drivers/misc/vmw_vmci/vmci_handle_array.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VMware VMCI Driver
   4  *
   5  * Copyright (C) 2012 VMware, Inc. All rights reserved.
   6  */
   7
   8 #include <linux/slab.h>
   9 #include "vmci_handle_array.h"
  10
  11 static size_t handle_arr_calc_size(size_t capacity)
  12 {
  13         return sizeof(struct vmci_handle_arr) +
  14             capacity * sizeof(struct vmci_handle);
  15 }
  16
  17 struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity)
  18 {
  19         struct vmci_handle_arr *array;
  20
  21         if (capacity == 0)
  22                 capacity = VMCI_HANDLE_ARRAY_DEFAULT_SIZE;
  23
  24         array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
  25         if (!array)
  26                 return NULL;
  27
  28         array->capacity = capacity;
  29         array->size = 0;
  30
  31         return array;
  32 }
  33
  34 void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
  35 {
  36         kfree(array);
  37 }
  38
  39 void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
  40                                   struct vmci_handle handle)
  41 {
  42         struct vmci_handle_arr *array = *array_ptr;
  43
  44         if (unlikely(array->size >= array->capacity)) {
  45                 /* reallocate. */
  46                 struct vmci_handle_arr *new_array;
  47                 size_t new_capacity = array->capacity * VMCI_ARR_CAP_MULT;
  48                 size_t new_size = handle_arr_calc_size(new_capacity);
  49
  50                 new_array = krealloc(array, new_size, GFP_ATOMIC);
  51                 if (!new_array)
  52                         return;
  53
  54                 new_array->capacity = new_capacity;
  55                 *array_ptr = array = new_array;
  56         }
  57
  58         array->entries[array->size] = handle;
  59         array->size++;
  60 }
  61
  62 /*
  63  * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
  64  */
  65 struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
  66                                                 struct vmci_handle entry_handle)
  67 {
  68         struct vmci_handle handle = VMCI_INVALID_HANDLE;
  69         size_t i;
  70
  71         for (i = 0; i < array->size; i++) {
  72                 if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
  73                         handle = array->entries[i];
  74                         array->size--;
  75                         array->entries[i] = array->entries[array->size];
  76                         array->entries[array->size] = VMCI_INVALID_HANDLE;
  77                         break;
  78                 }
  79         }
  80
  81         return handle;
  82 }
  83
  84 /*
  85  * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
  86  */
  87 struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
  88 {
  89         struct vmci_handle handle = VMCI_INVALID_HANDLE;
  90
  91         if (array->size) {
  92                 array->size--;
  93                 handle = array->entries[array->size];
  94                 array->entries[array->size] = VMCI_INVALID_HANDLE;
  95         }
  96
  97         return handle;
  98 }
  99
 100 /*
 101  * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
 102  */
 103 struct vmci_handle
 104 vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index)
 105 {
 106         if (unlikely(index >= array->size))
 107                 return VMCI_INVALID_HANDLE;
 108
 109         return array->entries[index];
 110 }
 111
 112 bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
 113                                struct vmci_handle entry_handle)
 114 {
 115         size_t i;
 116
 117         for (i = 0; i < array->size; i++)
 118                 if (vmci_handle_is_equal(array->entries[i], entry_handle))
 119                         return true;
 120
 121         return false;
 122 }
 123
 124 /*
 125  * NULL if the array is empty. Otherwise, a pointer to the array
 126  * of VMCI handles in the handle array.
 127  */
 128 struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
 129 {
 130         if (array->size)
 131                 return array->entries;
 132
 133         return NULL;
 134 }