xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
1 #ifndef __ASM_POWERPC_MMU_CONTEXT_H
2 #define __ASM_POWERPC_MMU_CONTEXT_H
3 #ifdef __KERNEL__
4 
5 #include <linux/kernel.h>
6 #include <linux/mm.h>
7 #include <linux/sched.h>
8 #include <linux/spinlock.h>
9 #include <asm/mmu.h>
10 #include <asm/cputable.h>
11 #include <asm/cputhreads.h>
12 
13 /*
14  * Most if the context management is out of line
15  */
16 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
17 extern void destroy_context(struct mm_struct *mm);
18 #ifdef CONFIG_SPAPR_TCE_IOMMU
19 struct mm_iommu_table_group_mem_t;
20 
21 extern bool mm_iommu_preregistered(void);
22 extern long mm_iommu_get(unsigned long ua, unsigned long entries,
23 		struct mm_iommu_table_group_mem_t **pmem);
24 extern long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem);
25 extern void mm_iommu_init(mm_context_t *ctx);
26 extern void mm_iommu_cleanup(mm_context_t *ctx);
27 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua,
28 		unsigned long size);
29 extern struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua,
30 		unsigned long entries);
31 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
32 		unsigned long ua, unsigned long *hpa);
33 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
34 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
35 #endif
36 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
37 extern void set_context(unsigned long id, pgd_t *pgd);
38 
39 #ifdef CONFIG_PPC_BOOK3S_64
40 extern void radix__switch_mmu_context(struct mm_struct *prev,
41 				     struct mm_struct *next);
42 static inline void switch_mmu_context(struct mm_struct *prev,
43 				      struct mm_struct *next,
44 				      struct task_struct *tsk)
45 {
46 	if (radix_enabled())
47 		return radix__switch_mmu_context(prev, next);
48 	return switch_slb(tsk, next);
49 }
50 
51 extern int __init_new_context(void);
52 extern void __destroy_context(int context_id);
53 static inline void mmu_context_init(void) { }
54 #else
55 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
56 			       struct task_struct *tsk);
57 extern unsigned long __init_new_context(void);
58 extern void __destroy_context(unsigned long context_id);
59 extern void mmu_context_init(void);
60 #endif
61 
62 extern void switch_cop(struct mm_struct *next);
63 extern int use_cop(unsigned long acop, struct mm_struct *mm);
64 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
65 
66 /*
67  * switch_mm is the entry point called from the architecture independent
68  * code in kernel/sched/core.c
69  */
70 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
71 			     struct task_struct *tsk)
72 {
73 	/* Mark this context has been used on the new CPU */
74 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
75 
76 	/* 32-bit keeps track of the current PGDIR in the thread struct */
77 #ifdef CONFIG_PPC32
78 	tsk->thread.pgdir = next->pgd;
79 #endif /* CONFIG_PPC32 */
80 
81 	/* 64-bit Book3E keeps track of current PGD in the PACA */
82 #ifdef CONFIG_PPC_BOOK3E_64
83 	get_paca()->pgd = next->pgd;
84 #endif
85 	/* Nothing else to do if we aren't actually switching */
86 	if (prev == next)
87 		return;
88 
89 #ifdef CONFIG_PPC_ICSWX
90 	/* Switch coprocessor context only if prev or next uses a coprocessor */
91 	if (prev->context.acop || next->context.acop)
92 		switch_cop(next);
93 #endif /* CONFIG_PPC_ICSWX */
94 
95 	/* We must stop all altivec streams before changing the HW
96 	 * context
97 	 */
98 #ifdef CONFIG_ALTIVEC
99 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
100 		asm volatile ("dssall");
101 #endif /* CONFIG_ALTIVEC */
102 	/*
103 	 * The actual HW switching method differs between the various
104 	 * sub architectures. Out of line for now
105 	 */
106 	switch_mmu_context(prev, next, tsk);
107 }
108 
109 #define deactivate_mm(tsk,mm)	do { } while (0)
110 
111 /*
112  * After we have set current->mm to a new value, this activates
113  * the context for the new mm so we see the new mappings.
114  */
115 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
116 {
117 	unsigned long flags;
118 
119 	local_irq_save(flags);
120 	switch_mm(prev, next, current);
121 	local_irq_restore(flags);
122 }
123 
124 /* We don't currently use enter_lazy_tlb() for anything */
125 static inline void enter_lazy_tlb(struct mm_struct *mm,
126 				  struct task_struct *tsk)
127 {
128 	/* 64-bit Book3E keeps track of current PGD in the PACA */
129 #ifdef CONFIG_PPC_BOOK3E_64
130 	get_paca()->pgd = NULL;
131 #endif
132 }
133 
134 static inline void arch_dup_mmap(struct mm_struct *oldmm,
135 				 struct mm_struct *mm)
136 {
137 }
138 
139 static inline void arch_exit_mmap(struct mm_struct *mm)
140 {
141 }
142 
143 static inline void arch_unmap(struct mm_struct *mm,
144 			      struct vm_area_struct *vma,
145 			      unsigned long start, unsigned long end)
146 {
147 	if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
148 		mm->context.vdso_base = 0;
149 }
150 
151 static inline void arch_bprm_mm_init(struct mm_struct *mm,
152 				     struct vm_area_struct *vma)
153 {
154 }
155 
156 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
157 		bool write, bool execute, bool foreign)
158 {
159 	/* by default, allow everything */
160 	return true;
161 }
162 
163 static inline bool arch_pte_access_permitted(pte_t pte, bool write)
164 {
165 	/* by default, allow everything */
166 	return true;
167 }
168 #endif /* __KERNEL__ */
169 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
170