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Commit f51246ef authored by Ralf Baechle's avatar Ralf Baechle
Browse files

MIPS: Get rid of finish_arch_switch(). 



MIPS was using finish_arch_switch() as a hook to restore and initialize
CPU context for all threads, even newly created kernel and user threads.
This is however entirely solvable within switch_to() so get rid of
finish_arch_switch() which is in the way of scheduler cleanups.

Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent f1f5e414

arch/mips/include/asm/switch_to.h

+23 −25
Original line number Diff line number Diff line
@@ -83,45 +83,43 @@ do { if (cpu_has_rw_llb) { \ 
	}								\

} while (0)



/*

 * For newly created kernel threads switch_to() will return to

 * ret_from_kernel_thread, newly created user threads to ret_from_fork.

 * That is, everything following resume() will be skipped for new threads.

 * So everything that matters to new threads should be placed before resume().

 */

#define switch_to(prev, next, last)					\

do {									\

	u32 __c0_stat;							\

	s32 __fpsave = FP_SAVE_NONE;					\

	__mips_mt_fpaff_switch_to(prev);				\

	if (cpu_has_dsp)						\

	if (cpu_has_dsp) {						\

		__save_dsp(prev);					\

	if (cop2_present && (KSTK_STATUS(prev) & ST0_CU2)) {		\

		__restore_dsp(next);					\

	}								\

	if (cop2_present) {						\

		set_c0_status(ST0_CU2);					\

		if ((KSTK_STATUS(prev) & ST0_CU2)) {			\

			if (cop2_lazy_restore)				\

				KSTK_STATUS(prev) &= ~ST0_CU2;		\

		__c0_stat = read_c0_status();				\

		write_c0_status(__c0_stat | ST0_CU2);			\

			cop2_save(prev);				\

		write_c0_status(__c0_stat & ~ST0_CU2);			\

		}							\

		if (KSTK_STATUS(next) & ST0_CU2 &&			\

		    !cop2_lazy_restore) {				\

			cop2_restore(next);				\

		}							\

		clear_c0_status(ST0_CU2);				\

	}								\

	__clear_software_ll_bit();					\

	if (test_and_clear_tsk_thread_flag(prev, TIF_USEDFPU))		\

		__fpsave = FP_SAVE_SCALAR;				\

	if (test_and_clear_tsk_thread_flag(prev, TIF_USEDMSA))		\

		__fpsave = FP_SAVE_VECTOR;				\

	(last) = resume(prev, next, task_thread_info(next), __fpsave);	\

} while (0)



#define finish_arch_switch(prev)					\

do {									\

	u32 __c0_stat;							\

	if (cop2_present && !cop2_lazy_restore &&			\

			(KSTK_STATUS(current) & ST0_CU2)) {		\

		__c0_stat = read_c0_status();				\

		write_c0_status(__c0_stat | ST0_CU2);			\

		cop2_restore(current);					\

		write_c0_status(__c0_stat & ~ST0_CU2);			\

	}								\

	if (cpu_has_dsp)						\

		__restore_dsp(current);					\

	if (cpu_has_userlocal)						\

		write_c0_userlocal(current_thread_info()->tp_value);	\

		write_c0_userlocal(task_thread_info(next)->tp_value);	\

	__restore_watch();						\

	disable_msa();							\

	(last) = resume(prev, next, task_thread_info(next), __fpsave);	\

} while (0)



#endif /* _ASM_SWITCH_TO_H */