Hi Corentin,
Here is a quick review, there surely are a lot of other things I didn't
spot.
On Mon, 16 Mar 2015 20:01:22 +0100
LABBE Corentin <clabbe.montjoie@xxxxxxxxx> wrote:
> Add support for the Security System included in Allwinner SoC A20.
> The Security System is a hardware cryptographic accelerator that support:
> - MD5 and SHA1 hash algorithms
> - AES block cipher in CBC mode with 128/196/256bits keys.
> - DES and 3DES block cipher in CBC mode
>
> Signed-off-by: LABBE Corentin <clabbe.montjoie@xxxxxxxxx>
> ---
[...]
> +static int sunxi_ss_cipher(struct ablkcipher_request *areq, u32 mode)
> +{
> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm);
> + const char *cipher_type;
> + struct sunxi_ss_ctx *ss = op->ss;
> +
> + if (areq->nbytes == 0)
> + return 0;
> +
> + if (areq->info == NULL) {
> + dev_err(ss->dev, "ERROR: Empty IV\n");
> + return -EINVAL;
> + }
> +
> + if (areq->src == NULL || areq->dst == NULL) {
> + dev_err(ss->dev, "ERROR: Some SGs are NULL\n");
> + return -EINVAL;
> + }
> +
> + cipher_type = crypto_tfm_alg_name(crypto_ablkcipher_tfm(tfm));
> +
> + if (strcmp("cbc(aes)", cipher_type) == 0) {
> + mode |= SS_OP_AES | SS_CBC | SS_ENABLED | op->keymode;
> + return sunxi_ss_aes_poll(areq, mode);
> + }
> +
> + if (strcmp("cbc(des)", cipher_type) == 0) {
> + mode |= SS_OP_DES | SS_CBC | SS_ENABLED | op->keymode;
> + return sunxi_ss_des_poll(areq, mode);
> + }
> +
> + if (strcmp("cbc(des3_ede)", cipher_type) == 0) {
> + mode |= SS_OP_3DES | SS_CBC | SS_ENABLED | op->keymode;
> + return sunxi_ss_des_poll(areq, mode);
> + }
Hm, I'm not sure doing these string comparisons in the crypto operation
path is a good idea.
Moreover, you're doing 3 string comparisons, even though only one can
be valid at a time (using 'else if' would have been a bit better).
Anyway, IMHO this function should be split into 3 functions, and
referenced by your alg template definitions.
Something like:
int sunxi_ss_xxx_encrypt(struct ablkcipher_request *areq)
{
/* put your cipher specific intialization here */
return sunxi_ss_xxx_poll(areq, SS_ENCRYPTION);
}
int sunxi_ss_xxx_decrypt(struct ablkcipher_request *areq)
{
/* put your cipher specific intialization here */
return sunxi_ss_xxx_poll(areq, SS_DECRYPTION);
}
> +
> +int sunxi_ss_cipher_init(struct crypto_tfm *tfm)
> +{
> + const char *name = crypto_tfm_alg_name(tfm);
> + struct sunxi_tfm_ctx *op = crypto_tfm_ctx(tfm);
> + struct crypto_alg *alg = tfm->__crt_alg;
> + struct sunxi_ss_alg_template *algt;
> + struct sunxi_ss_ctx *ss;
> +
> + memset(op, 0, sizeof(struct sunxi_tfm_ctx));
> +
> + algt = container_of(alg, struct sunxi_ss_alg_template, alg.crypto);
> + ss = algt->ss;
> + op->ss = algt->ss;
> +
> + /* fallback is needed only for DES/3DES */
> + if (strcmp("cbc(des)", name) == 0 ||
> + strcmp("cbc(des3_ede)", name) == 0) {
> + op->fallback = crypto_alloc_ablkcipher(name, 0,
> + CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
> + if (IS_ERR(op->fallback)) {
> + dev_err(ss->dev, "ERROR: allocating fallback algo %s\n",
> + name);
> + return PTR_ERR(op->fallback);
> + }
> + }
Ditto: just create a specific init function for the des case:
int sunxi_ss_cbc_des_init(struct crypto_tfm *tfm)
{
sunxi_ss_cipher_init(tfm);
op->fallback = crypto_alloc_ablkcipher(name, 0,
CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(op->fallback)) {
dev_err(ss->dev, "ERROR: allocating fallback algo %s\n",
name);
return PTR_ERR(op->fallback);
}
return 0;
}
[..]
