From: Fionnuala Gunter <f...@linux.vnet.ibm.com>

This patch updates the NX driver to perform several hyper calls when necessary
so that the length limits of scatter/gather lists are respected.

Reviewed-by: Marcelo Cerri <mhce...@linux.vnet.ibm.com>
Signed-off-by: Joy Latten <jmlat...@linux.vnet.ibm.com>
Signed-off-by: Fionnuala Gunter <f...@linux.vnet.ibm.com>
---
 drivers/crypto/nx/nx-aes-ccm.c | 297 +++++++++++++++++++++++++++++------------
 1 file changed, 215 insertions(+), 82 deletions(-)

diff --git a/drivers/crypto/nx/nx-aes-ccm.c b/drivers/crypto/nx/nx-aes-ccm.c
index 666a35b..5ecd4c2 100644
--- a/drivers/crypto/nx/nx-aes-ccm.c
+++ b/drivers/crypto/nx/nx-aes-ccm.c
@@ -179,13 +179,26 @@ static int generate_pat(u8                   *iv,
        struct nx_sg *nx_insg = nx_ctx->in_sg;
        struct nx_sg *nx_outsg = nx_ctx->out_sg;
        unsigned int iauth_len = 0;
-       struct vio_pfo_op *op = NULL;
        u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL;
        int rc;
 
        /* zero the ctr value */
        memset(iv + 15 - iv[0], 0, iv[0] + 1);
 
+       /* page 78 of nx_wb.pdf has,
+        * Note: RFC3610 allows the AAD data to be up to 2^64 -1 bytes
+        * in length. If a full message is used, the AES CCA implementation
+        * restricts the maximum AAD length to 2^32 -1 bytes.
+        * If partial messages are used, the implementation supports
+        * 2^64 -1 bytes maximum AAD length.
+        *
+        * However, in the cryptoapi's aead_request structure,
+        * assoclen is an unsigned int, thus it cannot hold a length
+        * value greater than 2^32 - 1.
+        * Thus the AAD is further constrained by this and is never
+        * greater than 2^32.
+        */
+
        if (!req->assoclen) {
                b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
        } else if (req->assoclen <= 14) {
@@ -195,7 +208,46 @@ static int generate_pat(u8                   *iv,
                b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
                b1 = nx_ctx->priv.ccm.iauth_tag;
                iauth_len = req->assoclen;
+       } else if (req->assoclen <= 65280) {
+               /* if associated data is less than (2^16 - 2^8), we construct
+                * B1 differently and feed in the associated data to a CCA
+                * operation */
+               b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
+               b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
+               iauth_len = 14;
+       } else {
+               b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
+               b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
+               iauth_len = 10;
+       }
 
+       /* generate B0 */
+       rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0);
+       if (rc)
+               return rc;
+
+       /* generate B1:
+        * add control info for associated data
+        * RFC 3610 and NIST Special Publication 800-38C
+        */
+       if (b1) {
+               memset(b1, 0, 16);
+               if (req->assoclen <= 65280) {
+                       *(u16 *)b1 = (u16)req->assoclen;
+                       scatterwalk_map_and_copy(b1 + 2, req->assoc, 0,
+                                        iauth_len, SCATTERWALK_FROM_SG);
+               } else {
+                       *(u16 *)b1 = (u16)(0xfffe);
+                       *(u32 *)&b1[2] = (u32)req->assoclen;
+                       scatterwalk_map_and_copy(b1 + 6, req->assoc, 0,
+                                        iauth_len, SCATTERWALK_FROM_SG);
+               }
+       }
+
+       /* now copy any remaining AAD to scatterlist and call nx... */
+       if (!req->assoclen) {
+               return rc;
+       } else if (req->assoclen <= 14) {
                nx_insg = nx_build_sg_list(nx_insg, b1, 16, nx_ctx->ap->sglen);
                nx_outsg = nx_build_sg_list(nx_outsg, tmp, 16,
                                            nx_ctx->ap->sglen);
@@ -210,56 +262,74 @@ static int generate_pat(u8                   *iv,
                NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT;
                NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE;
 
