From 0a9b26306d6a10573cdc4dbbc804bfff264ae878 Mon Sep 17 00:00:00 2001 From: Daniele Ceraolo Spurio Date: Fri, 9 Aug 2019 07:31:16 +0100 Subject: [PATCH] drm/i915: split out uncore_mmio_debug Multiple uncore structures will share the debug infrastructure, so move it to a common place and add extra locking around it. Also, since we now have a separate object, it is cleaner to have dedicated functions working on the object to stop and restart the mmio debug. Apart from the cosmetic changes, this patch introduces 2 functional updates: - All calls to check_for_unclaimed_mmio will now return false when the debug is suspended, not just the ones that are active only when i915_modparams.mmio_debug is set. If we don't trust the result of the check while a user is doing mmio access then we shouldn't attempt the check anywhere. - i915_modparams.mmio_debug is not save/restored anymore around user access. The value is now never touched by the kernel while debug is disabled so no need for save/restore. v2: squash mmio_debug patches, restrict mmio_debug lock usage (Chris) Signed-off-by: Daniele Ceraolo Spurio Cc: Chris Wilson Reviewed-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20190809063116.7527-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_debugfs.c | 2 +- drivers/gpu/drm/i915/i915_drv.c | 3 +- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_uncore.c | 91 ++++++++++++++++++++++++++----------- drivers/gpu/drm/i915/intel_uncore.h | 18 +++++--- 5 files changed, 79 insertions(+), 36 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index e4f173f..3d9cd97 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -1149,7 +1149,7 @@ static int i915_forcewake_domains(struct seq_file *m, void *data) unsigned int tmp; seq_printf(m, "user.bypass_count = %u\n", - uncore->user_forcewake.count); + uncore->user_forcewake_count); for_each_fw_domain(fw_domain, uncore, tmp) seq_printf(m, "%s.wake_count = %u\n", diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index ca91758..96bf70b 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -485,6 +485,7 @@ static int i915_driver_early_probe(struct drm_i915_private *dev_priv) intel_device_info_subplatform_init(dev_priv); + intel_uncore_mmio_debug_init_early(&dev_priv->mmio_debug); intel_uncore_init_early(&dev_priv->uncore, dev_priv); spin_lock_init(&dev_priv->irq_lock); @@ -1785,7 +1786,7 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation) out: enable_rpm_wakeref_asserts(rpm); - if (!dev_priv->uncore.user_forcewake.count) + if (!dev_priv->uncore.user_forcewake_count) intel_runtime_pm_driver_release(rpm); return ret; diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 71db63c..4397c6f 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1369,6 +1369,7 @@ struct drm_i915_private { resource_size_t stolen_usable_size; /* Total size minus reserved ranges */ struct intel_uncore uncore; + struct intel_uncore_mmio_debug mmio_debug; struct i915_virtual_gpu vgpu; diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 39e8710..9e583f1 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -34,6 +34,32 @@ #define __raw_posting_read(...) ((void)__raw_uncore_read32(__VA_ARGS__)) +void +intel_uncore_mmio_debug_init_early(struct intel_uncore_mmio_debug *mmio_debug) +{ + spin_lock_init(&mmio_debug->lock); + mmio_debug->unclaimed_mmio_check = 1; +} + +static void mmio_debug_suspend(struct intel_uncore_mmio_debug *mmio_debug) +{ + lockdep_assert_held(&mmio_debug->lock); + + /* Save and disable mmio debugging for the user bypass */ + if (!mmio_debug->suspend_count++) { + mmio_debug->saved_mmio_check = mmio_debug->unclaimed_mmio_check; + mmio_debug->unclaimed_mmio_check = 0; + } +} + +static void mmio_debug_resume(struct intel_uncore_mmio_debug *mmio_debug) +{ + lockdep_assert_held(&mmio_debug->lock); + + if (!--mmio_debug->suspend_count) + mmio_debug->unclaimed_mmio_check = mmio_debug->saved_mmio_check; +} + static const char * const forcewake_domain_names[] = { "render", "blitter", @@ -476,6 +502,11 @@ check_for_unclaimed_mmio(struct intel_uncore *uncore) { bool ret = false; + lockdep_assert_held(&uncore->debug->lock); + + if (uncore->debug->suspend_count) + return false; + if (intel_uncore_has_fpga_dbg_unclaimed(uncore)) ret |= fpga_check_for_unclaimed_mmio(uncore); @@ -608,17 +639,11 @@ void intel_uncore_forcewake_get(struct intel_uncore *uncore, void intel_uncore_forcewake_user_get(struct intel_uncore *uncore) { spin_lock_irq(&uncore->lock); - if (!uncore->user_forcewake.count++) { + if (!uncore->user_forcewake_count++) { intel_uncore_forcewake_get__locked(uncore, FORCEWAKE_ALL); - - /* Save and disable mmio debugging for the user bypass */ - uncore->user_forcewake.saved_mmio_check = - uncore->unclaimed_mmio_check; - uncore->user_forcewake.saved_mmio_debug = - i915_modparams.mmio_debug; - - uncore->unclaimed_mmio_check = 0; - i915_modparams.mmio_debug = 0; + spin_lock(&uncore->debug->lock); + mmio_debug_suspend(uncore->debug); + spin_unlock(&uncore->debug->lock); } spin_unlock_irq(&uncore->lock); } @@ -633,15 +658,14 @@ void intel_uncore_forcewake_user_get(struct intel_uncore *uncore) void intel_uncore_forcewake_user_put(struct intel_uncore *uncore) { spin_lock_irq(&uncore->lock); - if (!