[PATCH 7/7] crypto: marvell: Add support for chaining crypto requests in TDMA mode

Boris Brezillon boris.brezillon at free-electrons.com
Wed Jun 15 14:43:53 PDT 2016


On Wed, 15 Jun 2016 21:15:34 +0200
Romain Perier <romain.perier at free-electrons.com> wrote:

> The Cryptographic Engines and Security Accelerators (CESA) supports the
> Multi-Packet Chain Mode. With this mode enabled, multiple tdma requests
> can be chained and processed by the hardware without software
> interferences.

intervention.

> This mode was already activated, however the crypto
> requests were not chained together. By doing so, we reduce significantly

						   significantly reduce

> the number of IRQs. Instead of being interrupted at the end of each
> crypto request, we are interrupted at the end of the last cryptographic
> request processed by the engine.
> 
> This commits re-factorizes the code, changes the code architecture and
> adds the required data structures to chain cryptographic requests
> together before sending them to an engine.

Not necessarily before sending them to the engine, it can be done while
the engine is running.

> 
> Signed-off-by: Romain Perier <romain.perier at free-electrons.com>
> ---
>  drivers/crypto/marvell/cesa.c   | 117 +++++++++++++++++++++++++++++++---------
>  drivers/crypto/marvell/cesa.h   |  38 ++++++++++++-
>  drivers/crypto/marvell/cipher.c |   3 +-
>  drivers/crypto/marvell/hash.c   |   9 +++-
>  drivers/crypto/marvell/tdma.c   |  81 ++++++++++++++++++++++++++++
>  5 files changed, 218 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/crypto/marvell/cesa.c b/drivers/crypto/marvell/cesa.c
> index f9e6688..33411f6 100644
> --- a/drivers/crypto/marvell/cesa.c
> +++ b/drivers/crypto/marvell/cesa.c
> @@ -32,7 +32,7 @@
>  #include "cesa.h"
>  
>  /* Limit of the crypto queue before reaching the backlog */
> -#define CESA_CRYPTO_DEFAULT_MAX_QLEN 50
> +#define CESA_CRYPTO_DEFAULT_MAX_QLEN 128
>  
>  static int allhwsupport = !IS_ENABLED(CONFIG_CRYPTO_DEV_MV_CESA);
>  module_param_named(allhwsupport, allhwsupport, int, 0444);
> @@ -40,23 +40,83 @@ MODULE_PARM_DESC(allhwsupport, "Enable support for all hardware (even it if over
>  
>  struct mv_cesa_dev *cesa_dev;
>  
> -static void mv_cesa_dequeue_req_unlocked(struct mv_cesa_engine *engine)
> +struct crypto_async_request *mv_cesa_dequeue_req_locked(
> +	struct mv_cesa_engine *engine, struct crypto_async_request **backlog)

Coding style issue:

struct crypto_async_request *
mv_cesa_dequeue_req_locked(struct mv_cesa_engine *engine,
			   struct crypto_async_request **backlog)

> +{
> +	struct crypto_async_request *req;
> +
> +	*backlog = crypto_get_backlog(&engine->queue);
> +	req = crypto_dequeue_request(&engine->queue);
> +
> +	if (!req)
> +		return NULL;
> +
> +	return req;
> +}
> +
> +static void mv_cesa_rearm_engine(struct mv_cesa_engine *engine)
>  {
>  	struct crypto_async_request *req, *backlog;
>  	struct mv_cesa_ctx *ctx;
>  
> -	backlog = crypto_get_backlog(&engine->queue);
> -	req = crypto_dequeue_request(&engine->queue);
> -	engine->req = req;
>  
> +	spin_lock_bh(&engine->lock);
> +	if (engine->req)
> +		goto out_unlock;
> +
> +	req = mv_cesa_dequeue_req_locked(engine, &backlog);
>  	if (!req)
> -		return;
> +		goto out_unlock;
> +
> +	engine->req = req;
> +	spin_unlock_bh(&engine->lock);

I'm not a big fan of those multiple 'unlock() locations', and since
your code is pretty simple I'd prefer seeing something like.

	spin_lock_bh(&engine->lock);
	if (!engine->req) {
		req = mv_cesa_dequeue_req_locked(engine, &backlog);
		engine->req = req;
	}
	spin_unlock_bh(&engine->lock);

	if (!req)
		return;

With req and backlog initialized to NULL at the beginning of the
function.

