linux/drivers/misc/vmw_vmci/vmci_handle_array.c
George Zhang b484b26cc7 VMCI: handle array implementation.
VMCI handle code adds support for dynamic arrays that will grow if they need to.

Signed-off-by: George Zhang <georgezhang@vmware.com>
Acked-by: Andy king <acking@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-08 16:15:55 -08:00

143 lines
3.3 KiB
C

/*
* VMware VMCI Driver
*
* Copyright (C) 2012 VMware, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 and no later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include <linux/slab.h>
#include "vmci_handle_array.h"
static size_t handle_arr_calc_size(size_t capacity)
{
return sizeof(struct vmci_handle_arr) +
capacity * sizeof(struct vmci_handle);
}
struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity)
{
struct vmci_handle_arr *array;
if (capacity == 0)
capacity = VMCI_HANDLE_ARRAY_DEFAULT_SIZE;
array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
if (!array)
return NULL;
array->capacity = capacity;
array->size = 0;
return array;
}
void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
{
kfree(array);
}
void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
struct vmci_handle handle)
{
struct vmci_handle_arr *array = *array_ptr;
if (unlikely(array->size >= array->capacity)) {
/* reallocate. */
struct vmci_handle_arr *new_array;
size_t new_capacity = array->capacity * VMCI_ARR_CAP_MULT;
size_t new_size = handle_arr_calc_size(new_capacity);
new_array = krealloc(array, new_size, GFP_ATOMIC);
if (!new_array)
return;
new_array->capacity = new_capacity;
*array_ptr = array = new_array;
}
array->entries[array->size] = handle;
array->size++;
}
/*
* Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
*/
struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
struct vmci_handle entry_handle)
{
struct vmci_handle handle = VMCI_INVALID_HANDLE;
size_t i;
for (i = 0; i < array->size; i++) {
if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
handle = array->entries[i];
array->size--;
array->entries[i] = array->entries[array->size];
array->entries[array->size] = VMCI_INVALID_HANDLE;
break;
}
}
return handle;
}
/*
* Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
*/
struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
{
struct vmci_handle handle = VMCI_INVALID_HANDLE;
if (array->size) {
array->size--;
handle = array->entries[array->size];
array->entries[array->size] = VMCI_INVALID_HANDLE;
}
return handle;
}
/*
* Handle at given index, VMCI_INVALID_HANDLE if invalid index.
*/
struct vmci_handle
vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index)
{
if (unlikely(index >= array->size))
return VMCI_INVALID_HANDLE;
return array->entries[index];
}
bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
struct vmci_handle entry_handle)
{
size_t i;
for (i = 0; i < array->size; i++)
if (vmci_handle_is_equal(array->entries[i], entry_handle))
return true;
return false;
}
/*
* NULL if the array is empty. Otherwise, a pointer to the array
* of VMCI handles in the handle array.
*/
struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
{
if (array->size)
return array->entries;
return NULL;
}