Currently Ironlake operates under the assumption that rpm awake (and its error checking is disabled). As such, we have missed a few places where we access registers without taking the rpm wakeref and thus trigger warnings. intel_ips being one culprit.
As this involved adding a potentially sleeping rpm_get, we have to rearrange the spinlocks slightly and so switch to acquiring a device-ref under the spinlock rather than hold the spinlock for the whole operation. To be consistent, we make the change in pattern common to the intel_ips interface even though this adds a few more atomic operations than necessary in a few cases. v2: Sagar noted the mb around setting mch_dev were overkill as we only need ordering there, and that i915_emon_status was still using struct_mutex for no reason, but lacked rpm. Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Sagar Arun Kamble <sagar.a.kam...@intel.com> --- drivers/gpu/drm/i915/i915_debugfs.c | 32 ++---- drivers/gpu/drm/i915/i915_drv.c | 3 + drivers/gpu/drm/i915/intel_pm.c | 172 ++++++++++++++-------------- 3 files changed, 102 insertions(+), 105 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 58994f12cfa8..99cde93fa9c7 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -1741,32 +1741,24 @@ static int i915_sr_status(struct seq_file *m, void *unused) static int i915_emon_status(struct seq_file *m, void *unused) { - struct drm_i915_private *dev_priv = node_to_i915(m->private); - struct drm_device *dev = &dev_priv->drm; - unsigned long temp, chipset, gfx; + struct drm_i915_private *i915 = node_to_i915(m->private); intel_wakeref_t wakeref; - int ret; - if (!IS_GEN(dev_priv, 5)) + if (!IS_GEN(i915, 5)) return -ENODEV; - ret = mutex_lock_interruptible(&dev->struct_mutex); - if (ret) - return ret; + with_intel_runtime_pm(i915, wakeref) { + unsigned long temp, chipset, gfx; - wakeref = intel_runtime_pm_get(dev_priv); - - temp = i915_mch_val(dev_priv); - chipset = i915_chipset_val(dev_priv); - gfx = i915_gfx_val(dev_priv); - mutex_unlock(&dev->struct_mutex); + temp = i915_mch_val(i915); + chipset = i915_chipset_val(i915); + gfx = i915_gfx_val(i915); - intel_runtime_pm_put(dev_priv, wakeref); - - seq_printf(m, "GMCH temp: %ld\n", temp); - seq_printf(m, "Chipset power: %ld\n", chipset); - seq_printf(m, "GFX power: %ld\n", gfx); - seq_printf(m, "Total power: %ld\n", chipset + gfx); + seq_printf(m, "GMCH temp: %ld\n", temp); + seq_printf(m, "Chipset power: %ld\n", chipset); + seq_printf(m, "GFX power: %ld\n", gfx); + seq_printf(m, "Total power: %ld\n", chipset + gfx); + } return 0; } diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 1af88534ee0d..aa6e782afbe5 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1775,6 +1775,9 @@ void i915_driver_unload(struct drm_device *dev) i915_driver_unregister(dev_priv); + /* Flush any external code that still may be under the RCU lock */ + synchronize_rcu(); + if (i915_gem_suspend(dev_priv)) DRM_ERROR("failed to idle hardware; continuing to unload!\n"); diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index ff6b58d4efa6..690a8e20c119 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -6203,10 +6203,6 @@ void intel_init_ipc(struct drm_i915_private *dev_priv) */ 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_i915_private *dev_priv, u8 val) { u16 rgvswctl; @@ -7849,16 +7845,17 @@ static unsigned long __i915_chipset_val(struct drm_i915_private *dev_priv) unsigned long i915_chipset_val(struct drm_i915_private *dev_priv) { - unsigned long val; + intel_wakeref_t wakeref; + unsigned long val = 0; if (!IS_GEN(dev_priv, 5)) return 0; - spin_lock_irq(&mchdev_lock); - - val = __i915_chipset_val(dev_priv); - - spin_unlock_irq(&mchdev_lock); + with_intel_runtime_pm(dev_priv, wakeref) { + spin_lock_irq(&mchdev_lock); + val = __i915_chipset_val(dev_priv); + spin_unlock_irq(&mchdev_lock); + } return val; } @@ -7935,14 +7932,16 @@ static void __i915_update_gfx_val(struct drm_i915_private *dev_priv) void i915_update_gfx_val(struct drm_i915_private *dev_priv) { + intel_wakeref_t wakeref; + if (!IS_GEN(dev_priv, 5)) return; - spin_lock_irq(&mchdev_lock); - - __i915_update_gfx_val(dev_priv); - - spin_unlock_irq(&mchdev_lock); + with_intel_runtime_pm(dev_priv, wakeref) { + spin_lock_irq(&mchdev_lock); + __i915_update_gfx_val(dev_priv); + spin_unlock_irq(&mchdev_lock); + } } static unsigned long __i915_gfx_val(struct drm_i915_private *dev_priv) @@ -7984,18 +7983,34 @@ static unsigned long __i915_gfx_val(struct drm_i915_private *dev_priv) unsigned long i915_gfx_val(struct drm_i915_private *dev_priv) { - unsigned long val; + intel_wakeref_t wakeref; + unsigned long