEMMODE_SWMODE_EN;

	I915_WRITE(MEMMODECTL, rgvmodectl);



	if (wait_for((I915_READ(MEMSWCTL) & MEMCTL_CMD_STS) == 0, 10))

	if (wait_for_atomic((I915_READ(MEMSWCTL) & MEMCTL_CMD_STS) == 0, 10))

		DRM_ERROR("stuck trying to change perf mode\n");

	msleep(1);

	mdelay(1);



	ironlake_set_drps(dev, fstart);
@@ -2244,12 +2263,18 @@ static void ironlake_enable_drps(struct drm_device *dev) 
	dev_priv->last_time1 = jiffies_to_msecs(jiffies);

	dev_priv->last_count2 = I915_READ(0x112f4);

	getrawmonotonic(&dev_priv->last_time2);



	spin_unlock_irq(&mchdev_lock);

}



static void ironlake_disable_drps(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	u16 rgvswctl = I915_READ16(MEMSWCTL);

	u16 rgvswctl;



	spin_lock_irq(&mchdev_lock);



	rgvswctl = I915_READ16(MEMSWCTL);



	/* Ack interrupts, disable EFC interrupt */

	I915_WRITE(MEMINTREN, I915_READ(MEMINTREN) & ~MEMINT_EVAL_CHG_EN);
@@ -2260,11 +2285,12 @@ static void ironlake_disable_drps(struct drm_device *dev) 


	/* Go back to the starting frequency */

	ironlake_set_drps(dev, dev_priv->fstart);

	msleep(1);

	mdelay(1);

	rgvswctl |= MEMCTL_CMD_STS;

	I915_WRITE(MEMSWCTL, rgvswctl);

	msleep(1);

	mdelay(1);



	spin_unlock_irq(&mchdev_lock);

}



/* There's a funny hw issue where the hw returns all 0 when reading from
@@ -2713,21 +2739,6 @@ static const struct cparams { 
	{ 0, 800, 231, 23784 },

};



/**

 * Lock protecting IPS related data structures

 *   - i915_mch_dev

 *   - dev_priv->max_delay

 *   - dev_priv->min_delay

 *   - dev_priv->fmax

 *   - dev_priv->gpu_busy

 *   - dev_priv->gfx_power

 */

static DEFINE_SPINLOCK(mchdev_lock);



/* Global for IPS driver to get at the current i915 device. Protected by

 * mchdev_lock. */

static struct drm_i915_private *i915_mch_dev;



unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)

{

	u64 total_count, diff, ret;
@@ -2978,11 +2989,11 @@ void i915_update_gfx_val(struct drm_i915_private *dev_priv) 
	if (dev_priv->info->gen != 5)

		return;



	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);



	__i915_update_gfx_val(dev_priv);



	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);

}



unsigned long i915_gfx_val(struct drm_i915_private *dev_priv)
@@ -3033,7 +3044,7 @@ unsigned long i915_read_mch_val(void) 
	struct drm_i915_private *dev_priv;

	unsigned long chipset_val, graphics_val, ret = 0;



	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	if (!i915_mch_dev)

		goto out_unlock;

	dev_priv = i915_mch_dev;
@@ -3044,7 +3055,7 @@ unsigned long i915_read_mch_val(void) 
	ret = chipset_val + graphics_val;



out_unlock:

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);



	return ret;

}
@@ -3060,7 +3071,7 @@ bool i915_gpu_raise(void) 
	struct drm_i915_private *dev_priv;

	bool ret = true;



	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	if (!i915_mch_dev) {

		ret = false;

		goto out_unlock;
@@ -3071,7 +3082,7 @@ bool i915_gpu_raise(void) 
		dev_priv->max_delay--;



out_unlock:

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);



	return ret;

}
@@ -3088,7 +3099,7 @@ bool i915_gpu_lower(void) 
	struct drm_i915_private *dev_priv;

	bool ret = true;



	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	if (!i915_mch_dev) {

		ret = false;

		goto out_unlock;
@@ -3099,7 +3110,7 @@ bool i915_gpu_lower(void) 
		dev_priv->max_delay++;



out_unlock:

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);



	return ret;

}
@@ -3117,7 +3128,7 @@ bool i915_gpu_busy(void) 
	bool ret = false;

	int i;



	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	if (!i915_mch_dev)

		goto out_unlock;

	dev_priv = i915_mch_dev;
@@ -3126,7 +3137,7 @@ bool i915_gpu_busy(void) 
		ret |= !list_empty(&ring->request_list);



out_unlock:

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);



	return ret;

}
@@ -3143,7 +3154,7 @@ bool i915_gpu_turbo_disable(void) 
	struct drm_i915_private *dev_priv;

	bool ret = true;



	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	if (!i915_mch_dev) {

		ret = false;

		goto out_unlock;
@@ -3156,7 +3167,7 @@ bool i915_gpu_turbo_disable(void) 
		ret = false;



out_unlock:

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);



	return ret;

}
@@ -3186,18 +3197,18 @@ void intel_gpu_ips_init(struct drm_i915_private *dev_priv) 
{

	/* We only register the i915 ips part with intel-ips once everything is

	 * set up, to avoid intel-ips sneaking in and reading bogus values. */

	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	i915_mch_dev = dev_priv;

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);



	ips_ping_for_i915_load();

}



void intel_gpu_ips_teardown(void)

{

	spin_lock(&mchdev_lock);

	spin_lock_irq(&mchdev_lock);

	i915_mch_dev = NULL;

	spin_unlock(&mchdev_lock);

	spin_unlock_irq(&mchdev_lock);

}

static void intel_init_emon(struct drm_device *dev)

{