diff options
| -rw-r--r-- | arch/blackfin/kernel/entry.S | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/arch/blackfin/kernel/entry.S b/arch/blackfin/kernel/entry.S index a9cfba9946b..3f8769b7db5 100644 --- a/arch/blackfin/kernel/entry.S +++ b/arch/blackfin/kernel/entry.S @@ -43,8 +43,28 @@ ENTRY(_ret_from_fork) #ifdef CONFIG_IPIPE - [--sp] = reti; /* IRQs on. */ - SP += 4; + /* + * Hw IRQs are off on entry, and we don't want the scheduling tail + * code to starve high priority domains from interrupts while it + * runs. Therefore we first stall the root stage to have the + * virtual interrupt state reflect IMASK. + */ + p0.l = ___ipipe_root_status; + p0.h = ___ipipe_root_status; + r4 = [p0]; + bitset(r4, 0); + [p0] = r4; + /* + * Then we may enable hw IRQs, allowing preemption from high + * priority domains. schedule_tail() will do local_irq_enable() + * since Blackfin does not define __ARCH_WANT_UNLOCKED_CTXSW, so + * there is no need to unstall the root domain by ourselves + * afterwards. + */ + p0.l = _bfin_irq_flags; + p0.h = _bfin_irq_flags; + r4 = [p0]; + sti r4; #endif /* CONFIG_IPIPE */ SP += -12; call _schedule_tail; |