val = 0; if (!IS_GEN(dev_priv, 5)) return 0; - spin_lock_irq(&mchdev_lock); + with_intel_runtime_pm(dev_priv, wakeref) { + spin_lock_irq(&mchdev_lock); + val = __i915_gfx_val(dev_priv); + spin_unlock_irq(&mchdev_lock); + } - val = __i915_gfx_val(dev_priv); + return val; +} - spin_unlock_irq(&mchdev_lock); +static struct drm_i915_private *i915_mch_dev; - return val; +static struct drm_i915_private *mchdev_get(void) +{ + struct drm_i915_private *i915; + + rcu_read_lock(); + i915 = i915_mch_dev; + if (!kref_get_unless_zero(&i915->drm.ref)) + i915 = NULL; + rcu_read_unlock(); + + return i915; } /** @@ -8006,23 +8021,24 @@ unsigned long i915_gfx_val(struct drm_i915_private *dev_priv) */ unsigned long i915_read_mch_val(void) { - struct drm_i915_private *dev_priv; - unsigned long chipset_val, graphics_val, ret = 0; - - spin_lock_irq(&mchdev_lock); - if (!i915_mch_dev) - goto out_unlock; - dev_priv = i915_mch_dev; - - chipset_val = __i915_chipset_val(dev_priv); - graphics_val = __i915_gfx_val(dev_priv); + struct drm_i915_private *i915; + unsigned long chipset_val = 0; + unsigned long graphics_val = 0; + intel_wakeref_t wakeref; - ret = chipset_val + graphics_val; + i915 = mchdev_get(); + if (!i915) + return 0; -out_unlock: - spin_unlock_irq(&mchdev_lock); + with_intel_runtime_pm(i915, wakeref) { + spin_lock_irq(&mchdev_lock); + chipset_val = __i915_chipset_val(i915); + graphics_val = __i915_gfx_val(i915); + spin_unlock_irq(&mchdev_lock); + } - return ret; + drm_dev_put(&i915->drm); + return chipset_val + graphics_val; } EXPORT_SYMBOL_GPL(i915_read_mch_val); @@ -8033,23 +8049,19 @@ EXPORT_SYMBOL_GPL(i915_read_mch_val); */ bool i915_gpu_raise(void) { - struct drm_i915_private *dev_priv; - bool ret = true; - - spin_lock_irq(&mchdev_lock); - if (!i915_mch_dev) { - ret = false; - goto out_unlock; - } - dev_priv = i915_mch_dev; + struct drm_i915_private *i915; - if (dev_priv->ips.max_delay > dev_priv->ips.fmax) - dev_priv->ips.max_delay--; + i915 = mchdev_get(); + if (!i915) + return false; -out_unlock: + spin_lock_irq(&mchdev_lock); + if (i915->ips.max_delay > i915->ips.fmax) + i915->ips.max_delay--; spin_unlock_irq(&mchdev_lock); - return ret; + drm_dev_put(&i915->drm); + return true; } EXPORT_SYMBOL_GPL(i915_gpu_raise); @@ -8061,23 +8073,19 @@ EXPORT_SYMBOL_GPL(i915_gpu_raise); */ bool i915_gpu_lower(void) { - struct drm_i915_private *dev_priv; - bool ret = true; - - spin_lock_irq(&mchdev_lock); - if (!i915_mch_dev) { - ret = false; - goto out_unlock; - } - dev_priv = i915_mch_dev; + struct drm_i915_private *i915; - if (dev_priv->ips.max_delay < dev_priv->ips.min_delay) - dev_priv->ips.max_delay++; + i915 = mchdev_get(); + if (!i915) + return false; -out_unlock: + spin_lock_irq(&mchdev_lock); + if (i915->ips.max_delay < i915->ips.min_delay) + i915->ips.max_delay++; spin_unlock_irq(&mchdev_lock); - return ret; + drm_dev_put(&i915->drm); + return true; } EXPORT_SYMBOL_GPL(i915_gpu_lower); @@ -8088,13 +8096,16 @@ EXPORT_SYMBOL_GPL(i915_gpu_lower); */ bool i915_gpu_busy(void) { - bool ret = false; + struct drm_i915_private *i915; + bool ret; - spin_lock_irq(&mchdev_lock); - if (i915_mch_dev) - ret = i915_mch_dev->gt.awake; - spin_unlock_irq(&mchdev_lock); + i915 = mchdev_get(); + if (!i915) + return false; + ret = i915->gt.awake; + + drm_dev_put(&i915->drm); return ret; } EXPORT_SYMBOL_GPL(i915_gpu_busy); @@ -8107,24 +8118,19 @@ EXPORT_SYMBOL_GPL(i915_gpu_busy); */ bool i915_gpu_turbo_disable(void) { - struct drm_i915_private *dev_priv; - bool ret = true; - - spin_lock_irq(&mchdev_lock); - if (!i915_mch_dev) { - ret = false; - goto out_unlock; - } - dev_priv = i915_mch_dev; - - dev_priv->ips.max_delay = dev_priv->ips.fstart; + struct drm_i915_private *i915; + bool ret; - if (!ironlake_set_drps(dev_priv, dev_priv->ips.fstart)) - ret = false; + i915 = mchdev_get(); + if (!i915) + return false; -out_unlock: + spin_lock_irq(&mchdev_lock); + i915->ips.max_delay = i915->ips.fstart; + ret = ironlake_set_drps(i915, i915->ips.fstart); spin_unlock_irq(&mchdev_lock); + drm_dev_put(&i915->drm); return ret; } EXPORT_SYMBOL_GPL(i915_gpu_turbo_disable); @@ -8153,18 +8159,14 @@ 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_irq(&mchdev_lock); - i915_mch_dev = dev_priv; - spin_unlock_irq(&mchdev_lock); + rcu_assign_pointer(i915_mch_dev, dev_priv); ips_ping_for_i915_load(); } void intel_gpu_ips_teardown(void) { - spin_lock_irq(&mchdev_lock); - i915_mch_dev = NULL; - spin_unlock_irq(&mchdev_lock); + rcu_assign_pointer(i915_mch_dev, NULL); } static void intel_init_emon(struct drm_i915_private *dev_priv) -- 2.20.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx