text: /* SPDX-License-Identifier: GPL-2.0 */
  #ifndef __ASM_POWERPC_MMU_CONTEXT_H
  #define __ASM_POWERPC_MMU_CONTEXT_H
  #ifdef __KERNEL__
  
  #include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/sched.h>
  #include <linux/spinlock.h>
  #include <asm/mmu.h>	
  #include <asm/cputable.h>
  #include <asm/cputhreads.h>
  
  /*
   * Most if the context management is out of line
   */
  extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  extern void destroy_context(struct mm_struct *mm);
  #ifdef CONFIG_SPAPR_TCE_IOMMU
  struct mm_iommu_table_group_mem_t;
  
  extern int isolate_lru_page(struct page *page);	/* from internal.h */
  extern bool mm_iommu_preregistered(struct mm_struct *mm);
  extern long mm_iommu_get(struct mm_struct *mm,
  		unsigned long ua, unsigned long entries,
  		struct mm_iommu_table_group_mem_t **pmem);
  extern long mm_iommu_put(struct mm_struct *mm,
  		struct mm_iommu_table_group_mem_t *mem);
  extern void mm_iommu_init(struct mm_struct *mm);
  extern void mm_iommu_cleanup(struct mm_struct *mm);
  extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
  		unsigned long ua, unsigned long size);
  extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(
  		struct mm_struct *mm, unsigned long ua, unsigned long size);
  extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
  		unsigned long ua, unsigned long entries);
  extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
  		unsigned long ua, unsigned long *hpa);
  extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
  		unsigned long ua, unsigned long *hpa);
  extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
  extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
  #endif
  extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
  extern void set_context(unsigned long id, pgd_t *pgd);
  
  #ifdef CONFIG_PPC_BOOK3S_64
  extern void radix__switch_mmu_context(struct mm_struct *prev,
  				      struct mm_struct *next);
  static inline void switch_mmu_context(struct mm_struct *prev,
  				      struct mm_struct *next,
  				      struct task_struct *tsk)
  {
  	if (radix_enabled())
  		return radix__switch_mmu_context(prev, next);
  	return switch_slb(tsk, next);
  }
  
  extern int hash__alloc_context_id(void);
  extern void hash__reserve_context_id(int id);
  extern void __destroy_context(int context_id);
  static inline void mmu_context_init(void) { }
  #else
  extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
  			       struct task_struct *tsk);
  extern unsigned long __init_new_context(void);
  extern void __destroy_context(unsigned long context_id);
  extern void mmu_context_init(void);
  #endif
  
  #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
  extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
  #else
  static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
  #endif
  
  extern void switch_cop(struct mm_struct *next);
  extern int use_cop(unsigned long acop, struct mm_struct *mm);
  extern void drop_cop(unsigned long acop, struct mm_struct *mm);
  
  extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
  			       struct task_struct *tsk);
  
  static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  			     struct task_struct *tsk)
  {
  	unsigned long flags;
  
  	local_irq_save(flags);
  	switch_mm_irqs_off(prev, next, tsk);
  	local_irq_restore(flags);
  }
  #define switch_mm_irqs_off switch_mm_irqs_off
  
  
  #define deactivate_mm(tsk,mm)	do { } while (0)
  
  /*
   * After we have set current->mm to a new value, this activates
   * the context for the new mm so we see the new mappings.
   */
  static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  {
  	switch_mm(prev, next, current);
  }
  
  /* We don't currently use enter_lazy_tlb() for anything */
  static inline void enter_lazy_tlb(struct mm_struct *mm,
  				  struct task_struct *tsk)
  {
  	/* 64-bit Book3E keeps track of current PGD in the PACA */
  #ifdef CONFIG_PPC_BOOK3E_64
  	get_paca()->pgd = NULL;
  #endif
  }
  
  static inline int arch_dup_mmap(struct mm_struct *oldmm,
  				struct mm_struct *mm)
  {
  	return 0;
  }
  
  static inline void arch_exit_mmap(struct mm_struct *mm)
  {
  }
  
  static inline void arch_unmap(struct mm_struct *mm,
  			      struct vm_area_struct *vma,
  			      unsigned long start, unsigned long end)
  {
  	if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
  		mm->context.vdso_base = 0;
  }
  
  static inline void arch_bprm_mm_init(struct mm_struct *mm,
  				     struct vm_area_struct *vma)
  {
  }
  
  static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
  		bool write, bool execute, bool foreign)
  {
  	/* by default, allow everything */
  	return true;
  }
  #endif /* __KERNEL__ */
  #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
  