On Tue, 8 Feb 2011 15:56:16 +0000
Jamie Iles <ja...@jamieiles.com> wrote:
> Picochip picoXcell devices have two crypto engines, one targeted
> at IPSEC offload and the other at WCDMA layer 2 ciphering.
>
> Cc: Herbert Xu <herb...@gondor.apana.org.au>
> Signed-off-by: Jamie Iles <ja...@jamieiles.com>
> ---
nice driver ;). Have a couple of comments though.
> + help
> + This option enables support for the hardware offload engines in the
> + Picochip picoXcell SoC devices. Select this for IPSEC ESP offload
> + and for 3gpp Layer 2 ciphering support.
it'd be nice to mention what name the module will have.
> +#define SPACC_CRYPTO_AES_MAX_KEY_LEN 32
> +#define SPACC_CRYPTO_AES_IV_LEN 16
> +#define SPACC_CRYPTO_DES_IV_LEN 8
these are identical to algorithm-generic symbolic constants
AES_MAX_KEY_SIZE, [AD]ES_BLOCK_SIZE - why not use them instead?
> +struct spacc_generic_ctx;
this declaration isn't used prior to its definition, so it's not needed.
> +/* DDT format. This must match the hardware DDT format exactly. */
> +struct spacc_ddt {
> + u32 p, len;
type-consistency: p should be a dma_addr_t
> + /* AEAD specifc bits. */
specific
> +static inline struct spacc_ablk_ctx *
> +to_spacc_ablk_ctx(struct spacc_generic_ctx *ctx)
> +{
> + return ctx ? container_of(ctx, struct spacc_ablk_ctx, generic) : NULL;
> +}
> +
> +static inline struct spacc_aead_ctx *
> +to_spacc_aead_ctx(struct spacc_generic_ctx *ctx)
> +{
> + return ctx ? container_of(ctx, struct spacc_aead_ctx, generic) : NULL;
> +}
these aren't being used anywhere.
> +static inline struct spacc_alg *to_spacc_alg(struct crypto_alg *alg);
define it here - forward declarations should only be necessary when
dealing with circular dependencies.
> +/*
> + * Take a crypto request and scatterlists for the data and turn them into
> DDTs
> + * for passing to the crypto engines. This also DMA maps the data so that the
> + * crypto engines can DMA to/from them.
> + */
> +static struct spacc_ddt *spacc_sg_to_ddt(struct spacc_engine *engine,
> + struct scatterlist *payload,
> + unsigned nbytes,
> + enum dma_data_direction dir,
> + dma_addr_t *ddt_phys)
> +{
> + unsigned nents, mapped_ents;
> + struct scatterlist *cur;
> + struct spacc_ddt *ddt;
> + int i;
> +
> + nents = sg_count(payload, nbytes);
> + mapped_ents = dma_map_sg(engine->dev, payload, nents, dir);
> +
> + if (mapped_ents + 1 > MAX_DDT_LEN) {
> + dma_unmap_sg(engine->dev, payload, nents, dir);
> + return NULL;
> + }
> +
> + ddt = dma_pool_alloc(engine->req_pool, GFP_ATOMIC, ddt_phys);
> + if (ddt) {
> + for_each_sg(payload, cur, mapped_ents, i) {
> + ddt[i].p = sg_dma_address(cur);
> + ddt[i].len = sg_dma_len(cur);
> + }
> +
> + ddt[mapped_ents].p = 0;
> + ddt[mapped_ents].len = 0;
> + } else {
> + dma_unmap_sg(engine->dev, payload, nents, dir);
> + ddt = NULL;
> + }
> +
> + return ddt;
> +}
easier to read would be:
if (mapped_ents + 1 > MAX_DDT_LEN)
goto out;
ddt = dma_pool_alloc(engine->req_pool, GFP_ATOMIC, ddt_phys);
if (!ddt)
goto out;
for_each_sg(payload, cur, mapped_ents, i) {
ddt[i].p = sg_dma_address(cur);
ddt[i].len = sg_dma_len(cur);
}
ddt[mapped_ents].p = 0;
ddt[mapped_ents].len = 0;
return ddt;
out:
dma_unmap_sg(engine->dev, payload, nents, dir);
return NULL;
}
even more so by moving ddt_set() above it, and then using ddt_set() to
assign the p, len pairs.
