Commit ae486033 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge tag 'tip_x86_fpu' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/fpu 



Pull x86/fpu updates from Borislav Petkov:

 "Three more cleanups/improvements to the FPU handling code. (Oleg Nesterov)"

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents f353e612 110d7f75

arch/x86/kernel/i387.c

+6 −5
Original line number Diff line number Diff line
@@ -41,8 +41,8 @@ void kernel_fpu_enable(void) 
 * be set (so that the clts/stts pair does nothing that is

 * visible in the interrupted kernel thread).

 *

 * Except for the eagerfpu case when we return 1 unless we've already

 * been eager and saved the state in kernel_fpu_begin().

 * Except for the eagerfpu case when we return true; in the likely case

 * the thread has FPU but we are not going to set/clear TS.

 */

static inline bool interrupted_kernel_fpu_idle(void)

{
@@ -50,7 +50,7 @@ static inline bool interrupted_kernel_fpu_idle(void) 
		return false;



	if (use_eager_fpu())

		return __thread_has_fpu(current);

		return true;



	return !__thread_has_fpu(current) &&

		(read_cr0() & X86_CR0_TS);
@@ -93,8 +93,9 @@ void __kernel_fpu_begin(void) 


	if (__thread_has_fpu(me)) {

		__save_init_fpu(me);

	} else if (!use_eager_fpu()) {

	} else {

		this_cpu_write(fpu_owner_task, NULL);

		if (!use_eager_fpu())

			clts();

	}

}

arch/x86/kernel/process.c

+7 −0
Original line number Diff line number Diff line
@@ -130,6 +130,7 @@ void flush_thread(void) 


	flush_ptrace_hw_breakpoint(tsk);

	memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));



	drop_init_fpu(tsk);

	/*

	 * Free the FPU state for non xsave platforms. They get reallocated
@@ -137,6 +138,12 @@ void flush_thread(void) 
	 */

	if (!use_eager_fpu())

		free_thread_xstate(tsk);

	else if (!used_math()) {

		/* kthread execs. TODO: cleanup this horror. */

		if (WARN_ON(init_fpu(current)))

			force_sig(SIGKILL, current);

		math_state_restore();

	}

}



static void hard_disable_TSC(void)

arch/x86/kernel/xsave.c

+1 −12
Original line number Diff line number Diff line
@@ -688,7 +688,7 @@ void eager_fpu_init(void) 
{

	static __refdata void (*boot_func)(void) = eager_fpu_init_bp;



	clear_used_math();

	WARN_ON(used_math());

	current_thread_info()->status = 0;



	if (eagerfpu == ENABLE)
@@ -703,17 +703,6 @@ void eager_fpu_init(void) 
		boot_func();

		boot_func = NULL;

	}



	/*

	 * This is same as math_state_restore(). But use_xsave() is

	 * not yet patched to use math_state_restore().

	 */

	init_fpu(current);

	__thread_fpu_begin(current);

	if (cpu_has_xsave)

		xrstor_state(init_xstate_buf, -1);

	else

		fxrstor_checking(&init_xstate_buf->i387);

}



/*