xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision 906fd46a65383cd639e5eec72a047efc33045d86)
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 extern int use_cop(unsigned long acop, struct mm_struct *mm);
120 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
121 
122 #ifdef CONFIG_PPC_BOOK3S_64
123 static inline void inc_mm_active_cpus(struct mm_struct *mm)
124 {
125 	atomic_inc(&mm->context.active_cpus);
126 }
127 
128 static inline void dec_mm_active_cpus(struct mm_struct *mm)
129 {
130 	VM_WARN_ON_ONCE(atomic_read(&mm->context.active_cpus) <= 0);
131 	atomic_dec(&mm->context.active_cpus);
132 }
133 
134 static inline void mm_context_add_copro(struct mm_struct *mm)
135 {
136 	/*
137 	 * If any copro is in use, increment the active CPU count
138 	 * in order to force TLB invalidations to be global as to
139 	 * propagate to the Nest MMU.
140 	 */
141 	if (atomic_inc_return(&mm->context.copros) == 1)
142 		inc_mm_active_cpus(mm);
143 }
144 
145 static inline void mm_context_remove_copro(struct mm_struct *mm)
146 {
147 	int c;
148 
149 	/*
150 	 * When removing the last copro, we need to broadcast a global
151 	 * flush of the full mm, as the next TLBI may be local and the
152 	 * nMMU and/or PSL need to be cleaned up.
153 	 *
154 	 * Both the 'copros' and 'active_cpus' counts are looked at in
155 	 * radix__flush_all_mm() to determine the scope (local/global)
156 	 * of the TLBIs, so we need to flush first before decrementing
157 	 * 'copros'. If this API is used by several callers for the
158 	 * same context, it can lead to over-flushing. It's hopefully
159 	 * not common enough to be a problem.
160 	 *
161 	 * Skip on hash, as we don't know how to do the proper flush
162 	 * for the time being. Invalidations will remain global if
163 	 * used on hash. Note that we can't drop 'copros' either, as
164 	 * it could make some invalidations local with no flush
165 	 * in-between.
166 	 */
167 	if (radix_enabled()) {
168 		radix__flush_all_mm(mm);
169 
170 		c = atomic_dec_if_positive(&mm->context.copros);
171 		/* Detect imbalance between add and remove */
172 		WARN_ON(c < 0);
173 
174 		if (c == 0)
175 			dec_mm_active_cpus(mm);
176 	}
177 }
178 
179 /*
180  * vas_windows counter shows number of open windows in the mm
181  * context. During context switch, use this counter to clear the
182  * foreign real address mapping (CP_ABORT) for the thread / process
183  * that intend to use COPY/PASTE. When a process closes all windows,
184  * disable CP_ABORT which is expensive to run.
185  *
186  * For user context, register a copro so that TLBIs are seen by the
187  * nest MMU. mm_context_add/remove_vas_window() are used only for user
188  * space windows.
189  */
190 static inline void mm_context_add_vas_window(struct mm_struct *mm)
191 {
192 	atomic_inc(&mm->context.vas_windows);
193 	mm_context_add_copro(mm);
194 }
195 
196 static inline void mm_context_remove_vas_window(struct mm_struct *mm)
197 {
198 	int v;
199 
200 	mm_context_remove_copro(mm);
201 	v = atomic_dec_if_positive(&mm->context.vas_windows);
202 
203 	/* Detect imbalance between add and remove */
204 	WARN_ON(v < 0);
205 }
206 #else
207 static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
208 static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
209 static inline void mm_context_add_copro(struct mm_struct *mm) { }
210 static inline void mm_context_remove_copro(struct mm_struct *mm) { }
211 #endif
212 
213 #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
214 void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
215 			     unsigned long type, unsigned long pg_sizes,
216 			     unsigned long start, unsigned long end);
217 #else
218 static inline void do_h_rpt_invalidate_prt(unsigned long pid,
219 					   unsigned long lpid,
220 					   unsigned long type,
221 					   unsigned long pg_sizes,
222 					   unsigned long start,
223 					   unsigned long end) { }
224 #endif
225 
226 extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
227 			       struct task_struct *tsk);
228 
229 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
230 			     struct task_struct *tsk)
231 {
232 	unsigned long flags;
233 
234 	local_irq_save(flags);
235 	switch_mm_irqs_off(prev, next, tsk);
236 	local_irq_restore(flags);
237 }
238 #define switch_mm_irqs_off switch_mm_irqs_off
239 
240 /*
241  * After we have set current->mm to a new value, this activates
242  * the context for the new mm so we see the new mappings.
243  */
244 #define activate_mm activate_mm
245 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
246 {
247 	switch_mm_irqs_off(prev, next, current);
248 }
249 
250 /* We don't currently use enter_lazy_tlb() for anything */
251 #ifdef CONFIG_PPC_BOOK3E_64
252 #define enter_lazy_tlb enter_lazy_tlb
253 static inline void enter_lazy_tlb(struct mm_struct *mm,
254 				  struct task_struct *tsk)
255 {
256 	/* 64-bit Book3E keeps track of current PGD in the PACA */
257 	get_paca()->pgd = NULL;
258 }
259 #endif
260 
261 extern void arch_exit_mmap(struct mm_struct *mm);
262 
263 static inline void arch_unmap(struct mm_struct *mm,
264 			      unsigned long start, unsigned long end)
265 {
266 	unsigned long vdso_base = (unsigned long)mm->context.vdso;
267 
268 	if (start <= vdso_base && vdso_base < end)
269 		mm->context.vdso = NULL;
270 }
271 
272 #ifdef CONFIG_PPC_MEM_KEYS
273 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
274 			       bool execute, bool foreign);
275 void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm);
276 #else /* CONFIG_PPC_MEM_KEYS */
277 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
278 		bool write, bool execute, bool foreign)
279 {
280 	/* by default, allow everything */
281 	return true;
282 }
283 
284 #define pkey_mm_init(mm)
285 #define arch_dup_pkeys(oldmm, mm)
286 
287 static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
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 #include <asm-generic/mmu_context.h>
302 
303 #endif /* __KERNEL__ */
304 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
305