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Message-ID: <20170925182713.ti4esyznyrjr7xh7@kozik-lap>
Date:   Mon, 25 Sep 2017 20:27:13 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Kamil Konieczny <k.konieczny@...tner.samsung.com>
Cc:     linux-crypto@...r.kernel.org,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Vladimir Zapolskiy <vz@...ia.com>,
        "David S. Miller" <davem@...emloft.net>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] crypto: s5p-sss: Add HASH support for Exynos

On Fri, Sep 22, 2017 at 08:00:17PM +0200, Kamil Konieczny wrote:
> On 19.09.2017 21:03, Krzysztof Kozlowski wrote:
> > On Fri, Sep 15, 2017 at 07:50:06PM +0200, Kamil Konieczny wrote:

(...)

> >> +
> >> +/* HASH flags */
> >
> > All defines below have "HASH_FLAGS" prefix... so actually useful would
> > be to explain also what is a hash flag.
> 
> These are bit numbers used by device driver, setting in dev->hash_flags,
> used with set_bit(), clear_bit() or test_bit(), and with macro BIT(),
> to keep device state BUSY or FREE, or to signal state from irq_handler
> to hash_tasklet.

Then add something similar as comment to the code.

>  
> >> +#define HASH_FLAGS_BUSY		0
> >> +#define HASH_FLAGS_FINAL	1
> >> +#define HASH_FLAGS_DMA_ACTIVE	2
> >> +#define HASH_FLAGS_OUTPUT_READY	3
> >> +#define HASH_FLAGS_INIT		4
> >> +#define HASH_FLAGS_DMA_READY	6
> >> +
> >> +#define HASH_FLAGS_SGS_COPIED	9
> >> +#define HASH_FLAGS_SGS_ALLOCED	10
> >> +/* HASH context flags */
> >
> > Same here.
> 
> These are bit numbers internal for request context, reqctx->flags
> 
> >
> >> +#define HASH_FLAGS_FINUP	16
> >> +#define HASH_FLAGS_ERROR	17
> >> +
> >> +#define HASH_FLAGS_MODE_MD5	18
> >> +#define HASH_FLAGS_MODE_SHA1	19
> >> +#define HASH_FLAGS_MODE_SHA256	20
> >
> > These are set and not read?
> 
> It is leftover from omap driver, it was used in hmac alg.
> I will remove it.
> 
> >
> >> +
> >> +#define HASH_FLAGS_MODE_MASK	(BIT(18) | BIT(19) | BIT(20))
> >
> > Not used.
> >
> >> +/* HASH op codes */
> >> +#define HASH_OP_UPDATE		1
> >> +#define HASH_OP_FINAL		2
> >> +
> >> +/* HASH HW constants */
> >> +#define HASH_ALIGN_MASK		(HASH_BLOCK_SIZE-1)
> >
> > Not used.
> >
> >> +
> >> +#define BUFLEN			HASH_BLOCK_SIZE
> >> +
> >> +#define SSS_DMA_ALIGN		16
> >> +#define SSS_ALIGNED		__attribute__((aligned(SSS_DMA_ALIGN)))
> >> +#define SSS_DMA_ALIGN_MASK	(SSS_DMA_ALIGN-1)
> >
> > Please make it consistent with existing code, e.g.: by replacing
> > AES .cra_alignmask with same macro. In separate patch of course.
> 
> Thank you, I will do it in next patches.
> 
> DMA align for AES is 16, and for HASH is 8 (both aligned up),
> but I think it is simpler to have it both 16. This align is for length,
> e.g when len is not divisible by 8 (HASH case), DMA FC will round it up
> by 8, but HASH IP consumes only bytes set by len registers (so HASH will
> be correctly computed).
> 
> >
> >> +
> >> +/* HASH queue constant */
> >
> > Pretty useless comment. Do not use comments which copy the code. You
> > could explain here why you have chosen 10 (existing AES code uses 1).
> >
> >> +#define SSS_HASH_QUEUE_LENGTH	10
> 
> Number 10 was copied from omap-sham.c
> 
> The question why to use queue in device driver is good topic for RFC,
> I do not see any advantages for it except for corner cases,
> when driver receives many digest() request,
> or many update() from different contexts.
> 
> Basically it will not queue more than one update() from one context
> because the state for HASH is kept in request context, e.g. once 
> crypto user calls update() it must wait for its end before sending next.
> 
> It does have some effect on design, as it allows copy bytes for small
> update into request context (instead of putting it in queue).
> 
> >> +
> >> +/**
> >> + * struct sss_hash_algs_info - platform specific SSS HASH algorithms
> >> + * @algs_list:	array of transformations (algorithms)
> >> + * @size:	size
> >> + * @registered:	counter used at probe/remove
> >> + *
> >> + * Specifies platform specific information about hash algorithms
> >> + * of SSS module.
> >> + */
> >> +struct sss_hash_algs_info {
> >> +	struct ahash_alg	*algs_list;
> >> +	unsigned int		size;
> >> +	unsigned int		registered;
> >> +};
> >> +
> >>  /**
> >>   * struct samsung_aes_variant - platform specific SSS driver data
> >>   * @aes_offset: AES register offset from SSS module's base.
> >> + * @hash_offset: HASH register offset from SSS module's base.
> >> + *
> >> + * @hash_algs_info: HASH transformations provided by SS module
> >> + * @hash_algs_size: size of hash_algs_info
> >>   *
> >>   * Specifies platform specific configuration of SSS module.
> >>   * Note: A structure for driver specific platform data is used for future
> >> @@ -156,6 +279,10 @@
> >>   */
> >>  struct samsung_aes_variant {
> >>  	unsigned int			aes_offset;
> >> +	unsigned int			hash_offset;
> >> +
> >> +	struct sss_hash_algs_info	*hash_algs_info;
> >> +	unsigned int			hash_algs_size;
> >>  };
> >>  
> >>  struct s5p_aes_reqctx {
> >> @@ -194,7 +321,21 @@ struct s5p_aes_ctx {
> >>   *		req, ctx, sg_src/dst (and copies).  This essentially
> >>   *		protects against concurrent access to these fields.
> >>   * @lock:	Lock for protecting both access to device hardware registers
> >> - *		and fields related to current request (including the busy field).
> >> + *		and fields related to current request (including the busy
> >> + *		field).
> >> + * @res:	Resources for hash.
> >> + * @io_hash_base: Per-variant offset for HASH block IO memory.
> >> + * @hash_lock:	Lock for protecting hash_req and other HASH variables.
> >
> > I must admit that I do not see how it protects the hash_req. The
> > hash_req looks untouched (not read, not modified) during this lock
> > critical section. Can you share some more thoughts about it?
> 
> It protects dev->hash_queue and dev->hash_flags
> in begin of function s5p_hash_handle_queue.
> 
> After dequeue non-null request, bit HASH_BUSY is set in dd->hash_flags,
> and this bit protects dd->hash_req and other fields. From there device
> works with dd->hash_req until finish in irq_handler and hash_tasklet.

Few thoughts here:
1. Other accesses to HASH_BUSY bit of hash_flags are not protected with
   lock and you are using set_bit/clear_bit which are atomic operations,
   so from this perspective it does not protect hash_flags.
2. This means the only field protected here is hash_queue so I guess you
   expect possibility of multiple concurrent calls to s5p_hash_handle_queue().
   This makes sense but then description has to be updated.

> 
> >> + * @hash_err:	Error flags for current HASH op.
> >> + * @hash_tasklet: New HASH request scheduling job.
> >> + * @xmit_buf:	Buffer for current HASH request transfer into SSS block.
> >> + * @hash_flags:	Flags for current HASH op.
> >
> > What is the purpose of them?
> >
> 
> See above.
> 
> >> + * @hash_queue:	Async hash queue.
> >> + * @hash_req:	Current request sending to SSS HASH block.
> >> + * @hash_sg_iter: Scatterlist transferred through DMA into SSS HASH block.
> >> + * @hash_sg_cnt: Counter for hash_sg_iter.
> >> + *
> >> + * @pdata:	Per-variant algorithms for HASH ops.
> >>   */
> >>  struct s5p_aes_dev {
> >>  	struct device			*dev;
> >> @@ -215,16 +356,85 @@ struct s5p_aes_dev {
> >>  	struct crypto_queue		queue;
> >>  	bool				busy;
> >>  	spinlock_t			lock;
> >> +
> >> +	struct resource			*res;
> >> +	void __iomem			*io_hash_base;
> >> +
> >> +	spinlock_t			hash_lock;
> >> +	int				hash_err;
> >
> > I do not see any setter to hash_err, except '= 0'.
>  
> You are right, I blindly copied this from omap,
> and as I check for errors before in processing request context,
> this one from device is not used.
> I will remove it.
> 
> >> +	struct tasklet_struct		hash_tasklet;
> >> +	u8				xmit_buf[BUFLEN] SSS_ALIGNED;
> >> +
> >> +	unsigned long			hash_flags;
> >
> > This should be probably DECLARE_BITMAP.
> 
> I do not get it, it is used for bits HASH_FLAGS_... and is not HW related.
> This will grow this patch even longer.

Why longer? Only declaration changes, rest should be the same.
Just instead of playing with bits over unsigned long explicitly use a
type for that purpose - DECLARE_BITMAP.

