mmu_context.h

  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
 18extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
 19#define destroy_context destroy_context
 20extern void destroy_context(struct mm_struct *mm);
 21#ifdef CONFIG_SPAPR_TCE_IOMMU
 22struct mm_iommu_table_group_mem_t;
 23
 24extern bool mm_iommu_preregistered(struct mm_struct *mm);
 25extern long mm_iommu_new(struct mm_struct *mm,
 26		unsigned long ua, unsigned long entries,
 27		struct mm_iommu_table_group_mem_t **pmem);
 28extern 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);
 31extern long mm_iommu_put(struct mm_struct *mm,
 32		struct mm_iommu_table_group_mem_t *mem);
 33extern void mm_iommu_init(struct mm_struct *mm);
 34extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
 35		unsigned long ua, unsigned long size);
 36extern struct mm_iommu_table_group_mem_t *mm_iommu_get(struct mm_struct *mm,
 37		unsigned long ua, unsigned long entries);
 38extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
 39		unsigned long ua, unsigned int pageshift, unsigned long *hpa);
 40extern bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
 41		unsigned int pageshift, unsigned long *size);
 42extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
 43extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
 44#else
 45static 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}
 50static inline void mm_iommu_init(struct mm_struct *mm) { }
 51#endif
 52extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
 53
 54#ifdef CONFIG_PPC_BOOK3S_64
 55extern void radix__switch_mmu_context(struct mm_struct *prev,
 56				      struct mm_struct *next);
 57static 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
 66extern int hash__alloc_context_id(void);
 67void __init hash__reserve_context_id(int id);
 68extern void __destroy_context(int context_id);
 69static inline void mmu_context_init(void) { }
 70
 71#ifdef CONFIG_PPC_64S_HASH_MMU
 72static 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
 88static 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
100extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
101			       struct task_struct *tsk);
102extern unsigned long __init_new_context(void);
103extern void __destroy_context(unsigned long context_id);
104extern void mmu_context_init(void);
105static 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
113static 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
120static inline void inc_mm_active_cpus(struct mm_struct *mm)
121{
122	atomic_inc(&mm->context.active_cpus);
123}
124
125static 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
131static 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
142static 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 */
187static 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
193static 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
204static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
205static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
206static inline void mm_context_add_copro(struct mm_struct *mm) { }
207static 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)
211void 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
215static 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
223extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
224			       struct task_struct *tsk);
225
226static 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
242static 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
250static 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
258extern void arch_exit_mmap(struct mm_struct *mm);
259
260#ifdef CONFIG_PPC_MEM_KEYS
261bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
262			       bool execute, bool foreign);
263void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm);
264#else /* CONFIG_PPC_MEM_KEYS */
265static 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
275static 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
282static 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 */