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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: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2015-07-29 12:14:42 +02:00
parent f1f5e41485
commit f51246efee
1 changed files with 25 additions and 27 deletions
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52
arch/mips/include/asm/switch_to.h
View File

@ -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)) { \
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); \
__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; \
cop2_save(prev); \
} \
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; \
if (cpu_has_userlocal) \
write_c0_userlocal(task_thread_info(next)->tp_value); \
__restore_watch(); \
disable_msa(); \
(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); \
__restore_watch(); \
disable_msa(); \
} while (0)
#endif /* _ASM_SWITCH_TO_H */