> 
> >> +	struct crypto_queue		hash_queue;
> >> +	struct ahash_request		*hash_req;
> >> +	struct scatterlist		*hash_sg_iter;
> >> +	int				hash_sg_cnt;
> >> +
> >> +	struct samsung_aes_variant	*pdata;
> >
> > This should be const as pdata should not be modified.
> 
> You are right, and I do not modify _offsets parts, but only hash
> functions pointers and hash array size. It is made non-const due
> to keeping it in the place, and not moving struct samsung_aes_variant
> below hash functions definitions.
> 
> If I need to keep them const, then I will move whole part below, just
> before _probe, so I can properly set hash_algs_info and
> hash_algs_size (and again, small change, but bigger patch).
> 
> I can do this, if you think it is safer to have them const.

I see, you are modifiying the variant->hash_algs_info and
variant->hash_algs_size. However all of them should be static const as
this is not a dynamic data. It does not depend on any runtime
conditions, except of course choosing the variant itself.

> 
> >>  };
> >>  
> >> -static struct s5p_aes_dev *s5p_dev;
> >> +/**
> >> + * struct s5p_hash_reqctx - HASH request context
> >> + * @dev:	Associated device
> >> + * @flags:	Bits for current HASH request
> >> + * @op:		Current request operation (OP_UPDATE or UP_FINAL)
> >> + * @digcnt:	Number of bytes processed by HW (without buffer[] ones)
> >> + * @digest:	Digest message or IV for partial result
> >> + * @bufcnt:	Number of bytes holded in buffer[]
> >> + * @buflen:	Max length of the input data buffer
> >> + * @nregs:	Number of HW registers for digest or IV read/write.
> >
> > Skip the trailing dot for consistency.
> >
> >> + * @engine:	Flags for setting HASH SSS block.
> >> + * @sg:		sg for DMA transfer.
> >> + * @sg_len:	Length of sg for DMA transfer.
> >> + * @sgl[]:	sg for joining buffer and req->src scatterlist.
> >> + * @skip:	Skip offset in req->src for current op.
> >> + * @total:	Total number of bytes for current request.
> >> + * @buffer[]:	For byte(s) from end of req->src in UPDATE op.
> >> + */
> >> +struct s5p_hash_reqctx {
> >> +	struct s5p_aes_dev	*dd;
> >> +	unsigned long		flags;
> >> +	int			op;
> >> +
> >> +	u64			digcnt;
> >> +	u8			digest[SHA256_DIGEST_SIZE] SSS_ALIGNED;
> >> +	u32			bufcnt;
> >> +	u32			buflen;
> >> +
> >> +	int			nregs; /* digest_size / sizeof(reg) */
> >> +	u32			engine;
> >> +
> >> +	struct scatterlist	*sg;
> >> +	int			sg_len;
> >> +	struct scatterlist	sgl[2];
> >> +	int			skip;	/* skip offset in req->src sg */
> >> +	unsigned int		total;	/* total request */
> >> +
> >> +	u8			buffer[0] SSS_ALIGNED;
> >> +};
> >> +
> >> +/**
> >> + * struct s5p_hash_ctx - HASH transformation context
> >> + * @dd:		Associated device
> >> + * @flags:	Bits for algorithm HASH.
> >> + * @fallback:	Software transformation for zero message or size < BUFLEN.
> >> + */
> >> +struct s5p_hash_ctx {
> >> +	struct s5p_aes_dev	*dd;
> >> +	unsigned long		flags;
> >> +	struct crypto_shash	*fallback;
> >> +};
> >>  
> >> -static const struct samsung_aes_variant s5p_aes_data = {
> >> +static struct samsung_aes_variant s5p_aes_data = {
> >
> > Why do you need to drop the const? This should not be modified.
> 
> I explained this above.
> 
> >>  	.aes_offset	= 0x4000,
> >> +	.hash_offset	= 0x6000,
> >> +	.hash_algs_size	= 0,
> >>  };
> >>  
> >> -static const struct samsung_aes_variant exynos_aes_data = {
> >> -	.aes_offset	= 0x200,
> >> +static struct samsung_aes_variant exynos_aes_data = {
> >> +	.aes_offset		= 0x200,
> >> +	.hash_offset		= 0x400,
> >>  };
> >>  
> >>  static const struct of_device_id s5p_sss_dt_match[] = {
> >> @@ -254,6 +464,8 @@ static inline struct samsung_aes_variant *find_s5p_sss_version
> >>  			platform_get_device_id(pdev)->driver_data;
> >>  }
> >>  
> >> +static struct s5p_aes_dev *s5p_dev;
> >> +
> >
> > Still some weird moves of untouched lines... this is weird.
> >
> >>  static void s5p_set_dma_indata(struct s5p_aes_dev *dev, struct scatterlist *sg)
> >>  {
> >>  	SSS_WRITE(dev, FCBRDMAS, sg_dma_address(sg));
> >> @@ -436,19 +648,85 @@ static int s5p_aes_rx(struct s5p_aes_dev *dev/*, bool *set_dma*/)
> >>  	return ret;
> >>  }
> >>  
> >> +static inline u32 s5p_hash_read(struct s5p_aes_dev *dd, u32 offset)
> >> +{
> >> +	return __raw_readl(dd->io_hash_base + offset);
> >> +}
> >> +
> >> +static inline void s5p_hash_write(struct s5p_aes_dev *dd,
> >> +				  u32 offset, u32 value)
> >> +{
> >> +	__raw_writel(value, dd->io_hash_base + offset);
> >> +}
> >> +
> >> +static inline void s5p_hash_write_mask(struct s5p_aes_dev *dd, u32 address,
> >> +				       u32 value, u32 mask)
> >> +{
> >> +	u32 val;
> >> +
> >> +	val = s5p_hash_read(dd, address);
> >> +	val &= ~mask;
> >> +	val |= value;
> >> +	s5p_hash_write(dd, address, val);
> >> +}
> >> +
> >> +/**
> >> + * s5p_set_dma_hashdata - start DMA with sg
> >> + * @dev:	device
> >> + * @sg:		scatterlist ready to DMA transmit
> >> + *
> >> + * decrement sg counter
> >> + * write addr and len into HASH regs
> >
> > Please apply some sentence formatting.
> 
> Hmm, I will just delete this, as it rewrites code.
> 
> 
> >> + *
> >> + * DMA starts after writing length
> >> + */
> >> +static void s5p_set_dma_hashdata(struct s5p_aes_dev *dev,
> >> +				 struct scatterlist *sg)
> >> +{
> >> +	dev->hash_sg_cnt--;
> >> +	WARN_ON(dev->hash_sg_cnt < 0);
> >> +	WARN_ON(sg_dma_len(sg) <= 0);
> >
> > It cannot be less than 0... Probably decent compiler or Smatch or Sparse
> > points this. The question is whether you really need these checks. When
> > could they happen?
> 
> It was for debugging only, when len hit zero driver hangs.
> I will remove it.
>  
> >> +	SSS_WRITE(dev, FCHRDMAS, sg_dma_address(sg));
> >> +	SSS_WRITE(dev, FCHRDMAL, sg_dma_len(sg)); /* DMA starts */
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_rx - get next hash_sg_iter
> >> + * @dev:	device
> >> + *
> >> + * Return:
> >> + * 2	if there is no more data,
> >> + * 1	if new receiving (input) data is ready and can be written to
> >> + *	device
> >
> > This looks weird, if this returns only two variables this should be
> > bool (or 0/non-zero or enum). Or you wanted to make it consistent with
> > AES-stuff?
> 
> Yes, it is for AES-stuff consistency.
> I can have two variables, both bool, or one int with three states,
> 0 = HASH not used, and 1 or 2 from this function.
> State '2' is needed for update case, so I need write HASH_PAUSE.

Okay, makes sense.