> +static inline void ddt_set(struct spacc_ddt *ddt, unsigned long phys,
phys should be dma_addr_t
> +static int spacc_aead_make_ddts(struct spacc_req *req, u8 *giv)
> +{
> + struct aead_request *areq = container_of(req->req, struct aead_request,
> + base);
> + struct spacc_alg *alg = to_spacc_alg(req->req->tfm->__crt_alg);
> + struct spacc_engine *engine = req->engine;
> + struct spacc_ddt *src_ddt, *dst_ddt;
> + unsigned ivsize = alg->alg.cra_aead.ivsize;
no need to go through all those hoops to get to the ivsize - use helper
fns crypto_aead_reqtfm() and crypto_aead_ivsize(), as is done at the
callsite, or just pass it in from there.
> +static int spacc_aead_des_setkey(struct crypto_aead *aead, const u8 *key,
> + unsigned int len)
> +{
> + struct crypto_tfm *tfm = crypto_aead_tfm(aead);
> + struct spacc_aead_ctx *ctx = crypto_tfm_ctx(tfm);
> + int err = 0;
> + u32 tmp[DES_EXPKEY_WORDS];
> +
> + err = des_ekey(tmp, key);
> + if (unlikely(!err) &&
might want to change the name of the variable err here to something
like ret or is_weak so as to not mislead the reader.
> + (crypto_aead_get_flags(aead)) & CRYPTO_TFM_REQ_WEAK_KEY) {
> + tfm->crt_flags |= CRYPTO_TFM_RES_WEAK_KEY;
> + return -EINVAL;
> + }
> + err = 0;
> +
> + memcpy(ctx->cipher_key, key, len);
> + ctx->cipher_key_len = len;
> +
> + return err;
actually, it doesn't look like this fn needs a return variable
at all.
> +/* Set the key for the AES block cipher component of the AEAD transform. */
> +static int spacc_aead_aes_setkey(struct crypto_aead *aead, const u8 *key,
> + unsigned int len)
> +{
> + struct crypto_tfm *tfm = crypto_aead_tfm(aead);
> + struct spacc_aead_ctx *ctx = crypto_tfm_ctx(tfm);
> + int err;
> +
> + /*
> + * IPSec engine only supports 128 and 256 bit AES keys. If we get a
> + * request for any other size (192 bits) then we need to do a software
> + * fallback.
> + */
> + if (!(16 == len || 32 == len)) {
if (len != AES_KEYSIZE_128 && len != AES_KEYSIZE_256)
> + /*
> + * Set the fallback transform to use the same request flags as
> + * the hardware transform.
> + */
> + ctx->sw_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
> + ctx->sw_cipher->base.crt_flags |=
> + (tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
parens not needed.
> + err = crypto_aead_setkey(ctx->sw_cipher, key, len);
> + } else {
> + memcpy(ctx->cipher_key, key, len);
> + ctx->cipher_key_len = len;
> + err = 0;
> + }
> +
> + return err;
return crypto_aead_setkey(ctx->sw_cipher, key, len);
}
memcpy(ctx->cipher_key, key, len);
ctx->cipher_key_len = len;
return 0;
> +static int spacc_aead_setkey(struct crypto_aead *tfm, const u8 *key,
> + unsigned int keylen)
> +{
> + struct spacc_aead_ctx *ctx = crypto_aead_ctx(tfm);
> + struct spacc_alg *alg = to_spacc_alg(tfm->base.__crt_alg);
> + struct rtattr *rta = (void *)key;
> + struct crypto_authenc_key_param *param;
> + unsigned int authkeylen, enckeylen;
> + int err = -EINVAL;
> +
> + if (!RTA_OK(rta, keylen))
> + goto badkey;
> +
> + if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
> + goto badkey;
> +
> + if (RTA_PAYLOAD(rta) < sizeof(*param))
> + goto badkey;
I'm not sure, but it should be safe to remove the above three checks -
they cause a false badkey failure if the keys aren't within an rtattr
struct, which, e.g., something like testmgr.c wouldn't do.
> + param = RTA_DATA(rta);
> + enckeylen = be32_to_cpu(param->enckeylen);
> +
> + key += RTA_ALIGN(rta->rta_len);
> + keylen -= RTA_ALIGN(rta->rta_len);
actually, I doubt crypto drivers should be including rtnetlink.h at
all...but it's probably ok for now - talitos still does :)
> + if ((spacc_alg->ctrl_default & SPACC_CRYPTO_ALG_MASK) ==
> + SPA_CTRL_CIPH_ALG_AES &&
> + !(16 == ctx->cipher_key_len || 32 == ctx->cipher_key_len))
as above, please use symbolic equivalents
> +static void spacc_aead_complete(struct spacc_req *req)
> +{
> + spacc_aead_free_ddts(req);
> +
> + if (req->req->complete)
> + req->req->complete(req->req, req->result);
when is there not a completion function?
