linux/crypto/crypto_engine.c
Olivier Bacon 4140aafcff crypto: engine - fix crypto_queue backlog handling
CRYPTO_TFM_REQ_MAY_BACKLOG tells the crypto driver that it should
internally backlog requests until the crypto hw's queue becomes
full. At that point, crypto_engine backlogs the request and returns
-EBUSY. Calling driver such as dm-crypt then waits until the
complete() function is called with a status of -EINPROGRESS before
sending a new request.

The problem lies in the call to complete() with a value of -EINPROGRESS
that is made when a backlog item is present on the queue. The call is
done before the successful execution of the crypto request. In the case
that do_one_request() returns < 0 and the retry support is available,
the request is put back in the queue. This leads upper drivers to send
a new request even if the queue is still full.

The problem can be reproduced by doing a large dd into a crypto
dm-crypt device. This is pretty easy to see when using
Freescale CAAM crypto driver and SWIOTLB dma. Since the actual amount
of requests that can be hold in the queue is unlimited we get IOs error
and dma allocation.

The fix is to call complete with a value of -EINPROGRESS only if
the request is not enqueued back in crypto_queue. This is done
by calling complete() later in the code. In order to delay the decision,
crypto_queue is modified to correctly set the backlog pointer
when a request is enqueued back.

Fixes: 6a89f492f8 ("crypto: engine - support for parallel requests based on retry mechanism")
Co-developed-by: Sylvain Ouellet <souellet@genetec.com>
Signed-off-by: Sylvain Ouellet <souellet@genetec.com>
Signed-off-by: Olivier Bacon <obacon@genetec.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-04-28 17:50:43 +08:00