> 
> >
> >> + */
> >> +static int s5p_hash_rx(struct s5p_aes_dev *dev)
> >> +{
> >> +	int ret = 2;
> >> +
> >> +	if (dev->hash_sg_cnt > 0) {
> >> +		dev->hash_sg_iter = sg_next(dev->hash_sg_iter);
> >> +		ret = 1;
> >> +	} else {
> >> +		set_bit(HASH_FLAGS_DMA_READY, &dev->hash_flags);
> >> +	}
> >> +
> >> +	return ret;
> >> +}
> >> +
> >>  static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
> >>  {
> >>  	struct platform_device *pdev = dev_id;
> >>  	struct s5p_aes_dev *dev = platform_get_drvdata(pdev);
> >>  	int err_dma_tx = 0;
> >>  	int err_dma_rx = 0;
> >> +	int err_dma_hx = 0;
> >>  	bool tx_end = false;
> >> +	bool hx_end = false;
> >>  	unsigned long flags;
> >> -	uint32_t status;
> >> +	u32 status, st_bits;
> >>  	int err;
> >>  
> >>  	spin_lock_irqsave(&dev->lock, flags);
> >> -
> >
> > No cleanups mixed with real change. This is already a big patch...
> 
> OK, sorry, I will remove this one.
> 
> >
> >>  	/*
> >>  	 * Handle rx or tx interrupt. If there is still data (scatterlist did not
> >>  	 * reach end), then map next scatterlist entry.
> >> @@ -456,6 +734,8 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
> >>  	 *
> >>  	 * If there is no more data in tx scatter list, call s5p_aes_complete()
> >>  	 * and schedule new tasklet.
> >> +	 *
> >> +	 * Handle hx interrupt. If there is still data map next entry.
> >>  	 */
> >>  	status = SSS_READ(dev, FCINTSTAT);
> >>  	if (status & SSS_FCINTSTAT_BRDMAINT)
> >> @@ -467,7 +747,29 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
> >>  		err_dma_tx = s5p_aes_tx(dev);
> >>  	}
> >>  
> >> -	SSS_WRITE(dev, FCINTPEND, status);
> >> +	if (status & SSS_FCINTSTAT_HRDMAINT)
> >> +		err_dma_hx = s5p_hash_rx(dev);
> >> +
> >> +	st_bits = status & (SSS_FCINTSTAT_BRDMAINT | SSS_FCINTSTAT_BTDMAINT |
> >> +				SSS_FCINTSTAT_HRDMAINT);
> >> +	/* clear DMA bits */
> >
> > Why only DMA bits?
> 
> This is documented in Exynos 4412 spec for SecSS, DMA bits are cleared by writing
> the same bits to FCINTPEND, and HASH bits by writing HASH status bits into
> HAST_STATUS register, and the hash irq DONE and PART bits do not match hash
> status ones.
> 
> HASH bits can be written into FCINPEND but they will be ignored.
> 
> >> +	SSS_WRITE(dev, FCINTPEND, st_bits);
> >> +
> >> +	/* clear HASH irq bits */
> >> +	if (status & (SSS_FCINTSTAT_HDONEINT | SSS_FCINTSTAT_HPARTINT)) {
> >> +		/* cannot have both HPART and HDONE */
> >> +		if (status & SSS_FCINTSTAT_HPARTINT)
> >> +			st_bits = SSS_HASH_STATUS_PARTIAL_DONE;
> >> +
> >> +		if (status & SSS_FCINTSTAT_HDONEINT)
> >> +			st_bits = SSS_HASH_STATUS_MSG_DONE;
> >> +
> >> +		set_bit(HASH_FLAGS_OUTPUT_READY, &dev->hash_flags);
> >> +		s5p_hash_write(dev, SSS_REG_HASH_STATUS, st_bits);
> >> +		hx_end = true;
> >> +		/* when DONE or PART, do not handle HASH DMA */
> >> +		err_dma_hx = 0;
> >> +	}
> >>  
> >>  	if (err_dma_rx < 0) {
> >>  		err = err_dma_rx;
> >> @@ -480,6 +782,8 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
> >>  
> >>  	if (tx_end) {
> >>  		s5p_sg_done(dev);
> >> +		if (err_dma_hx == 1)
> >> +			s5p_set_dma_hashdata(dev, dev->hash_sg_iter);
> >>  
> >>  		spin_unlock_irqrestore(&dev->lock, flags);
> >>  
> >> @@ -497,21 +801,1274 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
> >>  			s5p_set_dma_outdata(dev, dev->sg_dst);
> >>  		if (err_dma_rx == 1)
> >>  			s5p_set_dma_indata(dev, dev->sg_src);
> >> +		if (err_dma_hx == 1)
> >> +			s5p_set_dma_hashdata(dev, dev->hash_sg_iter);
> >>  
> >>  		spin_unlock_irqrestore(&dev->lock, flags);
> >>  	}
> >>  
> >> -	return IRQ_HANDLED;
> >> +	goto hash_irq_end;
> >>  
> >>  error:
> >>  	s5p_sg_done(dev);
> >>  	dev->busy = false;
> >> +	if (err_dma_hx == 1)
> >> +		s5p_set_dma_hashdata(dev, dev->hash_sg_iter);
> >> +
> >>  	spin_unlock_irqrestore(&dev->lock, flags);
> >>  	s5p_aes_complete(dev, err);
> >>  
> >> +hash_irq_end:
> >> +	/*
> >> +	 * Note about else if:
> >> +	 *   when hash_sg_iter reaches end and its UPDATE op,
> >> +	 *   issue SSS_HASH_PAUSE and wait for HPART irq
> >> +	 */
> >> +	if (hx_end)
> >> +		tasklet_schedule(&dev->hash_tasklet);
> >> +	else if ((err_dma_hx == 2) &&
> >> +		!test_bit(HASH_FLAGS_FINAL, &dev->hash_flags))
> >> +		s5p_hash_write(dev, SSS_REG_HASH_CTRL_PAUSE,
> >> +			       SSS_HASH_PAUSE);
> >> +
> >>  	return IRQ_HANDLED;
> >>  }
> >>  
> >> +/**
> >> + * s5p_hash_read_msg - read message or IV from HW
> >> + * @req:	AHASH request
> >> + */
> >> +static void s5p_hash_read_msg(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	struct s5p_aes_dev *dd = ctx->dd;
> >> +	u32 *hash = (u32 *)ctx->digest;
> >> +	int i;
> >> +
> >> +	for (i = 0; i < ctx->nregs; i++)
> >> +		hash[i] = s5p_hash_read(dd, SSS_REG_HASH_OUT(i));
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_write_ctx_iv - write IV for next partial/finup op.
> >> + * @dd:		device
> >> + * @ctx:	request context
> >> + */
> >> +static void s5p_hash_write_ctx_iv(struct s5p_aes_dev *dd,
> >> +				  struct s5p_hash_reqctx *ctx)
> >> +{
> >> +	u32 *hash = (u32 *)ctx->digest;
> >> +	int i;
> >> +
> >> +	for (i = 0; i < ctx->nregs; i++)
> >> +		s5p_hash_write(dd, SSS_REG_HASH_IV(i), hash[i]);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_write_iv - write IV for next partial/finup op.
> >> + * @req:	AHASH request
> >> + */
> >> +static void s5p_hash_write_iv(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	struct s5p_aes_dev *dd = ctx->dd;
> >> +
> >> +	s5p_hash_write_ctx_iv(dd, ctx);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_copy_result - copy digest into req->result
> >> + * @req:	AHASH request
> >> + */
> >> +static void s5p_hash_copy_result(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	int d = ctx->nregs;
> >> +
> >> +	if (!req->result)
> >> +		return;
> >> +
> >> +	memcpy(req->result, (u8 *)ctx->digest, d * HASH_REG_SIZEOF);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_dma_flush - flush HASH DMA
> >> + * @dev:	secss device
> >> + */
> >> +static void s5p_hash_dma_flush(struct s5p_aes_dev *dev)
> >> +{
> >> +	SSS_WRITE(dev, FCHRDMAC, SSS_FCHRDMAC_FLUSH);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_dma_enable()
> >> + * @dev:	secss device
> >> + *
> >> + * enable DMA mode for HASH
> >> + */
> >> +static void s5p_hash_dma_enable(struct s5p_aes_dev *dev)
> >> +{
> >> +	s5p_hash_write(dev, SSS_REG_HASH_CTRL_FIFO, SSS_HASH_FIFO_MODE_DMA);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_irq_disable - disable irq HASH signals
> >> + * @dev:	secss device
> >> + * @flags:	bitfield with irq's to be disabled
> >> + */
> >> +static void s5p_hash_irq_disable(struct s5p_aes_dev *dev, u32 flags)
> >> +{
> >> +	SSS_WRITE(dev, FCINTENCLR, flags);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_irq_enable - enable irq signals
> >> + * @dev:	secss device
> >> + * @flags:	bitfield with irq's to be enabled
> >> + */
> >> +static void s5p_hash_irq_enable(struct s5p_aes_dev *dev, int flags)
> >> +{
> >> +	SSS_WRITE(dev, FCINTENSET, flags);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_set_flow()
> >> + * @dev:	secss device
> >> + * @hashflow:	HASH stream flow with/without crypto AES/DES
> >> + */
> >> +static void s5p_hash_set_flow(struct s5p_aes_dev *dev, u32 hashflow)
> >> +{
> >> +	unsigned long flags;
> >> +	u32 flow;
> >> +
> >> +	spin_lock_irqsave(&dev->lock, flags);
> >> +
> >> +	flow = SSS_READ(dev, FCFIFOCTRL);
> >> +
> >> +	hashflow &= SSS_HASHIN_MASK;
> >> +	flow &= ~SSS_HASHIN_MASK;
> >> +	flow |= hashflow;
> >> +
> >> +	SSS_WRITE(dev, FCFIFOCTRL, hashflow);
> >> +
> >> +	spin_unlock_irqrestore(&dev->lock, flags);
> >> +}
> >> +
> >> +/**
> >> + * s5p_ahash_dma_init -
> >> + * @dev:	secss device
> >> + * @hashflow:	HASH stream flow with/without AES/DES
> >> + *
> >> + * flush HASH DMA and enable DMA,
> >> + * set HASH stream flow inside SecSS HW
> >> + * enable HASH irq's HRDMA, HDONE, HPART
> >> + */
> >> +static void s5p_ahash_dma_init(struct s5p_aes_dev *dev, u32 hashflow)
> >> +{
> >> +	s5p_hash_irq_disable(dev, SSS_FCINTENCLR_HRDMAINTENCLR |
> >> +			     SSS_FCINTENCLR_HDONEINTENCLR |
> >> +			     SSS_FCINTENCLR_HPARTINTENCLR);
> >> +	s5p_hash_dma_flush(dev);
> >> +
> >> +	s5p_hash_dma_enable(dev);
> >> +	s5p_hash_set_flow(dev, hashflow);
> >> +
> >> +	s5p_hash_irq_enable(dev, SSS_FCINTENSET_HRDMAINTENSET |
> >> +			    SSS_FCINTENSET_HDONEINTENSET |
> >> +			    SSS_FCINTENSET_HPARTINTENSET);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_hw_init -
> >> + * @dev:	secss device
> >> + */
> >> +static int s5p_hash_hw_init(struct s5p_aes_dev *dev)
> >> +{
> >> +	set_bit(HASH_FLAGS_INIT, &dev->hash_flags);
> >> +	s5p_ahash_dma_init(dev, SSS_HASHIN_INDEPENDENT);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_write_ctrl -
> >> + * @dd:		secss device
> >> + * @length:	length for request
> >> + * @final:	0=not final
