text: /* SPDX-License-Identifier: GPL-2.0 */
  /*
   *  KVM guest address space mapping code
   *
   *    Copyright IBM Corp. 2007, 2016
   *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   */
  
  #ifndef _ASM_S390_GMAP_H
  #define _ASM_S390_GMAP_H
  
  #include <linux/radix-tree.h>
  #include <linux/refcount.h>
  
  /* Generic bits for GMAP notification on DAT table entry changes. */
  #define GMAP_NOTIFY_SHADOW	0x2
  #define GMAP_NOTIFY_MPROT	0x1
  
  /* Status bits only for huge segment entries */
  #define _SEGMENT_ENTRY_GMAP_IN		0x8000	/* invalidation notify bit */
  #define _SEGMENT_ENTRY_GMAP_UC		0x4000	/* dirty (migration) */
  
  /**
   * struct gmap_struct - guest address space
   * @list: list head for the mm->context gmap list
   * @crst_list: list of all crst tables used in the guest address space
   * @mm: pointer to the parent mm_struct
   * @guest_to_host: radix tree with guest to host address translation
   * @host_to_guest: radix tree with pointer to segment table entries
   * @guest_table_lock: spinlock to protect all entries in the guest page table
   * @ref_count: reference counter for the gmap structure
   * @table: pointer to the page directory
   * @asce: address space control element for gmap page table
   * @pfault_enabled: defines if pfaults are applicable for the guest
   * @guest_handle: protected virtual machine handle for the ultravisor
   * @host_to_rmap: radix tree with gmap_rmap lists
   * @children: list of shadow gmap structures
   * @pt_list: list of all page tables used in the shadow guest address space
   * @shadow_lock: spinlock to protect the shadow gmap list
   * @parent: pointer to the parent gmap for shadow guest address spaces
   * @orig_asce: ASCE for which the shadow page table has been created
   * @edat_level: edat level to be used for the shadow translation
   * @removed: flag to indicate if a shadow guest address space has been removed
   * @initialized: flag to indicate if a shadow guest address space can be used
   */
  struct gmap {
  	struct list_head list;
  	struct list_head crst_list;
  	struct mm_struct *mm;
  	struct radix_tree_root guest_to_host;
  	struct radix_tree_root host_to_guest;
  	spinlock_t guest_table_lock;
  	refcount_t ref_count;
  	unsigned long *table;
  	unsigned long asce;
  	unsigned long asce_end;
  	void *private;
  	bool pfault_enabled;
  	/* only set for protected virtual machines */
  	unsigned long guest_handle;
  	/* Additional data for shadow guest address spaces */
  	struct radix_tree_root host_to_rmap;
  	struct list_head children;
  	struct list_head pt_list;
  	spinlock_t shadow_lock;
  	struct gmap *parent;
  	unsigned long orig_asce;
  	int edat_level;
  	bool removed;
  	bool initialized;
  };
  
  /**
   * struct gmap_rmap - reverse mapping for shadow page table entries
   * @next: pointer to next rmap in the list
   * @raddr: virtual rmap address in the shadow guest address space
   */
  struct gmap_rmap {
  	struct gmap_rmap *next;
  	unsigned long raddr;
  };
  
  #define gmap_for_each_rmap(pos, head) \
  	for (pos = (head); pos; pos = pos->next)
  
  #define gmap_for_each_rmap_safe(pos, n, head) \
  	for (pos = (head); n = pos ? pos->next : NULL, pos; pos = n)
  
  /**
   * struct gmap_notifier - notify function block for page invalidation
   * @notifier_call: address of callback function
   */
  struct gmap_notifier {
  	struct list_head list;
  	struct rcu_head rcu;
  	void (*notifier_call)(struct gmap *gmap, unsigned long start,
  			      unsigned long end);
  };
  
  static inline int gmap_is_shadow(struct gmap *gmap)
  {
  	return !!gmap->parent;
  }
  
  struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
  void gmap_remove(struct gmap *gmap);
  struct gmap *gmap_get(struct gmap *gmap);
  void gmap_put(struct gmap *gmap);
  
  void gmap_enable(struct gmap *gmap);
  void gmap_disable(struct gmap *gmap);
  struct gmap *gmap_get_enabled(void);
  int gmap_map_segment(struct gmap *gmap, unsigned long from,
  		     unsigned long to, unsigned long len);
  int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
  unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
  unsigned long gmap_translate(struct gmap *, unsigned long gaddr);
  int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
  int gmap_fault(struct gmap *, unsigned long gaddr, unsigned int fault_flags);
  void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
  void __gmap_zap(struct gmap *, unsigned long gaddr);
  void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
  
  int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
  
  struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
  			 int edat_level);
  int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level);
  int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
  		    int fake);
  int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
  		    int fake);
  int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
  		    int fake);
  int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
  		    int fake);
  int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
  			   unsigned long *pgt, int *dat_protection, int *fake);
  int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
  
  void gmap_register_pte_notifier(struct gmap_notifier *);
  void gmap_unregister_pte_notifier(struct gmap_notifier *);
  void gmap_pte_notify(struct mm_struct *, unsigned long addr, pte_t *,
  		     unsigned long bits);
  
  int gmap_mprotect_notify(struct gmap *, unsigned long start,
  			 unsigned long len, int prot);
  
  void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
  			     unsigned long gaddr, unsigned long vmaddr);
  int gmap_mark_unmergeable(void);
  void s390_reset_acc(struct mm_struct *mm);
  #endif /* _ASM_S390_GMAP_H */
  