--uncore->user_forcewake.count) { - if (intel_uncore_unclaimed_mmio(uncore)) + if (!--uncore->user_forcewake_count) { + spin_lock(&uncore->debug->lock); + mmio_debug_resume(uncore->debug); + + if (check_for_unclaimed_mmio(uncore)) dev_info(uncore->i915->drm.dev, "Invalid mmio detected during user access\n"); - - uncore->unclaimed_mmio_check = - uncore->user_forcewake.saved_mmio_check; - i915_modparams.mmio_debug = - uncore->user_forcewake.saved_mmio_debug; + spin_unlock(&uncore->debug->lock); intel_uncore_forcewake_put__locked(uncore, FORCEWAKE_ALL); } @@ -1088,7 +1112,16 @@ unclaimed_reg_debug(struct intel_uncore *uncore, if (likely(!i915_modparams.mmio_debug)) return; + /* interrupts are disabled and re-enabled around uncore->lock usage */ + lockdep_assert_held(&uncore->lock); + + if (before) + spin_lock(&uncore->debug->lock); + __unclaimed_reg_debug(uncore, reg, read, before); + + if (!before) + spin_unlock(&uncore->debug->lock); } #define GEN2_READ_HEADER(x) \ @@ -1607,6 +1640,7 @@ void intel_uncore_init_early(struct intel_uncore *uncore, spin_lock_init(&uncore->lock); uncore->i915 = i915; uncore->rpm = &i915->runtime_pm; + uncore->debug = &i915->mmio_debug; } static void uncore_raw_init(struct intel_uncore *uncore) @@ -1632,7 +1666,6 @@ static int uncore_forcewake_init(struct intel_uncore *uncore) ret = intel_uncore_fw_domains_init(uncore); if (ret) return ret; - forcewake_early_sanitize(uncore, 0); if (IS_GEN_RANGE(i915, 6, 7)) { @@ -1681,8 +1714,6 @@ int intel_uncore_init_mmio(struct intel_uncore *uncore) if (INTEL_GEN(i915) > 5 && !intel_vgpu_active(i915)) uncore->flags |= UNCORE_HAS_FORCEWAKE; - uncore->unclaimed_mmio_check = 1; - if (!intel_uncore_has_forcewake(uncore)) { uncore_raw_init(uncore); } else { @@ -1707,7 +1738,7 @@ int intel_uncore_init_mmio(struct intel_uncore *uncore) uncore->flags |= UNCORE_HAS_FIFO; /* clear out unclaimed reg detection bit */ - if (check_for_unclaimed_mmio(uncore)) + if (intel_uncore_unclaimed_mmio(uncore)) DRM_DEBUG("unclaimed mmio detected on uncore init, clearing\n"); return 0; @@ -1952,7 +1983,13 @@ int __intel_wait_for_register(struct intel_uncore *uncore, bool intel_uncore_unclaimed_mmio(struct intel_uncore *uncore) { - return check_for_unclaimed_mmio(uncore); + bool ret; + + spin_lock_irq(&uncore->debug->lock); + ret = check_for_unclaimed_mmio(uncore); + spin_unlock_irq(&uncore->debug->lock); + + return ret; } bool @@ -1960,24 +1997,24 @@ intel_uncore_arm_unclaimed_mmio_detection(struct intel_uncore *uncore) { bool ret = false; - spin_lock_irq(&uncore->lock); + spin_lock_irq(&uncore->debug->lock); - if (unlikely(uncore->unclaimed_mmio_check <= 0)) + if (unlikely(uncore->debug->unclaimed_mmio_check <= 0)) goto out; - if (unlikely(intel_uncore_unclaimed_mmio(uncore))) { + if (unlikely(check_for_unclaimed_mmio(uncore))) { if (!i915_modparams.mmio_debug) { DRM_DEBUG("Unclaimed register detected, " "enabling oneshot unclaimed register reporting. " "Please use i915.mmio_debug=N for more information.\n"); i915_modparams.mmio_debug++; } - uncore->unclaimed_mmio_check--; + uncore->debug->unclaimed_mmio_check--; ret = true; } out: - spin_unlock_irq(&uncore->lock); + spin_unlock_irq(&uncore->debug->lock); return ret; } diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h index e603d21..414fc2c 100644 --- a/drivers/gpu/drm/i915/intel_uncore.h +++ b/drivers/gpu/drm/i915/intel_uncore.h @@ -36,6 +36,13 @@ struct drm_i915_private; struct intel_runtime_pm; struct intel_uncore; +struct intel_uncore_mmio_debug { + spinlock_t lock; /** lock is also taken in irq contexts. */ + int unclaimed_mmio_check; + int saved_mmio_check; + u32 suspend_count; +}; + enum forcewake_domain_id { FW_DOMAIN_ID_RENDER = 0, FW_DOMAIN_ID_BLITTER, @@ -137,14 +144,9 @@ struct intel_uncore { u32 __iomem *reg_ack; } *fw_domain[FW_DOMAIN_ID_COUNT]; - struct { - unsigned int count; - - int saved_mmio_check; - int saved_mmio_debug; - } user_forcewake; + unsigned int user_forcewake_count; - int unclaimed_mmio_check; + struct intel_uncore_mmio_debug *debug; }; /* Iterate over initialised fw domains */ @@ -179,6 +181,8 @@ intel_uncore_has_fifo(const struct intel_uncore *uncore) return uncore->flags & UNCORE_HAS_FIFO; } +void +intel_uncore_mmio_debug_init_early(struct intel_uncore_mmio_debug *mmio_debug); void intel_uncore_init_early(struct intel_uncore *uncore, struct drm_i915_private *i915); int intel_uncore_init_mmio(struct intel_uncore *uncore); -- 2.7.4