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| author | Ralf Baechle <ralf@linux-mips.org> | 2015-07-29 12:14:42 +0200 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2015-09-03 12:08:01 +0200 |
| commit | f51246efee2b6bc72e86bc1d16599fc7c455b986 (patch) | |
| tree | f7087e74fb1f827ed70271f0d8ce03466535bb6c | |
| parent | f1f5e414851fdb69a3200e5c15799ea4788d423e (diff) | |
| download | lwn-f51246efee2b6bc72e86bc1d16599fc7c455b986.tar.gz lwn-f51246efee2b6bc72e86bc1d16599fc7c455b986.zip | |
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>
| -rw-r--r-- | arch/mips/include/asm/switch_to.h | 48 |
1 files changed, 23 insertions, 25 deletions
diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h index 7163cd7fdd69..9733cd0266e4 100644 --- a/arch/mips/include/asm/switch_to.h +++ b/arch/mips/include/asm/switch_to.h @@ -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; \ - (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 */ |