Message ID | eb314ccd1fc96aa729667fc18322cc4cbb3d79cf.1688463863.git.jani.nikula@intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | drm/i915/uncore: unclaimed reg debug race fix and optimization | expand |
On 04/07/2023 10:48, Jani Nikula wrote: > Only check the conditions for unclaimed reg debug once to avoid locking > problems when i915->params.mmio_debug changes between header and footer. > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8749 > Cc: Lee Shawn C <shawn.c.lee@intel.com> > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/i915/intel_uncore.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c > index a88aa342b623..dfefad5a5fec 100644 > --- a/drivers/gpu/drm/i915/intel_uncore.c > +++ b/drivers/gpu/drm/i915/intel_uncore.c > @@ -1925,27 +1925,26 @@ __unclaimed_previous_reg_debug(struct intel_uncore *uncore, > i915_mmio_reg_offset(reg)); > } > > -static inline void > +static inline bool __must_check > unclaimed_reg_debug_header(struct intel_uncore *uncore, > const i915_reg_t reg, const bool read) > { > if (likely(!uncore->i915->params.mmio_debug) || !uncore->debug) > - return; > + return false; > > /* interrupts are disabled and re-enabled around uncore->lock usage */ > lockdep_assert_held(&uncore->lock); > > spin_lock(&uncore->debug->lock); > __unclaimed_previous_reg_debug(uncore, reg, read); > + > + return true; > } > > static inline void > unclaimed_reg_debug_footer(struct intel_uncore *uncore, > const i915_reg_t reg, const bool read) > { > - if (likely(!uncore->i915->params.mmio_debug) || !uncore->debug) > - return; > - > /* interrupts are disabled and re-enabled around uncore->lock usage */ > lockdep_assert_held(&uncore->lock); > > @@ -2008,13 +2007,15 @@ __gen2_read(64) > #define GEN6_READ_HEADER(x) \ > u32 offset = i915_mmio_reg_offset(reg); \ > unsigned long irqflags; \ > + bool unclaimed_reg_debug; \ > u##x val = 0; \ > assert_rpm_wakelock_held(uncore->rpm); \ > spin_lock_irqsave(&uncore->lock, irqflags); \ > - unclaimed_reg_debug_header(uncore, reg, true) > + unclaimed_reg_debug = unclaimed_reg_debug_header(uncore, reg, true) > > #define GEN6_READ_FOOTER \ > - unclaimed_reg_debug_footer(uncore, reg, true); \ > + if (unclaimed_reg_debug) \ > + unclaimed_reg_debug_footer(uncore, reg, true); \ > spin_unlock_irqrestore(&uncore->lock, irqflags); \ > trace_i915_reg_rw(false, reg, val, sizeof(val), trace); \ > return val > @@ -2112,13 +2113,15 @@ __gen2_write(32) > #define GEN6_WRITE_HEADER \ > u32 offset = i915_mmio_reg_offset(reg); \ > unsigned long irqflags; \ > + bool unclaimed_reg_debug; \ > trace_i915_reg_rw(true, reg, val, sizeof(val), trace); \ > assert_rpm_wakelock_held(uncore->rpm); \ > spin_lock_irqsave(&uncore->lock, irqflags); \ > - unclaimed_reg_debug_header(uncore, reg, false) > + unclaimed_reg_debug = unclaimed_reg_debug_header(uncore, reg, false) > > #define GEN6_WRITE_FOOTER \ > - unclaimed_reg_debug_footer(uncore, reg, false); \ > + if (unclaimed_reg_debug) \ > + unclaimed_reg_debug_footer(uncore, reg, false); \ > spin_unlock_irqrestore(&uncore->lock, irqflags) > > #define __gen6_write(x) \ Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index a88aa342b623..dfefad5a5fec 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -1925,27 +1925,26 @@ __unclaimed_previous_reg_debug(struct intel_uncore *uncore, i915_mmio_reg_offset(reg)); } -static inline void +static inline bool __must_check unclaimed_reg_debug_header(struct intel_uncore *uncore, const i915_reg_t reg, const bool read) { if (likely(!uncore->i915->params.mmio_debug) || !uncore->debug) - return; + return false; /* interrupts are disabled and re-enabled around uncore->lock usage */ lockdep_assert_held(&uncore->lock); spin_lock(&uncore->debug->lock); __unclaimed_previous_reg_debug(uncore, reg, read); + + return true; } static inline void unclaimed_reg_debug_footer(struct intel_uncore *uncore, const i915_reg_t reg, const bool read) { - if (likely(!uncore->i915->params.mmio_debug) || !uncore->debug) - return; - /* interrupts are disabled and re-enabled around uncore->lock usage */ lockdep_assert_held(&uncore->lock); @@ -2008,13 +2007,15 @@ __gen2_read(64) #define GEN6_READ_HEADER(x) \ u32 offset = i915_mmio_reg_offset(reg); \ unsigned long irqflags; \ + bool unclaimed_reg_debug; \ u##x val = 0; \ assert_rpm_wakelock_held(uncore->rpm); \ spin_lock_irqsave(&uncore->lock, irqflags); \ - unclaimed_reg_debug_header(uncore, reg, true) + unclaimed_reg_debug = unclaimed_reg_debug_header(uncore, reg, true) #define GEN6_READ_FOOTER \ - unclaimed_reg_debug_footer(uncore, reg, true); \ + if (unclaimed_reg_debug) \ + unclaimed_reg_debug_footer(uncore, reg, true); \ spin_unlock_irqrestore(&uncore->lock, irqflags); \ trace_i915_reg_rw(false, reg, val, sizeof(val), trace); \ return val @@ -2112,13 +2113,15 @@ __gen2_write(32) #define GEN6_WRITE_HEADER \ u32 offset = i915_mmio_reg_offset(reg); \ unsigned long irqflags; \ + bool unclaimed_reg_debug; \ trace_i915_reg_rw(true, reg, val, sizeof(val), trace); \ assert_rpm_wakelock_held(uncore->rpm); \ spin_lock_irqsave(&uncore->lock, irqflags); \ - unclaimed_reg_debug_header(uncore, reg, false) + unclaimed_reg_debug = unclaimed_reg_debug_header(uncore, reg, false) #define GEN6_WRITE_FOOTER \ - unclaimed_reg_debug_footer(uncore, reg, false); \ + if (unclaimed_reg_debug) \ + unclaimed_reg_debug_footer(uncore, reg, false); \ spin_unlock_irqrestore(&uncore->lock, irqflags) #define __gen6_write(x) \
Only check the conditions for unclaimed reg debug once to avoid locking problems when i915->params.mmio_debug changes between header and footer. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8749 Cc: Lee Shawn C <shawn.c.lee@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> --- drivers/gpu/drm/i915/intel_uncore.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)