crypto: talitos - ensure request ordering within a single tfm

Assign single target channel per tfm in talitos_cra_init instead of
performing channel scheduling dynamically during the encryption request.
This changes the talitos_submit interface to accept a new channel
number argument.  Without this, rapid bursts of misc. sized requests
could make it possible for IPsec packets to be encrypted out-of-order,
which would result in packet drops due to sequence numbers falling
outside the anti-reply window on a peer gateway.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 14 insertions, 9 deletions

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index 854e2632f9a6..b8ca58394f05 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -1,7 +1,7 @@
 /*
  * talitos - Freescale Integrated Security Engine (SEC) device driver
  *
- * Copyright (c) 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright (c) 2008-2011 Freescale Semiconductor, Inc.
  *
  * Scatterlist Crypto API glue code copied from files with the following:
  * Copyright (c) 2006-2007 Herbert Xu <herbert@gondor.apana.org.au>
@@ -282,6 +282,7 @@ static int init_device(struct device *dev)
 /**
  * talitos_submit - submits a descriptor to the device for processing
  * @dev:        the SEC device to be used
+ * @ch:         the SEC device channel to be used
  * @desc:       the descriptor to be processed by the device
  * @callback:   whom to call when processing is complete
  * @context:    a handle for use by caller (optional)
@@ -290,7 +291,7 @@ static int init_device(struct device *dev)
  * callback must check err and feedback in descriptor header
  * for device processing status.
  */
-static int talitos_submit(struct device *dev, struct talitos_desc *desc,
+static int talitos_submit(struct device *dev, int ch, struct talitos_desc *desc,
                           void (*callback)(struct device *dev,
                                            struct talitos_desc *desc,
                                            void *context, int error),
@@ -298,15 +299,12 @@ static int talitos_submit(struct device *dev, struct talitos_desc *desc,
 {
         struct talitos_private *priv = dev_get_drvdata(dev);
         struct talitos_request *request;
-        unsigned long flags, ch;
+        unsigned long flags;
         int head;
 
         /* select done notification */
         desc->hdr |= DESC_HDR_DONE_NOTIFY;
 
-        /* emulate SEC's round-robin channel fifo polling scheme */
-        ch = atomic_inc_return(&priv->last_chan) & (priv->num_channels - 1);
-
         spin_lock_irqsave(&priv->chan[ch].head_lock, flags);
 
         if (!atomic_inc_not_zero(&priv->chan[ch].submit_count)) {
@@ -706,6 +704,7 @@ static void talitos_unregister_rng(struct device *dev)
 
 struct talitos_ctx {
         struct device *dev;
+        int ch;
         __be32 desc_hdr_template;
         u8 key[TALITOS_MAX_KEY_SIZE];
         u8 iv[TALITOS_MAX_IV_LENGTH];
@@ -1117,7 +1116,7 @@ static int ipsec_esp(struct talitos_edesc *edesc, struct aead_request *areq,
         map_single_talitos_ptr(dev, &desc->ptr[6], ivsize, ctx->iv, 0,
                                DMA_FROM_DEVICE);
 
-        ret = talitos_submit(dev, desc, callback, areq);
+        ret = talitos_submit(dev, ctx->ch, desc, callback, areq);
         if (ret != -EINPROGRESS) {
                 ipsec_esp_unmap(dev, edesc, areq);
                 kfree(edesc);
@@ -1524,7 +1523,7 @@ static int common_nonsnoop(struct talitos_edesc *edesc,
         to_talitos_ptr(&desc->ptr[6], 0);
         desc->ptr[6].j_extent = 0;
 
-        ret = talitos_submit(dev, desc, callback, areq);
+        ret = talitos_submit(dev, ctx->ch, desc, callback, areq);
         if (ret != -EINPROGRESS) {
                 common_nonsnoop_unmap(dev, edesc, areq);
                 kfree(edesc);
@@ -1703,7 +1702,7 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
         /* last DWORD empty */
         desc->ptr[6] = zero_entry;
 
-        ret = talitos_submit(dev, desc, callback, areq);
+        ret = talitos_submit(dev, ctx->ch, desc, callback, areq);
         if (ret != -EINPROGRESS) {
                 common_nonsnoop_hash_unmap(dev, edesc, areq);
                 kfree(edesc);
@@ -2244,6 +2243,7 @@ static int talitos_cra_init(struct crypto_tfm *tfm)
         struct crypto_alg *alg = tfm->__crt_alg;
         struct talitos_crypto_alg *talitos_alg;
         struct talitos_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct talitos_private *priv;
 
         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_AHASH)
                 talitos_alg = container_of(__crypto_ahash_alg(alg),
@@ -2256,6 +2256,11 @@ static int talitos_cra_init(struct crypto_tfm *tfm)
         /* update context with ptr to dev */
         ctx->dev = talitos_alg->dev;
 
+        /* assign SEC channel to tfm in round-robin fashion */
+        priv = dev_get_drvdata(ctx->dev);
+        ctx->ch = atomic_inc_return(&priv->last_chan) &
+                  (priv->num_channels - 1);
+
         /* copy descriptor header template value */
         ctx->desc_hdr_template = talitos_alg->algt.desc_hdr_template;