diff options
Diffstat (limited to 'include/asm-i386/system.h')
| -rw-r--r-- | include/asm-i386/system.h | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h index 772f85da1206..9c0593b7a94e 100644 --- a/include/asm-i386/system.h +++ b/include/asm-i386/system.h @@ -54,23 +54,7 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ ); } while(0) #define set_base(ldt,base) _set_base( ((char *)&(ldt)) , (base) ) -#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1)>>12 ) - -static inline unsigned long _get_base(char * addr) -{ - unsigned long __base; - __asm__("movb %3,%%dh\n\t" - "movb %2,%%dl\n\t" - "shll $16,%%edx\n\t" - "movw %1,%%dx" - :"=&d" (__base) - :"m" (*((addr)+2)), - "m" (*((addr)+4)), - "m" (*((addr)+7))); - return __base; -} - -#define get_base(ldt) _get_base( ((char *)&(ldt)) ) +#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1) ) /* * Load a segment. Fall back on loading the zero @@ -140,6 +124,19 @@ static inline unsigned long _get_base(char * addr) :"=r" (__dummy)); \ __dummy; \ }) + +#define read_cr4_safe() ({ \ + unsigned int __dummy; \ + /* This could fault if %cr4 does not exist */ \ + __asm__("1: movl %%cr4, %0 \n" \ + "2: \n" \ + ".section __ex_table,\"a\" \n" \ + ".long 1b,2b \n" \ + ".previous \n" \ + : "=r" (__dummy): "0" (0)); \ + __dummy; \ +}) + #define write_cr4(x) \ __asm__ __volatile__("movl %0,%%cr4": :"r" (x)); #define stts() write_cr0(8 | read_cr0()) |