| Message ID | 20230928130015.6758-1-nirmoy.das@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v7,1/4] drm/i915: Introduce intel_gt_mcr_lock_sanitize() | expand |
Hi Nirmoy, On Thu, Sep 28, 2023 at 03:00:12PM +0200, Nirmoy Das wrote: > Implement intel_gt_mcr_lock_sanitize() to provide a mechanism > for cleaning the steer semaphore when absolutely necessary. > > v2: remove unnecessary lock(Andi, Matt) > improve the kernel doc(Matt) > s/intel_gt_mcr_lock_clear/intel_gt_mcr_lock_sanitize > > Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Andi
On Thu, Sep 28, 2023 at 03:00:12PM +0200, Nirmoy Das wrote: > Implement intel_gt_mcr_lock_sanitize() to provide a mechanism > for cleaning the steer semaphore when absolutely necessary. > > v2: remove unnecessary lock(Andi, Matt) > improve the kernel doc(Matt) > s/intel_gt_mcr_lock_clear/intel_gt_mcr_lock_sanitize > > Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 22 ++++++++++++++++++++++ > drivers/gpu/drm/i915/gt/intel_gt_mcr.h | 1 + > 2 files changed, 23 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > index bf4a933de03a..326c2ed1d99b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > @@ -419,6 +419,28 @@ void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags) > intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); > } > > +/** > + * intel_gt_mcr_lock_sanitize - Sanitize MCR steering lock > + * @gt: GT structure > + * > + * This will be used to sanitize the initial status of the hardware lock > + * during driver load and resume since there won't be any concurrent access > + * from other agents at those times, but it's possible that boot firmware > + * may have left the lock in a bad state. > + * > + */ > +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt) > +{ > + /* > + * This gets called at load/resume time, so we shouldn't be > + * racing with other driver threads grabbing the mcr lock. > + */ > + lockdep_assert_not_held(>->mcr_lock); > + > + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70)) > + intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); > +} > + > /** > * intel_gt_mcr_read - read a specific instance of an MCR register > * @gt: GT structure > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > index 41684495b7da..01ac565a56a4 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > @@ -11,6 +11,7 @@ > void intel_gt_mcr_init(struct intel_gt *gt); > void intel_gt_mcr_lock(struct intel_gt *gt, unsigned long *flags); > void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags); > +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt); > > u32 intel_gt_mcr_read(struct intel_gt *gt, > i915_mcr_reg_t reg, > -- > 2.41.0 >
On 28.09.2023 15:00, Nirmoy Das wrote: > Implement intel_gt_mcr_lock_sanitize() to provide a mechanism > for cleaning the steer semaphore when absolutely necessary. > > v2: remove unnecessary lock(Andi, Matt) > improve the kernel doc(Matt) > s/intel_gt_mcr_lock_clear/intel_gt_mcr_lock_sanitize > > Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 22 ++++++++++++++++++++++ > drivers/gpu/drm/i915/gt/intel_gt_mcr.h | 1 + > 2 files changed, 23 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > index bf4a933de03a..326c2ed1d99b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > @@ -419,6 +419,28 @@ void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags) > intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); > } > > +/** > + * intel_gt_mcr_lock_sanitize - Sanitize MCR steering lock > + * @gt: GT structure > + * > + * This will be used to sanitize the initial status of the hardware lock > + * during driver load and resume since there won't be any concurrent access > + * from other agents at those times, but it's possible that boot firmware > + * may have left the lock in a bad state. > + * > + */ > +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt) > +{ > + /* > + * This gets called at load/resume time, so we shouldn't be > + * racing with other driver threads grabbing the mcr lock. > + */ > + lockdep_assert_not_held(>->mcr_lock); > + > + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70)) > + intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); I wonder if it wouldn't be useful to check and report if it is locked before unconditional release, no strong feelings. Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> Regards Andrzej > +} > + > /** > * intel_gt_mcr_read - read a specific instance of an MCR register > * @gt: GT structure > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > index 41684495b7da..01ac565a56a4 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > @@ -11,6 +11,7 @@ > void intel_gt_mcr_init(struct intel_gt *gt); > void intel_gt_mcr_lock(struct intel_gt *gt, unsigned long *flags); > void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags); > +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt); > > u32 intel_gt_mcr_read(struct intel_gt *gt, > i915_mcr_reg_t reg,
Thanks reviewing this series. Merged it in gt-next so hopefully we have bit greener CI for MTL now. Regards, Nirmoy On 9/28/2023 3:00 PM, Nirmoy Das wrote: > Implement intel_gt_mcr_lock_sanitize() to provide a mechanism > for cleaning the steer semaphore when absolutely necessary. > > v2: remove unnecessary lock(Andi, Matt) > improve the kernel doc(Matt) > s/intel_gt_mcr_lock_clear/intel_gt_mcr_lock_sanitize > > Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 22 ++++++++++++++++++++++ > drivers/gpu/drm/i915/gt/intel_gt_mcr.h | 1 + > 2 files changed, 23 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > index bf4a933de03a..326c2ed1d99b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c > @@ -419,6 +419,28 @@ void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags) > intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); > } > > +/** > + * intel_gt_mcr_lock_sanitize - Sanitize MCR steering lock > + * @gt: GT structure > + * > + * This will be used to sanitize the initial status of the hardware lock > + * during