bitkeeper revision 1.1236.1.1 (421bba88ZaitlU4qEVN6Xp2WKaq8Vg)

FPU fixes.
Signed-off-by: Keir Fraser <keir@xensource.com>

xen/arch/x86/i387.c

@@ -16,42 +16,43 @@
 
 void init_fpu(void)
 {
-    __asm__("fninit");
-    if ( cpu_has_xmm ) load_mxcsr(0x1f80);
+    __asm__ __volatile__ ( "fninit" );
+    if ( cpu_has_xmm )
+        load_mxcsr(0x1f80);
     set_bit(EDF_DONEFPUINIT, &current->ed_flags);
 }
 
-static inline void __save_init_fpu( struct exec_domain *tsk )
-{
-    if ( cpu_has_fxsr ) {
-        asm volatile( "fxsave %0 ; fnclex"
-                      : "=m" (tsk->arch.i387) );
-    } else {
-        asm volatile( "fnsave %0 ; fwait"
-                      : "=m" (tsk->arch.i387) );
-    }
-    clear_bit(EDF_USEDFPU, &tsk->ed_flags);
-}
-
-void save_init_fpu( struct exec_domain *tsk )
+void save_init_fpu(struct exec_domain *tsk)
 {
     /*
      * The guest OS may have set the 'virtual STTS' flag.
      * This causes us to set the real flag, so we'll need
      * to temporarily clear it while saving f-p state.
      */
-    if ( test_bit(EDF_GUEST_STTS, &tsk->ed_flags) ) clts();
-    __save_init_fpu(tsk);
+    if ( test_bit(EDF_GUEST_STTS, &tsk->ed_flags) )
+        clts();
+
+    if ( cpu_has_fxsr )
+        __asm__ __volatile__ (
+            "fxsave %0 ; fnclex"
+            : "=m" (tsk->arch.i387) );
+    else
+        __asm__ __volatile__ (
+            "fnsave %0 ; fwait"
+            : "=m" (tsk->arch.i387) );
+
+    clear_bit(EDF_USEDFPU, &tsk->ed_flags);
     stts();
 }
 
-void restore_fpu( struct exec_domain *tsk )
+void restore_fpu(struct exec_domain *tsk)
 {
-    if ( cpu_has_fxsr ) {
-        asm volatile( "fxrstor %0"
-                      : : "m" (tsk->arch.i387) );
-    } else {
-        asm volatile( "frstor %0"
-                      : : "m" (tsk->arch.i387) );
-    }
+    if ( cpu_has_fxsr )
+        __asm__ __volatile__ (
+            "fxrstor %0"
+            : : "m" (tsk->arch.i387) );
+    else
+        __asm__ __volatile__ (
+            "frstor %0"
+            : : "m" (tsk->arch.i387) );
 }

xen/arch/x86/traps.c

@@ -371,7 +371,9 @@ static int emulate_privileged_op(struct xen_regs *regs)
     switch ( opcode )
     {
     case 0x06: /* CLTS */
-        (void)do_fpu_taskswitch();
+        clear_bit(EDF_GUEST_STTS, &ed->ed_flags);
+        if ( test_bit(EDF_USEDFPU, &ed->ed_flags) )
+            clts();
         break;
 
     case 0x09: /* WBINVD */
@@ -420,8 +422,8 @@ static int emulate_privileged_op(struct xen_regs *regs)
         switch ( (opcode >> 3) & 7 )
         {
         case 0: /* Write CR0 */
-            if ( *reg & X86_CR0_TS ) /* XXX ignore all but TS bit */
-                (void)do_fpu_taskswitch;
+            if ( *reg & X86_CR0_TS )
+                (void)do_fpu_taskswitch();
             break;
 
         case 2: /* Write CR2 */

xen/include/asm-x86/i387.h

@@ -15,24 +15,17 @@
 #include <asm/processor.h>
 
 extern void init_fpu(void);
-extern void save_init_fpu( struct exec_domain *tsk );
-extern void restore_fpu( struct exec_domain *tsk );
+extern void save_init_fpu(struct exec_domain *tsk);
+extern void restore_fpu(struct exec_domain *tsk);
 
-#define unlazy_fpu( tsk ) do { \
-	if ( test_bit(EDF_USEDFPU, &tsk->ed_flags) ) \
-		save_init_fpu( tsk ); \
-} while (0)
-
-#define clear_fpu( tsk ) do { \
-	if ( test_and_clear_bit(EDF_USEDFPU, &tsk->ed_flags) ) { \
-		asm volatile("fwait"); \
-		stts(); \
-	} \
-} while (0)
+#define unlazy_fpu(_tsk) do { \
+    if ( test_bit(EDF_USEDFPU, &(_tsk)->ed_flags) ) \
+        save_init_fpu(_tsk); \
+} while ( 0 )
 
 #define load_mxcsr( val ) do { \
-        unsigned long __mxcsr = ((unsigned long)(val) & 0xffbf); \
-        asm volatile( "ldmxcsr %0" : : "m" (__mxcsr) ); \
-} while (0)
+    unsigned long __mxcsr = ((unsigned long)(val) & 0xffbf); \
+    __asm__ __volatile__ ( "ldmxcsr %0" : : "m" (__mxcsr) ); \
+} while ( 0 )
 
 #endif /* __ASM_I386_I387_H */