/* * Handle async block request by crypto hardware engine. * * Copyright (C) 2016 Linaro, Inc. * * Author: Baolin Wang <baolin.wang@linaro.org> * * 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; either version 2 of the License, or (at your option) * any later version. * */ #include <linux/err.h> #include <linux/delay.h> #include "internal.h" #define CRYPTO_ENGINE_MAX_QLEN 10 void crypto_finalize_request(struct crypto_engine *engine, struct ablkcipher_request *req, int err); /** * crypto_pump_requests - dequeue one request from engine queue to process * @engine: the hardware engine * @in_kthread: true if we are in the context of the request pump thread * * This function checks if there is any request in the engine queue that * needs processing and if so call out to the driver to initialize hardware * and handle each request. */ static void crypto_pump_requests(struct crypto_engine *engine, bool in_kthread) { struct crypto_async_request *async_req, *backlog; struct ablkcipher_request *req; unsigned long flags; bool was_busy = false; int ret; spin_lock_irqsave(&engine->queue_lock, flags); /* Make sure we are not already running a request */ if (engine->cur_req) goto out; /* If another context is idling then defer */ if (engine->idling) { queue_kthread_work(&engine->kworker, &engine->pump_requests); goto out; } /* Check if the engine queue is idle */ if (!crypto_queue_len(&engine->queue) || !engine->running) { if (!engine->busy) goto out; /* Only do teardown in the thread */ if (!in_kthread) { queue_kthread_work(&engine->kworker, &engine->pump_requests); goto out; } engine->busy = false; engine->idling = true; spin_unlock_irqrestore(&engine->queue_lock, flags); if (engine->unprepare_crypt_hardware && engine->unprepare_crypt_hardware(engine)) pr_err("failed to unprepare crypt hardware\n"); spin_lock_irqsave(&engine->queue_lock, flags); engine->idling = false; goto out; } /* Get the fist request from the engine queue to handle */ backlog = crypto_get_backlog(&engine->queue); async_req = crypto_dequeue_request(&engine->queue); if (!async_req) goto out; req = ablkcipher_request_cast(async_req); engine->cur_req = req; if (backlog) backlog->complete(backlog, -EINPROGRESS); if (engine->busy) was_busy = true; else engine->busy = true; spin_unlock_irqrestore(&engine->queue_lock, flags); /* Until here we get the request need to be encrypted successfully */ if (!was_busy && engine->prepare_crypt_hardware) { ret = engine->prepare_crypt_hardware(engine); if (ret) { pr_err("failed to prepare crypt hardware\n"); goto req_err; } } if (engine->prepare_request) { ret = engine->prepare_request(engine, engine->cur_req); if (ret) { pr_err("failed to prepare request: %d\n", ret); goto req_err; } engine->cur_req_prepared = true; } ret = engine->crypt_one_request(engine, engine->cur_req); if (ret) { pr_err("failed to crypt one request from queue\n"); goto req_err; } return; req_err: crypto_finalize_request(engine, engine->cur_req, ret); return; out: spin_unlock_irqrestore(&engine->queue_lock, flags); } static void crypto_pump_work(struct kthread_work *work) { struct crypto_engine *engine = container_of(work, struct crypto_engine, pump_requests); crypto_pump_requests(engine, true); } /** * crypto_transfer_request - transfer the new request into the engine queue * @engine: the hardware engine * @req: the request need to be listed into the engine queue */ int crypto_transfer_request(struct crypto_engine *engine, struct ablkcipher_request *req, bool need_pump) { unsigned long flags; int ret; spin_lock_irqsave(&engine->queue_lock, flags); if (!engine->running) { spin_unlock_irqrestore(&engine->queue_lock, flags); return -ESHUTDOWN; } ret = ablkcipher_enqueue_request(&engine->queue, req); if (!engine->busy && need_pump) queue_kthread_work(&engine->kworker, &engine->pump_requests); spin_unlock_irqrestore(&engine->queue_lock, flags); return ret; } EXPORT_SYMBOL_GPL(crypto_transfer_request); /** * crypto_transfer_request_to_engine - transfer one request to list into the * engine queue * @engine: the hardware engine * @req: the request need to be listed into the engine queue */ int crypto_transfer_request_to_engine(struct crypto_engine *engine, struct ablkcipher_request *req) { return crypto_transfer_request(engine, req, true); } EXPORT_SYMBOL_GPL(crypto_transfer_request_to_engine); /** * crypto_finalize_request - finalize one request if the request is done * @engine: the hardware engine * @req: the request need to be finalized * @err: error number */ void crypto_finalize_request(struct crypto_engine *engine, struct ablkcipher_request *req, int err) { unsigned long flags; bool finalize_cur_req = false; int ret; spin_lock_irqsave(&engine->queue_lock, flags); if (engine->cur_req == req) finalize_cur_req = true; spin_unlock_irqrestore(&engine->queue_lock, flags); if (finalize_cur_req) { if (engine->cur_req_prepared && engine->unprepare_request) { ret = engine->unprepare_request(engine, req); if (ret) pr_err("failed to unprepare request\n"); } spin_lock_irqsave(&engine->queue_lock, flags); engine->cur_req = NULL; engine->cur_req_prepared = false; spin_unlock_irqrestore(&engine->queue_lock, flags); } req->base.complete(&req->base, err); queue_kthread_work(&engine->kworker, &engine->pump_requests); } EXPORT_SYMBOL_GPL(crypto_finalize_request); /** * crypto_engine_start - start the hardware engine * @engine: the hardware engine need to be started * * Return 0 on success, else on fail. */ int crypto_engine_start(struct crypto_engine *engine) { unsigned long flags; spin_lock_irqsave(&engine->queue_lock, flags); if (engine->running || engine->busy) { spin_unlock_irqrestore(&engine->queue_lock, flags); return -EBUSY; } engine->running = true; spin_unlock_irqrestore(&engine->queue_lock, flags); queue_kthread_work(&engine->kworker, &engine->pump_requests); return 0; } EXPORT_SYMBOL_GPL(crypto_engine_start); /** * crypto_engine_stop - stop the hardware engine * @engine: the hardware engine need to be stopped * * Return 0 on success, else on fail. */ int crypto_engine_stop(struct crypto_engine *engine) { unsigned long flags; unsigned limit = 500; int ret = 0; spin_lock_irqsave(&engine->queue_lock, flags); /* * If the engine queue is not empty or the engine is on busy state, * we need to wait for a while to pump the requests of engine queue. */ while ((crypto_queue_len(&engine->queue) || engine->busy) && limit--) { spin_unlock_irqrestore(&engine->queue_lock, flags); msleep(20); spin_lock_irqsave(&engine->queue_lock, flags); } if (crypto_queue_len(&engine->queue) || engine->busy) ret = -EBUSY; else engine->running = false; spin_unlock_irqrestore(&engine->queue_lock, flags); if (ret) pr_warn("could not stop engine\n"); return ret; } EXPORT_SYMBOL_GPL(crypto_engine_stop); /** * crypto_engine_alloc_init - allocate crypto hardware engine structure and * initialize it. * @dev: the device attached with one hardware engine * @rt: whether this queue is set to run as a realtime task * * This must be called from context that can sleep. * Return: the crypto engine structure on success, else NULL. */ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt) { struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; struct crypto_engine *engine; if (!dev) return NULL; engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL); if (!engine) return NULL; engine->rt = rt; engine->running = false; engine->busy = false; engine->idling = false; engine->cur_req_prepared = false; engine->priv_data = dev; snprintf(engine->name, sizeof(engine->name), "%s-engine", dev_name(dev)); crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_QLEN); spin_lock_init(&engine->queue_lock); init_kthread_worker(&engine->kworker); engine->kworker_task = kthread_run(kthread_worker_fn, &engine->kworker, "%s", engine->name); if (IS_ERR(engine->kworker_task)) { dev_err(dev, "failed to create crypto request pump task\n"); return NULL; } init_kthread_work(&engine->pump_requests, crypto_pump_work); if (engine->rt) { dev_info(dev, "will run requests pump with realtime priority\n"); sched_setscheduler(engine->kworker_task, SCHED_FIFO, ¶m); } return engine; } EXPORT_SYMBOL_GPL(crypto_engine_alloc_init); /** * crypto_engine_exit - free the resources of hardware engine when exit * @engine: the hardware engine need to be freed * * Return 0 for success. */ int crypto_engine_exit(struct crypto_engine *engine) { int ret; ret = crypto_engine_stop(engine); if (ret) return ret; flush_kthread_worker(&engine->kworker); kthread_stop(engine->kworker_task); return 0; } EXPORT_SYMBOL_GPL(crypto_engine_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Crypto hardware engine framework");