Hi Evgeniey:
Sorry for taking so long to get back to you. I've been busy lately.
On Mon, Jun 04, 2007 at 05:42:48PM +0400, Evgeniy Polyakov wrote:
>
> +static int hifn_setup_crypto(struct ablkcipher_request *req, u8 op, u8 type, u8 mode)
> +{
> + struct hifn_device *dev = ablkcipher_request_ctx(req);
> + int err = -EBUSY;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dev->lock, flags);
> + if (dev->started < HIFN_QUEUE_LENGTH) {
> + err = hifn_setup_session(dev, req->src, 1, req->dst, 1,
> + (dev->flags & HIFN_FLAG_OLD_KEY)?NULL:dev->current_key, dev->current_key_len,
> + NULL, 0,
> + op, type, mode, dev->snum, req);
> + dev->snum++;
> + dev->started++;
> + }
> + spin_unlock_irqrestore(&dev->lock, flags);
> +
> + /*
> + * HEAVY TODO: needs to kick Herbert XU to write documentation.
> + * HEAVY TODO: needs to kick Herbert XU to write documentation.
> + * HEAVY TODO: needs to kick Herbert XU to write documentation.
> + *
> + * Actually I need to think about how to handle the case, when queue is full.
> + * So far error (-EINVAL) is returned.
> + */
OK you need to provide a software queue here. Since you already
have a hardware queue, you may choose to have a queue with a
(advisory) maximum length of zero. However, a queue is still
necessary since requests with the MAY_BACKLOG flag must never
be discarded.
This is (or will be) used by users such as dm-crypt that must be
able to add at least one request but can throttle themselves
afterwards .
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
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