xtensa: add fairness to IRQ handling

Track which IRQs have been served at each level to make sure that no IRQ
is served more than once while other IRQs at the same level are pending.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2021-07-09 04:13:23 -07:00
parent ed5aacc81c
commit 43ba223728

View File

@ -268,6 +268,7 @@ void do_interrupt(struct pt_regs *regs)
XCHAL_INTLEVEL7_MASK,
};
struct pt_regs *old_regs;
unsigned unhandled = ~0u;
trace_hardirqs_off();
@ -283,6 +284,10 @@ void do_interrupt(struct pt_regs *regs)
for (level = LOCKLEVEL; level > 0; --level) {
if (int_at_level & int_level_mask[level]) {
int_at_level &= int_level_mask[level];
if (int_at_level & unhandled)
int_at_level &= unhandled;
else
unhandled |= int_level_mask[level];
break;
}
}
@ -290,6 +295,8 @@ void do_interrupt(struct pt_regs *regs)
if (level == 0)
break;
/* clear lowest pending irq in the unhandled mask */
unhandled ^= (int_at_level & -int_at_level);
do_IRQ(__ffs(int_at_level), regs);
}