1 files changed, 22 insertions, 0 deletions

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index bb36a989db77..f0c4060bd4d5 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -1098,6 +1098,28 @@ void __init trap_init(void)
 #endif
         set_trap_gate(19,&simd_coprocessor_error);
 
+        if (cpu_has_fxsr) {
+                /*
+                 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
+                 * Generates a compile-time "error: zero width for bit-field" if
+                 * the alignment is wrong.
+                 */
+                struct fxsrAlignAssert {
+                        int _:!(offsetof(struct task_struct,
+                                        thread.i387.fxsave) & 15);
+                };
+
+                printk(KERN_INFO "Enabling fast FPU save and restore... ");
+                set_in_cr4(X86_CR4_OSFXSR);
+                printk("done.\n");
+        }
+        if (cpu_has_xmm) {
+                printk(KERN_INFO "Enabling unmasked SIMD FPU exception "
+                                "support... ");
+                set_in_cr4(X86_CR4_OSXMMEXCPT);
+                printk("done.\n");
+        }
+
         set_system_gate(SYSCALL_VECTOR,&system_call);
 
         /*