> +/*
> + * Optimized function for the case where we have only one SG,
> + * so we can use kmap_atomic
> + */
> +static int sunxi_ss_aes_poll_atomic(struct ablkcipher_request *areq)
> +{
> + u32 spaces;
> + struct scatterlist *in_sg = areq->src;
> + struct scatterlist *out_sg = areq->dst;
> + void *src_addr;
> + void *dst_addr;
> + unsigned int ileft = areq->nbytes;
> + unsigned int oleft = areq->nbytes;
> + unsigned int todo;
> + u32 *src32;
> + u32 *dst32;
> + u32 rx_cnt = 32;
> + u32 tx_cnt = 0;
> + int i;
> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm);
> + struct sunxi_ss_ctx *ss = op->ss;
> +
> + src_addr = kmap_atomic(sg_page(in_sg)) + in_sg->offset;
> + if (src_addr == NULL) {
> + dev_err(ss->dev, "kmap_atomic error for src SG\n");
> + return -EINVAL;
> + }
> +
> + dst_addr = kmap_atomic(sg_page(out_sg)) + out_sg->offset;
> + if (dst_addr == NULL) {
> + dev_err(ss->dev, "kmap_atomic error for dst SG\n");
> + kunmap_atomic(src_addr);
> + return -EINVAL;
> + }
> +
> + src32 = (u32 *)src_addr;
> + dst32 = (u32 *)dst_addr;
> + ileft = areq->nbytes / 4;
> + oleft = areq->nbytes / 4;
> + i = 0;
> + do {
> + if (ileft > 0 && rx_cnt > 0) {
> + todo = min(rx_cnt, ileft);
> + ileft -= todo;
> + writesl(ss->base + SS_RXFIFO, src32, todo);
> + src32 += todo;
> + }
> + if (tx_cnt > 0) {
> + todo = min(tx_cnt, oleft);
> + oleft -= todo;
> + readsl(ss->base + SS_TXFIFO, dst32, todo);
> + dst32 += todo;
> + }
> + spaces = readl(ss->base + SS_FCSR);
> + rx_cnt = SS_RXFIFO_SPACES(spaces);
> + tx_cnt = SS_TXFIFO_SPACES(spaces);
> + } while (oleft > 0);
> + kunmap_atomic(dst_addr);
> + kunmap_atomic(src_addr);
> + return 0;
> +}
> +
> +int sunxi_ss_aes_poll(struct ablkcipher_request *areq, u32 mode)
> +{
> + u32 spaces;
> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm);
> + struct sunxi_ss_ctx *ss = op->ss;
> + unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
> + /* when activating SS, the default FIFO space is 32 */
> + u32 rx_cnt = 32;
> + u32 tx_cnt = 0;
> + u32 v;
> + int i, err = 0;
> + struct scatterlist *in_sg = areq->src;
> + struct scatterlist *out_sg = areq->dst;
> + void *src_addr;
> + void *dst_addr;
> + unsigned int ileft = areq->nbytes;
> + unsigned int oleft = areq->nbytes;
> + unsigned int sgileft = areq->src->length;
> + unsigned int sgoleft = areq->dst->length;
> + unsigned int todo;
> + u32 *src32;
> + u32 *dst32;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&ss->slock, flags);
> +
> + for (i = 0; i < op->keylen; i += 4)
> + writel(*(op->key + i/4), ss->base + SS_KEY0 + i);
> +
> + if (areq->info != NULL) {
> + for (i = 0; i < 4 && i < ivsize / 4; i++) {
> + v = *(u32 *)(areq->info + i * 4);
> + writel(v, ss->base + SS_IV0 + i * 4);
> + }
> + }
> + writel(mode, ss->base + SS_CTL);
> +
> + /* If we have only one SG, we can use kmap_atomic */
> + if (sg_next(in_sg) == NULL && sg_next(out_sg) == NULL) {
> + err = sunxi_ss_aes_poll_atomic(areq);
> + goto release_ss;
> + }
> +
> + /*
> + * If we have more than one SG, we cannot use kmap_atomic since
> + * we hold the mapping too long
> + */
> + src_addr = kmap(sg_page(in_sg)) + in_sg->offset;
> + if (src_addr == NULL) {
> + dev_err(ss->dev, "KMAP error for src SG\n");
> + err = -EINVAL;
> + goto release_ss;
> + }
> + dst_addr = kmap(sg_page(out_sg)) + out_sg->offset;
> + if (dst_addr == NULL) {
> + kunmap(sg_page(in_sg));
> + dev_err(ss->dev, "KMAP error for dst SG\n");
> + err = -EINVAL;
> + goto release_ss;
> + }
> + src32 = (u32 *)src_addr;
> + dst32 = (u32 *)dst_addr;