596 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Handle async block request by crypto hardware engine.
*
* Copyright (C) 2016 Linaro, Inc.
*
* Author: Baolin Wang <baolin.wang@linaro.org>
*/
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <crypto/engine.h>
#include <uapi/linux/sched/types.h>
#include "internal.h"
#define CRYPTO_ENGINE_MAX_QLEN 10
/**
* 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
*/
static void crypto_finalize_request(struct crypto_engine *engine,
struct crypto_async_request *req, int err)
{
unsigned long flags;
bool finalize_req = false;
int ret;
struct crypto_engine_ctx *enginectx;
/*
* If hardware cannot enqueue more requests
* and retry mechanism is not supported
* make sure we are completing the current request
*/
if (!engine->retry_support) {
spin_lock_irqsave(&engine->queue_lock, flags);
if (engine->cur_req == req) {
finalize_req = true;
engine->cur_req = NULL;
}
spin_unlock_irqrestore(&engine->queue_lock, flags);
}
if (finalize_req || engine->retry_support) {
enginectx = crypto_tfm_ctx(req->tfm);
if (enginectx->op.prepare_request &&
enginectx->op.unprepare_request) {
ret = enginectx->op.unprepare_request(engine, req);
if (ret)
dev_err(engine->dev, "failed to unprepare request\n");
}
}
lockdep_assert_in_softirq();
crypto_request_complete(req, err);
kthread_queue_work(engine->kworker, &engine->pump_requests);
}
/**
* 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;
unsigned long flags;
bool was_busy = false;
int ret;
struct crypto_engine_ctx *enginectx;
spin_lock_irqsave(&engine->queue_lock, flags);
/* Make sure we are not already running a request */
if (!engine->retry_support && engine->cur_req)
goto out;
/* If another context is idling then defer */
if (engine->idling) {
kthread_queue_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) {
kthread_queue_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))
dev_err(engine->dev, "failed to unprepare crypt hardware\n");
spin_lock_irqsave(&engine->queue_lock, flags);
engine->idling = false;
goto out;
}
start_request:
/* 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;
/*
* If hardware doesn't support the retry mechanism,
* keep track of the request we are processing now.
* We'll need it on completion (crypto_finalize_request).
*/
if (!engine->retry_support)
engine->cur_req = async_req;
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) {
dev_err(engine->dev, "failed to prepare crypt hardware\n");
goto req_err_2;
}
}
enginectx = crypto_tfm_ctx(async_req->tfm);
if (enginectx->op.prepare_request) {
ret = enginectx->op.prepare_request(engine, async_req);
if (ret) {
dev_err(engine->dev, "failed to prepare request: %d\n",
ret);
goto req_err_2;
}
}
if (!enginectx->op.do_one_request) {
dev_err(engine->dev, "failed to do request\n");
ret = -EINVAL;
goto req_err_1;
}
ret = enginectx->op.do_one_request(engine, async_req);
/* Request unsuccessfully executed by hardware */
if (ret < 0) {
/*
* If hardware queue is full (-ENOSPC), requeue request
* regardless of backlog flag.
* Otherwise, unprepare and complete the request.
*/
if (!engine->retry_support ||
(ret != -ENOSPC)) {
dev_err(engine->dev,
"Failed to do one request from queue: %d\n",
ret);
goto req_err_1;
}
/*
* If retry mechanism is supported,
* unprepare current request and
* enqueue it back into crypto-engine queue.
*/
if (enginectx->op.unprepare_request) {
ret = enginectx->op.unprepare_request(engine,
async_req);
if (ret)
dev_err(engine->dev,
"failed to unprepare request\n");
}
spin_lock_irqsave(&engine->queue_lock, flags);
/*
* If hardware was unable to execute request, enqueue it
* back in front of crypto-engine queue, to keep the order
* of requests.
*/
crypto_enqueue_request_head(&engine->queue, async_req);
kthread_queue_work(engine->kworker, &engine->pump_requests);
goto out;
}
goto retry;
req_err_1:
if (enginectx->op.unprepare_request) {
ret = enginectx->op.unprepare_request(engine, async_req);
if (ret)
dev_err(engine->dev, "failed to unprepare request\n");
}
req_err_2:
crypto_request_complete(async_req, ret);
retry:
if (backlog)
crypto_request_complete(backlog, -EINPROGRESS);
/* If retry mechanism is supported, send new requests to engine */
if (engine->retry_support) {
spin_lock_irqsave(&engine->queue_lock, flags);
goto start_request;
}
return;
out:
spin_unlock_irqrestore(&engine->queue_lock, flags);
/*
* Batch requests is possible only if
* hardware can enqueue multiple requests
*/
if (engine->do_batch_requests) {
ret = engine->do_batch_requests(engine);
if (ret)
dev_err(engine->dev, "failed to do batch requests: %d\n",
ret);
}
return;
}
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
* @need_pump: indicates whether queue the pump of request to kthread_work
*/
static int crypto_transfer_request(struct crypto_engine *engine,
struct crypto_async_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 = crypto_enqueue_request(&engine->queue, req);
if (!engine->busy && need_pump)
kthread_queue_work(engine->kworker, &engine->pump_requests);
spin_unlock_irqrestore(&engine->queue_lock, flags);
return ret;
}
/**
* 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
*/
static int crypto_transfer_request_to_engine(struct crypto_engine *engine,
struct crypto_async_request *req)
{
return crypto_transfer_request(engine, req, true);
}
/**
* crypto_transfer_aead_request_to_engine - transfer one aead_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_aead_request_to_engine(struct crypto_engine *engine,
struct aead_request *req)
{
return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_aead_request_to_engine);
/**
* crypto_transfer_akcipher_request_to_engine - transfer one akcipher_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_akcipher_request_to_engine(struct crypto_engine *engine,
struct akcipher_request *req)
{
return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_akcipher_request_to_engine);
/**
* crypto_transfer_hash_request_to_engine - transfer one ahash_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_hash_request_to_engine(struct crypto_engine *engine,
struct ahash_request *req)
{
return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);
/**
* crypto_transfer_kpp_request_to_engine - transfer one kpp_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_kpp_request_to_engine(struct crypto_engine *engine,
struct kpp_request *req)
{
return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_kpp_request_to_engine);
/**
* crypto_transfer_skcipher_request_to_engine - transfer one skcipher_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_skcipher_request_to_engine(struct crypto_engine *engine,
struct skcipher_request *req)
{
return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_skcipher_request_to_engine);
/**
* crypto_finalize_aead_request - finalize one aead_request if
* the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_aead_request(struct crypto_engine *engine,
struct aead_request *req, int err)
{
return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_aead_request);
/**
* crypto_finalize_akcipher_request - finalize one akcipher_request if
* the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_akcipher_request(struct crypto_engine *engine,
struct akcipher_request *req, int err)
{
return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_akcipher_request);
/**
* crypto_finalize_hash_request - finalize one ahash_request if
* the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_hash_request(struct crypto_engine *engine,
struct ahash_request *req, int err)
{
return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_hash_request);
/**
* crypto_finalize_kpp_request - finalize one kpp_request if the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_kpp_request(struct crypto_engine *engine,
struct kpp_request *req, int err)
{
return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_kpp_request);
/**
* crypto_finalize_skcipher_request - finalize one skcipher_request if
* the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_skcipher_request(struct crypto_engine *engine,
struct skcipher_request *req, int err)
{
return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_skcipher_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);
kthread_queue_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 int 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)
dev_warn(engine->dev, "could not stop engine\n");
return ret;
}
EXPORT_SYMBOL_GPL(crypto_engine_stop);
/**
* crypto_engine_alloc_init_and_set - allocate crypto hardware engine structure
* and initialize it by setting the maximum number of entries in the software
* crypto-engine queue.
* @dev: the device attached with one hardware engine
* @retry_support: whether hardware has support for retry mechanism
* @cbk_do_batch: pointer to a callback function to be invoked when executing
* a batch of requests.
* This has the form:
* callback(struct crypto_engine *engine)
* where:
* engine: the crypto engine structure.
* @rt: whether this queue is set to run as a realtime task
* @qlen: maximum size of the crypto-engine queue
*
* 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_and_set(struct device *dev,
bool retry_support,
int (*cbk_do_batch)(struct crypto_engine *engine),
bool rt, int qlen)
{
struct crypto_engine *engine;
if (!dev)
return NULL;
engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
if (!engine)
return NULL;
engine->dev = dev;
engine->rt = rt;
engine->running = false;
engine->busy = false;
engine->idling = false;
engine->retry_support = retry_support;
engine->priv_data = dev;
/*
* Batch requests is possible only if
* hardware has support for retry mechanism.
*/
engine->do_batch_requests = retry_support ? cbk_do_batch : NULL;
snprintf(engine->name, sizeof(engine->name),
"%s-engine", dev_name(dev));
crypto_init_queue(&engine->queue, qlen);
spin_lock_init(&engine->queue_lock);
engine->kworker = kthread_create_worker(0, "%s", engine->name);
if (IS_ERR(engine->kworker)) {
dev_err(dev, "failed to create crypto request pump task\n");
return NULL;
}
kthread_init_work(&engine->pump_requests, crypto_pump_work);
if (engine->rt) {
dev_info(dev, "will run requests pump with realtime priority\n");
sched_set_fifo(engine->kworker->task);
}
return engine;
}
EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);
/**
* 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)
{
return crypto_engine_alloc_init_and_set(dev, false, NULL, rt,
CRYPTO_ENGINE_MAX_QLEN);
}
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;
kthread_destroy_worker(engine->kworker);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_engine_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Crypto hardware engine framework");