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