George Zhang | b484b26 | 2013-01-08 15:54:39 -0800 | [diff] [blame] | 1 | /* |
| 2 | * VMware VMCI Driver |
| 3 | * |
| 4 | * Copyright (C) 2012 VMware, Inc. All rights reserved. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License as published by the |
| 8 | * Free Software Foundation version 2 and no later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 12 | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 13 | * for more details. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/slab.h> |
| 17 | #include "vmci_handle_array.h" |
| 18 | |
| 19 | static size_t handle_arr_calc_size(size_t capacity) |
| 20 | { |
| 21 | return sizeof(struct vmci_handle_arr) + |
| 22 | capacity * sizeof(struct vmci_handle); |
| 23 | } |
| 24 | |
| 25 | struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity) |
| 26 | { |
| 27 | struct vmci_handle_arr *array; |
| 28 | |
| 29 | if (capacity == 0) |
| 30 | capacity = VMCI_HANDLE_ARRAY_DEFAULT_SIZE; |
| 31 | |
| 32 | array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC); |
| 33 | if (!array) |
| 34 | return NULL; |
| 35 | |
| 36 | array->capacity = capacity; |
| 37 | array->size = 0; |
| 38 | |
| 39 | return array; |
| 40 | } |
| 41 | |
| 42 | void vmci_handle_arr_destroy(struct vmci_handle_arr *array) |
| 43 | { |
| 44 | kfree(array); |
| 45 | } |
| 46 | |
| 47 | void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr, |
| 48 | struct vmci_handle handle) |
| 49 | { |
| 50 | struct vmci_handle_arr *array = *array_ptr; |
| 51 | |
| 52 | if (unlikely(array->size >= array->capacity)) { |
| 53 | /* reallocate. */ |
| 54 | struct vmci_handle_arr *new_array; |
| 55 | size_t new_capacity = array->capacity * VMCI_ARR_CAP_MULT; |
| 56 | size_t new_size = handle_arr_calc_size(new_capacity); |
| 57 | |
| 58 | new_array = krealloc(array, new_size, GFP_ATOMIC); |
| 59 | if (!new_array) |
| 60 | return; |
| 61 | |
| 62 | new_array->capacity = new_capacity; |
| 63 | *array_ptr = array = new_array; |
| 64 | } |
| 65 | |
| 66 | array->entries[array->size] = handle; |
| 67 | array->size++; |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Handle that was removed, VMCI_INVALID_HANDLE if entry not found. |
| 72 | */ |
| 73 | struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array, |
| 74 | struct vmci_handle entry_handle) |
| 75 | { |
| 76 | struct vmci_handle handle = VMCI_INVALID_HANDLE; |
| 77 | size_t i; |
| 78 | |
| 79 | for (i = 0; i < array->size; i++) { |
| 80 | if (vmci_handle_is_equal(array->entries[i], entry_handle)) { |
| 81 | handle = array->entries[i]; |
| 82 | array->size--; |
| 83 | array->entries[i] = array->entries[array->size]; |
| 84 | array->entries[array->size] = VMCI_INVALID_HANDLE; |
| 85 | break; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | return handle; |
| 90 | } |
| 91 | |
| 92 | /* |
| 93 | * Handle that was removed, VMCI_INVALID_HANDLE if array was empty. |
| 94 | */ |
| 95 | struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array) |
| 96 | { |
| 97 | struct vmci_handle handle = VMCI_INVALID_HANDLE; |
| 98 | |
| 99 | if (array->size) { |
| 100 | array->size--; |
| 101 | handle = array->entries[array->size]; |
| 102 | array->entries[array->size] = VMCI_INVALID_HANDLE; |
| 103 | } |
| 104 | |
| 105 | return handle; |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * Handle at given index, VMCI_INVALID_HANDLE if invalid index. |
| 110 | */ |
| 111 | struct vmci_handle |
| 112 | vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index) |
| 113 | { |
| 114 | if (unlikely(index >= array->size)) |
| 115 | return VMCI_INVALID_HANDLE; |
| 116 | |
| 117 | return array->entries[index]; |
| 118 | } |
| 119 | |
| 120 | bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array, |
| 121 | struct vmci_handle entry_handle) |
| 122 | { |
| 123 | size_t i; |
| 124 | |
| 125 | for (i = 0; i < array->size; i++) |
| 126 | if (vmci_handle_is_equal(array->entries[i], entry_handle)) |
| 127 | return true; |
| 128 | |
| 129 | return false; |
| 130 | } |
| 131 | |
| 132 | /* |
| 133 | * NULL if the array is empty. Otherwise, a pointer to the array |
| 134 | * of VMCI handles in the handle array. |
| 135 | */ |
| 136 | struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array) |
| 137 | { |
| 138 | if (array->size) |
| 139 | return array->entries; |
| 140 | |
| 141 | return NULL; |
| 142 | } |