drivers/infiniband/hw/hfi1/mmu_rb.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
   2 /*
   3  * Copyright(c) 2020 Cornelis Networks, Inc.
   4  * Copyright(c) 2016 Intel Corporation.
   5  */
   6
   7 #ifndef _HFI1_MMU_RB_H
   8 #define _HFI1_MMU_RB_H
   9
  10 #include "hfi.h"
  11
  12 struct mmu_rb_node {
  13         unsigned long addr;
  14         unsigned long len;
  15         unsigned long __last;
  16         struct rb_node node;
  17         struct mmu_rb_handler *handler;
  18         struct list_head list;
  19         struct kref refcount;
  20 };
  21
  22 /* filter and evict must not sleep. Only remove is allowed to sleep. */
  23 struct mmu_rb_ops {
  24         bool (*filter)(struct mmu_rb_node *node, unsigned long addr,
  25                        unsigned long len);
  26         void (*remove)(void *ops_arg, struct mmu_rb_node *mnode);
  27         int (*evict)(void *ops_arg, struct mmu_rb_node *mnode,
  28                      void *evict_arg, bool *stop);
  29 };
  30
  31 struct mmu_rb_handler {
  32         /*
  33          * struct mmu_notifier is 56 bytes, and spinlock_t is 4 bytes, so
  34          * they fit together in one cache line.  mn is relatively rarely
  35          * accessed, so co-locating the spinlock with it achieves much of
  36          * the cacheline contention reduction of giving the spinlock its own
  37          * cacheline without the overhead of doing so.
  38          */
  39         struct mmu_notifier mn;
  40         spinlock_t lock;        /* protect the RB tree */
  41
  42         /* Begin on a new cachline boundary here */
  43         struct rb_root_cached root ____cacheline_aligned_in_smp;
  44         void *ops_arg;
  45         const struct mmu_rb_ops *ops;
  46         struct list_head lru_list;
  47         struct work_struct del_work;
  48         struct list_head del_list;
  49         struct workqueue_struct *wq;
  50         void *free_ptr;
  51 };
  52
  53 int hfi1_mmu_rb_register(void *ops_arg,
  54                          const struct mmu_rb_ops *ops,
  55                          struct workqueue_struct *wq,
  56                          struct mmu_rb_handler **handler);
  57 void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler);
  58 int hfi1_mmu_rb_insert(struct mmu_rb_handler *handler,
  59                        struct mmu_rb_node *mnode);
  60 void hfi1_mmu_rb_release(struct kref *refcount);
  61
  62 void hfi1_mmu_rb_evict(struct mmu_rb_handler *handler, void *evict_arg);
  63 struct mmu_rb_node *hfi1_mmu_rb_get_first(struct mmu_rb_handler *handler,
  64                                           unsigned long addr,
  65                                           unsigned long len);
  66
  67 #endif /* _HFI1_MMU_RB_H */