diff options
| -rw-r--r-- | arch/parisc/Kconfig | 8 | ||||
| -rw-r--r-- | arch/parisc/include/asm/processor.h | 19 | ||||
| -rw-r--r-- | arch/parisc/kernel/entry.S | 41 | ||||
| -rw-r--r-- | arch/parisc/kernel/irq.c | 28 |
4 files changed, 94 insertions, 2 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index fe4afb0f152..cad060f288c 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -243,6 +243,14 @@ config SMP If you don't know what to do here, say N. +config IRQSTACKS + bool "Use separate kernel stacks when processing interrupts" + default n + help + If you say Y here the kernel will use separate kernel stacks + for handling hard and soft interrupts. This can help avoid + overflowing the process kernel stacks. + config HOTPLUG_CPU bool default y if SMP diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index 09b54a57a48..242f06a5fbd 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -20,8 +20,6 @@ #endif /* __ASSEMBLY__ */ -#define KERNEL_STACK_SIZE (4*PAGE_SIZE) - /* * Default implementation of macro that returns current * instruction pointer ("program counter"). @@ -61,6 +59,23 @@ #ifndef __ASSEMBLY__ /* + * IRQ STACK - used for irq handler + */ +#ifdef __KERNEL__ + +#define IRQ_STACK_SIZE (4096 << 2) /* 16k irq stack size */ + +union irq_stack_union { + unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)]; +}; + +DECLARE_PER_CPU(union irq_stack_union, irq_stack_union); + +void call_on_stack(unsigned long p1, void *func, unsigned long new_stack); + +#endif /* __KERNEL__ */ + +/* * Data detected about CPUs at boot time which is the same for all CPU's. * HP boxes are SMP - ie identical processors. * diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 3f3326d876f..4bb96ad9b0b 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -2010,6 +2010,47 @@ ftrace_stub: ENDPROC(return_to_handler) #endif /* CONFIG_FUNCTION_TRACER */ +#ifdef CONFIG_IRQSTACKS +/* void call_on_stack(unsigned long param1, void *func, + unsigned long new_stack) */ +ENTRY(call_on_stack) + copy %sp, %r1 + + /* Regarding the HPPA calling conventions for function pointers, + we assume the PIC register is not changed across call. For + CONFIG_64BIT, the argument pointer is left to point at the + argument region allocated for the call to call_on_stack. */ +# ifdef CONFIG_64BIT + /* Switch to new stack. We allocate two 128 byte frames. */ + ldo 256(%arg2), %sp + /* Save previous stack pointer and return pointer in frame marker */ + STREG %rp, -144(%sp) + /* Calls always use function descriptor */ + LDREG 16(%arg1), %arg1 + bve,l (%arg1), %rp + STREG %r1, -136(%sp) + LDREG -144(%sp), %rp + bve (%rp) + LDREG -136(%sp), %sp +# else + /* Switch to new stack. We allocate two 64 byte frames. */ + ldo 128(%arg2), %sp + /* Save previous stack pointer and return pointer in frame marker */ + STREG %r1, -68(%sp) + STREG %rp, -84(%sp) + /* Calls use function descriptor if PLABEL bit is set */ + bb,>=,n %arg1, 30, 1f + depwi 0,31,2, %arg1 + LDREG 0(%arg1), %arg1 +1: + be,l 0(%sr4,%arg1), %sr0, %r31 + copy %r31, %rp + LDREG -84(%sp), %rp + bv (%rp) + LDREG -68(%sp), %sp +# endif /* CONFIG_64BIT */ +ENDPROC(call_on_stack) +#endif /* CONFIG_IRQSTACKS */ get_register: /* diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 61e51ac8565..810f9cf89e4 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(); |