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 struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
  12 {
  13         struct vmci_handle_arr *array;
  14
  15         if (max_capacity == 0 || capacity > max_capacity)
  16                 return NULL;
  17
  18         if (capacity == 0)
  19                 capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
  20                                max_capacity);
  21
  22         array = kmalloc(struct_size(array, entries, capacity), GFP_ATOMIC);
  23         if (!array)
  24                 return NULL;
  25
  26         array->capacity = capacity;
  27         array->max_capacity = max_capacity;
  28         array->size = 0;
  29
  30         return array;
  31 }
  32
  33 void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
  34 {
  35         kfree(array);
  36 }
  37
  38 int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
  39                                  struct vmci_handle handle)
  40 {
  41         struct vmci_handle_arr *array = *array_ptr;
  42
  43         if (unlikely(array->size >= array->capacity)) {
  44                 /* reallocate. */
  45                 struct vmci_handle_arr *new_array;
  46                 u32 capacity_bump = min(array->max_capacity - array->capacity,
  47                                         array->capacity);
  48                 size_t new_size = struct_size(array, entries,
  49                                               size_add(array->capacity, capacity_bump));
  50
  51                 if (array->size >= array->max_capacity)
  52                         return VMCI_ERROR_NO_MEM;
  53
  54                 new_array = krealloc(array, new_size, GFP_ATOMIC);
  55                 if (!new_array)
  56                         return VMCI_ERROR_NO_MEM;
  57
  58                 new_array->capacity += capacity_bump;
  59                 *array_ptr = array = new_array;
  60         }
  61
  62         array->entries[array->size] = handle;
  63         array->size++;
  64
  65         return VMCI_SUCCESS;
  66 }
  67
  68 /*
  69  * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
  70  */
  71 struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
  72                                                 struct vmci_handle entry_handle)
  73 {
  74         struct vmci_handle handle = VMCI_INVALID_HANDLE;
  75         u32 i;
  76
  77         for (i = 0; i < array->size; i++) {
  78                 if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
  79                         handle = array->entries[i];
  80                         array->size--;
  81                         array->entries[i] = array->entries[array->size];
  82                         array->entries[array->size] = VMCI_INVALID_HANDLE;
  83                         break;
  84                 }
  85         }
  86
  87         return handle;
  88 }
  89
  90 /*
  91  * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
  92  */
  93 struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
  94 {
  95         struct vmci_handle handle = VMCI_INVALID_HANDLE;
  96
  97         if (array->size) {
  98                 array->size--;
  99                 handle = array->entries[array->size];
 100                 array->entries[array->size] = VMCI_INVALID_HANDLE;
 101         }
 102
 103         return handle;
 104 }
 105
 106 /*
 107  * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
 108  */
 109 struct vmci_handle
 110 vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
 111 {
 112         if (unlikely(index >= array->size))
 113                 return VMCI_INVALID_HANDLE;
 114
 115         return array->entries[index];
 116 }
 117
 118 bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
 119                                struct vmci_handle entry_handle)
 120 {
 121         u32 i;
 122
 123         for (i = 0; i < array->size; i++)
 124                 if (vmci_handle_is_equal(array->entries[i], entry_handle))
 125                         return true;
 126
 127         return false;
 128 }
 129
 130 /*
 131  * NULL if the array is empty. Otherwise, a pointer to the array
 132  * of VMCI handles in the handle array.
 133  */
 134 struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
 135 {
 136         if (array->size)
 137                 return array->entries;
 138
 139         return NULL;
 140 }