diff options
Diffstat (limited to 'arch/s390/include/asm/system.h')
| -rw-r--r-- | arch/s390/include/asm/system.h | 51 |
1 files changed, 22 insertions, 29 deletions
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h index 1f2ebc4afd8..3ad16dbf622 100644 --- a/arch/s390/include/asm/system.h +++ b/arch/s390/include/asm/system.h @@ -85,14 +85,16 @@ static inline void restore_access_regs(unsigned int *acrs) asm volatile("lam 0,15,%0" : : "Q" (*acrs)); } -#define switch_to(prev,next,last) do { \ - if (prev == next) \ - break; \ - save_fp_regs(&prev->thread.fp_regs); \ - restore_fp_regs(&next->thread.fp_regs); \ - save_access_regs(&prev->thread.acrs[0]); \ - restore_access_regs(&next->thread.acrs[0]); \ - prev = __switch_to(prev,next); \ +#define switch_to(prev,next,last) do { \ + if (prev->mm) { \ + save_fp_regs(&prev->thread.fp_regs); \ + save_access_regs(&prev->thread.acrs[0]); \ + } \ + if (next->mm) { \ + restore_fp_regs(&next->thread.fp_regs); \ + restore_access_regs(&next->thread.acrs[0]); \ + } \ + prev = __switch_to(prev,next); \ } while (0) extern void account_vtime(struct task_struct *, struct task_struct *); @@ -418,30 +420,21 @@ extern void smp_ctl_clear_bit(int cr, int bit); #endif /* CONFIG_SMP */ -static inline unsigned int stfl(void) -{ - asm volatile( - " .insn s,0xb2b10000,0(0)\n" /* stfl */ - "0:\n" - EX_TABLE(0b,0b)); - return S390_lowcore.stfl_fac_list; -} +#define MAX_FACILITY_BIT (256*8) /* stfle_fac_list has 256 bytes */ -static inline int __stfle(unsigned long long *list, int doublewords) +/* + * The test_facility function uses the bit odering where the MSB is bit 0. + * That makes it easier to query facility bits with the bit number as + * documented in the Principles of Operation. + */ +static inline int test_facility(unsigned long nr) { - typedef struct { unsigned long long _[doublewords]; } addrtype; - register unsigned long __nr asm("0") = doublewords - 1; - - asm volatile(".insn s,0xb2b00000,%0" /* stfle */ - : "=m" (*(addrtype *) list), "+d" (__nr) : : "cc"); - return __nr + 1; -} + unsigned char *ptr; -static inline int stfle(unsigned long long *list, int doublewords) -{ - if (!(stfl() & (1UL << 24))) - return -EOPNOTSUPP; - return __stfle(list, doublewords); + if (nr >= MAX_FACILITY_BIT) + return 0; + ptr = (unsigned char *) &S390_lowcore.stfle_fac_list + (nr >> 3); + return (*ptr & (0x80 >> (nr & 7))) != 0; } static inline unsigned short stap(void) |