From ff340d2472ec7618443913928af9fb85a7009270 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 7 Sep 2017 17:03:19 +0200 Subject: s390: add stack switch helper Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/processor.h | 49 +++++++++++++++++++++++++++++++++++++++ arch/s390/kernel/irq.c | 10 +------- 2 files changed, 50 insertions(+), 9 deletions(-) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 7f2953c15c37..43494a014d5b 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -250,6 +250,55 @@ static inline unsigned short stap(void) return cpu_address; } +#define CALL_ARGS_0() \ + register unsigned long r2 asm("2") +#define CALL_ARGS_1(arg1) \ + register unsigned long r2 asm("2") = (unsigned long)(arg1) +#define CALL_ARGS_2(arg1, arg2) \ + CALL_ARGS_1(arg1); \ + register unsigned long r3 asm("3") = (unsigned long)(arg2) +#define CALL_ARGS_3(arg1, arg2, arg3) \ + CALL_ARGS_2(arg1, arg2); \ + register unsigned long r4 asm("4") = (unsigned long)(arg3) +#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \ + CALL_ARGS_3(arg1, arg2, arg3); \ + register unsigned long r4 asm("5") = (unsigned long)(arg4) +#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \ + CALL_ARGS_4(arg1, arg2, arg3, arg4); \ + register unsigned long r4 asm("6") = (unsigned long)(arg5) + +#define CALL_FMT_0 +#define CALL_FMT_1 CALL_FMT_0, "0" (r2) +#define CALL_FMT_2 CALL_FMT_1, "d" (r3) +#define CALL_FMT_3 CALL_FMT_2, "d" (r4) +#define CALL_FMT_4 CALL_FMT_3, "d" (r5) +#define CALL_FMT_5 CALL_FMT_4, "d" (r6) + +#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" +#define CALL_CLOBBER_4 CALL_CLOBBER_5 +#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" +#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" +#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" +#define CALL_CLOBBER_0 CALL_CLOBBER_1 + +#define CALL_ON_STACK(fn, stack, nr, args...) \ +({ \ + CALL_ARGS_##nr(args); \ + unsigned long prev; \ + \ + asm volatile( \ + " la %[_prev],0(15)\n" \ + " la 15,0(%[_stack])\n" \ + " stg %[_prev],%[_bc](15)\n" \ + " brasl 14,%[_fn]\n" \ + " la 15,0(%[_prev])\n" \ + : "+&d" (r2), [_prev] "=&a" (prev) \ + : [_stack] "a" (stack), \ + [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ + [_fn] "X" (fn) CALL_FMT_##nr : CALL_CLOBBER_##nr); \ + r2; \ +}) + /* * Give up the time slice of the virtual PU. */ diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 3d17c41074ca..0e8d68bac82c 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -172,15 +172,7 @@ void do_softirq_own_stack(void) /* Check against async. stack address range. */ new = S390_lowcore.async_stack; if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) { - /* Need to switch to the async. stack. */ - new -= STACK_FRAME_OVERHEAD; - ((struct stack_frame *) new)->back_chain = old; - asm volatile(" la 15,0(%0)\n" - " brasl 14,__do_softirq\n" - " la 15,0(%1)\n" - : : "a" (new), "a" (old) - : "0", "1", "2", "3", "4", "5", "14", - "cc", "memory" ); + CALL_ON_STACK(__do_softirq, new, 0); } else { /* We are already on the async stack. */ __do_softirq(); -- cgit v1.2.3