Commit-ID: 8f4d81863ba4e8dfee93bd50840f1099a296251f Gitweb: http://git.kernel.org/tip/8f4d81863ba4e8dfee93bd50840f1099a296251f Author: Oleg Nesterov <[email protected]> AuthorDate: Wed, 11 Mar 2015 18:34:29 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 23 Mar 2015 10:13:58 +0100
x86/fpu: Introduce restore_init_xstate() Extract the "use_eager_fpu()" code from drop_init_fpu() into a new, simple helper restore_init_xstate(). The next patch adds another user. - It is not clear why we do not check use_fxsr() like fpu_restore_checking() does. eager_fpu_init_bp() calls setup_init_fpu_buf() too, and we have the "eagerfpu=on" kernel option. - Ignoring the fact that init_xstate_buf is "struct xsave_struct *", not "union thread_xstate *", it is not clear why we can not simply use fpu_restore_checking() and avoid the code duplication. - It is not clear why we can't call setup_init_fpu_buf() unconditionally to always create init_xstate_buf(). Then do_device_not_available() path (at least) could use restore_init_xstate() too. It doesn't need to init fpu->state, its content doesn't matter until unlazy_fpu()/__switch_to()/etc which overwrites this memory anyway. Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Pekka Riikonen <[email protected]> Cc: Quentin Casasnovas <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Suresh Siddha <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/include/asm/fpu-internal.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index c58c930..7d2f7fa 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -401,16 +401,20 @@ static inline void drop_fpu(struct task_struct *tsk) preempt_enable(); } +static inline void restore_init_xstate(void) +{ + if (use_xsave()) + xrstor_state(init_xstate_buf, -1); + else + fxrstor_checking(&init_xstate_buf->i387); +} + static inline void drop_init_fpu(struct task_struct *tsk) { if (!use_eager_fpu()) drop_fpu(tsk); - else { - if (use_xsave()) - xrstor_state(init_xstate_buf, -1); - else - fxrstor_checking(&init_xstate_buf->i387); - } + else + restore_init_xstate(); } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
