xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision a0efa2f362a69e47b9d8b48f770ef3a0249a7911)
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 bool mm_iommu_preregistered(struct mm_struct *mm);
25 extern long mm_iommu_new(struct mm_struct *mm,
26 		unsigned long ua, unsigned long entries,
27 		struct mm_iommu_table_group_mem_t **pmem);
28 extern long mm_iommu_newdev(struct mm_struct *mm, unsigned long ua,
29 		unsigned long entries, unsigned long dev_hpa,
30 		struct mm_iommu_table_group_mem_t **pmem);
31 extern long mm_iommu_put(struct mm_struct *mm,
32 		struct mm_iommu_table_group_mem_t *mem);
33 extern void mm_iommu_init(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_get(struct mm_struct *mm,
37 		unsigned long ua, unsigned long entries);
38 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
39 		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
40 extern bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
41 		unsigned int pageshift, unsigned long *size);
42 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
43 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
44 #else
45 static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
46 		unsigned int pageshift, unsigned long *size)
47 {
48 	return false;
49 }
50 static inline void mm_iommu_init(struct mm_struct *mm) { }
51 #endif
52 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
53 
54 #ifdef CONFIG_PPC_BOOK3S_64
55 extern void radix__switch_mmu_context(struct mm_struct *prev,
56 				      struct mm_struct *next);
57 static inline void switch_mmu_context(struct mm_struct *prev,
58 				      struct mm_struct *next,
59 				      struct task_struct *tsk)
60 {
61 	if (radix_enabled())
62 		return radix__switch_mmu_context(prev, next);
63 	return switch_slb(tsk, next);
64 }
65 
66 extern int hash__alloc_context_id(void);
67 void __init hash__reserve_context_id(int id);
68 extern void __destroy_context(int context_id);
69 static inline void mmu_context_init(void) { }
70 
71 #ifdef CONFIG_PPC_64S_HASH_MMU
72 static inline int alloc_extended_context(struct mm_struct *mm,
73 					 unsigned long ea)
74 {
75 	int context_id;
76 
77 	int index = ea >> MAX_EA_BITS_PER_CONTEXT;
78 
79 	context_id = hash__alloc_context_id();
80 	if (context_id < 0)
81 		return context_id;
82 
83 	VM_WARN_ON(mm->context.extended_id[index]);
84 	mm->context.extended_id[index] = context_id;
85 	return context_id;
86 }
87 
88 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
89 {
90 	int context_id;
91 
92 	context_id = get_user_context(&mm->context, ea);
93 	if (!context_id)
94 		return true;
95 	return false;
96 }
97 #endif
98 
99 #else
100 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
101 			       struct task_struct *tsk);
102 extern unsigned long __init_new_context(void);
103 extern void __destroy_context(unsigned long context_id);
104 extern void mmu_context_init(void);
105 static inline int alloc_extended_context(struct mm_struct *mm,
106 					 unsigned long ea)
107 {
108 	/* non book3s_64 should never find this called */
109 	WARN_ON(1);
110 	return -ENOMEM;
111 }
112 
113 static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
114 {
115 	return false;
116 }
117 #endif
118 
119 #ifdef CONFIG_PPC_BOOK3S_64
120 static inline void inc_mm_active_cpus(struct mm_struct *mm)
121 {
122 	atomic_inc(&mm->context.active_cpus);
123 }
124 
125 static inline void dec_mm_active_cpus(struct mm_struct *mm)
126 {
127 	VM_WARN_ON_ONCE(atomic_read(&mm->context.active_cpus) <= 0);
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 	 * radix__flush_all_mm() to determine the scope (local/global)
153 	 * of the 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 		radix__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 
176 /*
177  * vas_windows counter shows number of open windows in the mm
178  * context. During context switch, use this counter to clear the
179  * foreign real address mapping (CP_ABORT) for the thread / process
180  * that intend to use COPY/PASTE. When a process closes all windows,
181  * disable CP_ABORT which is expensive to run.
182  *
183  * For user context, register a copro so that TLBIs are seen by the
184  * nest MMU. mm_context_add/remove_vas_window() are used only for user
185  * space windows.
186  */
187 static inline void mm_context_add_vas_window(struct mm_struct *mm)
188 {
189 	atomic_inc(&mm->context.vas_windows);
190 	mm_context_add_copro(mm);
191 }
192 
193 static inline void mm_context_remove_vas_window(struct mm_struct *mm)
194 {
195 	int v;
196 
197 	mm_context_remove_copro(mm);
198 	v = atomic_dec_if_positive(&mm->context.vas_windows);
199 
200 	/* Detect imbalance between add and remove */
201 	WARN_ON(v < 0);
202 }
203 #else
204 static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
205 static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
206 static inline void mm_context_add_copro(struct mm_struct *mm) { }
207 static inline void mm_context_remove_copro(struct mm_struct *mm) { }
208 #endif
209 
210 #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
211 void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
212 			     unsigned long type, unsigned long pg_sizes,
213 			     unsigned long start, unsigned long end);
214 #else
215 static inline void do_h_rpt_invalidate_prt(unsigned long pid,
216 					   unsigned long lpid,
217 					   unsigned long type,
218 					   unsigned long pg_sizes,
219 					   unsigned long start,
220 					   unsigned long end) { }
221 #endif
222 
223 extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
224 			       struct task_struct *tsk);
225 
226 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
227 			     struct task_struct *tsk)
228 {
229 	unsigned long flags;
230 
231 	local_irq_save(flags);
232 	switch_mm_irqs_off(prev, next, tsk);
233 	local_irq_restore(flags);
234 }
235 #define switch_mm_irqs_off switch_mm_irqs_off
236 
237 /*
238  * After we have set current->mm to a new value, this activates
239  * the context for the new mm so we see the new mappings.
240  */
241 #define activate_mm activate_mm
242 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
243 {
244 	switch_mm_irqs_off(prev, next, current);
245 }
246 
247 /* We don't currently use enter_lazy_tlb() for anything */
248 #ifdef CONFIG_PPC_BOOK3E_64
249 #define enter_lazy_tlb enter_lazy_tlb
250 static inline void enter_lazy_tlb(struct mm_struct *mm,
251 				  struct task_struct *tsk)
252 {
253 	/* 64-bit Book3E keeps track of current PGD in the PACA */
254 	get_paca()->pgd = NULL;
255 }
256 #endif
257 
258 extern void arch_exit_mmap(struct mm_struct *mm);
259 
260 #ifdef CONFIG_PPC_MEM_KEYS
261 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
262 			       bool execute, bool foreign);
263 void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm);
264 #else /* CONFIG_PPC_MEM_KEYS */
265 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
266 		bool write, bool execute, bool foreign)
267 {
268 	/* by default, allow everything */
269 	return true;
270 }
271 
272 #define pkey_mm_init(mm)
273 #define arch_dup_pkeys(oldmm, mm)
274 
275 static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
276 {
277 	return 0x0UL;
278 }
279 
280 #endif /* CONFIG_PPC_MEM_KEYS */
281 
282 static inline int arch_dup_mmap(struct mm_struct *oldmm,
283 				struct mm_struct *mm)
284 {
285 	arch_dup_pkeys(oldmm, mm);
286 	return 0;
287 }
288 
289 #include <asm-generic/mmu_context.h>
290 
291 #endif /* __KERNEL__ */
292 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
293