V4L/DVB (5271): Add VIDIOC_TRY_ENCODER_CMD and VIDIOC_ENCODER_CMD ioctls.

[linux-2.6-omap-h63xx.git] / include / asm-i386 / system.h

diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h
index 49928eb33f8bbd830ac1937a7ff5b50de1adec5d..a6d20d9a1a307b0f6bbf55351e91fb26f48ad6b0 100644 (file)
--- a/include/asm-i386/system.h
+++ b/include/asm-i386/system.h
@@ -11,9 +11,14 @@
 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 */          \
@@ -21,6 +26,7 @@ extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struc
                     "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),    \
@@ -82,6 +88,9 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \
 #define savesegment(seg, value) \
        asm volatile("mov %%" #seg ",%0":"=rm" (value))
 
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
 #define read_cr0() ({ \
        unsigned int __dummy; \
        __asm__ __volatile__( \
@@ -133,17 +142,18 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \
 #define write_cr4(x) \
        __asm__ __volatile__("movl %0,%%cr4": :"r" (x))
 
-/*
- * Clear and set 'TS' bit respectively
- */
+#define wbinvd() \
+       __asm__ __volatile__ ("wbinvd": : :"memory")
+
+/* Clear the 'TS' bit */
 #define clts() __asm__ __volatile__ ("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;
@@ -261,6 +271,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 #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,
@@ -290,6 +303,39 @@ 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