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_new(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_newdev(struct mm_struct *mm, unsigned long ua,
28 		unsigned long entries, unsigned long dev_hpa,
29 		struct mm_iommu_table_group_mem_t **pmem);
30 extern long mm_iommu_put(struct mm_struct *mm,
31 		struct mm_iommu_table_group_mem_t *mem);
32 extern void mm_iommu_init(struct mm_struct *mm);
33 extern void mm_iommu_cleanup(struct mm_struct *mm);
34 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
35 		unsigned long ua, unsigned long size);
36 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(
37 		struct mm_struct *mm, unsigned long ua, unsigned long size);
38 extern struct mm_iommu_table_group_mem_t *mm_iommu_get(struct mm_struct *mm,
39 		unsigned long ua, unsigned long entries);
40 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
41 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
42 extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
43 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
44 extern void mm_iommu_ua_mark_dirty_rm(struct mm_struct *mm, unsigned long ua);
45 extern bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
46 		unsigned int pageshift, unsigned long *size);
47 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
48 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
49 #else
50 static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
51 		unsigned int pageshift, unsigned long *size)
52 {
53 	return false;
54 }
55 static inline void mm_iommu_init(struct mm_struct *mm) { }
56 #endif
57 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
58 extern void set_context(unsigned long id, pgd_t *pgd);
59 
60 #ifdef CONFIG_PPC_BOOK3S_64
61 extern void radix__switch_mmu_context(struct mm_struct *prev,
62 				      struct mm_struct *next);
63 static inline void switch_mmu_context(struct mm_struct *prev,
64 				      struct mm_struct *next,
65 				      struct task_struct *tsk)
66 {
67 	if (radix_enabled())
68 		return radix__switch_mmu_context(prev, next);
69 	return switch_slb(tsk, next);
70 }
71 
72 extern int hash__alloc_context_id(void);
73 extern void hash__reserve_context_id(int id);
74 extern void __destroy_context(int context_id);
75 static inline void mmu_context_init(void) { }
76 
77 static inline int alloc_extended_context(struct mm_struct *mm,
78 					 unsigned long ea)
79 {
80 	int context_id;
81 
82 	int index = ea >> MAX_EA_BITS_PER_CONTEXT;
83 
84 	context_id = hash__alloc_context_id();
85 	if (context_id < 0)
86 		return context_id;
87 
88 	VM_WARN_ON(mm->context.extended_id[index]);
89 	mm->context.extended_id[index] = context_id;
90 	return context_id;
91 }
92 
93 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
94 {
95 	int context_id;
96 
97 	context_id = get_user_context(&mm->context, ea);
98 	if (!context_id)
99 		return true;
100 	return false;
101 }
102 
103 #else
104 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
105 			       struct task_struct *tsk);
106 extern unsigned long __init_new_context(void);
107 extern void __destroy_context(unsigned long context_id);
108 extern void mmu_context_init(void);
109 static inline int alloc_extended_context(struct mm_struct *mm,
110 					 unsigned long ea)
111 {
112 	/* non book3s_64 should never find this called */
113 	WARN_ON(1);
114 	return -ENOMEM;
115 }
116 
117 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
118 {
119 	return false;
120 }
121 #endif
122 
123 #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
124 extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
125 #else
126 static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
127 #endif
128 
129 extern void switch_cop(struct mm_struct *next);
130 extern int use_cop(unsigned long acop, struct mm_struct *mm);
131 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
132 
133 #ifdef CONFIG_PPC_BOOK3S_64
134 static inline void inc_mm_active_cpus(struct mm_struct *mm)
135 {
136 	atomic_inc(&mm->context.active_cpus);
137 }
138 
139 static inline void dec_mm_active_cpus(struct mm_struct *mm)
140 {
141 	atomic_dec(&mm->context.active_cpus);
142 }
143 
144 static inline void mm_context_add_copro(struct mm_struct *mm)
145 {
146 	/*
147 	 * If any copro is in use, increment the active CPU count
148 	 * in order to force TLB invalidations to be global as to
149 	 * propagate to the Nest MMU.
150 	 */
151 	if (atomic_inc_return(&mm->context.copros) == 1)
152 		inc_mm_active_cpus(mm);
153 }
154 
155 static inline void mm_context_remove_copro(struct mm_struct *mm)
156 {
157 	int c;
158 
159 	/*
160 	 * When removing the last copro, we need to broadcast a global
161 	 * flush of the full mm, as the next TLBI may be local and the
162 	 * nMMU and/or PSL need to be cleaned up.