>  
>  	if (backlog)
>  		backlog->complete(backlog, -EINPROGRESS);
>  
>  	ctx = crypto_tfm_ctx(req->tfm);
>  	ctx->ops->step(req);
> +	return;

Missing blank line.

> +out_unlock:
> +	spin_unlock_bh(&engine->lock);
> +}
> +
> +static int mv_cesa_std_process(struct mv_cesa_engine *engine, u32 status)
> +{
> +	struct crypto_async_request *req;
> +	struct mv_cesa_ctx *ctx;
> +	int res;
> +
> +	req = engine->req;
> +	ctx = crypto_tfm_ctx(req->tfm);
> +	res = ctx->ops->process(req, status);
> +
> +	if (res == 0) {
> +		ctx->ops->complete(req);
> +		mv_cesa_engine_enqueue_complete_request(engine, req);
> +	} else if (res == -EINPROGRESS) {
> +		ctx->ops->step(req);
> +	} else {
> +		ctx->ops->complete(req);

Do we really have to call ->complete() in this case?

> +	}
> +
> +	return res;
> +}
> +
> +static int mv_cesa_int_process(struct mv_cesa_engine *engine, u32 status)
> +{
> +	if (engine->chain.first && engine->chain.last)
> +		return mv_cesa_tdma_process(engine, status);

Missing blank line.

> +	return mv_cesa_std_process(engine, status);
> +}
> +
> +static inline void mv_cesa_complete_req(struct mv_cesa_ctx *ctx,
> +	struct crypto_async_request *req, int res)

Align parameters to the open parenthesis.

> +{
> +	ctx->ops->cleanup(req);
> +	local_bh_disable();
> +	req->complete(req, res);
> +	local_bh_enable();
>  }
>  
>  static irqreturn_t mv_cesa_int(int irq, void *priv)
> @@ -83,26 +143,31 @@ static irqreturn_t mv_cesa_int(int irq, void *priv)
>  		writel(~status, engine->regs + CESA_SA_FPGA_INT_STATUS);
>  		writel(~status, engine->regs + CESA_SA_INT_STATUS);
>  
> +		/* Process fetched requests */
> +		res = mv_cesa_int_process(engine, status & mask);
>  		ret = IRQ_HANDLED;
> +
>  		spin_lock_bh(&engine->lock);
>  		req = engine->req;
> +		if (res != -EINPROGRESS)
> +			engine->req = NULL;
>  		spin_unlock_bh(&engine->lock);
> -		if (req) {
> -			ctx = crypto_tfm_ctx(req->tfm);
> -			res = ctx->ops->process(req, status & mask);
> -			if (res != -EINPROGRESS) {
> -				spin_lock_bh(&engine->lock);
> -				engine->req = NULL;
> -				mv_cesa_dequeue_req_unlocked(engine);
> -				spin_unlock_bh(&engine->lock);
> -				ctx->ops->complete(req);
> -				ctx->ops->cleanup(req);
> -				local_bh_disable();
> -				req->complete(req, res);
> -				local_bh_enable();
> -			} else {
> -				ctx->ops->step(req);
> -			}
> +
> +		ctx = crypto_tfm_ctx(req->tfm);
> +
> +		if (res && res != -EINPROGRESS)
> +			mv_cesa_complete_req(ctx, req, res);
> +
> +		/* Launch the next pending request */
> +		mv_cesa_rearm_engine(engine);
> +
> +		/* Iterate over the complete queue */
> +		while (true) {
> +			req = mv_cesa_engine_dequeue_complete_request(engine);
> +			if (!req)
> +				break;
> +
> +			mv_cesa_complete_req(ctx, req, 0);
>  		}
>  	}
>  
> @@ -116,16 +181,15 @@ int mv_cesa_queue_req(struct crypto_async_request *req,
>  	struct mv_cesa_engine *engine = creq->engine;
>  
>  	spin_lock_bh(&engine->lock);
> +	if (mv_cesa_req_get_type(creq) == CESA_DMA_REQ)
> +		mv_cesa_tdma_chain(engine, creq);

Missing blank line.