driver load and resume since there won't be any concurrent access > + * from other agents at those times, but it's possible that boot firmware > + * may have left the lock in a bad state. > + * > + */ > +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt) > +{ > + /* > + * This gets called at load/resume time, so we shouldn't be > + * racing with other driver threads grabbing the mcr lock. > + */ > + lockdep_assert_not_held(>->mcr_lock); > + > + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70)) > + intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); > +} > + > /** > * intel_gt_mcr_read - read a specific instance of an MCR register > * @gt: GT structure > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > index 41684495b7da..01ac565a56a4 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h > @@ -11,6 +11,7 @@ > void intel_gt_mcr_init(struct intel_gt *gt); > void intel_gt_mcr_lock(struct intel_gt *gt, unsigned long *flags); > void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags); > +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt); > > u32 intel_gt_mcr_read(struct intel_gt *gt, > i915_mcr_reg_t reg,
On 9/28/2023 11:42 PM, Andrzej Hajda wrote: > On 28.09.2023 15:00, Nirmoy Das wrote: >> Implement intel_gt_mcr_lock_sanitize() to provide a mechanism >> for cleaning the steer semaphore when absolutely necessary. >> >> v2: remove unnecessary lock(Andi, Matt) >> improve the kernel doc(Matt) >> s/intel_gt_mcr_lock_clear/intel_gt_mcr_lock_sanitize >> >> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> >> --- >> drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 22 ++++++++++++++++++++++ >> drivers/gpu/drm/i915/gt/intel_gt_mcr.h | 1 + >> 2 files changed, 23 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c >> b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c >> index bf4a933de03a..326c2ed1d99b 100644 >> --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c >> +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c >> @@ -419,6 +419,28 @@ void intel_gt_mcr_unlock(struct intel_gt *gt, >> unsigned long flags) >> intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); >> } >> +/** >> + * intel_gt_mcr_lock_sanitize - Sanitize MCR steering lock >> + * @gt: GT structure >> + * >> + * This will be used to sanitize the initial status of the hardware >> lock >> + * during driver load and resume since there won't be any concurrent >> access >> + * from other agents at those times, but it's possible that boot >> firmware >> + * may have left the lock in a bad state. >> + * >> + */ >> +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt) >> +{ >> + /* >> + * This gets called at load/resume time, so we shouldn't be >> + * racing with other driver threads grabbing the mcr lock. >> + */ >> + lockdep_assert_not_held(>->mcr_lock); >> + >> + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70)) >> + intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); > > I wonder if it wouldn't be useful to check and report if it is locked > before unconditional release, no strong feelings. Not so useful for user but may be as debug log if we need. > > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> Thanks, Nirmoy > > Regards > Andrzej > > >> +} >> + >> /** >> * intel_gt_mcr_read - read a specific instance of an MCR register >> * @gt: GT structure >> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h >> b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h >> index 41684495b7da..01ac565a56a4 100644 >> --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h >> +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h >> @@ -11,6 +11,7 @@ >> void intel_gt_mcr_init(struct intel_gt *gt); >> void intel_gt_mcr_lock(struct intel_gt *gt, unsigned long *flags); >> void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags); >> +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt); >> u32 intel_gt_mcr_read(struct intel_gt *gt, >> i915_mcr_reg_t reg, >
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c index bf4a933de03a..326c2ed1d99b 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c @@ -419,6 +419,28 @@ void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags) intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); } +/** + * intel_gt_mcr_lock_sanitize - Sanitize MCR steering lock + * @gt: GT structure + * + * This will be used to sanitize the initial status of the hardware lock + * during driver load and resume since there won't be any concurrent access + * from other agents at those times, but it's possible that boot firmware + * may have left the lock in a bad state. + * + */ +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt) +{ + /* + * This gets called at load/resume time, so we shouldn't be + * racing with other driver threads grabbing the mcr lock. + */ + lockdep_assert_not_held(>->mcr_lock); + + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70)) + intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1); +} + /** * intel_gt_mcr_read - read a specific instance of an MCR register * @gt: GT structure diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h index 41684495b7da..01ac565a56a4 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h @@ -11,6 +11,7 @@ void intel_gt_mcr_init(struct intel_gt *gt); void intel_gt_mcr_lock(struct intel_gt *gt, unsigned long *flags); void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags); +void intel_gt_mcr_lock_sanitize(struct intel_gt *gt); u32 intel_gt_mcr_read(struct intel_gt *gt, i915_mcr_reg_t reg,
Implement intel_gt_mcr_lock_sanitize() to provide a mechanism for cleaning the steer semaphore when absolutely necessary. v2: remove unnecessary lock(Andi, Matt) improve the kernel doc(Matt) s/intel_gt_mcr_lock_clear/intel_gt_mcr_lock_sanitize Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> --- drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 22 ++++++++++++++++++++++ drivers/gpu/drm/i915/gt/intel_gt_mcr.h | 1 + 2 files changed, 23 insertions(+)