xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 int isolate_lru_page(struct page *page);	/* from internal.h */
22 extern bool mm_iommu_preregistered(struct mm_struct *mm);
23 extern long mm_iommu_get(struct mm_struct *mm,
24 		unsigned long ua, unsigned long entries,
25 		struct mm_iommu_table_group_mem_t **pmem);
26 extern long mm_iommu_put(struct mm_struct *mm,
27 		struct mm_iommu_table_group_mem_t *mem);
28 extern void mm_iommu_init(struct mm_struct *mm);
29 extern void mm_iommu_cleanup(struct mm_struct *mm);
30 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
31 		unsigned long ua, unsigned long size);
32 extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
33 		unsigned long ua, unsigned long entries);
34 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
35 		unsigned long ua, unsigned long *hpa);
36 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
37 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
38 #endif
39 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
40 extern void set_context(unsigned long id, pgd_t *pgd);
41 
42 #ifdef CONFIG_PPC_BOOK3S_64
43 extern void radix__switch_mmu_context(struct mm_struct *prev,
44 				     struct mm_struct *next);
45 static inline void switch_mmu_context(struct mm_struct *prev,
46 				      struct mm_struct *next,
47 				      struct task_struct *tsk)
48 {
49 	if (radix_enabled())
50 		return radix__switch_mmu_context(prev, next);
51 	return switch_slb(tsk, next);
52 }
53 
54 extern int __init_new_context(void);
55 extern void __destroy_context(int context_id);
56 static inline void mmu_context_init(void) { }
57 #else
58 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
59 			       struct task_struct *tsk);
60 extern unsigned long __init_new_context(void);
61 extern void __destroy_context(unsigned long context_id);
62 extern void mmu_context_init(void);
63 #endif
64 
65 extern void switch_cop(struct mm_struct *next);
66 extern int use_cop(unsigned long acop, struct mm_struct *mm);
67 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
68 
69 /*
70  * switch_mm is the entry point called from the architecture independent
71  * code in kernel/sched/core.c
72  */
73 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
74 			     struct task_struct *tsk)
75 {
76 	/* Mark this context has been used on the new CPU */
77 	if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next)))
78 		cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
79 
80 	/* 32-bit keeps track of the current PGDIR in the thread struct */
81 #ifdef CONFIG_PPC32
82 	tsk->thread.pgdir = next->pgd;
83 #endif /* CONFIG_PPC32 */
84 
85 	/* 64-bit Book3E keeps track of current PGD in the PACA */
86 #ifdef CONFIG_PPC_BOOK3E_64
87 	get_paca()->pgd = next->pgd;
88 #endif
89 	/* Nothing else to do if we aren't actually switching */
90 	if (prev == next)
91 		return;
92 
93 #ifdef CONFIG_PPC_ICSWX
94 	/* Switch coprocessor context only if prev or next uses a coprocessor */
95 	if (prev->context.acop || next->context.acop)
96 		switch_cop(next);
97 #endif /* CONFIG_PPC_ICSWX */
98 
99 	/* We must stop all altivec streams before changing the HW
100 	 * context
101 	 */
102 #ifdef CONFIG_ALTIVEC
103 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
104 		asm volatile ("dssall");
105 #endif /* CONFIG_ALTIVEC */
106 	/*
107 	 * The actual HW switching method differs between the various
108 	 * sub architectures. Out of line for now
109 	 */
110 	switch_mmu_context(prev, next, tsk);
111 }
112 
113 #define deactivate_mm(tsk,mm)	do { } while (0)
114 
115 /*
116  * After we have set current->mm to a new value, this activates
117  * the context for the new mm so we see the new mappings.
118  */
119 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
120 {
121 	unsigned long flags;
122 
123 	local_irq_save(flags);
124 	switch_mm(prev, next, current);
125 	local_irq_restore(flags);
126 }
127 
128 /* We don't currently use enter_lazy_tlb() for anything */
129 static inline void enter_lazy_tlb(struct mm_struct *mm,
130 				  struct task_struct *tsk)
131 {
132 	/* 64-bit Book3E keeps track of current PGD in the PACA */
133 #ifdef CONFIG_PPC_BOOK3E_64
134 	get_paca()->pgd = NULL;
135 #endif
136 }
137 
138 static inline void arch_dup_mmap(struct mm_struct *oldmm,
139 				 struct mm_struct *mm)
140 {
141 }
142 
143 static inline void arch_exit_mmap(struct mm_struct *mm)
144 {
145 }
146 
147 static inline void arch_unmap(struct mm_struct *mm,
148 			      struct vm_area_struct *vma,
149 			      unsigned long start, unsigned long end)
150 {
151 	if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
152 		mm->context.vdso_base = 0;
153 }
154 
155 static inline void arch_bprm_mm_init(struct mm_struct *mm,
156 				     struct vm_area_struct *vma)
157 {
158 }
159 
160 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
161 		bool write, bool execute, bool foreign)
162 {
163 	/* by default, allow everything */
164 	return true;
165 }
166 
167 static inline bool arch_pte_access_permitted(pte_t pte, bool write)
168 {
169 	/* by default, allow everything */
170 	return true;
171 }
172 #endif /* __KERNEL__ */
173 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
174