xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision a1ea0ca8a6f17d7b79bbc4d05dd4e6ca162d8f15)
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 #define init_new_context init_new_context
18 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
19 #define destroy_context destroy_context
20 extern void destroy_context(struct mm_struct *mm);
21 #ifdef CONFIG_SPAPR_TCE_IOMMU
22 struct mm_iommu_table_group_mem_t;
23 
24 extern int isolate_lru_page(struct page *page);	/* from internal.h */
25 extern bool mm_iommu_preregistered(struct mm_struct *mm);
26 extern long mm_iommu_new(struct mm_struct *mm,
27 		unsigned long ua, unsigned long entries,
28 		struct mm_iommu_table_group_mem_t **pmem);
29 extern long mm_iommu_newdev(struct mm_struct *mm, unsigned long ua,
30 		unsigned long entries, unsigned long dev_hpa,
31 		struct mm_iommu_table_group_mem_t **pmem);
32 extern long mm_iommu_put(struct mm_struct *mm,
33 		struct mm_iommu_table_group_mem_t *mem);
34 extern void mm_iommu_init(struct mm_struct *mm);
35 extern void mm_iommu_cleanup(struct mm_struct *mm);
36 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
37 		unsigned long ua, unsigned long size);
38 extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(
39 		struct mm_struct *mm, unsigned long ua, unsigned long size);
40 extern struct mm_iommu_table_group_mem_t *mm_iommu_get(struct mm_struct *mm,
41 		unsigned long ua, unsigned long entries);
42 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
43 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
44 extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
45 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
46 extern void mm_iommu_ua_mark_dirty_rm(struct mm_struct *mm, unsigned long ua);
47 extern bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
48 		unsigned int pageshift, unsigned long *size);
49 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
50 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
51 #else
52 static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
53 		unsigned int pageshift, unsigned long *size)
54 {
55 	return false;
56 }
57 static inline void mm_iommu_init(struct mm_struct *mm) { }
58 #endif
59 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
60 
61 #ifdef CONFIG_PPC_BOOK3S_64
62 extern void radix__switch_mmu_context(struct mm_struct *prev,
63 				      struct mm_struct *next);
64 static inline void switch_mmu_context(struct mm_struct *prev,
65 				      struct mm_struct *next,
66 				      struct task_struct *tsk)
67 {
68 	if (radix_enabled())
69 		return radix__switch_mmu_context(prev, next);
70 	return switch_slb(tsk, next);
71 }
72 
73 extern int hash__alloc_context_id(void);
74 extern void hash__reserve_context_id(int id);
75 extern void __destroy_context(int context_id);
76 static inline void mmu_context_init(void) { }
77 
78 static inline int alloc_extended_context(struct mm_struct *mm,
79 					 unsigned long ea)
80 {
81 	int context_id;
82 
83 	int index = ea >> MAX_EA_BITS_PER_CONTEXT;
84 
85 	context_id = hash__alloc_context_id();
86 	if (context_id < 0)
87 		return context_id;
88 
89 	VM_WARN_ON(mm->context.extended_id[index]);
90 	mm->context.extended_id[index] = context_id;
91 	return context_id;
92 }
93 
94 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
95 {
96 	int context_id;
97 
98 	context_id = get_user_context(&mm->context, ea);
99 	if (!context_id)
100 		return true;
101 	return false;
102 }
103 
104 #else
105 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
106 			       struct task_struct *tsk);
107 extern unsigned long __init_new_context(void);
108 extern void __destroy_context(unsigned long context_id);
109 extern void mmu_context_init(void);
110 static inline int alloc_extended_context(struct mm_struct *mm,
111 					 unsigned long ea)
112 {
113 	/* non book3s_64 should never find this called */
114 	WARN_ON(1);
115 	return -ENOMEM;
116 }
117 
118 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
119 {
120 	return false;
121 }
122 #endif
123 
124 #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
125 extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
126 #else
127 static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
128 #endif
129 
130 extern void switch_cop(struct mm_struct *next);
131 extern int use_cop(unsigned long acop, struct mm_struct *mm);
132 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
133 
134 #ifdef CONFIG_PPC_BOOK3S_64
135 static inline void inc_mm_active_cpus(struct mm_struct *mm)
136 {
137 	atomic_inc(&mm->context.active_cpus);
138 }
139 
140 static inline void dec_mm_active_cpus(struct mm_struct *mm)
141 {
142 	atomic_dec(&mm->context.active_cpus);
143 }
144 
145 static inline void mm_context_add_copro(struct mm_struct *mm)
146 {
147 	/*
148 	 * If any copro is in use, increment the active CPU count
149 	 * in order to force TLB invalidations to be global as to
150 	 * propagate to the Nest MMU.
