Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[net-next-2.6.git] / arch / x86 / kernel / i387.c

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index a46cb3522c0c19d67f2d474c6e1f09fb616004ff..58bb239a2fd76d67121bd1c25e48512bad529825 100644 (file)
--- 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);