s390/mm: Select ARCH_WANT_IRQS_OFF_ACTIVATE_MM

Select ARCH_WANT_IRQS_OFF_ACTIVATE_MM so that activate_mm() is called with
irqs disabled. This allows to call switch_mm_irqs_off() instead of
switch_mm() and saves two local_irq_save() / local_irq_restore() pairs.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 99fb986fca6e8d3eabb3a364f8adb30a36af4486..0c16dc443e2f65fc6bd71352e1cc8d7aa60a7c6a 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -146,6 +146,7 @@ config S390
        select ARCH_WANTS_NO_INSTR
        select ARCH_WANT_DEFAULT_BPF_JIT
        select ARCH_WANT_IPC_PARSE_VERSION
+       select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
        select ARCH_WANT_KERNEL_PMD_MKWRITE
        select ARCH_WANT_LD_ORPHAN_WARN
        select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP

diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index dabc51511b8911238f06fb9c56df29e4fdd9fd4f..d9b8501bc93d07403728e6907a01b0c3755aa53a 100644 (file)
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -124,17 +124,13 @@ static inline void finish_arch_post_lock_switch(void)
 static inline void activate_mm(struct mm_struct *prev,
                                struct mm_struct *next)
 {
-       unsigned long flags;
-
-       switch_mm(prev, next, current);
+       switch_mm_irqs_off(prev, next, current);
        cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
-       local_irq_save(flags);
        if (test_thread_flag(TIF_ASCE_PRIMARY))
                local_ctl_load(1, &get_lowcore()->kernel_asce);
        else
                local_ctl_load(1, &get_lowcore()->user_asce);
        local_ctl_load(7, &get_lowcore()->user_asce);
-       local_irq_restore(flags);
 }
 
 #include <asm-generic/mmu_context.h>