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_MMU_CONTEXT_H
15 #define _ASM_RISCV_MMU_CONTEXT_H
16 
17 #include <asm-generic/mm_hooks.h>
18 
19 #include <linux/mm.h>
20 #include <linux/sched.h>
21 #include <asm/tlbflush.h>
22 
23 static inline void enter_lazy_tlb(struct mm_struct *mm,
24 	struct task_struct *task)
25 {
26 }
27 
28 /* Initialize context-related info for a new mm_struct */
29 static inline int init_new_context(struct task_struct *task,
30 	struct mm_struct *mm)
31 {
32 	return 0;
33 }
34 
35 static inline void destroy_context(struct mm_struct *mm)
36 {
37 }
38 
39 static inline pgd_t *current_pgdir(void)
40 {
41 	return pfn_to_virt(csr_read(sptbr) & SPTBR_PPN);
42 }
43 
44 static inline void set_pgdir(pgd_t *pgd)
45 {
46 	csr_write(sptbr, virt_to_pfn(pgd) | SPTBR_MODE);
47 }
48 
49 static inline void switch_mm(struct mm_struct *prev,
50 	struct mm_struct *next, struct task_struct *task)
51 {
52 	if (likely(prev != next)) {
53 		set_pgdir(next->pgd);
54 		local_flush_tlb_all();
55 	}
56 }
57 
58 static inline void activate_mm(struct mm_struct *prev,
59 			       struct mm_struct *next)
60 {
61 	switch_mm(prev, next, NULL);
62 }
63 
64 static inline void deactivate_mm(struct task_struct *task,
65 	struct mm_struct *mm)
66 {
67 }
68 
69 #endif /* _ASM_RISCV_MMU_CONTEXT_H */
70