From e20800fd5cec2a75639a32e956b1cdc023cb87ce Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Sun, 7 Apr 2013 21:36:11 +1200 Subject: alpha: irq: run all handlers with interrupts disabled Linux has expected that interrupt handlers are executed with local interrupts disabled for a while now, so ensure that this is the case on Alpha even for non-device interrupts such as IPIs. Without this patch, secondary boot results in the following backtrace: warning: at kernel/softirq.c:139 __local_bh_enable+0xb8/0xd0() trace: __local_bh_enable+0xb8/0xd0 irq_enter+0x74/0xa0 scheduler_ipi+0x50/0x100 handle_ipi+0x84/0x260 do_entint+0x1ac/0x2e0 irq_exit+0x60/0xa0 handle_irq+0x98/0x100 do_entint+0x2c8/0x2e0 ret_from_sys_call+0x0/0x10 load_balance+0x3e4/0x870 cpu_idle+0x24/0x80 rcu_eqs_enter_common.isra.38+0x0/0x120 cpu_idle+0x40/0x80 rest_init+0xc0/0xe0 _stext+0x1c/0x20 A similar dump occurs if you try to reboot using magic-sysrq. Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Reviewed-by: Matt Turner Signed-off-by: Will Deacon Signed-off-by: Michael Cree Signed-off-by: Linus Torvalds --- arch/alpha/kernel/irq.c | 7 ------- arch/alpha/kernel/irq_alpha.c | 9 ++++++++- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c index 2872accd2215..7b2be251c30f 100644 --- a/arch/alpha/kernel/irq.c +++ b/arch/alpha/kernel/irq.c @@ -117,13 +117,6 @@ handle_irq(int irq) return; } - /* - * From here we must proceed with IPL_MAX. Note that we do not - * explicitly enable interrupts afterwards - some MILO PALcode - * (namely LX164 one) seems to have severe problems with RTI - * at IPL 0. - */ - local_irq_disable(); irq_enter(); generic_handle_irq_desc(irq, desc); irq_exit(); diff --git a/arch/alpha/kernel/irq_alpha.c b/arch/alpha/kernel/irq_alpha.c index 772ddfdb71a8..1216dfb4fcc5 100644 --- a/arch/alpha/kernel/irq_alpha.c +++ b/arch/alpha/kernel/irq_alpha.c @@ -45,6 +45,14 @@ do_entInt(unsigned long type, unsigned long vector, unsigned long la_ptr, struct pt_regs *regs) { struct pt_regs *old_regs; + + /* + * Disable interrupts during IRQ handling. + * Note that there is no matching local_irq_enable() due to + * severe problems with RTI at IPL0 and some MILO PALcode + * (namely LX164). + */ + local_irq_disable(); switch (type) { case 0: #ifdef CONFIG_SMP @@ -62,7 +70,6 @@ do_entInt(unsigned long type, unsigned long vector, { long cpu; - local_irq_disable(); smp_percpu_timer_interrupt(regs); cpu = smp_processor_id(); if (cpu != boot_cpuid) { -- cgit v1.2.3-59-g8ed1b