>  	ret = crypto_enqueue_request(&engine->queue, req);
>  	spin_unlock_bh(&engine->lock);
>  
>  	if (ret != -EINPROGRESS)
>  		return ret;
>  
> -	spin_lock_bh(&engine->lock);
> -	if (!engine->req)
> -		mv_cesa_dequeue_req_unlocked(engine);
> -	spin_unlock_bh(&engine->lock);
> +	mv_cesa_rearm_engine(engine);
>  
>  	return -EINPROGRESS;
>  }
> @@ -496,6 +560,7 @@ static int mv_cesa_probe(struct platform_device *pdev)
>  
>  		crypto_init_queue(&engine->queue, CESA_CRYPTO_DEFAULT_MAX_QLEN);
>  		atomic_set(&engine->load, 0);
> +		INIT_LIST_HEAD(&engine->complete_queue);
>  	}
>  
>  	cesa_dev = cesa;
> diff --git a/drivers/crypto/marvell/cesa.h b/drivers/crypto/marvell/cesa.h
> index 5626aa7..e0fee1f 100644
> --- a/drivers/crypto/marvell/cesa.h
> +++ b/drivers/crypto/marvell/cesa.h
> @@ -271,7 +271,9 @@ struct mv_cesa_op_ctx {
>  /* TDMA descriptor flags */
>  #define CESA_TDMA_DST_IN_SRAM			BIT(31)
>  #define CESA_TDMA_SRC_IN_SRAM			BIT(30)
> -#define CESA_TDMA_TYPE_MSK			GENMASK(29, 0)
> +#define CESA_TDMA_END_OF_REQ			BIT(29)
> +#define CESA_TDMA_NOT_CHAIN			BIT(28)

I would name it CESA_TDMA_BREAK_CHAIN.

> +#define CESA_TDMA_TYPE_MSK			GENMASK(27, 0)
>  #define CESA_TDMA_DUMMY				0
>  #define CESA_TDMA_DATA				1
>  #define CESA_TDMA_OP				2
> @@ -431,6 +433,9 @@ struct mv_cesa_dev {
>   *			SRAM
>   * @queue:		fifo of the pending crypto requests
>   * @load:		engine load counter, useful for load balancing
> + * @chain:		list of the current tdma descriptors being processed
> + * 			by this engine.
> + * @complete_queue:	fifo of the processed requests by the engine
>   *
>   * Structure storing CESA engine information.
>   */
> @@ -448,6 +453,8 @@ struct mv_cesa_engine {
>  	struct gen_pool *pool;
>  	struct crypto_queue queue;
>  	atomic_t load;
> +	struct mv_cesa_tdma_chain chain;
> +	struct list_head complete_queue;
>  };
>  
>  /**
> @@ -618,6 +625,28 @@ struct mv_cesa_ahash_req {
>  
>  extern struct mv_cesa_dev *cesa_dev;
>  
> +
> +static inline void mv_cesa_engine_enqueue_complete_request(
> +	struct mv_cesa_engine *engine, struct crypto_async_request *req)

Coding style issue (see my previous comments).

> +{
> +	list_add_tail(&req->list, &engine->complete_queue);
> +}
> +
> +static inline struct crypto_async_request *
> +mv_cesa_engine_dequeue_complete_request(struct mv_cesa_engine *engine)
> +{
> +	struct crypto_async_request *req;
> +
> +	req = list_first_entry_or_null(&engine->complete_queue,
> +				       struct crypto_async_request,
> +				       list);
> +	if (req)
> +		list_del(&req->list);
> +
> +	return req;
> +}
> +
> +
>  static inline enum mv_cesa_req_type
>  mv_cesa_req_get_type(struct mv_cesa_req *req)
>  {
> @@ -699,6 +728,10 @@ static inline bool mv_cesa_mac_op_is_first_frag(const struct mv_cesa_op_ctx *op)
>  int mv_cesa_queue_req(struct crypto_async_request *req,
>  		      struct mv_cesa_req *creq);
>  
> +struct crypto_async_request *mv_cesa_dequeue_req_locked(
> +		      struct mv_cesa_engine *engine,
> +		      struct crypto_async_request **backlog);

Ditto.