163 	 *
164 	 * Both the 'copros' and 'active_cpus' counts are looked at in
165 	 * flush_all_mm() to determine the scope (local/global) of the
166 	 * TLBIs, so we need to flush first before decrementing
167 	 * 'copros'. If this API is used by several callers for the
168 	 * same context, it can lead to over-flushing. It's hopefully
169 	 * not common enough to be a problem.
170 	 *
171 	 * Skip on hash, as we don't know how to do the proper flush
172 	 * for the time being. Invalidations will remain global if
173 	 * used on hash. Note that we can't drop 'copros' either, as
174 	 * it could make some invalidations local with no flush
175 	 * in-between.
176 	 */
177 	if (radix_enabled()) {
178 		flush_all_mm(mm);
179 
180 		c = atomic_dec_if_positive(&mm->context.copros);
181 		/* Detect imbalance between add and remove */
182 		WARN_ON(c < 0);
183 
184 		if (c == 0)
185 			dec_mm_active_cpus(mm);
186 	}
187 }
188 
189 /*
190  * vas_windows counter shows number of open windows in the mm
191  * context. During context switch, use this counter to clear the
192  * foreign real address mapping (CP_ABORT) for the thread / process
193  * that intend to use COPY/PASTE. When a process closes all windows,
194  * disable CP_ABORT which is expensive to run.
195  *
196  * For user context, register a copro so that TLBIs are seen by the
197  * nest MMU. mm_context_add/remove_vas_window() are used only for user
198  * space windows.
199  */
200 static inline void mm_context_add_vas_window(struct mm_struct *mm)
201 {
202 	atomic_inc(&mm->context.vas_windows);
203 	mm_context_add_copro(mm);
204 }
205 
206 static inline void mm_context_remove_vas_window(struct mm_struct *mm)
207 {
208 	int v;
209 
210 	mm_context_remove_copro(mm);
211 	v = atomic_dec_if_positive(&mm->context.vas_windows);
212 
213 	/* Detect imbalance between add and remove */
214 	WARN_ON(v < 0);
215 }
216 #else
217 static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
218 static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
219 static inline void mm_context_add_copro(struct mm_struct *mm) { }
220 static inline void mm_context_remove_copro(struct mm_struct *mm) { }
221 #endif
222 
223 
224 extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
225 			       struct task_struct *tsk);
226 
227 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
228 			     struct task_struct *tsk)
229 {
230 	unsigned long flags;
231 
232 	local_irq_save(flags);
233 	switch_mm_irqs_off(prev, next, tsk);
234 	local_irq_restore(flags);
235 }
236 #define switch_mm_irqs_off switch_mm_irqs_off
237 
238 
239 #define deactivate_mm(tsk,mm)	do { } while (0)
240 
241 /*
242  * After we have set current->mm to a new value, this activates
243  * the context for the new mm so we see the new mappings.
244  */
245 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
246 {
247 	switch_mm(prev, next, current);
248 }
249 
250 /* We don't currently use enter_lazy_tlb() for anything */
251 static inline void enter_lazy_tlb(struct mm_struct *mm,
252 				  struct task_struct *tsk)
253 {
254 	/* 64-bit Book3E keeps track of current PGD in the PACA */
255 #ifdef CONFIG_PPC_BOOK3E_64
256 	get_paca()->pgd = NULL;
257 #endif
258 }
259 
260 extern void arch_exit_mmap(struct mm_struct *mm);
261 
262 static inline void arch_unmap(struct mm_struct *mm,
263 			      unsigned long start, unsigned long end)
264 {
265 	if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
266 		mm->context.vdso_base = 0;
267 }
268 
269 #ifdef CONFIG_PPC_MEM_KEYS
270 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
271 			       bool execute, bool foreign);
272 void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm);
273 #else /* CONFIG_PPC_MEM_KEYS */
274 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
275 		bool write, bool execute, bool foreign)
276 {
277 	/* by default, allow everything */
278 	return true;
279 }
280 
281 #define pkey_mm_init(mm)
282 #define thread_pkey_regs_save(thread)
283 #define thread_pkey_regs_restore(new_thread, old_thread)
284 #define thread_pkey_regs_init(thread)
285 #define arch_dup_pkeys(oldmm, mm)
286 
287 static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
288 {
289 	return 0x0UL;
290 }
291 
292 #endif /* CONFIG_PPC_MEM_KEYS */
293 
294 static inline int arch_dup_mmap(struct mm_struct *oldmm,
295 				struct mm_struct *mm)
296 {
297 	arch_dup_pkeys(oldmm, mm);
298 	return 0;
299 }
300 
301 #endif /* __KERNEL__ */
302 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
303