2022-09-13 08:25:35

by Peter Harliman Liem

Subject: [PATCH v3 1/2] crypto: inside_secure - Avoid dma map if size is zero

From commit d03c54419274 ("dma-mapping: disallow .map_sg
operations from returning zero on error"), dma_map_sg()
produces warning if size is 0. This results in visible
warnings if crypto length is zero.
To avoid that, we avoid calling dma_map_sg if size is zero.

Signed-off-by: Peter Harliman Liem <[email protected]>
---
v3:
Remove fixes tag
Add corresponding change for dma_unmap_sg
v2:
Add fixes tag

.../crypto/inside-secure/safexcel_cipher.c | 44 +++++++++++++------
1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/crypto/inside-secure/safexcel_cipher.c b/drivers/crypto/inside-secure/safexcel_cipher.c
index d68ef16650d4..5a222c228c3b 100644
--- a/drivers/crypto/inside-secure/safexcel_cipher.c
+++ b/drivers/crypto/inside-secure/safexcel_cipher.c
@@ -642,10 +642,16 @@ static int safexcel_handle_req_result(struct safexcel_crypto_priv *priv, int rin
safexcel_complete(priv, ring);

if (src == dst) {
- dma_unmap_sg(priv->dev, src, sreq->nr_src, DMA_BIDIRECTIONAL);
+ if (sreq->nr_src > 0)
+ dma_unmap_sg(priv->dev, src, sreq->nr_src,
+ DMA_BIDIRECTIONAL);
} else {
- dma_unmap_sg(priv->dev, src, sreq->nr_src, DMA_TO_DEVICE);
- dma_unmap_sg(priv->dev, dst, sreq->nr_dst, DMA_FROM_DEVICE);
+ if (sreq->nr_src > 0)
+ dma_unmap_sg(priv->dev, src, sreq->nr_src,
+ DMA_TO_DEVICE);
+ if (sreq->nr_dst > 0)
+ dma_unmap_sg(priv->dev, dst, sreq->nr_dst,
+ DMA_FROM_DEVICE);
}

/*
@@ -737,23 +743,29 @@ static int safexcel_send_req(struct crypto_async_request *base, int ring,
max(totlen_src, totlen_dst));
return -EINVAL;
}
- dma_map_sg(priv->dev, src, sreq->nr_src, DMA_BIDIRECTIONAL);
+ if (sreq->nr_src > 0)
+ dma_map_sg(priv->dev, src, sreq->nr_src,
+ DMA_BIDIRECTIONAL);
} else {
if (unlikely(totlen_src && (sreq->nr_src <= 0))) {
dev_err(priv->dev, "Source buffer not large enough (need %d bytes)!",
totlen_src);
return -EINVAL;
}
- dma_map_sg(priv->dev, src, sreq->nr_src, DMA_TO_DEVICE);
+
+ if (sreq->nr_src > 0)
+ dma_map_sg(priv->dev, src, sreq->nr_src, DMA_TO_DEVICE);

if (unlikely(totlen_dst && (sreq->nr_dst <= 0))) {
dev_err(priv->dev, "Dest buffer not large enough (need %d bytes)!",
totlen_dst);
- dma_unmap_sg(priv->dev, src, sreq->nr_src,
- DMA_TO_DEVICE);
- return -EINVAL;
+ ret = -EINVAL;
+ goto unmap;
}
- dma_map_sg(priv->dev, dst, sreq->nr_dst, DMA_FROM_DEVICE);
+
+ if (sreq->nr_dst > 0)
+ dma_map_sg(priv->dev, dst, sreq->nr_dst,
+ DMA_FROM_DEVICE);
}

memcpy(ctx->base.ctxr->data, ctx->key, ctx->key_len);
@@ -883,12 +895,18 @@ static int safexcel_send_req(struct crypto_async_request *base, int ring,
cdesc_rollback:
for (i = 0; i < n_cdesc; i++)
safexcel_ring_rollback_wptr(priv, &priv->ring[ring].cdr);
-
+unmap:
if (src == dst) {
- dma_unmap_sg(priv->dev, src, sreq->nr_src, DMA_BIDIRECTIONAL);
+ if (sreq->nr_src > 0)
+ dma_unmap_sg(priv->dev, src, sreq->nr_src,
+ DMA_BIDIRECTIONAL);
} else {
- dma_unmap_sg(priv->dev, src, sreq->nr_src, DMA_TO_DEVICE);
- dma_unmap_sg(priv->dev, dst, sreq->nr_dst, DMA_FROM_DEVICE);
+ if (sreq->nr_src > 0)
+ dma_unmap_sg(priv->dev, src, sreq->nr_src,
+ DMA_TO_DEVICE);
+ if (sreq->nr_dst > 0)
+ dma_unmap_sg(priv->dev, dst, sreq->nr_dst,
+ DMA_FROM_DEVICE);
}

return ret;
--
2.17.1

2022-09-24 08:23:08

by Herbert Xu

Subject: Re: [PATCH v3 1/2] crypto: inside_secure - Avoid dma map if size is zero

On Tue, Sep 13, 2022 at 04:03:47PM +0800, Peter Harliman Liem wrote:
> >From commit d03c54419274 ("dma-mapping: disallow .map_sg
> operations from returning zero on error"), dma_map_sg()
> produces warning if size is 0. This results in visible
> warnings if crypto length is zero.
> To avoid that, we avoid calling dma_map_sg if size is zero.
>
> Signed-off-by: Peter Harliman Liem <[email protected]>
> ---
> v3:
> Remove fixes tag
> Add corresponding change for dma_unmap_sg
> v2:
> Add fixes tag
>
> .../crypto/inside-secure/safexcel_cipher.c | 44 +++++++++++++------
> 1 file changed, 31 insertions(+), 13 deletions(-)

All applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt