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1// SPDX-License-Identifier: GPL-2.0-or-later2 /* Management for virtio crypto devices (refer to adf_dev_mgr.c)3 *4 * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.5 */6 7#include <linux/mutex.h>8#include <linux/list.h>9#include <linux/module.h>10 11#include <uapi/linux/virtio_crypto.h>12#include "virtio_crypto_common.h"13 14static LIST_HEAD(virtio_crypto_table);15static uint32_t num_devices;16 17/* The table_lock protects the above global list and num_devices */18static DEFINE_MUTEX(table_lock);19 20#define VIRTIO_CRYPTO_MAX_DEVICES 3221 22 23/*24 * virtcrypto_devmgr_add_dev() - Add vcrypto_dev to the acceleration25 * framework.26 * @vcrypto_dev: Pointer to virtio crypto device.27 *28 * Function adds virtio crypto device to the global list.29 * To be used by virtio crypto device specific drivers.30 *31 * Return: 0 on success, error code othewise.32 */33int virtcrypto_devmgr_add_dev(struct virtio_crypto *vcrypto_dev)34{35 struct list_head *itr;36 37 mutex_lock(&table_lock);38 if (num_devices == VIRTIO_CRYPTO_MAX_DEVICES) {39 pr_info("virtio_crypto: only support up to %d devices\n",40 VIRTIO_CRYPTO_MAX_DEVICES);41 mutex_unlock(&table_lock);42 return -EFAULT;43 }44 45 list_for_each(itr, &virtio_crypto_table) {46 struct virtio_crypto *ptr =47 list_entry(itr, struct virtio_crypto, list);48 49 if (ptr == vcrypto_dev) {50 mutex_unlock(&table_lock);51 return -EEXIST;52 }53 }54 atomic_set(&vcrypto_dev->ref_count, 0);55 list_add_tail(&vcrypto_dev->list, &virtio_crypto_table);56 vcrypto_dev->dev_id = num_devices++;57 mutex_unlock(&table_lock);58 return 0;59}60 61struct list_head *virtcrypto_devmgr_get_head(void)62{63 return &virtio_crypto_table;64}65 66/*67 * virtcrypto_devmgr_rm_dev() - Remove vcrypto_dev from the acceleration68 * framework.69 * @vcrypto_dev: Pointer to virtio crypto device.70 *71 * Function removes virtio crypto device from the acceleration framework.72 * To be used by virtio crypto device specific drivers.73 *74 * Return: void75 */76void virtcrypto_devmgr_rm_dev(struct virtio_crypto *vcrypto_dev)77{78 mutex_lock(&table_lock);79 list_del(&vcrypto_dev->list);80 num_devices--;81 mutex_unlock(&table_lock);82}83 84/*85 * virtcrypto_devmgr_get_first()86 *87 * Function returns the first virtio crypto device from the acceleration88 * framework.89 *90 * To be used by virtio crypto device specific drivers.91 *92 * Return: pointer to vcrypto_dev or NULL if not found.93 */94struct virtio_crypto *virtcrypto_devmgr_get_first(void)95{96 struct virtio_crypto *dev = NULL;97 98 mutex_lock(&table_lock);99 if (!list_empty(&virtio_crypto_table))100 dev = list_first_entry(&virtio_crypto_table,101 struct virtio_crypto,102 list);103 mutex_unlock(&table_lock);104 return dev;105}106 107/*108 * virtcrypto_dev_in_use() - Check whether vcrypto_dev is currently in use109 * @vcrypto_dev: Pointer to virtio crypto device.110 *111 * To be used by virtio crypto device specific drivers.112 *113 * Return: 1 when device is in use, 0 otherwise.114 */115int virtcrypto_dev_in_use(struct virtio_crypto *vcrypto_dev)116{117 return atomic_read(&vcrypto_dev->ref_count) != 0;118}119 120/*121 * virtcrypto_dev_get() - Increment vcrypto_dev reference count122 * @vcrypto_dev: Pointer to virtio crypto device.123 *124 * Increment the vcrypto_dev refcount and if this is the first time125 * incrementing it during this period the vcrypto_dev is in use,126 * increment the module refcount too.127 * To be used by virtio crypto device specific drivers.128 *129 * Return: 0 when successful, EFAULT when fail to bump module refcount130 */131int virtcrypto_dev_get(struct virtio_crypto *vcrypto_dev)132{133 if (atomic_add_return(1, &vcrypto_dev->ref_count) == 1)134 if (!try_module_get(vcrypto_dev->owner))135 return -EFAULT;136 return 0;137}138 139/*140 * virtcrypto_dev_put() - Decrement vcrypto_dev reference count141 * @vcrypto_dev: Pointer to virtio crypto device.142 *143 * Decrement the vcrypto_dev refcount and if this is the last time144 * decrementing it during this period the vcrypto_dev is in use,145 * decrement the module refcount too.146 * To be used by virtio crypto device specific drivers.147 *148 * Return: void149 */150void virtcrypto_dev_put(struct virtio_crypto *vcrypto_dev)151{152 if (atomic_sub_return(1, &vcrypto_dev->ref_count) == 0)153 module_put(vcrypto_dev->owner);154}155 156/*157 * virtcrypto_dev_started() - Check whether device has started158 * @vcrypto_dev: Pointer to virtio crypto device.159 *160 * To be used by virtio crypto