> >> + *
> >> + * Prepare SSS HASH block for processing bytes in DMA mode.
> >> + * If it is called after previous updates, fill up IV words.
> >> + * For final, calculate and set lengths for SSS HASH so it can
> >> + * finalize hash.
> >> + * For partial, set SSS HASH length as 2^63 so it will be never
> >> + * reached and set to zero prelow and prehigh.
> >> + *
> >> + * This function do not start DMA transfer.
> >> + */
> >> +static void s5p_hash_write_ctrl(struct s5p_aes_dev *dd, size_t length,
> >> +				int final)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(dd->hash_req);
> >> +	u32 configflags, swapflags;
> >> +	u32 prelow, prehigh, low, high;
> >> +	u64 tmplen;
> >> +
> >> +	configflags = ctx->engine | SSS_HASH_INIT_BIT;
> >> +
> >> +	if (likely(ctx->digcnt)) {
> >> +		s5p_hash_write_ctx_iv(dd, ctx);
> >> +		configflags |= SSS_HASH_USER_IV_EN;
> >> +	}
> >> +
> >> +	if (final) {
> >> +		/* number of bytes for last part */
> >> +		low = length; high = 0;
> >> +		/* total number of bits prev hashed */
> >> +		tmplen = ctx->digcnt * 8;
> >> +		prelow = (u32)tmplen;
> >> +		prehigh = (u32)(tmplen >> 32);
> >> +	} else {
> >> +		prelow = 0; prehigh = 0;
> >> +		low = 0; high = BIT(31);
> >> +	}
> >> +
> >> +	swapflags = SSS_HASH_BYTESWAP_DI | SSS_HASH_BYTESWAP_DO |
> >> +		    SSS_HASH_BYTESWAP_IV | SSS_HASH_BYTESWAP_KEY;
> >> +
> >> +	s5p_hash_write(dd, SSS_REG_HASH_MSG_SIZE_LOW, low);
> >> +	s5p_hash_write(dd, SSS_REG_HASH_MSG_SIZE_HIGH, high);
> >> +	s5p_hash_write(dd, SSS_REG_HASH_PRE_MSG_SIZE_LOW, prelow);
> >> +	s5p_hash_write(dd, SSS_REG_HASH_PRE_MSG_SIZE_HIGH, prehigh);
> >> +
> >> +	s5p_hash_write(dd, SSS_REG_HASH_CTRL_SWAP, swapflags);
> >> +	s5p_hash_write(dd, SSS_REG_HASH_CTRL, configflags);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_xmit_dma - start DMA hash processing
> >> + * @dd:		secss device
> >> + * @length:	length for request
> >> + * @final:	0=not final
> >> + *
> >> + * Map ctx->sg into DMA_TO_DEVICE,
> >> + * remember sg and cnt in device dd->hash_sg_iter, dd->hash_sg_cnt
> >> + * so it can be used in loop inside irq handler.
> >> + * Update ctx->digcnt, need this to keep number of processed bytes
> >> + * for last final/finup request.
> >> + * Set dma address and length, this starts DMA,
> >> + * return with -EINPROGRESS.
> >> + * HW HASH block will issue signal for irq handler.
> >> + */
> >> +static int s5p_hash_xmit_dma(struct s5p_aes_dev *dd, size_t length,
> >> +			      int final)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(dd->hash_req);
> >> +	int cnt;
> >> +
> >> +	dev_dbg(dd->dev, "xmit_dma: digcnt: %lld, length: %u, final: %d\n",
> >> +						ctx->digcnt, length, final);
> >> +
> >> +	cnt = dma_map_sg(dd->dev, ctx->sg, ctx->sg_len, DMA_TO_DEVICE);
> >> +	if (!cnt) {
> >> +		dev_err(dd->dev, "dma_map_sg error\n");
> >> +		set_bit(HASH_FLAGS_ERROR, &ctx->flags);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	set_bit(HASH_FLAGS_DMA_ACTIVE, &dd->hash_flags);
> >> +	dd->hash_sg_iter = ctx->sg;
> >> +	dd->hash_sg_cnt = cnt;
> >> +	s5p_hash_write_ctrl(dd, length, final);
> >> +	/* update digcnt in request */
> >> +	ctx->digcnt += length;
> >> +	ctx->total -= length;
> >> +
> >> +	/* catch last interrupt */
> >> +	if (final)
> >> +		set_bit(HASH_FLAGS_FINAL, &dd->hash_flags);
> >> +
> >> +	s5p_set_dma_hashdata(dd, dd->hash_sg_iter); /* DMA starts */
> >> +
> >> +	return -EINPROGRESS;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_copy_sgs -
> >> + * @ctx:	request context
> >> + * @sg:		source scatterlist request
> >> + * @bs:		block size
> >> + * @new_len:	number of bytes to process from sg
> >> + *
> >> + * Allocate new buffer, copy data for HASH into it.
> >> + * If there was xmit_buf filled, copy it first, then
> >> + * copy data from sg into it.
> >> + * Prepare one sgl[0] with allocated buffer.
> >> + *
> >> + * Set ctx->sg to sgl[0].
> >> + * Set flag so we can free it after irq ends processing.
> >> + */
> >> +static int s5p_hash_copy_sgs(struct s5p_hash_reqctx *ctx,
> >> +			     struct scatterlist *sg, int bs, int new_len)
> >> +{
> >> +	int pages;
> >> +	void *buf;
> >> +	int len;
> >> +
> >> +	len = new_len + ctx->bufcnt;
> >> +	pages = get_order(len);
> >> +
> >> +	buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
> >> +	if (!buf) {
> >> +		dev_err(ctx->dd->dev, "alloc pages for unaligned case.\n");
> >> +		set_bit(HASH_FLAGS_ERROR, &ctx->flags);
> >> +		return -ENOMEM;
> >> +	}
> >> +
> >> +	if (ctx->bufcnt)
> >> +		memcpy(buf, ctx->dd->xmit_buf, ctx->bufcnt);
> >> +
> >> +	scatterwalk_map_and_copy(buf + ctx->bufcnt, sg, ctx->skip,
> >> +				 new_len, 0);
> >> +	sg_init_table(ctx->sgl, 1);
> >> +	sg_set_buf(ctx->sgl, buf, len);
> >> +	ctx->sg = ctx->sgl;
> >> +	ctx->sg_len = 1;
> >> +	ctx->bufcnt = 0;
> >> +	ctx->skip = 0;
> >> +	set_bit(HASH_FLAGS_SGS_COPIED, &ctx->dd->hash_flags);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_copy_sg_lists -
> >> + * @rctx:	request context
> >> + * @sg:		source scatterlist request
> >> + * @bs:		block size
> >> + * @new_len:	number of bytes to process from sg
> >> + *
> >> + * Allocate new scatterlist table, copy data for HASH into it.
> >> + * If there was xmit_buf filled, prepare it first, then
> >> + * copy page, length and offset from source sg into it,
> >> + * adjusting begin and/or end for skip offset and hash_later value.
> >> + *
> >> + * Resulting sg table will be assigned to ctx->sg.
> >> + * Set flag so we can free it after irq ends processing.
> >> + */
> >> +static int s5p_hash_copy_sg_lists(struct s5p_hash_reqctx *ctx,
> >> +				  struct scatterlist *sg, int bs, int new_len)
> >> +{
> >> +	int n = sg_nents(sg);
> >> +	struct scatterlist *tmp;
> >> +	int offset = ctx->skip;
> >
> > Here and in some other places - while declaring many variables, some
> > preassigned some note, please use some consistency. It is a matter of
> > taste but usually this would improve readability. Preferably - looking
> > at existing code in s5p-sss.c - first declarations with assignments,
> > then rest of declarations. Lines in each group ordered with
> > reversed-christmas-tree.  Something like in existing
> > s5p_aes_interrupt(), although there order comes also from code flow.
> >
> 
> OK, I will change this.
> 
> >> +
> >> +	if (ctx->bufcnt)
> >> +		n++;
> >> +
> >> +	ctx->sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);
> >> +	if (!ctx->sg) {
> >> +		set_bit(HASH_FLAGS_ERROR, &ctx->flags);
> >> +		return -ENOMEM;
> >> +	}
> >> +
> >> +	sg_init_table(ctx->sg, n);
> >> +
> >> +	tmp = ctx->sg;
> >> +
> >> +	ctx->sg_len = 0;
> >> +
> >> +	if (ctx->bufcnt) {
> >> +		sg_set_buf(tmp, ctx->dd->xmit_buf, ctx->bufcnt);
> >> +		tmp = sg_next(tmp);
> >> +		ctx->sg_len++;
> >> +	}
> >> +
> >> +	while (sg && new_len) {
> >> +		int len = sg->length - offset;
> >> +
> >> +		if (offset) {
> >> +			offset -= sg->length;
> >> +			if (offset < 0)
> >> +				offset = 0;
> >> +		}
> >> +
> >> +		if (new_len < len)
> >> +			len = new_len;
> >> +
> >> +		if (len > 0) {
> >> +			new_len -= len;
> >> +			sg_set_page(tmp, sg_page(sg), len, sg->offset);
> >> +			if (new_len <= 0)
> >> +				sg_mark_end(tmp);
> >> +			tmp = sg_next(tmp);
> >> +			ctx->sg_len++;
> >> +		}
> >> +
> >> +		sg = sg_next(sg);
> >> +	}
> >> +
> >> +	set_bit(HASH_FLAGS_SGS_ALLOCED, &ctx->dd->hash_flags);
> >> +
> >> +	ctx->bufcnt = 0;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_prepare_sgs -
> >> + * @sg:		source scatterlist request
> >> + * @nbytes:	number of bytes to process from sg
> >> + * @bs:		block size
> >> + * @final:	final flag
> >> + * @rctx:	request context
> >> + *
> >> + * Check two conditions: (1) if buffers in sg have len aligned data,
> >> + * and (2) sg table have good aligned elements (list_ok)
> >> + * If one of this checks fails, then either
> >> + * (1) allocates new buffer for data with s5p_hash_copy_sgs,
> >> + * copy data into this buffer and prepare request in sgl, or
> >> + * (2) allocates new sg table and prepare sg elements
> >> + *
> >> + * For digest or finup all conditions can be good, and we may not need
> >> + * any fixes.
> >> + */
> >> +static int s5p_hash_prepare_sgs(struct scatterlist *sg,
> >> +				int nbytes, int bs, bool final,
> >> +				struct s5p_hash_reqctx *rctx)
> >> +{
> >> +	int n = 0;
> >> +	bool aligned = true;
> >> +	bool list_ok = true;
> >> +	struct scatterlist *sg_tmp = sg;
> >> +	int offset = rctx->skip;
> >> +	int new_len;
> >> +
> >> +	if (!sg || !sg->length || !nbytes)
> >> +		return 0;
> >> +
> >> +	new_len = nbytes;
> >> +
> >> +	if (offset)
> >> +		list_ok = false;
> >> +
> >> +	if (!final)
> >> +		list_ok = false;
> >> +
> >> +	while (nbytes > 0 && sg_tmp) {
> >> +		n++;
> >> +
> >> +		if (offset < sg_tmp->length) {
> >> +			if (!IS_ALIGNED(sg_tmp->length - offset, bs)) {
> >> +				aligned = false;
