1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_POWERPC_MMU_CONTEXT_H
3 #define __ASM_POWERPC_MMU_CONTEXT_H
4 #ifdef __KERNEL__
5 
6 #include <linux/kernel.h>
7 #include <linux/mm.h>
8 #include <linux/sched.h>
9 #include <linux/spinlock.h>
10 #include <asm/mmu.h>
11 #include <asm/cputable.h>
12 #include <asm/cputhreads.h>
13 
14 /*
15  * Most if the context management is out of line
16  */
17 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
18 extern void destroy_context(struct mm_struct *mm);
19 #ifdef CONFIG_SPAPR_TCE_IOMMU
20 struct mm_iommu_table_group_mem_t;
21 
22 extern int isolate_lru_page(struct page *page);	/* from internal.h */
23 extern bool mm_iommu_preregistered(struct mm_struct *mm);
24 extern long mm_iommu_get(struct mm_struct *mm,
25 		unsigned long ua, unsigned long entries,
26 		struct mm_iommu_table_group_mem_t **pmem);
27 extern long mm_iommu_put(struct mm_struct *mm,
28 		struct mm_iommu_table_group_mem_t *mem);
29 extern void mm_iommu_init(struct mm_struct *mm);
30 extern void mm_iommu_cleanup(struct mm_struct *mm);
31 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
32 		unsigned long ua, unsigned long size);
33 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(
34 		struct mm_struct *mm, unsigned long ua, unsigned long size);
35 extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
36 		unsigned long ua, unsigned long entries);
37 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
38 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
39 extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
40 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
41 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
42 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
43 #endif
44 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
45 extern void set_context(unsigned long id, pgd_t *pgd);
46 
47 #ifdef CONFIG_PPC_BOOK3S_64
48 extern void radix__switch_mmu_context(struct mm_struct *prev,
49 				      struct mm_struct *next);
50 static inline void switch_mmu_context(struct mm_struct *prev,
51 				      struct mm_struct *next,
52 				      struct task_struct *tsk)
53 {
54 	if (radix_enabled())
55 		return radix__switch_mmu_context(prev, next);
56 	return switch_slb(tsk, next);
57 }
58 
59 extern int hash__alloc_context_id(void);
60 extern void hash__reserve_context_id(int id);
61 extern void __destroy_context(int context_id);
62 static inline void mmu_context_init(void) { }
63 
64 static inline int alloc_extended_context(struct mm_struct *mm,
65 					 unsigned long ea)
66 {
67 	int context_id;
68 
69 	int index = ea >> MAX_EA_BITS_PER_CONTEXT;
70 
71 	context_id = hash__alloc_context_id();
72 	if (context_id < 0)
73 		return context_id;
74 
75 	VM_WARN_ON(mm->context.extended_id[index]);
76 	mm->context.extended_id[index] = context_id;
77 	return context_id;
78 }
79 
80 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
81 {
82 	int context_id;
83 
84 	context_id = get_ea_context(&mm->context, ea);
85 	if (!context_id)
86 		return true;
87 	return false;
88 }
89 
90 #else
91 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
92 			       struct task_struct *tsk);
93 extern unsigned long __init_new_context(void);
94 extern void __destroy_context(unsigned long context_id);
95 extern void mmu_context_init(void);
96 static inline int alloc_extended_context(struct mm_struct *mm,
97 					 unsigned long ea)
98 {
99 	/* non book3s_64 should never find this called */
100 	WARN_ON(1);
101 	return -ENOMEM;
102 }
103 
104 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
105 {
106 	return false;
107 }
108 #endif
109 
110 #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
111 extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
112 #else
113 static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
114 #endif
115 
116 extern void switch_cop(struct mm_struct *next);
117 extern int use_cop(unsigned long acop, struct mm_struct *mm);
118 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
119 
120 #ifdef CONFIG_PPC_BOOK3S_64
121 static inline void inc_mm_active_cpus(struct mm_struct *mm)
122 {
123 	atomic_inc(&mm->context.active_cpus);
124 }
125 
126 static inline void dec_mm_active_cpus(struct mm_struct *mm)
127 {
128 	atomic_dec(&mm->context.active_cpus);
129 }
130 
131 static inline void mm_context_add_copro(struct mm_struct *mm)
132 {
133 	/*
134 	 * If any copro is in use, increment the active CPU count
135 	 * in order to force TLB invalidations to be global as to
136 	 * propagate to the Nest MMU.
