1 /* 2 * Copyright (C) 2012 Regents of the University of California 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #ifndef _ASM_RISCV_SWITCH_TO_H 15 #define _ASM_RISCV_SWITCH_TO_H 16 17 #include <asm/processor.h> 18 #include <asm/ptrace.h> 19 #include <asm/csr.h> 20 21 extern void __fstate_save(struct task_struct *save_to); 22 extern void __fstate_restore(struct task_struct *restore_from); 23 24 static inline void __fstate_clean(struct pt_regs *regs) 25 { 26 regs->sstatus |= (regs->sstatus & ~(SR_FS)) | SR_FS_CLEAN; 27 } 28 29 static inline void fstate_save(struct task_struct *task, 30 struct pt_regs *regs) 31 { 32 if ((regs->sstatus & SR_FS) == SR_FS_DIRTY) { 33 __fstate_save(task); 34 __fstate_clean(regs); 35 } 36 } 37 38 static inline void fstate_restore(struct task_struct *task, 39 struct pt_regs *regs) 40 { 41 if ((regs->sstatus & SR_FS) != SR_FS_OFF) { 42 __fstate_restore(task); 43 __fstate_clean(regs); 44 } 45 } 46 47 static inline void __switch_to_aux(struct task_struct *prev, 48 struct task_struct *next) 49 { 50 struct pt_regs *regs; 51 52 regs = task_pt_regs(prev); 53 if (unlikely(regs->sstatus & SR_SD)) 54 fstate_save(prev, regs); 55 fstate_restore(next, task_pt_regs(next)); 56 } 57 58 extern struct task_struct *__switch_to(struct task_struct *, 59 struct task_struct *); 60 61 #define switch_to(prev, next, last) \ 62 do { \ 63 struct task_struct *__prev = (prev); \ 64 struct task_struct *__next = (next); \ 65 __switch_to_aux(__prev, __next); \ 66 ((last) = __switch_to(__prev, __next)); \ 67 } while (0) 68 69 #endif /* _ASM_RISCV_SWITCH_TO_H */ 70