[PATCH 1/2] crypto: caam - remove double buffering for ahash

From: Andrei Botila
Date: Mon Dec 09 2019 - 12:00:11 EST


Previously double buffering was used for storing previous and next
"less-than-block-size" bytes. Double buffering can be removed by moving
the copy of next "less-than-block-size" bytes after current request is
executed by HW.

Signed-off-by: Andrei Botila <andrei.botila@xxxxxxx>
---
drivers/crypto/caam/caamhash.c | 158 ++++++++++++---------------------
1 file changed, 58 insertions(+), 100 deletions(-)

diff --git a/drivers/crypto/caam/caamhash.c b/drivers/crypto/caam/caamhash.c
index 65399cb2a770..50a8852ad276 100644
--- a/drivers/crypto/caam/caamhash.c
+++ b/drivers/crypto/caam/caamhash.c
@@ -107,15 +107,13 @@ struct caam_hash_state {
dma_addr_t buf_dma;
dma_addr_t ctx_dma;
int ctx_dma_len;
- u8 buf_0[CAAM_MAX_HASH_BLOCK_SIZE] ____cacheline_aligned;
- int buflen_0;
- u8 buf_1[CAAM_MAX_HASH_BLOCK_SIZE] ____cacheline_aligned;
- int buflen_1;
+ u8 buf[CAAM_MAX_HASH_BLOCK_SIZE] ____cacheline_aligned;
+ int buflen;
+ int next_buflen;
u8 caam_ctx[MAX_CTX_LEN] ____cacheline_aligned;
int (*update)(struct ahash_request *req);
int (*final)(struct ahash_request *req);
int (*finup)(struct ahash_request *req);
- int current_buf;
};

struct caam_export_state {
@@ -127,31 +125,6 @@ struct caam_export_state {
int (*finup)(struct ahash_request *req);
};

-static inline void switch_buf(struct caam_hash_state *state)
-{
- state->current_buf ^= 1;
-}
-
-static inline u8 *current_buf(struct caam_hash_state *state)
-{
- return state->current_buf ? state->buf_1 : state->buf_0;
-}
-
-static inline u8 *alt_buf(struct caam_hash_state *state)
-{
- return state->current_buf ? state->buf_0 : state->buf_1;
-}
-
-static inline int *current_buflen(struct caam_hash_state *state)
-{
- return state->current_buf ? &state->buflen_1 : &state->buflen_0;
-}
-
-static inline int *alt_buflen(struct caam_hash_state *state)
-{
- return state->current_buf ? &state->buflen_0 : &state->buflen_1;
-}
-
static inline bool is_cmac_aes(u32 algtype)
{
return (algtype & (OP_ALG_ALGSEL_MASK | OP_ALG_AAI_MASK)) ==
@@ -183,12 +156,12 @@ static inline int buf_map_to_sec4_sg(struct device *jrdev,
struct sec4_sg_entry *sec4_sg,
struct caam_hash_state *state)
{
- int buflen = *current_buflen(state);
+ int buflen = state->buflen;

if (!buflen)
return 0;

- state->buf_dma = dma_map_single(jrdev, current_buf(state), buflen,
+ state->buf_dma = dma_map_single(jrdev, state->buf, buflen,
DMA_TO_DEVICE);
if (dma_mapping_error(jrdev, state->buf_dma)) {
dev_err(jrdev, "unable to map buf\n");
@@ -578,7 +551,7 @@ static inline void ahash_unmap(struct device *dev,
edesc->sec4_sg_bytes, DMA_TO_DEVICE);

if (state->buf_dma) {
- dma_unmap_single(dev, state->buf_dma, *current_buflen(state),
+ dma_unmap_single(dev, state->buf_dma, state->buflen,
DMA_TO_DEVICE);
state->buf_dma = 0;
}
@@ -643,9 +616,17 @@ static void ahash_done_bi(struct device *jrdev, u32 *desc, u32 err,
ecode = caam_jr_strstatus(jrdev, err);

ahash_unmap_ctx(jrdev, edesc, req, ctx->ctx_len, DMA_BIDIRECTIONAL);
- switch_buf(state);
kfree(edesc);

+ scatterwalk_map_and_copy(state->buf, req->src,
+ req->nbytes - state->next_buflen,
+ state->next_buflen, 0);
+ state->buflen = state->next_buflen;
+
+ print_hex_dump_debug("buf@" __stringify(__LINE__)": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, state->buf,
+ state->buflen, 1);
+
print_hex_dump_debug("ctx@"__stringify(__LINE__)": ",
DUMP_PREFIX_ADDRESS, 16, 4, state->caam_ctx,
ctx->ctx_len, 1);
@@ -703,9 +684,17 @@ static void ahash_done_ctx_dst(struct device *jrdev, u32 *desc, u32 err,
ecode = caam_jr_strstatus(jrdev, err);

ahash_unmap_ctx(jrdev, edesc, req, ctx->ctx_len, DMA_FROM_DEVICE);
- switch_buf(state);
kfree(edesc);

