[PATCH 2/2] crypto: talitos - do not perform unnecessary dma synchronisation

From: Christophe Leroy
Date: Mon Feb 26 2018 - 11:40:23 EST


req_ctx->hw_context is mainly used only by the HW. So it is not needed
to sync the HW and the CPU each time hw_context in DMA mapped.
This patch modifies the DMA mapping in order to limit synchronisation
to necessary situations.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
drivers/crypto/talitos.c | 85 +++++++++++++++++++++++++++++++++++-------------
1 file changed, 63 insertions(+), 22 deletions(-)

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index bb44df1c1f2d..447cb8b1b16a 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -104,16 +104,34 @@ static void to_talitos_ptr_ext_or(struct talitos_ptr *ptr, u8 val, bool is_sec1)
/*
* map virtual single (contiguous) pointer to h/w descriptor pointer
*/
+static void __map_single_talitos_ptr(struct device *dev,
+ struct talitos_ptr *ptr,
+ unsigned int len, void *data,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ dma_addr_t dma_addr = dma_map_single_attrs(dev, data, len, dir, attrs);
+ struct talitos_private *priv = dev_get_drvdata(dev);
+ bool is_sec1 = has_ftr_sec1(priv);
+
+ to_talitos_ptr(ptr, dma_addr, len, is_sec1);
+}
+
static void map_single_talitos_ptr(struct device *dev,
struct talitos_ptr *ptr,
unsigned int len, void *data,
enum dma_data_direction dir)
{
- dma_addr_t dma_addr = dma_map_single(dev, data, len, dir);
- struct talitos_private *priv = dev_get_drvdata(dev);
- bool is_sec1 = has_ftr_sec1(priv);
+ __map_single_talitos_ptr(dev, ptr, len, data, dir, 0);
+}

- to_talitos_ptr(ptr, dma_addr, len, is_sec1);
+static void map_single_talitos_ptr_nosync(struct device *dev,
+ struct talitos_ptr *ptr,
+ unsigned int len, void *data,
+ enum dma_data_direction dir)
+{
+ __map_single_talitos_ptr(dev, ptr, len, data, dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
}

/*
@@ -1785,10 +1803,10 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,

/* hash context in */
if (!req_ctx->first || req_ctx->swinit) {
- map_single_talitos_ptr(dev, &desc->ptr[1],
- req_ctx->hw_context_size,
- (char *)req_ctx->hw_context,
- DMA_TO_DEVICE);
+ map_single_talitos_ptr_nosync(dev, &desc->ptr[1],
+ req_ctx->hw_context_size,
+ req_ctx->hw_context,
+ DMA_TO_DEVICE);
req_ctx->swinit = 0;
}
/* Indicate next op is not the first. */
@@ -1832,9 +1850,10 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
crypto_ahash_digestsize(tfm),
areq->result, DMA_FROM_DEVICE);
else
- map_single_talitos_ptr(dev, &desc->ptr[5],
- req_ctx->hw_context_size,
- req_ctx->hw_context, DMA_FROM_DEVICE);
+ map_single_talitos_ptr_nosync(dev, &desc->ptr[5],
+ req_ctx->hw_context_size,
+ req_ctx->hw_context,
+ DMA_FROM_DEVICE);

/* last DWORD empty */

@@ -1857,10 +1876,10 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
copy_talitos_ptr(&desc2->ptr[1], &desc->ptr[1],
is_sec1);
else
- map_single_talitos_ptr(dev, &desc2->ptr[1],
- req_ctx->hw_context_size,
- req_ctx->hw_context,
- DMA_TO_DEVICE);
+ map_single_talitos_ptr_nosync(dev, &desc2->ptr[1],
+ req_ctx->hw_context_size,
+ req_ctx->hw_context,
+ DMA_TO_DEVICE);
copy_talitos_ptr(&desc2->ptr[2], &desc->ptr[2], is_sec1);
sg_count = talitos_sg_map(dev, req_ctx->psrc, length, edesc,
&desc2->ptr[3], sg_count, offset, 0);
@@ -1868,10 +1887,10 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
sync_needed = true;
copy_talitos_ptr(&desc2->ptr[5], &desc->ptr[5], is_sec1);
if (req_ctx->last)
- map_single_talitos_ptr(dev, &desc->ptr[5],
- req_ctx->hw_context_size,
- req_ctx->hw_context,
- DMA_FROM_DEVICE);
+ map_single_talitos_ptr_nosync(dev, &desc->ptr[5],
+ req_ctx->hw_context_size,
+ req_ctx->hw_context,
+ DMA_FROM_DEVICE);

