cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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vmci_handle_array.c (3326B)

      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
     11static size_t handle_arr_calc_size(u32 capacity)
     12{
     13	return VMCI_HANDLE_ARRAY_HEADER_SIZE +
     14	    capacity * sizeof(struct vmci_handle);
     15}
     16
     17struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
     18{
     19	struct vmci_handle_arr *array;
     20
     21	if (max_capacity == 0 || capacity > max_capacity)
     22		return NULL;
     23
     24	if (capacity == 0)
     25		capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
     26			       max_capacity);
     27
     28	array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
     29	if (!array)
     30		return NULL;
     31
     32	array->capacity = capacity;
     33	array->max_capacity = max_capacity;
     34	array->size = 0;
     35
     36	return array;
     37}
     38
     39void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
     40{
     41	kfree(array);
     42}
     43
     44int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
     45				 struct vmci_handle handle)
     46{
     47	struct vmci_handle_arr *array = *array_ptr;
     48
     49	if (unlikely(array->size >= array->capacity)) {
     50		/* reallocate. */
     51		struct vmci_handle_arr *new_array;
     52		u32 capacity_bump = min(array->max_capacity - array->capacity,
     53					array->capacity);
     54		size_t new_size = handle_arr_calc_size(array->capacity +
     55						       capacity_bump);
     56
     57		if (array->size >= array->max_capacity)
     58			return VMCI_ERROR_NO_MEM;
     59
     60		new_array = krealloc(array, new_size, GFP_ATOMIC);
     61		if (!new_array)
     62			return VMCI_ERROR_NO_MEM;
     63
     64		new_array->capacity += capacity_bump;
     65		*array_ptr = array = new_array;
     66	}
     67
     68	array->entries[array->size] = handle;
     69	array->size++;
     70
     71	return VMCI_SUCCESS;
     72}
     73
     74/*
     75 * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
     76 */
     77struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
     78						struct vmci_handle entry_handle)
     79{
     80	struct vmci_handle handle = VMCI_INVALID_HANDLE;
     81	u32 i;
     82
     83	for (i = 0; i < array->size; i++) {
     84		if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
     85			handle = array->entries[i];
     86			array->size--;
     87			array->entries[i] = array->entries[array->size];
     88			array->entries[array->size] = VMCI_INVALID_HANDLE;
     89			break;
     90		}
     91	}
     92
     93	return handle;
     94}
     95
     96/*
     97 * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
     98 */
     99struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
    100{
    101	struct vmci_handle handle = VMCI_INVALID_HANDLE;
    102
    103	if (array->size) {
    104		array->size--;
    105		handle = array->entries[array->size];
    106		array->entries[array->size] = VMCI_INVALID_HANDLE;
    107	}
    108
    109	return handle;
    110}
    111
    112/*
    113 * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
    114 */
    115struct vmci_handle
    116vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
    117{
    118	if (unlikely(index >= array->size))
    119		return VMCI_INVALID_HANDLE;
    120
    121	return array->entries[index];
    122}
    123
    124bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
    125			       struct vmci_handle entry_handle)
    126{
    127	u32 i;
    128
    129	for (i = 0; i < array->size; i++)
    130		if (vmci_handle_is_equal(array->entries[i], entry_handle))
    131			return true;
    132
    133	return false;
    134}
    135
    136/*
    137 * NULL if the array is empty. Otherwise, a pointer to the array
    138 * of VMCI handles in the handle array.
    139 */
    140struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
    141{
    142	if (array->size)
    143		return array->entries;
    144
    145	return NULL;
    146}