1 files changed, 28 insertions, 30 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index a46cb3522c0c..58bb239a2fd7 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -68,19 +68,22 @@ static void __cpuinit init_thread_xstate(void)
          */
 
         if (!HAVE_HWFP) {
+                /*
+                 * Disable xsave as we do not support it if i387
+                 * emulation is enabled.
+                 */
+                setup_clear_cpu_cap(X86_FEATURE_XSAVE);
+                setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
                 xstate_size = sizeof(struct i387_soft_struct);
                 return;
         }
 
         if (cpu_has_fxsr)
                 xstate_size = sizeof(struct i387_fxsave_struct);
-#ifdef CONFIG_X86_32
         else
                 xstate_size = sizeof(struct i387_fsave_struct);
-#endif
 }
 
-#ifdef CONFIG_X86_64
 /*
  * Called at bootup to set up the initial FPU state that is later cloned
  * into all processes.
@@ -88,12 +91,21 @@ static void __cpuinit init_thread_xstate(void)
 
 void __cpuinit fpu_init(void)
 {
-        unsigned long oldcr0 = read_cr0();
-
-        set_in_cr4(X86_CR4_OSFXSR);
-        set_in_cr4(X86_CR4_OSXMMEXCPT);
+        unsigned long cr0;
+        unsigned long cr4_mask = 0;
 
-        write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
+        if (cpu_has_fxsr)
+                cr4_mask |= X86_CR4_OSFXSR;
+        if (cpu_has_xmm)
+                cr4_mask |= X86_CR4_OSXMMEXCPT;
+        if (cr4_mask)
+                set_in_cr4(cr4_mask);
+
+        cr0 = read_cr0();
+        cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
+        if (!HAVE_HWFP)
+                cr0 |= X86_CR0_EM;
+        write_cr0(cr0);
 
         if (!smp_processor_id())
                 init_thread_xstate();
@@ -104,24 +116,12 @@ void __cpuinit fpu_init(void)
         clear_used_math();
 }
 
-#else   /* CONFIG_X86_64 */
-
-void __cpuinit fpu_init(void)
-{
-        if (!smp_processor_id())
-                init_thread_xstate();
-}
-
-#endif  /* CONFIG_X86_32 */
-
 void fpu_finit(struct fpu *fpu)
 {
-#ifdef CONFIG_X86_32
         if (!HAVE_HWFP) {
                 finit_soft_fpu(&fpu->state->soft);
                 return;
         }
-#endif
 
         if (cpu_has_fxsr) {
                 struct i387_fxsave_struct *fx = &fpu->state->fxsave;
@@ -386,19 +386,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
 #ifdef CONFIG_X86_64
         env->fip = fxsave->rip;
         env->foo = fxsave->rdp;
+        /*
+         * should be actually ds/cs at fpu exception time, but
+         * that information is not available in 64bit mode.
+         */
+        env->fcs = task_pt_regs(tsk)->cs;
         if (tsk == current) {
-                /*
-                 * should be actually ds/cs at fpu exception time, but
-                 * that information is not available in 64bit mode.
-                 */
-                asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
-                asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
+                savesegment(ds, env->fos);
         } else {
-                struct pt_regs *regs = task_pt_regs(tsk);
-
-                env->fos = 0xffff0000 | tsk->thread.ds;
-                env->fcs = regs->cs;
+                env->fos = tsk->thread.ds;
         }
+        env->fos |= 0xffff0000;
 #else
         env->fip = fxsave->fip;
         env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);