151 	 */
152 	if (atomic_inc_return(&mm->context.copros) == 1)
153 		inc_mm_active_cpus(mm);
154 }
155 
156 static inline void mm_context_remove_copro(struct mm_struct *mm)
157 {
158 	int c;
159 
160 	/*
161 	 * When removing the last copro, we need to broadcast a global
162 	 * flush of the full mm, as the next TLBI may be local and the
163 	 * nMMU and/or PSL need to be cleaned up.
164 	 *
165 	 * Both the 'copros' and 'active_cpus' counts are looked at in
166 	 * flush_all_mm() to determine the scope (local/global) of the
167 	 * TLBIs, so we need to flush first before decrementing
168 	 * 'copros'. If this API is used by several callers for the
169 	 * same context, it can lead to over-flushing. It's hopefully
170 	 * not common enough to be a problem.
171 	 *
172 	 * Skip on hash, as we don't know how to do the proper flush
173 	 * for the time being. Invalidations will remain global if
174 	 * used on hash. Note that we can't drop 'copros' either, as
175 	 * it could make some invalidations local with no flush
176 	 * in-between.
177 	 */
178 	if (radix_enabled()) {
179 		flush_all_mm(mm);
180 
181 		c = atomic_dec_if_positive(&mm->context.copros);
182 		/* Detect imbalance between add and remove */
183 		WARN_ON(c < 0);
184 
185 		if (c == 0)
186 			dec_mm_active_cpus(mm);
187 	}
188 }
189 
190 /*
191  * vas_windows counter shows number of open windows in the mm
192  * context. During context switch, use this counter to clear the
193  * foreign real address mapping (CP_ABORT) for the thread / process
194  * that intend to use COPY/PASTE. When a process closes all windows,
195  * disable CP_ABORT which is expensive to run.
196  *
197  * For user context, register a copro so that TLBIs are seen by the
198  * nest MMU. mm_context_add/remove_vas_window() are used only for user
199  * space windows.
200  */
201 static inline void mm_context_add_vas_window(struct mm_struct *mm)
202 {
203 	atomic_inc(&mm->context.vas_windows);
204 	mm_context_add_copro(mm);
205 }
206 
207 static inline void mm_context_remove_vas_window(struct mm_struct *mm)
208 {
209 	int v;
210 
211 	mm_context_remove_copro(mm);
212 	v = atomic_dec_if_positive(&mm->context.vas_windows);
213 
214 	/* Detect imbalance between add and remove */
215 	WARN_ON(v < 0);
216 }
217 #else
218 static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
219 static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
220 static inline void mm_context_add_copro(struct mm_struct *mm) { }
221 static inline void mm_context_remove_copro(struct mm_struct *mm) { }
222 #endif
223 
224 
225 extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
226 			       struct task_struct *tsk);
227 
228 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
229 			     struct task_struct *tsk)
230 {
231 	unsigned long flags;
232 
233 	local_irq_save(flags);
234 	switch_mm_irqs_off(prev, next, tsk);
235 	local_irq_restore(flags);
236 }
237 #define switch_mm_irqs_off switch_mm_irqs_off
238 
239 /*
240  * After we have set current->mm to a new value, this activates
241  * the context for the new mm so we see the new mappings.
242  */
243 #define activate_mm activate_mm
244 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
245 {
246 	switch_mm_irqs_off(prev, next, current);
247 }
248 
249 /* We don't currently use enter_lazy_tlb() for anything */
250 #ifdef CONFIG_PPC_BOOK3E_64
251 #define enter_lazy_tlb enter_lazy_tlb
252 static inline void enter_lazy_tlb(struct mm_struct *mm,
253 				  struct task_struct *tsk)
254 {
255 	/* 64-bit Book3E keeps track of current PGD in the PACA */
256 	get_paca()->pgd = NULL;
257 }
258 #endif
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 	unsigned long vdso_base = (unsigned long)mm->context.vdso;
266 
267 	if (start <= vdso_base && vdso_base < end)
268 		mm->context.vdso = NULL;
269 }
270 
271 #ifdef CONFIG_PPC_MEM_KEYS
272 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
273 			       bool execute, bool foreign);
274 void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm);
275 #else /* CONFIG_PPC_MEM_KEYS */
276 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
277 		bool write, bool execute, bool foreign)
278 {
279 	/* by default, allow everything */
280 	return true;
281 }
282 
283 #define pkey_mm_init(mm)
284 #define arch_dup_pkeys(oldmm, mm)
285 
286 static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
287 {
288 	return 0x0UL;
289 }
290 
291 #endif /* CONFIG_PPC_MEM_KEYS */
292 
293 static inline int arch_dup_mmap(struct mm_struct *oldmm,
294 				struct mm_struct *mm)
295 {
296 	arch_dup_pkeys(oldmm, mm);
297 	return 0;
298 }
299 
300 #include <asm-generic/mmu_context.h>
301 
302 #endif /* __KERNEL__ */
303 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
304