From f8ef3464bf01aa246994bae8d35b79faa0ba13ba Mon Sep 17 00:00:00 2001 From: jsg Date: Thu, 4 Apr 2024 07:58:45 +0000 Subject: [PATCH] drm/i915/hwmon: Fix locking inversion in sysfs getter From Janusz Krzysztofik 510c5f5e4837cab803c4f594c5f79783ff7b463d in linux-6.6.y/6.6.24 b212b79768ccde74429f872c37618c543fa11333 in mainline linux --- sys/dev/pci/drm/i915/i915_hwmon.c | 37 ++++++++++++++++--------------- 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/sys/dev/pci/drm/i915/i915_hwmon.c b/sys/dev/pci/drm/i915/i915_hwmon.c index 77f7eca478f..4ad8ab02ee3 100644 --- a/sys/dev/pci/drm/i915/i915_hwmon.c +++ b/sys/dev/pci/drm/i915/i915_hwmon.c @@ -72,12 +72,13 @@ hwm_locked_with_pm_intel_uncore_rmw(struct hwm_drvdata *ddat, struct intel_uncore *uncore = ddat->uncore; intel_wakeref_t wakeref; - mutex_lock(&hwmon->hwmon_lock); + with_intel_runtime_pm(uncore->rpm, wakeref) { + mutex_lock(&hwmon->hwmon_lock); - with_intel_runtime_pm(uncore->rpm, wakeref) intel_uncore_rmw(uncore, reg, clear, set); - mutex_unlock(&hwmon->hwmon_lock); + mutex_unlock(&hwmon->hwmon_lock); + } } /* @@ -136,20 +137,21 @@ hwm_energy(struct hwm_drvdata *ddat, long *energy) else rgaddr = hwmon->rg.energy_status_all; - mutex_lock(&hwmon->hwmon_lock); + with_intel_runtime_pm(uncore->rpm, wakeref) { + mutex_lock(&hwmon->hwmon_lock); - with_intel_runtime_pm(uncore->rpm, wakeref) reg_val = intel_uncore_read(uncore, rgaddr); - if (reg_val >= ei->reg_val_prev) - ei->accum_energy += reg_val - ei->reg_val_prev; - else - ei->accum_energy += UINT_MAX - ei->reg_val_prev + reg_val; - ei->reg_val_prev = reg_val; + if (reg_val >= ei->reg_val_prev) + ei->accum_energy += reg_val - ei->reg_val_prev; + else + ei->accum_energy += UINT_MAX - ei->reg_val_prev + reg_val; + ei->reg_val_prev = reg_val; - *energy = mul_u64_u32_shr(ei->accum_energy, SF_ENERGY, - hwmon->scl_shift_energy); - mutex_unlock(&hwmon->hwmon_lock); + *energy = mul_u64_u32_shr(ei->accum_energy, SF_ENERGY, + hwmon->scl_shift_energy); + mutex_unlock(&hwmon->hwmon_lock); + } } static ssize_t @@ -404,6 +406,7 @@ hwm_power_max_write(struct hwm_drvdata *ddat, long val) /* Block waiting for GuC reset to complete when needed */ for (;;) { + wakeref = intel_runtime_pm_get(ddat->uncore->rpm); mutex_lock(&hwmon->hwmon_lock); prepare_to_wait(&ddat->waitq, &wait, TASK_INTERRUPTIBLE); @@ -417,14 +420,13 @@ hwm_power_max_write(struct hwm_drvdata *ddat, long val) } mutex_unlock(&hwmon->hwmon_lock); + intel_runtime_pm_put(ddat->uncore->rpm, wakeref); schedule(); } finish_wait(&ddat->waitq, &wait); if (ret) - goto unlock; - - wakeref = intel_runtime_pm_get(ddat->uncore->rpm); + goto exit; /* Disable PL1 limit and verify, because the limit cannot be disabled on all platforms */ if (val == PL1_DISABLE) { @@ -444,9 +446,8 @@ hwm_power_max_write(struct hwm_drvdata *ddat, long val) intel_uncore_rmw(ddat->uncore, hwmon->rg.pkg_rapl_limit, PKG_PWR_LIM_1_EN | PKG_PWR_LIM_1, nval); exit: - intel_runtime_pm_put(ddat->uncore->rpm, wakeref); -unlock: mutex_unlock(&hwmon->hwmon_lock); + intel_runtime_pm_put(ddat->uncore->rpm, wakeref); return ret; } -- 2.20.1