> + /* Set the source and destination DDT pointers. */
> + writel((u32)req->src_addr, engine->regs + SPA_SRC_PTR_REG_OFFSET);
> + writel((u32)req->dst_addr, engine->regs + SPA_DST_PTR_REG_OFFSET);
cast necessary?
> + ctrl = spacc_alg->ctrl_default;
> + ctrl |= ((req->ctx_id << SPA_CTRL_CTX_IDX) |
> + (1 << SPA_CTRL_ICV_APPEND) |
> + (req->is_encrypt ? (1 << SPA_CTRL_ENCRYPT_IDX) : 0) |
> + (req->is_encrypt ? (1 << SPA_CTRL_AAD_COPY) : 0));
> + if (!req->is_encrypt)
> + ctrl |= (1 << SPA_CTRL_KEY_EXP);
ctrl = spacc_alg->ctrl_default | (req->ctx_id << SPA_CTRL_CTX_IDX) |
(1 << SPA_CTRL_ICV_APPEND);
if (req->is_encrypt)
ctrl |= (1 << SPA_CTRL_ENCRYPT_IDX) | (1 << SPA_CTRL_AAD_COPY);
else
ctrl |= (1 << SPA_CTRL_KEY_EXP);
> +static int spacc_des_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
> + unsigned int len)
> +{
> + struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
> + struct spacc_ablk_ctx *ctx = crypto_tfm_ctx(tfm);
> + int err;
> + u32 tmp[DES_EXPKEY_WORDS];
> +
> + if (len > SPACC_CRYPTO_AES_MAX_KEY_LEN) {
AES left overs in a DES setkey
> +static int spacc_aes_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
> + unsigned int len)
> +{
> + struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
> + struct spacc_ablk_ctx *ctx = crypto_tfm_ctx(tfm);
> + int err = 0;
> +
> + if (len > SPACC_CRYPTO_AES_MAX_KEY_LEN) {
> + crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN);
> + return -EINVAL;
> + }
> +
> + /*
> + * IPSec engine only supports 128 and 256 bit AES keys. If we get a
> + * request for any other size (192 bits) then we need to do a software
> + * fallback.
> + */
> + if (!(16 == len || 32 == len) && ctx->sw_cipher) {
symbolic constants
> + /*
> + * Set the fallback transform to use the same request flags as
> + * the hardware transform.
> + */
> + ctx->sw_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
> + ctx->sw_cipher->base.crt_flags |=
> + (cipher->base.crt_flags & CRYPTO_TFM_REQ_MASK);
parens not necessary
> +static int spacc_ablk_need_fallback(struct spacc_req *req)
> +{
> + struct spacc_ablk_ctx *ctx;
> + struct crypto_tfm *tfm = req->req->tfm;
> + struct crypto_alg *alg = req->req->tfm->__crt_alg;
> + struct spacc_alg *spacc_alg = to_spacc_alg(alg);
> +
> + ctx = crypto_tfm_ctx(tfm);
> +
> + return (spacc_alg->ctrl_default & SPACC_CRYPTO_ALG_MASK) ==
> + SPA_CTRL_CIPH_ALG_AES &&
> + !(16 == ctx->key_len || 32 == ctx->key_len);
symbolic constants
> +static ssize_t spacc_stat_irq_thresh_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct spacc_engine *engine = spacc_dev_to_engine(dev);
> + unsigned thresh = simple_strtoul(buf, NULL, 0);
consider using strict_strtoul (checkpatch)
> +static struct spacc_alg ipsec_engine_algs[] = {
> + {
> + .ctrl_default = SPA_CTRL_CIPH_ALG_AES | SPA_CTRL_CIPH_MODE_CBC,
> + .key_offs = 0,
> + .iv_offs = SPACC_CRYPTO_AES_MAX_KEY_LEN,
> + .alg = {
> + .cra_name = "cbc(aes)",
> + .cra_driver_name = "cbc-aes-picoxcell",
> + .cra_priority = SPACC_CRYPTO_ALG_PRIORITY,
> + .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
> + CRYPTO_ALG_ASYNC |
> + CRYPTO_ALG_NEED_FALLBACK,
> + .cra_blocksize = 16,
symbolic constant, here and throughout the rest of this section.
Thanks,
Kim
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