4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Redfearn <matt.redfearn@xxxxxxxxxx> commit fe8bd18ffea5327344d4ec2bf11f47951212abd0 upstream. Allocate a per-cpu irq stack for use within interrupt handlers. Also add a utility function on_irq_stack to determine if a given stack pointer is within the irq stack for that cpu. Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx> Acked-by: Jason A. Donenfeld <jason@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: James Hogan <james.hogan@xxxxxxxxxx> Cc: Paul Burton <paul.burton@xxxxxxxxxx> Cc: Aaron Tomlin <atomlin@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/14740/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/include/asm/irq.h | 12 ++++++++++++ arch/mips/kernel/asm-offsets.c | 1 + arch/mips/kernel/irq.c | 11 +++++++++++ 3 files changed, 24 insertions(+) --- a/arch/mips/include/asm/irq.h +++ b/arch/mips/include/asm/irq.h @@ -17,6 +17,18 @@ #include <irq.h> +#define IRQ_STACK_SIZE THREAD_SIZE + +extern void *irq_stack[NR_CPUS]; + +static inline bool on_irq_stack(int cpu, unsigned long sp) +{ + unsigned long low = (unsigned long)irq_stack[cpu]; + unsigned long high = low + IRQ_STACK_SIZE; + + return (low <= sp && sp <= high); +} + #ifdef CONFIG_I8259 static inline int irq_canonicalize(int irq) { --- a/arch/mips/kernel/asm-offsets.c +++ b/arch/mips/kernel/asm-offsets.c @@ -101,6 +101,7 @@ void output_thread_info_defines(void) OFFSET(TI_REGS, thread_info, regs); DEFINE(_THREAD_SIZE, THREAD_SIZE); DEFINE(_THREAD_MASK, THREAD_MASK); + DEFINE(_IRQ_STACK_SIZE, IRQ_STACK_SIZE); BLANK(); } --- a/arch/mips/kernel/irq.c +++ b/arch/mips/kernel/irq.c @@ -25,6 +25,8 @@ #include <linux/atomic.h> #include <asm/uaccess.h> +void *irq_stack[NR_CPUS]; + /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves. @@ -55,6 +57,15 @@ void __init init_IRQ(void) irq_set_noprobe(i); arch_init_irq(); + + for_each_possible_cpu(i) { + int irq_pages = IRQ_STACK_SIZE / PAGE_SIZE; + void *s = (void *)__get_free_pages(GFP_KERNEL, irq_pages); + + irq_stack[i] = s; + pr_debug("CPU%d IRQ stack at 0x%p - 0x%p\n", i, + irq_stack[i], irq_stack[i] + IRQ_STACK_SIZE); + } } #ifdef CONFIG_DEBUG_STACKOVERFLOW
