diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index c2a62e9554b39..d8b4916e000ad 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -44,6 +44,10 @@ * contexts. Note that it's important that we check the condition again after * having timed out, since the timeout could be due to preemption or similar and * we've never had a chance to check the condition before the timeout. + * + * TODO: When modesetting has fully transitioned to atomic, the below + * drm_can_sleep() can be removed and in_atomic()/!in_atomic() asserts + * added. */ #define _wait_for(COND, US, W) ({ \ unsigned long timeout__ = jiffies + usecs_to_jiffies(US) + 1; \ @@ -66,8 +70,37 @@ #define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 1000) #define wait_for_us(COND, US) _wait_for((COND), (US), 1) -#define wait_for_atomic(COND, MS) _wait_for((COND), (MS) * 1000, 0) -#define wait_for_atomic_us(COND, US) _wait_for((COND), (US), 0) +/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */ +#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT) +# define _WAIT_FOR_ATOMIC_CHECK WARN_ON_ONCE(!in_atomic()) +#else +# define _WAIT_FOR_ATOMIC_CHECK do { } while (0) +#endif + +#define _wait_for_atomic(COND, US) ({ \ + unsigned long end__; \ + int ret__ = 0; \ + _WAIT_FOR_ATOMIC_CHECK; \ + BUILD_BUG_ON((US) > 50000); \ + end__ = (local_clock() >> 10) + (US) + 1; \ + while (!(COND)) { \ + if (time_after((unsigned long)(local_clock() >> 10), end__)) { \ + /* Unlike the regular wait_for(), this atomic variant \ + * cannot be preempted (and we'll just ignore the issue\ + * of irq interruptions) and so we know that no time \ + * has passed since the last check of COND and can \ + * immediately report the timeout. \ + */ \ + ret__ = -ETIMEDOUT; \ + break; \ + } \ + cpu_relax(); \ + } \ + ret__; \ +}) + +#define wait_for_atomic(COND, MS) _wait_for_atomic((COND), (MS) * 1000) +#define wait_for_atomic_us(COND, US) _wait_for_atomic((COND), (US)) #define KHz(x) (1000 * (x)) #define MHz(x) KHz(1000 * (x))