> + ileft = areq->nbytes / 4;
> + oleft = areq->nbytes / 4;
> + sgileft = in_sg->length / 4;
> + sgoleft = out_sg->length / 4;
> + do {
> + spaces = readl_relaxed(ss->base + SS_FCSR);
> + rx_cnt = SS_RXFIFO_SPACES(spaces);
> + tx_cnt = SS_TXFIFO_SPACES(spaces);
> + todo = min3(rx_cnt, ileft, sgileft);
> + if (todo > 0) {
> + ileft -= todo;
> + sgileft -= todo;
> + writesl(ss->base + SS_RXFIFO, src32, todo);
> + src32 += todo;
> + }
> + if (in_sg != NULL && sgileft == 0 && ileft > 0) {
> + kunmap(sg_page(in_sg));
> + in_sg = sg_next(in_sg);
> + while (in_sg != NULL && in_sg->length == 0)
> + in_sg = sg_next(in_sg);
> + if (in_sg != NULL && ileft > 0) {
> + src_addr = kmap(sg_page(in_sg)) + in_sg->offset;
> + if (src_addr == NULL) {
> + dev_err(ss->dev, "ERROR: KMAP for src SG\n");
> + err = -EINVAL;
> + goto release_ss;
> + }
> + src32 = src_addr;
> + sgileft = in_sg->length / 4;
> + }
> + }
> + /* do not test oleft since when oleft == 0 we have finished */
> + todo = min3(tx_cnt, oleft, sgoleft);
> + if (todo > 0) {
> + oleft -= todo;
> + sgoleft -= todo;
> + readsl(ss->base + SS_TXFIFO, dst32, todo);
> + dst32 += todo;
> + }
> + if (out_sg != NULL && sgoleft == 0 && oleft >= 0) {
> + kunmap(sg_page(out_sg));
> + out_sg = sg_next(out_sg);
> + while (out_sg != NULL && out_sg->length == 0)
> + out_sg = sg_next(out_sg);
> + if (out_sg != NULL && oleft > 0) {
> + dst_addr = kmap(sg_page(out_sg)) +
> + out_sg->offset;
> + if (dst_addr == NULL) {
> + dev_err(ss->dev, "KMAP error\n");
> + err = -EINVAL;
> + goto release_ss;
> + }
> + dst32 = dst_addr;
> + sgoleft = out_sg->length / 4;
> + }
> + }
> + } while (oleft > 0);
> +
> +release_ss:
> + writel_relaxed(0, ss->base + SS_CTL);
> + spin_unlock_irqrestore(&ss->slock, flags);
> + return err;
> +}
Do you really need to have both an "optimized" and "non-optimized"
function ?
BTW, you should take a look at the sg_copy_buffer function [1], which
is doing pretty much what you're doing here.
If you don't want to directly use sg_copy_buffer, you should at least
use the sg_miter_xxx function to iterate over you're sg list (it's
taking care of calling kmap or kmap_atomic depending on the
SG_MITER_ATOMIC flag).
> +
> +/* Pure CPU driven way of doing DES/3DES with SS */
> +int sunxi_ss_des_poll(struct ablkcipher_request *areq, u32 mode)
> +{
> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm);
> + struct sunxi_ss_ctx *ss = op->ss;
> + int i, err = 0;
> + int no_chunk = 1;
> + struct scatterlist *in_sg = areq->src;
> + struct scatterlist *out_sg = areq->dst;
> + u8 kkey[256 / 8];
> +
> + /*
> + * if we have only SGs with size multiple of 4,
> + * we can use the SS AES function
> + */
> + while (in_sg != NULL && no_chunk == 1) {
> + if ((in_sg->length % 4) != 0)
> + no_chunk = 0;
> + in_sg = sg_next(in_sg);
> + }
> + while (out_sg != NULL && no_chunk == 1) {
> + if ((out_sg->length % 4) != 0)
> + no_chunk = 0;
> + out_sg = sg_next(out_sg);
> + }
> +
> + if (no_chunk == 1)
> + return sunxi_ss_aes_poll(areq, mode);
> +
Given your explanations, I'm not sure the names sunxi_ss_aes_poll and
sunxi_ss_des_poll are appropriate.
What about sunxi_ss_aligned_cipher_op_poll and sunxi_ss_cipher_op_poll.
That's all I got for now.
I haven't reviewed the hash part yet, but I guess some of my comments
apply to this code too.
Best Regards,
Boris
[1]http://lxr.free-electrons.com/source/lib/scatterlist.c#L621
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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