[PATCH] x86: Pnp byte granularity

[pandora-kernel.git] / include / asm-i386 / system.h

diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h
index 97d52ac..9c0593b 100644 (file)
--- 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())
@@ -263,6 +260,10 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 
 #ifdef CONFIG_X86_CMPXCHG
 #define __HAVE_ARCH_CMPXCHG 1
+#define cmpxchg(ptr,o,n)\
+       ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
+                                       (unsigned long)(n),sizeof(*(ptr))))
+#endif
 
 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
                                      unsigned long new, int size)
@@ -291,10 +292,42 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
        return old;
 }
 
-#define cmpxchg(ptr,o,n)\
-       ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
-                                       (unsigned long)(n),sizeof(*(ptr))))
+#ifndef CONFIG_X86_CMPXCHG
+/*
+ * Building a kernel capable running on 80386. It may be necessary to
+ * simulate the cmpxchg on the 80386 CPU. For that purpose we define
+ * a function for each of the sizes we support.
+ */
+
+extern unsigned long cmpxchg_386_u8(volatile void *, u8, u8);
+extern unsigned long cmpxchg_386_u16(volatile void *, u16, u16);
+extern unsigned long cmpxchg_386_u32(volatile void *, u32, u32);
+
+static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
+                                     unsigned long new, int size)
+{
+       switch (size) {
+       case 1:
+               return cmpxchg_386_u8(ptr, old, new);
+       case 2:
+               return cmpxchg_386_u16(ptr, old, new);
+       case 4:
+               return cmpxchg_386_u32(ptr, old, new);
+       }
+       return old;
+}
 
+#define cmpxchg(ptr,o,n)                                               \
+({                                                                     \
+       __typeof__(*(ptr)) __ret;                                       \
+       if (likely(boot_cpu_data.x86 > 3))                              \
+               __ret = __cmpxchg((ptr), (unsigned long)(o),            \
+                                       (unsigned long)(n), sizeof(*(ptr))); \
+       else                                                            \
+               __ret = cmpxchg_386((ptr), (unsigned long)(o),          \
+                                       (unsigned long)(n), sizeof(*(ptr))); \
+       __ret;                                                          \
+})
 #endif
 
 #ifdef CONFIG_X86_CMPXCHG64