> +
>  static inline struct mv_cesa_engine *mv_cesa_select_engine(int weight)
>  {
>  	int i;
> @@ -804,6 +837,9 @@ static inline int mv_cesa_dma_process(struct mv_cesa_req *dreq,
>  void mv_cesa_dma_prepare(struct mv_cesa_req *dreq,
>  			 struct mv_cesa_engine *engine);
>  void mv_cesa_dma_cleanup(struct mv_cesa_req *dreq);
> +void mv_cesa_tdma_chain(struct mv_cesa_engine *engine,
> +			struct mv_cesa_req *dreq);
> +int mv_cesa_tdma_process(struct mv_cesa_engine *engine, u32 status);
>  
>  
>  static inline void
> diff --git a/drivers/crypto/marvell/cipher.c b/drivers/crypto/marvell/cipher.c
> index 02aa38f..9033191 100644
> --- a/drivers/crypto/marvell/cipher.c
> +++ b/drivers/crypto/marvell/cipher.c
> @@ -225,7 +225,6 @@ mv_cesa_ablkcipher_complete(struct crypto_async_request *req)
>  static const struct mv_cesa_req_ops mv_cesa_ablkcipher_req_ops = {
>  	.step = mv_cesa_ablkcipher_step,
>  	.process = mv_cesa_ablkcipher_process,
> -	.prepare = mv_cesa_ablkcipher_prepare,
>  	.cleanup = mv_cesa_ablkcipher_req_cleanup,
>  	.complete = mv_cesa_ablkcipher_complete,
>  };
> @@ -384,6 +383,7 @@ static int mv_cesa_ablkcipher_dma_req_init(struct ablkcipher_request *req,
>  		goto err_free_tdma;
>  
>  	dreq->chain = chain;
> +	dreq->chain.last->flags |= CESA_TDMA_END_OF_REQ;
>  
>  	return 0;
>  
> @@ -441,7 +441,6 @@ static int mv_cesa_ablkcipher_req_init(struct ablkcipher_request *req,
>  	mv_cesa_update_op_cfg(tmpl, CESA_SA_DESC_CFG_OP_CRYPT_ONLY,
>  			      CESA_SA_DESC_CFG_OP_MSK);
>  
> -	/* TODO: add a threshold for DMA usage */
>  	if (cesa_dev->caps->has_tdma)
>  		ret = mv_cesa_ablkcipher_dma_req_init(req, tmpl);
>  	else
> diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
> index 5946a69..c2ff353 100644
> --- a/drivers/crypto/marvell/hash.c
> +++ b/drivers/crypto/marvell/hash.c
> @@ -172,6 +172,9 @@ static void mv_cesa_ahash_std_step(struct ahash_request *req)
>  	for (i = 0; i < digsize / 4; i++)
>  		writel_relaxed(creq->state[i], engine->regs + CESA_IVDIG(i));
>  
> +	mv_cesa_adjust_op(engine, &creq->op_tmpl);
> +	memcpy_toio(engine->sram, &creq->op_tmpl, sizeof(creq->op_tmpl));
> +
>  	if (creq->cache_ptr)
>  		memcpy_toio(engine->sram + CESA_SA_DATA_SRAM_OFFSET,
>  			    creq->cache, creq->cache_ptr);
> @@ -282,6 +285,9 @@ static void mv_cesa_ahash_step(struct crypto_async_request *req)
>  {
>  	struct ahash_request *ahashreq = ahash_request_cast(req);
>  	struct mv_cesa_ahash_req *creq = ahash_request_ctx(ahashreq);
> +	struct mv_cesa_engine *engine = creq->req.base.engine;
> +	unsigned int digsize;
> +	int i;
>  
>  	if (mv_cesa_req_get_type(&creq->req.base) == CESA_DMA_REQ)
>  		mv_cesa_dma_step(&creq->req.base);
> @@ -367,7 +373,6 @@ static void mv_cesa_ahash_req_cleanup(struct crypto_async_request *req)
>  static const struct mv_cesa_req_ops mv_cesa_ahash_req_ops = {
>  	.step = mv_cesa_ahash_step,
>  	.process = mv_cesa_ahash_process,
> -	.prepare = mv_cesa_ahash_prepare,

Why are you doing that?

