diff options
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index bed0cb83fe24..82042f40fc45 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -387,7 +387,28 @@ set_register: bits_missing); } } -EXPORT_SYMBOL(native_write_cr4); +EXPORT_SYMBOL_GPL(native_write_cr4); + +void cr4_update_irqsoff(unsigned long set, unsigned long clear) +{ + unsigned long newval, cr4 = this_cpu_read(cpu_tlbstate.cr4); + + lockdep_assert_irqs_disabled(); + + newval = (cr4 & ~clear) | set; + if (newval != cr4) { + this_cpu_write(cpu_tlbstate.cr4, newval); + __write_cr4(newval); + } +} +EXPORT_SYMBOL(cr4_update_irqsoff); + +/* Read the CR4 shadow. */ +unsigned long cr4_read_shadow(void) +{ + return this_cpu_read(cpu_tlbstate.cr4); +} +EXPORT_SYMBOL_GPL(cr4_read_shadow); void cr4_init(void) { |