crypto: talitos - Preempt overflow interrupts
add requests pending/submit count to prevent request queue full
condition by preempting h/w overflow interrupts in software.
We do this due to the delay in the delivery and handling of the
channel overflow error interrupt.
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Acked-by: Lee Nipper <lee.nipper@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index f644fba..fdb0680 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -99,6 +99,9 @@
/* next channel to be assigned next incoming descriptor */
atomic_t last_chan;
+ /* per-channel number of requests pending in channel h/w fifo */
+ atomic_t *submit_count;
+
/* per-channel request fifo */
struct talitos_request **fifo;
@@ -263,15 +266,15 @@
spin_lock_irqsave(&priv->head_lock[ch], flags);
- head = priv->head[ch];
- request = &priv->fifo[ch][head];
-
- if (request->desc) {
- /* request queue is full */
+ if (!atomic_inc_not_zero(&priv->submit_count[ch])) {
+ /* h/w fifo is full */
spin_unlock_irqrestore(&priv->head_lock[ch], flags);
return -EAGAIN;
}
+ head = priv->head[ch];
+ request = &priv->fifo[ch][head];
+
/* map descriptor and save caller data */
request->dma_desc = dma_map_single(dev, desc, sizeof(*desc),
DMA_BIDIRECTIONAL);
@@ -335,6 +338,9 @@
priv->tail[ch] = (tail + 1) & (priv->fifo_len - 1);
spin_unlock_irqrestore(&priv->tail_lock[ch], flags);
+
+ atomic_dec(&priv->submit_count[ch]);
+
saved_req.callback(dev, saved_req.desc, saved_req.context,
status);
/* channel may resume processing in single desc error case */
@@ -1337,6 +1343,7 @@
if (hw_supports(dev, DESC_HDR_SEL0_RNG))
talitos_unregister_rng(dev);
+ kfree(priv->submit_count);
kfree(priv->tail);
kfree(priv->head);
@@ -1501,6 +1508,16 @@
}
}
+ priv->submit_count = kmalloc(sizeof(int) * priv->num_channels,
+ GFP_KERNEL);
+ if (!priv->submit_count) {
+ dev_err(dev, "failed to allocate fifo submit count space\n");
+ err = -ENOMEM;
+ goto err_out;
+ }
+ for (i = 0; i < priv->num_channels; i++)
+ atomic_set(&priv->submit_count[i], -priv->chfifo_len);
+
priv->head = kzalloc(sizeof(int) * priv->num_channels, GFP_KERNEL);
priv->tail = kzalloc(sizeof(int) * priv->num_channels, GFP_KERNEL);
if (!priv->head || !priv->tail) {