+ scatterwalk_map_and_copy(state->buf, req->src,
+ req->nbytes - state->next_buflen,
+ state->next_buflen, 0);
+ state->buflen = state->next_buflen;
+
+ print_hex_dump_debug("buf@" __stringify(__LINE__)": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, state->buf,
+ state->buflen, 1);
+
print_hex_dump_debug("ctx@"__stringify(__LINE__)": ",
DUMP_PREFIX_ADDRESS, 16, 4, state->caam_ctx,
ctx->ctx_len, 1);
@@ -786,18 +775,16 @@ static int ahash_update_ctx(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- u8 *buf = current_buf(state);
- int *buflen = current_buflen(state);
- u8 *next_buf = alt_buf(state);
+ u8 *buf = state->buf;
+ int *buflen = &state->buflen;
+ int *next_buflen = &state->next_buflen;
int blocksize = crypto_ahash_blocksize(ahash);
- int *next_buflen = alt_buflen(state), last_buflen;
int in_len = *buflen + req->nbytes, to_hash;
u32 *desc;
int src_nents, mapped_nents, sec4_sg_bytes, sec4_sg_src_index;
struct ahash_edesc *edesc;
int ret = 0;

- last_buflen = *next_buflen;
*next_buflen = in_len & (blocksize - 1);
to_hash = in_len - *next_buflen;

@@ -868,10 +855,6 @@ static int ahash_update_ctx(struct ahash_request *req)
sg_to_sec4_set_last(edesc->sec4_sg + sec4_sg_src_index -
1);

- if (*next_buflen)
- scatterwalk_map_and_copy(next_buf, req->src,
- to_hash - *buflen,
- *next_buflen, 0);
desc = edesc->hw_desc;

edesc->sec4_sg_dma = dma_map_single(jrdev, edesc->sec4_sg,
@@ -901,14 +884,11 @@ static int ahash_update_ctx(struct ahash_request *req)
scatterwalk_map_and_copy(buf + *buflen, req->src, 0,
req->nbytes, 0);
*buflen = *next_buflen;
- *next_buflen = last_buflen;
- }

- print_hex_dump_debug("buf@"__stringify(__LINE__)": ",
- DUMP_PREFIX_ADDRESS, 16, 4, buf, *buflen, 1);
- print_hex_dump_debug("next buf@"__stringify(__LINE__)": ",
- DUMP_PREFIX_ADDRESS, 16, 4, next_buf,
- *next_buflen, 1);
+ print_hex_dump_debug("buf@" __stringify(__LINE__)": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, buf,
+ *buflen, 1);
+ }

return ret;
unmap_ctx:
@@ -925,7 +905,7 @@ static int ahash_final_ctx(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- int buflen = *current_buflen(state);
+ int buflen = state->buflen;
u32 *desc;
int sec4_sg_bytes;
int digestsize = crypto_ahash_digestsize(ahash);
@@ -991,7 +971,7 @@ static int ahash_finup_ctx(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- int buflen = *current_buflen(state);
+ int buflen = state->buflen;
u32 *desc;
int sec4_sg_src_index;
int src_nents, mapped_nents;
@@ -1148,8 +1128,8 @@ static int ahash_final_no_ctx(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- u8 *buf = current_buf(state);
- int buflen = *current_buflen(state);
+ u8 *buf = state->buf;
+ int buflen = state->buflen;
u32 *desc;
int digestsize = crypto_ahash_digestsize(ahash);
struct ahash_edesc *edesc;
@@ -1207,11 +1187,10 @@ static int ahash_update_no_ctx(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- u8 *buf = current_buf(state);
- int *buflen = current_buflen(state);
+ u8 *buf = state->buf;
+ int *buflen = &state->buflen;
+ int *next_buflen = &state->next_buflen;
int blocksize = crypto_ahash_blocksize(ahash);
- u8 *next_buf = alt_buf(state);
- int *next_buflen = alt_buflen(state);
int in_len = *buflen + req->nbytes, to_hash;
int sec4_sg_bytes, src_nents, mapped_nents;
struct ahash_edesc *edesc;
@@ -1278,12 +1257,6 @@ static int ahash_update_no_ctx(struct ahash_request *req)

sg_to_sec4_sg_last(req->src, src_len, edesc->sec4_sg + 1, 0);

