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authorRik van Riel <riel@redhat.com>2015-02-06 20:02:02 (GMT)
committerBorislav Petkov <bp@suse.de>2015-02-19 10:15:53 (GMT)
commit33e03dedd759cc9396252d9641b25d01909a26bb (patch)
treeef6107500bdf187f06191588a03f8d14d2bbcdc2 /arch/x86/include/asm/fpu-internal.h
parent1c927eea4cad83c439cb51e9c96ad19cb005157d (diff)
downloadlinux-33e03dedd759cc9396252d9641b25d01909a26bb.tar.xz
x86/fpu: Introduce task_disable_lazy_fpu_restore() helper
Currently there are a few magic assignments sprinkled through the code that disable lazy FPU state restoring, some more effective than others, and all equally mystifying. It would be easier to have a helper to explicitly disable lazy FPU state restoring for a task. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/1423252925-14451-6-git-send-email-riel@redhat.com Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/include/asm/fpu-internal.h')
-rw-r--r--arch/x86/include/asm/fpu-internal.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 217d6d7..9c27f44 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -79,6 +79,16 @@ static inline void __cpu_disable_lazy_restore(unsigned int cpu)
per_cpu(fpu_owner_task, cpu) = NULL;
}
+/*
+ * Used to indicate that the FPU state in memory is newer than the FPU
+ * state in registers, and the FPU state should be reloaded next time the
+ * task is run. Only safe on the current task, or non-running tasks.
+ */
+static inline void task_disable_lazy_fpu_restore(struct task_struct *tsk)
+{
+ tsk->thread.fpu.last_cpu = ~0;
+}
+
static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu)
{
return new == this_cpu_read_stable(fpu_owner_task) &&