> >> +				break;
> >> +			}
> >> +		}
> >> +
> >> +		if (!sg_tmp->length) {
> >> +			aligned = false;
> >> +			break;
> >> +		}
> >> +
> >> +		if (offset) {
> >> +			offset -= sg_tmp->length;
> >> +			if (offset < 0) {
> >> +				nbytes += offset;
> >> +				offset = 0;
> >> +			}
> >> +		} else {
> >> +			nbytes -= sg_tmp->length;
> >> +		}
> >> +
> >> +		sg_tmp = sg_next(sg_tmp);
> >> +
> >> +		if (nbytes < 0) { /* when hash_later is > 0 */
> >> +			list_ok = false;
> >> +			break;
> >> +		}
> >> +	}
> >> +
> >> +	if (!aligned)
> >> +		return s5p_hash_copy_sgs(rctx, sg, bs, new_len);
> >> +	else if (!list_ok)
> >> +		return s5p_hash_copy_sg_lists(rctx, sg, bs, new_len);
> >> +
> >> +	/* have aligned data from previous operation and/or current
> >> +	 * Note: will enter here only if (digest or finup) and aligned
> >> +	 */
> >> +	if (rctx->bufcnt) {
> >> +		rctx->sg_len = n;
> >> +		sg_init_table(rctx->sgl, 2);
> >> +		sg_set_buf(rctx->sgl, rctx->dd->xmit_buf, rctx->bufcnt);
> >> +		sg_chain(rctx->sgl, 2, sg);
> >> +		rctx->sg = rctx->sgl;
> >> +		rctx->sg_len++;
> >> +	} else {
> >> +		rctx->sg = sg;
> >> +		rctx->sg_len = n;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_prepare_request -
> >> + * @req:	AHASH request
> >> + * @update:	true if UPDATE op
> >> + *
> >> + * Note 1: we can have update flag _and_ final flag at the same time.
> >> + * Note 2: we enter here when digcnt > BUFLEN (=HASH_BLOCK_SIZE) or
> >> + *	   either req->nbytes or ctx->bufcnt + req->nbytes is > BUFLEN or
> >> + *	   we have final op
> >> + */
> >> +static int s5p_hash_prepare_request(struct ahash_request *req, bool update)
> >> +{
> >> +	struct s5p_hash_reqctx *rctx = ahash_request_ctx(req);
> >> +	int bs;
> >
> > I do not see the reason for 'bs'. It is set once and then only read.
> >
> 
> You are right, I will remove this (leftover from HMAC omap).
> 
> >> +	int ret;
> >> +	int nbytes;
> >> +	bool final = rctx->flags & BIT(HASH_FLAGS_FINUP);
> >> +	int xmit_len, hash_later;
> >> +
> >> +	if (!req)
> >> +		return 0;
> >> +
> >> +	bs = BUFLEN;
> >> +	if (update)
> >> +		nbytes = req->nbytes;
> >> +	else
> >> +		nbytes = 0;
> >> +
> >> +	rctx->total = nbytes + rctx->bufcnt;
> >> +	if (!rctx->total)
> >> +		return 0;
> >> +
> >> +	if (nbytes && (!IS_ALIGNED(rctx->bufcnt, BUFLEN))) {
> >> +		/* bytes left from previous request, so fill up to BUFLEN */
> >> +		int len = BUFLEN - rctx->bufcnt % BUFLEN;
> >> +
> >> +		if (len > nbytes)
> >> +			len = nbytes;
> >> +
> >> +		scatterwalk_map_and_copy(rctx->buffer + rctx->bufcnt, req->src,
> >> +					 0, len, 0);
> >> +		rctx->bufcnt += len;
> >> +		nbytes -= len;
> >> +		rctx->skip = len;
> >> +	} else {
> >> +		rctx->skip = 0;
> >> +	}
> >> +
> >> +	if (rctx->bufcnt)
> >> +		memcpy(rctx->dd->xmit_buf, rctx->buffer, rctx->bufcnt);
> >> +
> >> +	xmit_len = rctx->total;
> >> +	if (final) {
> >> +		hash_later = 0;
> >> +	} else {
> >> +		if (IS_ALIGNED(xmit_len, bs))
> >> +			xmit_len -= bs;
> >> +		else
> >> +			xmit_len -= xmit_len & (bs - 1);
> >> +
> >> +		hash_later = rctx->total - xmit_len;
> >> +		WARN_ON(req->nbytes == 0);
> >> +		WARN_ON(hash_later <= 0);
> >> +		/* == if bufcnt was BUFLEN */
> >> +		WARN_ON(req->nbytes < hash_later);
> >> +		WARN_ON(rctx->skip > (req->nbytes - hash_later));
> >> +		/* copy hash_later bytes from end of req->src */
> >> +		/* previous bytes are in xmit_buf, so no overwrite */
> >> +		scatterwalk_map_and_copy(rctx->buffer, req->src,
> >> +					 req->nbytes - hash_later,
> >> +					 hash_later, 0);
> >> +	}
> >> +
> >> +	WARN_ON(hash_later < 0);
> >> +	WARN_ON(nbytes < hash_later);
> >> +	if (xmit_len > bs) {
> >> +		WARN_ON(nbytes <= hash_later);
> >> +		ret = s5p_hash_prepare_sgs(req->src, nbytes - hash_later, bs,
> >> +					   final, rctx);
> >> +		if (ret)
> >> +			return ret;
> >> +	} else {
> >> +		/* have buffered data only */
> >> +		if (unlikely(!rctx->bufcnt)) {
> >> +			/* first update didn't fill up buffer */
> >> +			WARN_ON(xmit_len != BUFLEN);
> >
> > You have pretty a lot of WARNs. This raises concerns...
> >
> 
> Some debugs lefts, I will remove this.
> 
> >> +			scatterwalk_map_and_copy(rctx->dd->xmit_buf, req->src,
> >> +				0, xmit_len, 0);
> >> +		}
> >> +
> >> +		sg_init_table(rctx->sgl, 1);
> >> +		sg_set_buf(rctx->sgl, rctx->dd->xmit_buf, xmit_len);
> >> +
> >> +		rctx->sg = rctx->sgl;
> >> +		rctx->sg_len = 1;
> >> +	}
> >> +
> >> +	rctx->bufcnt = hash_later;
> >> +	if (!final)
> >> +		rctx->total = xmit_len;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_update_dma_stop()
> >> + * @dd:		secss device
> >> + *
> >> + * Unmap scatterlist ctx->sg.
> >> + */
> >> +static int s5p_hash_update_dma_stop(struct s5p_aes_dev *dd)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(dd->hash_req);
> >> +
> >> +	dma_unmap_sg(dd->dev, ctx->sg, ctx->sg_len, DMA_TO_DEVICE);
> >> +	clear_bit(HASH_FLAGS_DMA_ACTIVE, &dd->hash_flags);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_update_req - process AHASH request
> >> + * @dd:		device s5p_aes_dev
> >> + *
> >> + * Processes the input data from AHASH request using DMA
> >> + * Current request should have ctx->sg prepared before.
> >> + *
> >> + * Returns: see s5p_hash_final below.
> >> + */
> >> +static int s5p_hash_update_req(struct s5p_aes_dev *dd)
> >> +{
> >> +	struct ahash_request *req = dd->hash_req;
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	int err;
> >> +	bool final = ctx->flags & BIT(HASH_FLAGS_FINUP);
> >> +
> >> +	dev_dbg(dd->dev, "update_req: total: %u, digcnt: %lld, finup: %d\n",
> >> +		 ctx->total, ctx->digcnt, final);
> >> +
> >> +	err = s5p_hash_xmit_dma(dd, ctx->total, final);
> >> +
> >> +	/* wait for dma completion before can take more data */
> >
> > Hmm... where is the wait?
> 
> xmit_dma starts DMA, so we wait for irq to come.
> The wait itself is in users of our driver. I will remove this comment.
> 
> >> +	dev_dbg(dd->dev, "update: err: %d, digcnt: %lld\n", err, ctx->digcnt);
> >
> > Do you really need this? If yes, then consistent prefix with previous.
> >
> 
> No, I do not need this debug.
> 
> >> +
> >> +	return err;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_final_req - process the final AHASH request
> >> + * @dd:		device s5p_aes_dev
> >> + *
> >> + * Processes the input data from the last AHASH request
> >> + * using . Resets the buffer counter (ctx->bufcnt)
> >> + *
> >> + * Returns: see s5p_hash_final below.
> >> + */
> >> +static int s5p_hash_final_req(struct s5p_aes_dev *dd)
> >> +{
> >> +	struct ahash_request *req = dd->hash_req;
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	int err = 0;
> >> +
> >> +	err = s5p_hash_xmit_dma(dd, ctx->total, 1);
> >> +	ctx->bufcnt = 0;
> >> +	dev_dbg(dd->dev, "final_req: err: %d\n", err);
> >> +
> >> +	return err;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_finish - copy calculated digest to crypto layer
> >> + * @req:	AHASH request
> >> + *
> >> + * Copies the calculated hash value to the buffer provided
> >> + * by req->result
> >> + *
> >> + * Returns 0 on success and negative values on error.
> >> + */
> >> +static int s5p_hash_finish(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	struct s5p_aes_dev *dd = ctx->dd;
> >> +	int err = 0;
> >> +
> >> +	if (ctx->digcnt)
> >> +		s5p_hash_copy_result(req);
> >> +
> >> +	dev_dbg(dd->dev, "digcnt: %lld, bufcnt: %d\n", ctx->digcnt,
> >> +		ctx->bufcnt);
> >> +
> >> +	return err;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_finish_req - finish request
> >> + * @req:	AHASH request
> >> + * @err:	error
> >> + *
> >> + * Clear flags, free memory,
> >> + * if FINAL then read output into ctx->digest,
> >> + * call completetion
> >> + */
> >> +static void s5p_hash_finish_req(struct ahash_request *req, int err)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	struct s5p_aes_dev *dd = ctx->dd;
> >> +
> >> +	if (test_bit(HASH_FLAGS_SGS_COPIED, &dd->hash_flags))
> >> +		free_pages((unsigned long)sg_virt(ctx->sg),
> >> +			   get_order(ctx->sg->length));
> >> +
> >> +	if (test_bit(HASH_FLAGS_SGS_ALLOCED, &dd->hash_flags))
> >> +		kfree(ctx->sg);
> >> +
> >> +	ctx->sg = NULL;
> >> +
> >> +	dd->hash_flags &= ~(BIT(HASH_FLAGS_SGS_ALLOCED) |
> >> +			    BIT(HASH_FLAGS_SGS_COPIED));
> >> +
> >> +	if (!err && !test_bit(HASH_FLAGS_ERROR, &ctx->flags)) {
> >> +		s5p_hash_read_msg(req);
> >> +		if (test_bit(HASH_FLAGS_FINAL, &dd->hash_flags))
> >> +			err = s5p_hash_finish(req);
> >> +	} else {
> >> +		ctx->flags |= BIT(HASH_FLAGS_ERROR);
> >> +	}
> >> +
> >> +	/* atomic operation is not needed here */
> >
> > Ok, but why?
> >
> 
> Good question, I frankly copy&paste this. The hash vars in s5p_aes_dev
> are no longer used as all transfers ended, we have req context here
> so after complete we can work on next request,
> and clearing bit HASH_FLAGS_BUSY allows this.

