50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright IBM Corp. 1999, 2009
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*
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#ifndef __ASM_SWITCH_TO_H
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#define __ASM_SWITCH_TO_H
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#include <linux/thread_info.h>
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#include <asm/fpu/api.h>
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#include <asm/ptrace.h>
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#include <asm/guarded_storage.h>
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extern struct task_struct *__switch_to(void *, void *);
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extern void update_cr_regs(struct task_struct *task);
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static inline void save_access_regs(unsigned int *acrs)
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{
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typedef struct { int _[NUM_ACRS]; } acrstype;
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asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
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}
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static inline void restore_access_regs(unsigned int *acrs)
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{
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typedef struct { int _[NUM_ACRS]; } acrstype;
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asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
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}
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#define switch_to(prev, next, last) do { \
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/* save_fpu_regs() sets the CIF_FPU flag, which enforces \
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* a restore of the floating point / vector registers as \
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* soon as the next task returns to user space \
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*/ \
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save_fpu_regs(); \
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save_access_regs(&prev->thread.acrs[0]); \
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save_ri_cb(prev->thread.ri_cb); \
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save_gs_cb(prev->thread.gs_cb); \
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update_cr_regs(next); \
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restore_access_regs(&next->thread.acrs[0]); \
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restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb); \
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restore_gs_cb(next->thread.gs_cb); \
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prev = __switch_to(prev, next); \
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} while (0)
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#endif /* __ASM_SWITCH_TO_H */
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