From 200c880420a2c02a0899120ce52d801fad705b90 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Tue, 7 May 2013 20:25:42 +0000 Subject: parisc: implement irq stacks Default kernel stack size on parisc is 16k. During tests we found that the kernel stack can easily grow beyond 13k, which leaves 3k left for irq processing. This patch adds the possibility to activate an additional stack of 16k per CPU which is being used during irq processing. This implementation does not yet uses this irq stack for the irq bh handler. The assembler code for call_on_stack was heavily cleaned up by John David Anglin. CC: John David Anglin Signed-off-by: Helge Deller --- arch/parisc/kernel/irq.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'arch/parisc/kernel/irq.c') diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 61e51ac85659..810f9cf89e48 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -358,6 +358,29 @@ static inline void stack_overflow_check(struct pt_regs *regs) #endif } +#ifdef CONFIG_IRQSTACKS +DEFINE_PER_CPU(union irq_stack_union, irq_stack_union); + +static void execute_on_irq_stack(void *func, unsigned long param1) +{ + unsigned long *irq_stack_start; + unsigned long irq_stack; + int cpu = smp_processor_id(); + + irq_stack_start = &per_cpu(irq_stack_union, cpu).stack[0]; + irq_stack = (unsigned long) irq_stack_start; + irq_stack = ALIGN(irq_stack, 16); /* align for stack frame usage */ + + BUG_ON(*irq_stack_start); /* report bug if we were called recursive. */ + *irq_stack_start = 1; + + /* This is where we switch to the IRQ stack. */ + call_on_stack(param1, func, irq_stack); + + *irq_stack_start = 0; +} +#endif /* CONFIG_IRQSTACKS */ + /* ONLY called from entry.S:intr_extint() */ void do_cpu_irq_mask(struct pt_regs *regs) { @@ -393,7 +416,12 @@ void do_cpu_irq_mask(struct pt_regs *regs) } #endif stack_overflow_check(regs); + +#ifdef CONFIG_IRQSTACKS + execute_on_irq_stack(&generic_handle_irq, irq); +#else generic_handle_irq(irq); +#endif /* CONFIG_IRQSTACKS */ out: irq_exit(); -- cgit v1.2.3