s390/irq,idle: simplify idle check

Use the per-cpu CIF_ENABLED_WAIT flag to decide if an interrupt
occurred while a cpu was idle, instead of checking two conditions
within the old psw.

Also move clearing of the CIF_ENABLED_WAIT bit to the early interrupt
handler, which in turn makes arch_vcpu_is_preempted() also a bit more
precise, since the flag is now cleared before interrupt handlers have
been called.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/include/asm/idle.h b/arch/s390/include/asm/idle.h
index af72a2b35758aed4c79088d6b5c25d36b6879a67..09f763b9eb40aa4d38a80642ecf86a412720fa77 100644 (file)
--- a/arch/s390/include/asm/idle.h
+++ b/arch/s390/include/asm/idle.h
@@ -23,6 +23,5 @@ extern struct device_attribute dev_attr_idle_count;
 extern struct device_attribute dev_attr_idle_time_us;
 
 void psw_idle(struct s390_idle_data *data, unsigned long psw_mask);
-void psw_idle_exit(void);
 
 #endif /* _S390_IDLE_H */

diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index dd8351e76539e0c02a69808622bb0fc488891dbf..1a1a419ed846db536fbb00d813e36d4d477bae3c 100644 (file)
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -28,7 +28,6 @@ void account_idle_time_irq(void)
        u64 cycles_new[8];
        int i;
 
-       clear_cpu_flag(CIF_ENABLED_WAIT);
        if (smp_cpu_mtid) {
                stcctm(MT_DIAG, smp_cpu_mtid, cycles_new);
                for (i = 0; i < smp_cpu_mtid; i++)

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 45393919fe615cb9da6799d60d7e4bbcecc2f048..b020ff17d206edd1fdc47c87caa23875ff3b8c5c 100644 (file)
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -136,7 +136,7 @@ void noinstr do_io_irq(struct pt_regs *regs)
 {
        irqentry_state_t state = irqentry_enter(regs);
        struct pt_regs *old_regs = set_irq_regs(regs);
-       int from_idle;
+       bool from_idle;
 
        irq_enter_rcu();
 
@@ -146,7 +146,7 @@ void noinstr do_io_irq(struct pt_regs *regs)
                        current->thread.last_break = regs->last_break;
        }
 
-       from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
+       from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
        if (from_idle)
                account_idle_time_irq();
 
@@ -171,7 +171,7 @@ void noinstr do_ext_irq(struct pt_regs *regs)
 {
        irqentry_state_t state = irqentry_enter(regs);
        struct pt_regs *old_regs = set_irq_regs(regs);
-       int from_idle;
+       bool from_idle;
 
        irq_enter_rcu();
 
@@ -185,7 +185,7 @@ void noinstr do_ext_irq(struct pt_regs *regs)
        regs->int_parm = S390_lowcore.ext_params;
        regs->int_parm_long = S390_lowcore.ext_params2;
 
-       from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
+       from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
        if (from_idle)
                account_idle_time_irq();