- if (*next_buflen) {
- scatterwalk_map_and_copy(next_buf, req->src,
- to_hash - *buflen,
- *next_buflen, 0);
- }
-
desc = edesc->hw_desc;

edesc->sec4_sg_dma = dma_map_single(jrdev, edesc->sec4_sg,
@@ -1317,14 +1290,11 @@ static int ahash_update_no_ctx(struct ahash_request *req)
scatterwalk_map_and_copy(buf + *buflen, req->src, 0,
req->nbytes, 0);
*buflen = *next_buflen;
- *next_buflen = 0;
- }

- print_hex_dump_debug("buf@"__stringify(__LINE__)": ",
- DUMP_PREFIX_ADDRESS, 16, 4, buf, *buflen, 1);
- print_hex_dump_debug("next buf@"__stringify(__LINE__)": ",
- DUMP_PREFIX_ADDRESS, 16, 4, next_buf, *next_buflen,
- 1);
+ print_hex_dump_debug("buf@" __stringify(__LINE__)": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, buf,
+ *buflen, 1);
+ }

return ret;
unmap_ctx:
@@ -1342,7 +1312,7 @@ static int ahash_finup_no_ctx(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- int buflen = *current_buflen(state);
+ int buflen = state->buflen;
u32 *desc;
int sec4_sg_bytes, sec4_sg_src_index, src_nents, mapped_nents;
int digestsize = crypto_ahash_digestsize(ahash);
@@ -1428,8 +1398,9 @@ static int ahash_update_first(struct ahash_request *req)
struct device *jrdev = ctx->jrdev;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
- u8 *next_buf = alt_buf(state);
- int *next_buflen = alt_buflen(state);
+ u8 *buf = state->buf;
+ int *buflen = &state->buflen;
+ int *next_buflen = &state->next_buflen;
int to_hash;
int blocksize = crypto_ahash_blocksize(ahash);
u32 *desc;
@@ -1491,10 +1462,6 @@ static int ahash_update_first(struct ahash_request *req)
if (ret)
goto unmap_ctx;

- if (*next_buflen)
- scatterwalk_map_and_copy(next_buf, req->src, to_hash,
- *next_buflen, 0);
-
desc = edesc->hw_desc;

ret = map_seq_out_ptr_ctx(desc, jrdev, state, ctx->ctx_len);
@@ -1517,14 +1484,14 @@ static int ahash_update_first(struct ahash_request *req)
state->update = ahash_update_no_ctx;
state->finup = ahash_finup_no_ctx;
state->final = ahash_final_no_ctx;
- scatterwalk_map_and_copy(next_buf, req->src, 0,
+ scatterwalk_map_and_copy(buf, req->src, 0,
req->nbytes, 0);
- switch_buf(state);
- }
+ *buflen = *next_buflen;

- print_hex_dump_debug("next buf@"__stringify(__LINE__)": ",
- DUMP_PREFIX_ADDRESS, 16, 4, next_buf, *next_buflen,
- 1);
+ print_hex_dump_debug("buf@" __stringify(__LINE__)": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, buf,
+ *buflen, 1);
+ }

return ret;
unmap_ctx:
@@ -1548,10 +1515,9 @@ static int ahash_init(struct ahash_request *req)

state->ctx_dma = 0;
state->ctx_dma_len = 0;
- state->current_buf = 0;
state->buf_dma = 0;
- state->buflen_0 = 0;
- state->buflen_1 = 0;
+ state->buflen = 0;
+ state->next_buflen = 0;

return 0;
}
@@ -1581,16 +1547,8 @@ static int ahash_export(struct ahash_request *req, void *out)
{
struct caam_hash_state *state = ahash_request_ctx(req);
struct caam_export_state *export = out;
- int len;
- u8 *buf;
-
- if (state->current_buf) {
- buf = state->buf_1;
- len = state->buflen_1;
- } else {
- buf = state->buf_0;
- len = state->buflen_0;
- }
+ u8 *buf = state->buf;
+ int len = state->buflen;

memcpy(export->buf, buf, len);
memcpy(export->caam_ctx, state->caam_ctx, sizeof(export->caam_ctx));
@@ -1608,9 +1566,9 @@ static int ahash_import(struct ahash_request *req, const void *in)
const struct caam_export_state *export = in;

memset(state, 0, sizeof(*state));
- memcpy(state->buf_0, export->buf, export->buflen);
+ memcpy(state->buf, export->buf, export->buflen);
memcpy(state->caam_ctx, export->caam_ctx, sizeof(state->caam_ctx));
- state->buflen_0 = export->buflen;
+ state->buflen = export->buflen;
state->update = export->update;
state->final = export->final;
state->finup = export->finup;
--
2.17.1