137 	 */
138 	if (atomic_inc_return(&mm->context.copros) == 1)
139 		inc_mm_active_cpus(mm);
140 }
141 
142 static inline void mm_context_remove_copro(struct mm_struct *mm)
143 {
144 	int c;
145 
146 	/*
147 	 * When removing the last copro, we need to broadcast a global
148 	 * flush of the full mm, as the next TLBI may be local and the
149 	 * nMMU and/or PSL need to be cleaned up.
150 	 *
151 	 * Both the 'copros' and 'active_cpus' counts are looked at in
152 	 * flush_all_mm() to determine the scope (local/global) of the
153 	 * TLBIs, so we need to flush first before decrementing
154 	 * 'copros'. If this API is used by several callers for the
155 	 * same context, it can lead to over-flushing. It's hopefully
156 	 * not common enough to be a problem.
157 	 *
158 	 * Skip on hash, as we don't know how to do the proper flush
159 	 * for the time being. Invalidations will remain global if
160 	 * used on hash. Note that we can't drop 'copros' either, as
161 	 * it could make some invalidations local with no flush
162 	 * in-between.
163 	 */
164 	if (radix_enabled()) {
165 		flush_all_mm(mm);
166 
167 		c = atomic_dec_if_positive(&mm->context.copros);
168 		/* Detect imbalance between add and remove */
169 		WARN_ON(c < 0);
170 
171 		if (c == 0)
172 			dec_mm_active_cpus(mm);
173 	}
174 }
175 #else
176 static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
177 static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
178 static inline void mm_context_add_copro(struct mm_struct *mm) { }
179 static inline void mm_context_remove_copro(struct mm_struct *mm) { }
180 #endif
181 
182 
183 extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
184 			       struct task_struct *tsk);
185 
186 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
187 			     struct task_struct *tsk)
188 {
189 	unsigned long flags;
190 
191 	local_irq_save(flags);
192 	switch_mm_irqs_off(prev, next, tsk);
193 	local_irq_restore(flags);
194 }
195 #define switch_mm_irqs_off switch_mm_irqs_off
196 
197 
198 #define deactivate_mm(tsk,mm)	do { } while (0)
199 
200 /*
201  * After we have set current->mm to a new value, this activates
202  * the context for the new mm so we see the new mappings.
203  */
204 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
205 {
206 	switch_mm(prev, next, current);
207 }
208 
209 /* We don't currently use enter_lazy_tlb() for anything */
210 static inline void enter_lazy_tlb(struct mm_struct *mm,
211 				  struct task_struct *tsk)
212 {
213 	/* 64-bit Book3E keeps track of current PGD in the PACA */
214 #ifdef CONFIG_PPC_BOOK3E_64
215 	get_paca()->pgd = NULL;
216 #endif
217 }
218 
219 static inline int arch_dup_mmap(struct mm_struct *oldmm,
220 				struct mm_struct *mm)
221 {
222 	return 0;
223 }
224 
225 #ifndef CONFIG_PPC_BOOK3S_64
226 static inline void arch_exit_mmap(struct mm_struct *mm)
227 {
228 }
229 #else
230 extern void arch_exit_mmap(struct mm_struct *mm);
231 #endif
232 
233 static inline void arch_unmap(struct mm_struct *mm,
234 			      struct vm_area_struct *vma,
235 			      unsigned long start, unsigned long end)
236 {
237 	if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
238 		mm->context.vdso_base = 0;
239 }
240 
241 static inline void arch_bprm_mm_init(struct mm_struct *mm,
242 				     struct vm_area_struct *vma)
243 {
244 }
245 
246 #ifdef CONFIG_PPC_MEM_KEYS
247 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
248 			       bool execute, bool foreign);
249 #else /* CONFIG_PPC_MEM_KEYS */
250 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
251 		bool write, bool execute, bool foreign)
252 {
253 	/* by default, allow everything */
254 	return true;
255 }
256 
257 #define pkey_mm_init(mm)
258 #define thread_pkey_regs_save(thread)
259 #define thread_pkey_regs_restore(new_thread, old_thread)
260 #define thread_pkey_regs_init(thread)
261 
262 static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
263 {
264 	return 0x0UL;
265 }
266 
267 #endif /* CONFIG_PPC_MEM_KEYS */
268 
269 #endif /* __KERNEL__ */
270 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
271