I think you need them. Here and few lines before. In
s5p_hash_handle_queue() you use spin-lock because it might be executed
multiple times. Having that assumption (multiple calls to
s5p_hash_handle_queue()) you can have:

Thread #1:                     Thread #2
 s5p_hash_finish_req()         s5p_hash_handle_queue()
 dd->hash_flags &= ...
   which equals to:
   tmp = dd->hash_flags;
   tmp &= ~(BIT...)
                                 set_bit(HASH_FLAGS_BUSY, &dd->hash_flags);
   dd->hash_flags = tmp

Which means that in last assignment you effectively lost the
HASH_FLAGS_BUSY bit.

In general, you need to use atomics (or locks) everywhere, unless you
are 100% sure that given lockless section cannot be executed with other
code which uses locks.  Otherwise the atomics/locks become uneffective.

> 
> >> +	dd->hash_flags &= ~(BIT(HASH_FLAGS_BUSY) | BIT(HASH_FLAGS_FINAL) |
> >> +			    BIT(HASH_FLAGS_DMA_READY) |
> >> +			    BIT(HASH_FLAGS_OUTPUT_READY));
> >> +
> >> +	if (req->base.complete)
> >> +		req->base.complete(&req->base, err);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_handle_queue - handle hash queue
> >> + * @dd:		device s5p_aes_dev
> >> + * @req:	AHASH request
> >> + *
> >> + * If req!=NULL enqueue it
> >> + *
> >> + * Enqueues the current AHASH request on dd->queue and
> >> + * if FLAGS_BUSY is not set on the device then processes
> >> + * the first request from the dd->queue
> >
> > Do not break lines too early. It makes reading difficult. Break at 80.
> 
> OK.
> 
> >
> >> + *
> >> + * Returns: see s5p_hash_final below.
> >> + */
> >> +static int s5p_hash_handle_queue(struct s5p_aes_dev *dd,
> >> +				  struct ahash_request *req)
> >> +{
> >> +	struct crypto_async_request *async_req, *backlog;
> >> +	struct s5p_hash_reqctx *ctx;
> >> +	unsigned long flags;
> >> +	int err = 0, ret = 0;
> >> +
> >> +retry:
> >> +	spin_lock_irqsave(&dd->hash_lock, flags);
> >> +	if (req)
> >> +		ret = ahash_enqueue_request(&dd->hash_queue, req);
> >> +	if (test_bit(HASH_FLAGS_BUSY, &dd->hash_flags)) {
> >> +		spin_unlock_irqrestore(&dd->hash_lock, flags);
> >> +		return ret;
> >> +	}
> >> +	backlog = crypto_get_backlog(&dd->hash_queue);
> >> +	async_req = crypto_dequeue_request(&dd->hash_queue);
> >> +	if (async_req)
> >> +		set_bit(HASH_FLAGS_BUSY, &dd->hash_flags);
> >> +	spin_unlock_irqrestore(&dd->hash_lock, flags);
> >> +
> >> +	if (!async_req)
> >> +		return ret;
> >> +
> >> +	if (backlog)
> >> +		backlog->complete(backlog, -EINPROGRESS);
> >> +
> >> +	req = ahash_request_cast(async_req);
> >> +	dd->hash_req = req;
> >> +	ctx = ahash_request_ctx(req);
> >> +
> >> +	err = s5p_hash_prepare_request(req, ctx->op == HASH_OP_UPDATE);
> >> +	if (err || !ctx->total)
> >> +		goto err1;
> >> +
> >> +	dev_dbg(dd->dev, "handling new req, op: %u, nbytes: %d\n",
> >> +						ctx->op, req->nbytes);
> >> +
> >> +	err = s5p_hash_hw_init(dd);
> >> +	if (err)
> >> +		goto err1;
> >> +
> >> +	dd->hash_err = 0;
> >> +	if (ctx->digcnt)
> >> +		/* request has changed - restore hash */
> >> +		s5p_hash_write_iv(req);
> >> +
> >> +	if (ctx->op == HASH_OP_UPDATE) {
> >> +		err = s5p_hash_update_req(dd);
> >> +		if (err != -EINPROGRESS &&
> >> +		   (ctx->flags & BIT(HASH_FLAGS_FINUP)))
> >> +			/* no final() after finup() */
> >> +			err = s5p_hash_final_req(dd);
> >> +	} else if (ctx->op == HASH_OP_FINAL) {
> >> +		err = s5p_hash_final_req(dd);
> >> +	}
> >> +err1:
> >
> > Just "out" as this is normal and err path.
> 
> OK.
> 
> >
> >> +	dev_dbg(dd->dev, "exit, err: %d\n", err);
> >
> > More meaningful debug message.
> 
> I will remove this.
> 
> >
> >> +
> >> +	if (err != -EINPROGRESS) {
> >> +		/* hash_tasklet_cb will not finish it, so do it here */
> >> +		s5p_hash_finish_req(req, err);
> >> +		req = NULL;
> >> +
> >> +		/*
> >> +		 * Execute next request immediately if there is anything
> >> +		 * in queue.
> >> +		 */
> >> +		goto retry;
> >> +	}
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_tasklet_cb - hash tasklet
> >> + * @data:	ptr to s5p_aes_dev
> >> + *
> >> + */
> >> +static void s5p_hash_tasklet_cb(unsigned long data)
> >> +{
> >> +	struct s5p_aes_dev *dd = (struct s5p_aes_dev *)data;
> >> +	int err = 0;
> >> +
> >> +	if (!test_bit(HASH_FLAGS_BUSY, &dd->hash_flags)) {
> >> +		s5p_hash_handle_queue(dd, NULL);
> >> +		return;
> >> +	}
> >> +
> >> +	if (test_bit(HASH_FLAGS_DMA_READY, &dd->hash_flags)) {
> >> +		if (test_and_clear_bit(HASH_FLAGS_DMA_ACTIVE,
> >> +				       &dd->hash_flags)) {
> >> +			s5p_hash_update_dma_stop(dd);
> >> +			if (dd->hash_err) {
> >> +				err = dd->hash_err;
> >> +				goto finish;
> >> +			}
> >> +		}
> >> +		if (test_and_clear_bit(HASH_FLAGS_OUTPUT_READY,
> >> +				       &dd->hash_flags)) {
> >> +			/* hash or semi-hash ready */
> >> +			clear_bit(HASH_FLAGS_DMA_READY, &dd->hash_flags);
> >> +				goto finish;
> >> +		}
> >> +	}
> >> +
> >> +	return;
> >> +
> >> +finish:
> >> +	dev_dbg(dd->dev, "update done: err: %d\n", err);
> >
> > More meaningful debug message.
> 
> I will remove this.
> 
> >> +	/* finish curent request */
> >> +	s5p_hash_finish_req(dd->hash_req, err);
> >> +
> >> +	/* If we are not busy, process next req */
> >> +	if (!test_bit(HASH_FLAGS_BUSY, &dd->hash_flags))
> >> +		s5p_hash_handle_queue(dd, NULL);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_enqueue - enqueue request
> >> + * @req:	AHASH request
> >> + * @op:		operation UPDATE or FINAL
> >> + *
> >> + * Sets the operation flag in the AHASH request context
> >> + * structure and calls s5p_hash_handle_queue().
> >> + *
> >> + * Returns: see s5p_hash_final below.
> >> + */
> >> +static int s5p_hash_enqueue(struct ahash_request *req, unsigned int op)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	struct s5p_hash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
> >> +	struct s5p_aes_dev *dd = tctx->dd;
> >> +
> >> +	ctx->op = op;
> >> +
> >> +	return s5p_hash_handle_queue(dd, req);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_update - process the hash input data
> >> + * @req:	AHASH request
> >> + *
> >> + * If request will fit in buffer, copy it and return immediately
> >> + * else enqueue it wit OP_UPDATE.
> >> + *
> >> + * Returns: see s5p_hash_final below.
> >> + */
> >> +static int s5p_hash_update(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +
> >> +	if (!req->nbytes)
> >> +		return 0;
> >> +
> >> +	if (ctx->bufcnt + req->nbytes <= BUFLEN) {
> >> +		scatterwalk_map_and_copy(ctx->buffer + ctx->bufcnt, req->src,
> >> +					 0, req->nbytes, 0);
> >> +		ctx->bufcnt += req->nbytes;
> >> +		return 0;
> >> +	}
> >> +
> >> +	return s5p_hash_enqueue(req, HASH_OP_UPDATE);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_shash_digest - calculate shash digest
> >> + * @tfm:	crypto transformation
> >> + * @flags:	tfm flags
> >> + * @data:	input data
> >> + * @len:	length of data
> >> + * @out:	output buffer
> >> + */
> >> +static int s5p_hash_shash_digest(struct crypto_shash *tfm, u32 flags,
> >> +				  const u8 *data, unsigned int len, u8 *out)
> >> +{
> >> +	SHASH_DESC_ON_STACK(shash, tfm);
> >> +
> >> +	shash->tfm = tfm;
> >> +	shash->flags = flags & CRYPTO_TFM_REQ_MAY_SLEEP;
> >> +
> >> +	return crypto_shash_digest(shash, data, len, out);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_final_shash - calculate shash digest
> >> + * @req:	AHASH request
> >> + *
> >> + * calculate digest from ctx->buffer,
> >> + * with data length ctx->bufcnt,
> >> + * store digest in req->result
> >> + */
> >> +static int s5p_hash_final_shash(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +
> >> +	return s5p_hash_shash_digest(tctx->fallback, req->base.flags,
> >> +				     ctx->buffer, ctx->bufcnt, req->result);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_final - close up hash and calculate digest
> >> + * @req:	AHASH request
> >> + *
> >> + * Set FLAGS_FINUP flag for the current AHASH request context.
> >> + *
> >> + * If there were no input data processed yet and the buffered
> >> + * hash data is less than BUFLEN (64) then calculate the final
> >> + * hash immediately by using SW algorithm fallback.
> >> + *
> >> + * Otherwise enqueues the current AHASH request with OP_FINAL
> >> + * operation flag and finalize hash message in HW.
> >> + * Note that if digcnt!=0 then there were previous update op,
> >> + * so there are always some buffered bytes in ctx->buffer,
> >> + * which means that ctx->bufcnt!=0
> >> + *
> >> + * Returns:
> >> + * 0 if the request has been processed immediately,
> >> + * -EINPROGRESS if the operation has been queued for later
> >> + *	execution or is set to processing by HW,
> >> + * -EBUSY if queue is full and request should be resubmitted later,
> >> + * other negative values on error.
