struct task_struct; /* one of the stranger aspects of C forward declarations.. */
extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next));
+/*
+ * Saving eflags is important. It switches not only IOPL between tasks,
+ * it also protects other tasks from NT leaking through sysenter etc.
+ */
#define switch_to(prev,next,last) do { \
unsigned long esi,edi; \
- asm volatile("pushl %%ebp\n\t" \
+ asm volatile("pushfl\n\t" /* Save flags */ \
+ "pushl %%ebp\n\t" \
"movl %%esp,%0\n\t" /* save ESP */ \
"movl %5,%%esp\n\t" /* restore ESP */ \
"movl $1f,%1\n\t" /* save EIP */ \
"jmp __switch_to\n" \
"1:\t" \
"popl %%ebp\n\t" \
+ "popfl" \
:"=m" (prev->thread.esp),"=m" (prev->thread.eip), \
"=a" (last),"=S" (esi),"=D" (edi) \
:"m" (next->thread.esp),"m" (next->thread.eip), \
#define savesegment(seg, value) \
asm volatile("mov %%" #seg ",%0":"=rm" (value))
-#define read_cr0() ({ \
- unsigned int __dummy; \
- __asm__ __volatile__( \
- "movl %%cr0,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-#define write_cr0(x) \
- __asm__ __volatile__("movl %0,%%cr0": :"r" (x))
-
-#define read_cr2() ({ \
- unsigned int __dummy; \
- __asm__ __volatile__( \
- "movl %%cr2,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-#define write_cr2(x) \
- __asm__ __volatile__("movl %0,%%cr2": :"r" (x))
-
-#define read_cr3() ({ \
- unsigned int __dummy; \
- __asm__ ( \
- "movl %%cr3,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-#define write_cr3(x) \
- __asm__ __volatile__("movl %0,%%cr3": :"r" (x))
-
-#define read_cr4() ({ \
- unsigned int __dummy; \
- __asm__( \
- "movl %%cr4,%0\n\t" \
- :"=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))
-/*
- * Clear and set 'TS' bit respectively
- */
-#define clts() __asm__ __volatile__ ("clts")
+static inline void native_clts(void)
+{
+ asm volatile ("clts");
+}
+
+static inline unsigned long native_read_cr0(void)
+{
+ unsigned long val;
+ asm volatile("movl %%cr0,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static inline void native_write_cr0(unsigned long val)
+{
+ asm volatile("movl %0,%%cr0": :"r" (val));
+}
+
+static inline unsigned long native_read_cr2(void)
+{
+ unsigned long val;
+ asm volatile("movl %%cr2,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static inline void native_write_cr2(unsigned long val)
+{
+ asm volatile("movl %0,%%cr2": :"r" (val));
+}
+
+static inline unsigned long native_read_cr3(void)
+{
+ unsigned long val;
+ asm volatile("movl %%cr3,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static inline void native_write_cr3(unsigned long val)
+{
+ asm volatile("movl %0,%%cr3": :"r" (val));
+}
+
+static inline unsigned long native_read_cr4(void)
+{
+ unsigned long val;
+ asm volatile("movl %%cr4,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static inline unsigned long native_read_cr4_safe(void)
+{
+ unsigned long val;
+ /* 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" (val): "0" (0));
+ return val;
+}
+
+static inline void native_write_cr4(unsigned long val)
+{
+ asm volatile("movl %0,%%cr4": :"r" (val));
+}
+
+static inline void native_wbinvd(void)
+{
+ asm volatile("wbinvd": : :"memory");
+}
+
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define read_cr0() (native_read_cr0())
+#define write_cr0(x) (native_write_cr0(x))
+#define read_cr2() (native_read_cr2())
+#define write_cr2(x) (native_write_cr2(x))
+#define read_cr3() (native_read_cr3())
+#define write_cr3(x) (native_write_cr3(x))
+#define read_cr4() (native_read_cr4())
+#define read_cr4_safe() (native_read_cr4_safe())
+#define write_cr4(x) (native_write_cr4(x))
+#define wbinvd() (native_wbinvd())
+
+/* Clear the 'TS' bit */
+#define clts() (native_clts())
+
+#endif/* CONFIG_PARAVIRT */
+
+/* Set the 'TS' bit */
#define stts() write_cr0(8 | read_cr0())
#endif /* __KERNEL__ */
-#define wbinvd() \
- __asm__ __volatile__ ("wbinvd": : :"memory")
-
static inline unsigned long get_limit(unsigned long segment)
{
unsigned long __limit;
#define cmpxchg(ptr,o,n)\
((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
(unsigned long)(n),sizeof(*(ptr))))
+#define sync_cmpxchg(ptr,o,n)\
+ ((__typeof__(*(ptr)))__sync_cmpxchg((ptr),(unsigned long)(o),\
+ (unsigned long)(n),sizeof(*(ptr))))
#endif
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
return old;
}
+/*
+ * Always use locked operations when touching memory shared with a
+ * hypervisor, since the system may be SMP even if the guest kernel
+ * isn't.
+ */
+static inline unsigned long __sync_cmpxchg(volatile void *ptr,
+ unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long prev;
+ switch (size) {
+ case 1:
+ __asm__ __volatile__("lock; cmpxchgb %b1,%2"
+ : "=a"(prev)
+ : "q"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ case 2:
+ __asm__ __volatile__("lock; cmpxchgw %w1,%2"
+ : "=a"(prev)
+ : "r"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ case 4:
+ __asm__ __volatile__("lock; cmpxchgl %1,%2"
+ : "=a"(prev)
+ : "r"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ }
+ return old;
+}
+
#ifndef CONFIG_X86_CMPXCHG
/*
* Building a kernel capable running on 80386. It may be necessary to
projects / powerpc.git / blobdiff