device specific drivers.161 *162 * Return: 1 when the device has started, 0 otherwise163 */164int virtcrypto_dev_started(struct virtio_crypto *vcrypto_dev)165{166 return (vcrypto_dev->status & VIRTIO_CRYPTO_S_HW_READY);167}168 169/*170 * virtcrypto_get_dev_node() - Get vcrypto_dev on the node.171 * @node: Node id the driver works.172 * @service: Crypto service that needs to be supported by the173 * dev174 * @algo: The algorithm number that needs to be supported by the175 * dev176 *177 * Function returns the virtio crypto device used fewest on the node,178 * and supports the given crypto service and algorithm.179 *180 * To be used by virtio crypto device specific drivers.181 *182 * Return: pointer to vcrypto_dev or NULL if not found.183 */184struct virtio_crypto *virtcrypto_get_dev_node(int node, uint32_t service,185 uint32_t algo)186{187 struct virtio_crypto *vcrypto_dev = NULL, *tmp_dev;188 unsigned long best = ~0;189 unsigned long ctr;190 191 mutex_lock(&table_lock);192 list_for_each_entry(tmp_dev, virtcrypto_devmgr_get_head(), list) {193 194 if ((node == dev_to_node(&tmp_dev->vdev->dev) ||195 dev_to_node(&tmp_dev->vdev->dev) < 0) &&196 virtcrypto_dev_started(tmp_dev) &&197 virtcrypto_algo_is_supported(tmp_dev, service, algo)) {198 ctr = atomic_read(&tmp_dev->ref_count);199 if (best > ctr) {200 vcrypto_dev = tmp_dev;201 best = ctr;202 }203 }204 }205 206 if (!vcrypto_dev) {207 pr_info("virtio_crypto: Could not find a device on node %d\n",208 node);209 /* Get any started device */210 list_for_each_entry(tmp_dev,211 virtcrypto_devmgr_get_head(), list) {212 if (virtcrypto_dev_started(tmp_dev) &&213 virtcrypto_algo_is_supported(tmp_dev,214 service, algo)) {215 vcrypto_dev = tmp_dev;216 break;217 }218 }219 }220 mutex_unlock(&table_lock);221 if (!vcrypto_dev)222 return NULL;223 224 virtcrypto_dev_get(vcrypto_dev);225 return vcrypto_dev;226}227 228/*229 * virtcrypto_dev_start() - Start virtio crypto device230 * @vcrypto: Pointer to virtio crypto device.231 *232 * Function notifies all the registered services that the virtio crypto device233 * is ready to be used.234 * To be used by virtio crypto device specific drivers.235 *236 * Return: 0 on success, EFAULT when fail to register algorithms237 */238int virtcrypto_dev_start(struct virtio_crypto *vcrypto)239{240 if (virtio_crypto_skcipher_algs_register(vcrypto)) {241 pr_err("virtio_crypto: Failed to register crypto skcipher algs\n");242 return -EFAULT;243 }244 245 if (virtio_crypto_akcipher_algs_register(vcrypto)) {246 pr_err("virtio_crypto: Failed to register crypto akcipher algs\n");247 virtio_crypto_skcipher_algs_unregister(vcrypto);248 return -EFAULT;249 }250 251 return 0;252}253 254/*255 * virtcrypto_dev_stop() - Stop virtio crypto device256 * @vcrypto: Pointer to virtio crypto device.257 *258 * Function notifies all the registered services that the virtio crypto device259 * is ready to be used.260 * To be used by virtio crypto device specific drivers.261 *262 * Return: void263 */264void virtcrypto_dev_stop(struct virtio_crypto *vcrypto)265{266 virtio_crypto_skcipher_algs_unregister(vcrypto);267 virtio_crypto_akcipher_algs_unregister(vcrypto);268}269 270/*271 * vcrypto_algo_is_supported()272 * @vcrypto: Pointer to virtio crypto device.273 * @service: The bit number for service validate.274 * See VIRTIO_CRYPTO_SERVICE_*275 * @algo : The bit number for the algorithm to validate.276 *277 *278 * Validate if the virtio crypto device supports a service and279 * algo.280 *281 * Return true if device supports a service and algo.282 */283 284bool virtcrypto_algo_is_supported(struct virtio_crypto *vcrypto,285 uint32_t service,286 uint32_t algo)287{288 uint32_t service_mask = 1u << service;289 uint32_t algo_mask = 0;290 bool low = true;291 292 if (algo > 31) {293 algo -= 32;294 low = false;295 }296 297 if (!(vcrypto->crypto_services & service_mask))298 return false;299 300 switch (service) {301 case VIRTIO_CRYPTO_SERVICE_CIPHER:302 if (low)303 algo_mask = vcrypto->cipher_algo_l;304 else305 algo_mask = vcrypto->cipher_algo_h;306 break;307 308 case VIRTIO_CRYPTO_SERVICE_HASH:309 algo_mask = vcrypto->hash_algo;310 break;311 312 case VIRTIO_CRYPTO_SERVICE_MAC:313 if (low)314 algo_mask = vcrypto->mac_algo_l;315 else316 algo_mask = vcrypto->mac_algo_h;317 break;318 319 case VIRTIO_CRYPTO_SERVICE_AEAD:320 algo_mask = vcrypto->aead_algo;321 break;322 323 case VIRTIO_CRYPTO_SERVICE_AKCIPHER:324 algo_mask = vcrypto->akcipher_algo;325 break;326 }327 328 if (!(algo_mask & (1u << algo)))329 return false;330 331 return true;332}333