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- /* SPDX-License-Identifier: GPL-2.0 */
- //
- // Code shared between 32 and 64 bit
- #include <asm/spec-ctrl.h>
- void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p);
- /*
- * This needs to be inline to optimize for the common case where no extra
- * work needs to be done.
- */
- static inline void switch_to_extra(struct task_struct *prev,
- struct task_struct *next)
- {
- unsigned long next_tif = read_task_thread_flags(next);
- unsigned long prev_tif = read_task_thread_flags(prev);
- if (IS_ENABLED(CONFIG_SMP)) {
- /*
- * Avoid __switch_to_xtra() invocation when conditional
- * STIBP is disabled and the only different bit is
- * TIF_SPEC_IB. For CONFIG_SMP=n TIF_SPEC_IB is not
- * in the TIF_WORK_CTXSW masks.
- */
- if (!static_branch_likely(&switch_to_cond_stibp)) {
- prev_tif &= ~_TIF_SPEC_IB;
- next_tif &= ~_TIF_SPEC_IB;
- }
- }
- /*
- * __switch_to_xtra() handles debug registers, i/o bitmaps,
- * speculation mitigations etc.
- */
- if (unlikely(next_tif & _TIF_WORK_CTXSW_NEXT ||
- prev_tif & _TIF_WORK_CTXSW_PREV))
- __switch_to_xtra(prev, next);
- }
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