>  	.cleanup = mv_cesa_ahash_req_cleanup,
>  	.complete = mv_cesa_ahash_complete,
>  };
> @@ -648,6 +653,8 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
>  	else
>  		creq->cache_ptr = 0;
>  
> +	dreq->chain.last->flags |= (CESA_TDMA_END_OF_REQ | CESA_TDMA_NOT_CHAIN);
> +
>  	return 0;
>  
>  err_free_tdma:
> diff --git a/drivers/crypto/marvell/tdma.c b/drivers/crypto/marvell/tdma.c
> index 9a424f9..ae50545 100644
> --- a/drivers/crypto/marvell/tdma.c
> +++ b/drivers/crypto/marvell/tdma.c
> @@ -98,6 +98,87 @@ void mv_cesa_dma_prepare(struct mv_cesa_req *dreq,
>  	}
>  }
>  
> +void
> +mv_cesa_tdma_chain(struct mv_cesa_engine *engine, struct mv_cesa_req *dreq)
> +{
> +	if (engine->chain.first == NULL && engine->chain.last == NULL) {
> +		engine->chain.first = dreq->chain.first;
> +		engine->chain.last  = dreq->chain.last;
> +	} else {
> +		struct mv_cesa_tdma_desc *last;
> +
> +		last = engine->chain.last;
> +		last->next = dreq->chain.first;
> +		engine->chain.last = dreq->chain.last;

Missing blank line.

> +		if (!(last->flags & CESA_TDMA_NOT_CHAIN))
> +			last->next_dma = dreq->chain.first->cur_dma;
> +	}
> +}
> +
> +int
> +mv_cesa_tdma_process(struct mv_cesa_engine *engine, u32 status)
> +{
> +	struct crypto_async_request *req = NULL;
> +	struct mv_cesa_tdma_desc *tdma = NULL, *next = NULL;
> +	dma_addr_t tdma_cur;
> +	int res = 0;
> +
> +	tdma_cur = readl(engine->regs + CESA_TDMA_CUR);
> +
> +	for (tdma = engine->chain.first; tdma; tdma = next) {
> +		spin_lock_bh(&engine->lock);
> +		next = tdma->next;
> +		spin_unlock_bh(&engine->lock);
> +
> +		if (tdma->flags & CESA_TDMA_END_OF_REQ) {
> +			struct crypto_async_request *backlog = NULL;
> +			struct mv_cesa_ctx *ctx;
> +
> +			spin_lock_bh(&engine->lock);
> +			/*
> +			 * if req is NULL, this means we're processing the
> +			 * request in engine->req.
> +			 */
> +			if (!req)
> +				req = engine->req;
> +			else
> +				req = mv_cesa_dequeue_req_locked(engine,
> +								 &backlog);
> +
> +			/* Re-chaining to the next request */
> +			engine->chain.first = tdma->next;
> +			tdma->next = NULL;
> +
> +			/* If this is the last request, clear the chain */
> +			if (engine->chain.first == NULL)
> +				engine->chain.last  = NULL;
> +			spin_unlock_bh(&engine->lock);
> +
> +			ctx = crypto_tfm_ctx(req->tfm);
> +			res = ctx->ops->process(req, status);

Hm, that's not exactly true. The status you're passing here is only
valid for the last request that has been processed. Say you queued 3
requests. 2 of them were correctly processed, but the last one
triggered an error. You don't want the first 2 requests to be
considered bad.

A solution would be to pass a 'fake' valid status, until we reach the
last request (IOW, tdma->cur_dma == tdma_cur).

> +			ctx->ops->complete(req);
> +
> +			if (res == 0)
> +				mv_cesa_engine_enqueue_complete_request(engine,
> +									req);
> +
> +			if (backlog)
> +				backlog->complete(backlog, -EINPROGRESS);
> +		}

Missing blank line.

> +		if (res || tdma->cur_dma == tdma_cur)
> +			break;
> +	}
> +
> +	if (res) {
> +		spin_lock_bh(&engine->lock);
> +		engine->req = req;
> +		spin_unlock_bh(&engine->lock);
> +	}

Maybe you can add a comment explaining that you are actually setting
the last processed request into engine->req, so that the core can know
which request was faulty.

> +
> +	return res;
> +}
> +
> +
>  static struct mv_cesa_tdma_desc *
>  mv_cesa_dma_add_desc(struct mv_cesa_tdma_chain *chain, gfp_t flags)
>  {



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com



More information about the linux-arm-kernel mailing list