next_desc = dma_map_single(dev, &desc2->hdr1, TALITOS_DESC_SIZE,
DMA_BIDIRECTIONAL);
@@ -1909,8 +1928,11 @@ static struct talitos_edesc *ahash_edesc_alloc(struct ahash_request *areq,
static int ahash_init(struct ahash_request *areq)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
+ struct talitos_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct device *dev = ctx->dev;
struct talitos_ahash_req_ctx *req_ctx = ahash_request_ctx(areq);
unsigned int size;
+ dma_addr_t dma;

/* Initialize the context */
req_ctx->buf_idx = 0;
@@ -1922,6 +1944,10 @@ static int ahash_init(struct ahash_request *areq)
: TALITOS_MDEU_CONTEXT_SIZE_SHA384_SHA512;
req_ctx->hw_context_size = size;

+ dma = dma_map_single(dev, req_ctx->hw_context, req_ctx->hw_context_size,
+ DMA_TO_DEVICE);
+ dma_unmap_single(dev, dma, req_ctx->hw_context_size, DMA_TO_DEVICE);
+
return 0;
}

@@ -1933,9 +1959,6 @@ static int ahash_init_sha224_swinit(struct ahash_request *areq)
{
struct talitos_ahash_req_ctx *req_ctx = ahash_request_ctx(areq);

- ahash_init(areq);
- req_ctx->swinit = 1;/* prevent h/w initting context with sha256 values*/
-
req_ctx->hw_context[0] = SHA224_H0;
req_ctx->hw_context[1] = SHA224_H1;
req_ctx->hw_context[2] = SHA224_H2;
@@ -1949,6 +1972,9 @@ static int ahash_init_sha224_swinit(struct ahash_request *areq)
req_ctx->hw_context[8] = 0;
req_ctx->hw_context[9] = 0;

+ ahash_init(areq);
+ req_ctx->swinit = 1;/* prevent h/w initting context with sha256 values*/
+
return 0;
}

@@ -2105,6 +2131,14 @@ static int ahash_export(struct ahash_request *areq, void *out)
{
struct talitos_ahash_req_ctx *req_ctx = ahash_request_ctx(areq);
struct talitos_export_state *export = out;
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
+ struct talitos_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct device *dev = ctx->dev;
+ dma_addr_t dma;
+
+ dma = dma_map_single(dev, req_ctx->hw_context, req_ctx->hw_context_size,
+ DMA_FROM_DEVICE);
+ dma_unmap_single(dev, dma, req_ctx->hw_context_size, DMA_FROM_DEVICE);

memcpy(export->hw_context, req_ctx->hw_context,
req_ctx->hw_context_size);
@@ -2122,8 +2156,11 @@ static int ahash_import(struct ahash_request *areq, const void *in)
{
struct talitos_ahash_req_ctx *req_ctx = ahash_request_ctx(areq);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
+ struct talitos_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct device *dev = ctx->dev;
const struct talitos_export_state *export = in;
unsigned int size;
+ dma_addr_t dma;

memset(req_ctx, 0, sizeof(*req_ctx));
size = (crypto_ahash_digestsize(tfm) <= SHA256_DIGEST_SIZE)
@@ -2138,6 +2175,10 @@ static int ahash_import(struct ahash_request *areq, const void *in)
req_ctx->to_hash_later = export->to_hash_later;
req_ctx->nbuf = export->nbuf;

+ dma = dma_map_single(dev, req_ctx->hw_context, req_ctx->hw_context_size,
+ DMA_TO_DEVICE);
+ dma_unmap_single(dev, dma, req_ctx->hw_context_size, DMA_TO_DEVICE);
+
return 0;
}

--
2.13.3