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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-14 07:58:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-14 07:58:08 -0700
commit625037cc405eabbfd2a39e9297e583a94886225f (patch)
treec0a62f6cb2a565efb7cd494f558f0acbadcbabb0 /arch/x86/kernel/traps.c
parent8fafa0a789faaff4318cbfa9c2f827d2198505dc (diff)
parent17950c5b243f99cbabef173415ee988c52104d7e (diff)
Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86-64: move clts into batch cpu state updates when preloading fpu x86-64: move unlazy_fpu() into lazy cpu state part of context switch x86-32: make sure clts is batched during context switch x86: split out core __math_state_restore
Diffstat (limited to 'arch/x86/kernel/traps.c')
-rw-r--r--arch/x86/kernel/traps.c33
1 files changed, 23 insertions, 10 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 6fe85c272a2..83264922a87 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -795,6 +795,28 @@ asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
}
/*
+ * __math_state_restore assumes that cr0.TS is already clear and the
+ * fpu state is all ready for use. Used during context switch.
+ */
+void __math_state_restore(void)
+{
+ struct thread_info *thread = current_thread_info();
+ struct task_struct *tsk = thread->task;
+
+ /*
+ * Paranoid restore. send a SIGSEGV if we fail to restore the state.
+ */
+ if (unlikely(restore_fpu_checking(tsk))) {
+ stts();
+ force_sig(SIGSEGV, tsk);
+ return;
+ }
+
+ thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
+ tsk->fpu_counter++;
+}
+
+/*
* 'math_state_restore()' saves the current math information in the
* old math state array, and gets the new ones from the current task
*
@@ -825,17 +847,8 @@ asmlinkage void math_state_restore(void)
}
clts(); /* Allow maths ops (or we recurse) */
- /*
- * Paranoid restore. send a SIGSEGV if we fail to restore the state.
- */
- if (unlikely(restore_fpu_checking(tsk))) {
- stts();
- force_sig(SIGSEGV, tsk);
- return;
- }
- thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
- tsk->fpu_counter++;
+ __math_state_restore();
}
EXPORT_SYMBOL_GPL(math_state_restore);