diff --git a/arch/s390/include/asm/ctl_reg.h b/arch/s390/include/asm/ctl_reg.h index 60f907516335..ed5efbb531c4 100644 --- a/arch/s390/include/asm/ctl_reg.h +++ b/arch/s390/include/asm/ctl_reg.h @@ -11,6 +11,7 @@ #include #define CR0_CLOCK_COMPARATOR_SIGN BIT(63 - 10) +#define CR0_LOW_ADDRESS_PROTECTION BIT(63 - 35) #define CR0_EMERGENCY_SIGNAL_SUBMASK BIT(63 - 49) #define CR0_EXTERNAL_CALL_SUBMASK BIT(63 - 50) #define CR0_CLOCK_COMPARATOR_SUBMASK BIT(63 - 52) diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index 2e99e01e4f62..0ed6ae6a8bde 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -260,6 +260,17 @@ static inline void save_vector_registers(void) #endif } +static inline void setup_control_registers(void) +{ + unsigned long reg; + + __ctl_store(reg, 0, 0); + reg |= CR0_LOW_ADDRESS_PROTECTION; + reg |= CR0_EMERGENCY_SIGNAL_SUBMASK; + reg |= CR0_EXTERNAL_CALL_SUBMASK; + __ctl_load(reg, 0, 0); +} + static int __init disable_vector_extension(char *str) { S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX; @@ -317,5 +328,6 @@ void __init startup_init(void) save_vector_registers(); setup_topology(); sclp_early_detect(); + setup_control_registers(); lockdep_on(); } diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S index 0d9ee198f4eb..5b21702ea080 100644 --- a/arch/s390/kernel/head64.S +++ b/arch/s390/kernel/head64.S @@ -42,12 +42,6 @@ ENTRY(startup_continue) # brasl %r14,startup_init -# check control registers - stctg %c0,%c15,0(%r15) - oi 6(%r15),0x60 # enable sigp emergency & external call - oi 4(%r15),0x10 # switch on low address proctection - lctlg %c0,%c15,0(%r15) - lam 0,15,.Laregs-.LPG1(%r13) # load acrs needed by uaccess brasl %r14,start_kernel # go to C code #