diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c index 4dc360f4e344a70eb8726fa220ae0deb02d830e2..1ed9bc4dccfd1e353c950babe99eb8512a494132 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c @@ -568,3 +568,58 @@ void intel_gt_mcr_get_ss_steering(struct intel_gt *gt, unsigned int dss, return; } } + +/** + * intel_gt_mcr_wait_for_reg_fw - wait until MCR register matches expected state + * @gt: GT structure + * @reg: the register to read + * @mask: mask to apply to register value + * @value: value to wait for + * @fast_timeout_us: fast timeout in microsecond for atomic/tight wait + * @slow_timeout_ms: slow timeout in millisecond + * + * This routine waits until the target register @reg contains the expected + * @value after applying the @mask, i.e. it waits until :: + * + * (intel_gt_mcr_read_any_fw(gt, reg) & mask) == value + * + * Otherwise, the wait will timeout after @slow_timeout_ms milliseconds. + * For atomic context @slow_timeout_ms must be zero and @fast_timeout_us + * must be not larger than 20,0000 microseconds. + * + * This function is basically an MCR-friendly version of + * __intel_wait_for_register_fw(). Generally this function will only be used + * on GAM registers which are a bit special --- although they're MCR registers, + * reads (e.g., waiting for status updates) are always directed to the primary + * instance. + * + * Note that this routine assumes the caller holds forcewake asserted, it is + * not suitable for very long waits. + * + * Return: 0 if the register matches the desired condition, or -ETIMEDOUT. + */ +int intel_gt_mcr_wait_for_reg_fw(struct intel_gt *gt, + i915_reg_t reg, + u32 mask, + u32 value, + unsigned int fast_timeout_us, + unsigned int slow_timeout_ms) +{ + u32 reg_value = 0; +#define done (((reg_value = intel_gt_mcr_read_any_fw(gt, reg)) & mask) == value) + int ret; + + /* Catch any overuse of this function */ + might_sleep_if(slow_timeout_ms); + GEM_BUG_ON(fast_timeout_us > 20000); + GEM_BUG_ON(!fast_timeout_us && !slow_timeout_ms); + + ret = -ETIMEDOUT; + if (fast_timeout_us && fast_timeout_us <= 20000) + ret = _wait_for_atomic(done, fast_timeout_us, 0); + if (ret && slow_timeout_ms) + ret = wait_for(done, slow_timeout_ms); + + return ret; +#undef done +} diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h index 781b267478db0683e3950c1e1bc0604b0e901e0d..548f922cd9face743f387990e99e4cd4cf9011bd 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.h @@ -37,6 +37,13 @@ void intel_gt_mcr_report_steering(struct drm_printer *p, struct intel_gt *gt, void intel_gt_mcr_get_ss_steering(struct intel_gt *gt, unsigned int dss, unsigned int *group, unsigned int *instance); +int intel_gt_mcr_wait_for_reg_fw(struct intel_gt *gt, + i915_reg_t reg, + u32 mask, + u32 value, + unsigned int fast_timeout_us, + unsigned int slow_timeout_ms); + /* * Helper for for_each_ss_steering loop. On pre-Xe_HP platforms, subslice * presence is determined by using the group/instance as direct lookups in the