> >> + *
> >> + * Note: req->src do not have any data
> >> + */
> >> +static int s5p_hash_final(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +
> >> +	ctx->flags |= BIT(HASH_FLAGS_FINUP);
> >> +
> >> +	if (ctx->flags & BIT(HASH_FLAGS_ERROR))
> >> +		return -EINVAL; /* uncompleted hash is not needed */
> >> +
> >> +	/*
> >> +	 * If message is small (digcnt==0) and buffersize is less
> >> +	 * than BUFLEN, we use fallback, as using DMA + HW in this
> >> +	 * case doesn't provide any benefit.
> >> +	 * This is also the case for zero-length message.
> >> +	 */
> >> +	if (!ctx->digcnt && ctx->bufcnt < BUFLEN)
> >> +		return s5p_hash_final_shash(req);
> >> +
> >> +	WARN_ON(ctx->bufcnt == 0);
> >> +
> >> +	return s5p_hash_enqueue(req, HASH_OP_FINAL);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_finup - process last req->src and calculate digest
> >> + * @req:	AHASH request containing the last update data
> >> + *
> >> + * Set FLAGS_FINUP flag in context.
> >> + * Call update(req) and exit if it was enqueued or is being processing.
> >> + * If update returns without enqueue, call final(req).
> >> + *
> >> + * Return values: see s5p_hash_final above.
> >> + */
> >> +static int s5p_hash_finup(struct ahash_request *req)
> >> +{
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	int err1, err2;
> >> +
> >> +	ctx->flags |= BIT(HASH_FLAGS_FINUP);
> >> +
> >> +	err1 = s5p_hash_update(req);
> >> +	if (err1 == -EINPROGRESS || err1 == -EBUSY)
> >> +		return err1;
> >> +	/*
> >> +	 * final() has to be always called to cleanup resources
> >> +	 * even if update() failed, except EINPROGRESS
> >> +	 * or calculate digest for small size
> >> +	 */
> >> +	err2 = s5p_hash_final(req);
> >> +
> >> +	return err1 ?: err2;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_init - initialize AHASH request contex
> >> + * @req:	AHASH request
> >> + *
> >> + * Init async hash request context.
> >> + */
> >> +static int s5p_hash_init(struct ahash_request *req)
> >> +{
> >> +	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
> >> +	struct s5p_hash_ctx *tctx = crypto_ahash_ctx(tfm);
> >> +	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
> >> +	struct s5p_aes_dev *dd = tctx->dd;
> >> +
> >> +	ctx->dd = dd;
> >> +	ctx->flags = 0;
> >> +
> >> +	dev_dbg(dd->dev, "init: digest size: %d\n",
> >> +		crypto_ahash_digestsize(tfm));
> >> +
> >> +	switch (crypto_ahash_digestsize(tfm)) {
> >> +	case MD5_DIGEST_SIZE:
> >> +		ctx->flags |= HASH_FLAGS_MODE_MD5;
> >> +		ctx->engine = SSS_HASH_ENGINE_MD5;
> >> +		ctx->nregs = HASH_MD5_MAX_REG;
> >> +		break;
> >> +	case SHA1_DIGEST_SIZE:
> >> +		ctx->flags |= HASH_FLAGS_MODE_SHA1;
> >> +		ctx->engine = SSS_HASH_ENGINE_SHA1;
> >> +		ctx->nregs = HASH_SHA1_MAX_REG;
> >> +		break;
> >> +	case SHA256_DIGEST_SIZE:
> >> +		ctx->flags |= HASH_FLAGS_MODE_SHA256;
> >> +		ctx->engine = SSS_HASH_ENGINE_SHA256;
> >> +		ctx->nregs = HASH_SHA256_MAX_REG;
> >> +		break;
> >> +	}
> >> +
> >> +	ctx->bufcnt = 0;
> >> +	ctx->digcnt = 0;
> >> +	ctx->total = 0;
> >> +	ctx->skip = 0;
> >> +	ctx->buflen = BUFLEN;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_digest - calculate digest from req->src
> >> + * @req:	AHASH request
> >> + *
> >> + * Return values: see s5p_hash_final above.
> >> + */
> >> +static int s5p_hash_digest(struct ahash_request *req)
> >> +{
> >> +	return s5p_hash_init(req) ?: s5p_hash_finup(req);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_cra_init_alg - init crypto alg transformation
> >> + * @tfm:	crypto transformation
> >> + */
> >> +static int s5p_hash_cra_init_alg(struct crypto_tfm *tfm)
> >> +{
> >> +	struct s5p_hash_ctx *tctx = crypto_tfm_ctx(tfm);
> >> +	const char *alg_name = crypto_tfm_alg_name(tfm);
> >> +
> >> +	tctx->dd = s5p_dev;
> >> +	/* Allocate a fallback and abort if it failed. */
> >> +	tctx->fallback = crypto_alloc_shash(alg_name, 0,
> >> +					    CRYPTO_ALG_NEED_FALLBACK);
> >> +	if (IS_ERR(tctx->fallback)) {
> >> +		pr_err("fallback alloc fails for '%s'\n", alg_name);
> >> +		return PTR_ERR(tctx->fallback);
> >> +	}
> >> +
> >> +	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
> >> +				 sizeof(struct s5p_hash_reqctx) + BUFLEN);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_cra_init - init crypto tfm
> >> + * @tfm:	crypto transformation
> >> + */
> >> +static int s5p_hash_cra_init(struct crypto_tfm *tfm)
> >> +{
> >> +	return s5p_hash_cra_init_alg(tfm);
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_cra_exit - exit crypto tfm
> >> + * @tfm:	crypto transformation
> >> + *
> >> + * free allocated fallback
> >> + */
> >> +static void s5p_hash_cra_exit(struct crypto_tfm *tfm)
> >> +{
> >> +	struct s5p_hash_ctx *tctx = crypto_tfm_ctx(tfm);
> >> +
> >> +	crypto_free_shash(tctx->fallback);
> >> +	tctx->fallback = NULL;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_export - export hash state
> >> + * @req:	AHASH request
> >> + * @out:	buffer for exported state
> >> + */
> >> +static int s5p_hash_export(struct ahash_request *req, void *out)
> >> +{
> >> +	struct s5p_hash_reqctx *rctx = ahash_request_ctx(req);
> >> +
> >> +	memcpy(out, rctx, sizeof(*rctx) + rctx->bufcnt);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * s5p_hash_import - import hash state
> >> + * @req:	AHASH request
> >> + * @in:		buffer with state to be imported from
> >> + */
> >> +static int s5p_hash_import(struct ahash_request *req, const void *in)
> >> +{
> >> +	struct s5p_hash_reqctx *rctx = ahash_request_ctx(req);
> >> +	const struct s5p_hash_reqctx *ctx_in = in;
> >> +
> >> +	WARN_ON(ctx_in->bufcnt < 0);
> >> +	WARN_ON(ctx_in->bufcnt > BUFLEN);
> >> +	memcpy(rctx, in, sizeof(*rctx) + BUFLEN);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * struct algs_sha1_md5
> >
> > True. This is struct algs_sha1_md5.
> >
> 
> I will remove this and next ones.
> 
> >> + */
> >> +static struct ahash_alg algs_sha1_md5[] = {
> >> +{
> >> +	.init		= s5p_hash_init,
> >> +	.update		= s5p_hash_update,
> >> +	.final		= s5p_hash_final,
> >> +	.finup		= s5p_hash_finup,
> >> +	.digest		= s5p_hash_digest,
> >> +	.halg.digestsize	= SHA1_DIGEST_SIZE,
> >> +	.halg.base	= {
> >> +		.cra_name		= "sha1",
> >> +		.cra_driver_name	= "exynos-sha1",
> >> +		.cra_priority		= 100,
> >> +		.cra_flags		= CRYPTO_ALG_TYPE_AHASH |
> >> +					  CRYPTO_ALG_KERN_DRIVER_ONLY |
> >> +					  CRYPTO_ALG_ASYNC |
> >> +					  CRYPTO_ALG_NEED_FALLBACK,
> >> +		.cra_blocksize		= HASH_BLOCK_SIZE,
> >> +		.cra_ctxsize		= sizeof(struct s5p_hash_ctx),
> >> +		.cra_alignmask		= SSS_DMA_ALIGN_MASK,
> >> +		.cra_module		= THIS_MODULE,
> >> +		.cra_init		= s5p_hash_cra_init,
> >> +		.cra_exit		= s5p_hash_cra_exit,
> >> +	}
> >> +},
> >> +{
> >> +	.init		= s5p_hash_init,
> >> +	.update		= s5p_hash_update,
> >> +	.final		= s5p_hash_final,
> >> +	.finup		= s5p_hash_finup,
> >> +	.digest		= s5p_hash_digest,
> >> +	.halg.digestsize	= MD5_DIGEST_SIZE,
> >> +	.halg.base	= {
> >> +		.cra_name		= "md5",
> >> +		.cra_driver_name	= "exynos-md5",
> >> +		.cra_priority		= 100,
> >> +		.cra_flags		= CRYPTO_ALG_TYPE_AHASH |
> >> +					  CRYPTO_ALG_KERN_DRIVER_ONLY |
> >> +					  CRYPTO_ALG_ASYNC |
> >> +					  CRYPTO_ALG_NEED_FALLBACK,
> >> +		.cra_blocksize		= HASH_BLOCK_SIZE,
> >> +		.cra_ctxsize		= sizeof(struct s5p_hash_ctx),
> >> +		.cra_alignmask		= SSS_DMA_ALIGN_MASK,
> >> +		.cra_module		= THIS_MODULE,
> >> +		.cra_init		= s5p_hash_cra_init,
> >> +		.cra_exit		= s5p_hash_cra_exit,
> >> +	}
> >> +}
> >> +};
> >> +
> >> +/**
> >> + * struct algs_sha256
> >
> > Exactly.
> >
> >> + */
> >> +static struct ahash_alg algs_sha256[] = {
> >> +{
> >> +	.init		= s5p_hash_init,
> >> +	.update		= s5p_hash_update,
> >> +	.final		= s5p_hash_final,
> >> +	.finup		= s5p_hash_finup,
> >> +	.digest		= s5p_hash_digest,
> >> +	.halg.digestsize	= SHA256_DIGEST_SIZE,
> >> +	.halg.base	= {
> >> +		.cra_name		= "sha256",
> >> +		.cra_driver_name	= "exynos-sha256",
> >> +		.cra_priority		= 100,
> >> +		.cra_flags		= CRYPTO_ALG_TYPE_AHASH |
> >> +					  CRYPTO_ALG_KERN_DRIVER_ONLY |
> >> +					  CRYPTO_ALG_ASYNC |
> >> +					  CRYPTO_ALG_NEED_FALLBACK,
> >> +		.cra_blocksize		= HASH_BLOCK_SIZE,
> >> +		.cra_ctxsize		= sizeof(struct s5p_hash_ctx),
> >> +		.cra_alignmask		= SSS_DMA_ALIGN_MASK,
> >> +		.cra_module		= THIS_MODULE,
> >> +		.cra_init		= s5p_hash_cra_init,
> >> +		.cra_exit		= s5p_hash_cra_exit,
> >> +	}
> >> +}
> >> +};
> >> +
> >> +/**
> >> + * struct exynos_hash_algs_info
> >
> > Yeah, I know that this is exynos_hash_algs_info.
> >
> >> + */
> >> +static struct sss_hash_algs_info exynos_hash_algs_info[] = {
> >
> > Can it be const?
> >
> 
> They can, but for this I must move aes variant structures and _variant function
> before _probe.

Ok, move them, maybe in different patch in that case since this is just
re-order and this commit is pretty big already.

> 
> >> +	{
> >> +		.algs_list	= algs_sha1_md5,
> >> +		.size		= ARRAY_SIZE(algs_sha1_md5),
> >> +	},
> >> +	{
> >> +		.algs_list	= algs_sha256,
> >> +		.size		= ARRAY_SIZE(algs_sha256),
> >> +	},
> >> +};
> >> +
> >>  static void s5p_set_aes(struct s5p_aes_dev *dev,
> >>  			uint8_t *key, uint8_t *iv, unsigned int keylen)
> >>  {
> >> @@ -822,13 +2379,16 @@ static struct crypto_alg algs[] = {
> >>  	},
> >>  };
> >>  
> >> +bool use_hash;
> >
> > No globals. This should not be a file-scope variable neither.
> >
> 
> Ok, I will make it local in device.
> 
> >> +
> >>  static int s5p_aes_probe(struct platform_device *pdev)
> >>  {
> >>  	struct device *dev = &pdev->dev;
> >> -	int i, j, err = -ENODEV;
> >> +	int i, hash_i, hash_algs_size = 0, j, err = -ENODEV;
> >>  	struct samsung_aes_variant *variant;
> >>  	struct s5p_aes_dev *pdata;
> >>  	struct resource *res;
> >> +	struct sss_hash_algs_info *hash_algs_i;
> >>  
> >>  	if (s5p_dev)
> >>  		return -EEXIST;
> >> @@ -837,12 +2397,38 @@ static int s5p_aes_probe(struct platform_device *pdev)
> >>  	if (!pdata)
> >>  		return -ENOMEM;
> >>  
> >> +	variant = find_s5p_sss_version(pdev);
> >> +	pdata->pdata = variant;
> >> +
> >>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> -	pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
> >> -	if (IS_ERR(pdata->ioaddr))
> >> -		return PTR_ERR(pdata->ioaddr);
> >> +	/* HACK: HASH and PRNG uses the same registers in secss,
> >> +	 * avoid overwrite each other. This will drop HASH when
> >> +	 * CONFIG_EXYNOS_RNG is enabled.
> >> +	 * We need larger size for HASH registers in secss, current
> >> +	 * describe only AES/DES
> >
> >
> > Run checkpatch.
> >
> 
> Can you write more ? What options I should use ?
> I ran and it gives zero errors, one warn about __attribute__(aligned()),
> and one about Kconfig change (description len too low).

Oh, my bad, I thought it would complain about comment coding style.
There should be opening /* before any text:
/*
 * this is
 * long comment
 */

But anyway you can run it with --strict and fix the minor issues for new
code (like "Alignment should match open parenthesis", "Please use a
blank line after"). These are not critical but for new code they are
welcomed, I think.



Best regards,
Krzysztof

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