-               op = &nx_ctx->op;
                result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac;
-       } else if (req->assoclen <= 65280) {
-               /* if associated data is less than (2^16 - 2^8), we construct
-                * B1 differently and feed in the associated data to a CCA
-                * operation */
-               b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
-               b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
-               iauth_len = 14;
-
-               /* remaining assoc data must have scatterlist built for it */
-               nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen,
-                                           req->assoc, iauth_len,
-                                           req->assoclen - iauth_len);
-               nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) *
+
+               rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
+                                  req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
+               if (rc)
+                       return rc;
+
+               atomic_inc(&(nx_ctx->stats->aes_ops));
+               atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes));
+
+       } else {
+               u32 max_sg_len;
+               unsigned int processed = 0, to_process;
+
+               /* page_limit: number of sg entries that fit on one page */
+               max_sg_len = min_t(u32,
+                                  nx_driver.of.max_sg_len/sizeof(struct nx_sg),
+                                  nx_ctx->ap->sglen);
+
+               processed += iauth_len;
+
+               do {
+                       to_process = min_t(u32, req->assoclen - processed,
+                                          nx_ctx->ap->databytelen);
+                       to_process = min_t(u64, to_process,
+                                          NX_PAGE_SIZE * (max_sg_len - 1));
+
+                       if ((to_process + processed) < req->assoclen) {
+                               NX_CPB_FDM(nx_ctx->csbcpb_aead) |=
+                                       NX_FDM_INTERMEDIATE;
+                       } else {
+                               NX_CPB_FDM(nx_ctx->csbcpb_aead) &=
+                                       ~NX_FDM_INTERMEDIATE;
+                       }
+
+                       nx_insg = nx_walk_and_build(nx_ctx->in_sg,
+                                                   nx_ctx->ap->sglen,
+                                                   req->assoc, processed,
+                                                   to_process);
+
+                       nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) *
                                                sizeof(struct nx_sg);
 
-               op = &nx_ctx->op_aead;
+                       result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0;
+
+                       rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,
+                                  req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
+                       if (rc)
+                               return rc;
+
+                       memcpy(nx_ctx->csbcpb_aead->cpb.aes_cca.b0,
+                               nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0,
+                               AES_BLOCK_SIZE);
+
+                       NX_CPB_FDM(nx_ctx->csbcpb_aead) |= NX_FDM_CONTINUATION;
+
+                       atomic_inc(&(nx_ctx->stats->aes_ops));
+                       atomic64_add(req->assoclen,
+                                       &(nx_ctx->stats->aes_bytes));
+
+                       processed += to_process;
+               } while (processed < req->assoclen);
+
                result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0;
-       } else {
-               /* if associated data is less than (2^32), we construct B1
-                * differently yet again and feed in the associated data to a
-                * CCA operation */
-               pr_err("associated data len is %u bytes (returning -EINVAL)\n",
-                      req->assoclen);
-               rc = -EINVAL;
        }
 
-       rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0);
-       if (rc)
-               goto done;
+       memcpy(out, result, AES_BLOCK_SIZE);
 
-       if (b1) {
-               memset(b1, 0, 16);
-               *(u16 *)b1 = (u16)req->assoclen;
-
-               scatterwalk_map_and_copy(b1 + 2, req->assoc, 0,
-                                        iauth_len, SCATTERWALK_FROM_SG);
-
-               rc = nx_hcall_sync(nx_ctx, op,
-                                  req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
-               if (rc)
-                       goto done;
-
-               atomic_inc(&(nx_ctx->stats->aes_ops));
-               atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes));
-
-               memcpy(out, result, AES_BLOCK_SIZE);
-       }
-done:
        return rc;
 }
 
@@ -272,15 +342,12 @@ static int ccm_nx_decrypt(struct aead_request   *req,
        unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
        struct nx_ccm_priv *priv = &nx_ctx->priv.ccm;
        unsigned long irq_flags;
+       unsigned int processed = 0, to_process;
+       u32 max_sg_len;
        int rc = -1;
 
        spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
-       if (nbytes > nx_ctx->ap->databytelen) {
-               rc = -EINVAL;
-               goto out;
-       }
-
        nbytes -= authsize;
 
        /* copy out the auth tag to compare with later */
@@ -293,22 +360,56 @@ static int ccm_nx_decrypt(struct aead_request   *req,
        if (rc)
                goto out;
 
-       rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes, 0,
-                              csbcpb->cpb.aes_ccm.iv_or_ctr);
-       if (rc)
-               goto out;
+       /* page_limit: number of sg entries that fit on one page */
+       max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
+                          nx_ctx->ap->sglen);
 
-       NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
-       NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_INTERMEDIATE;
+       do {
 
-       rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
+               /* to_process: the AES_BLOCK_SIZE data chunk to process in this
+                * update. This value is bound by sg list limits.
+                */
+               to_process = min_t(u64, nbytes - processed,
+                                  nx_ctx->ap->databytelen);
+               to_process = min_t(u64, to_process,
+                                  NX_PAGE_SIZE * (max_sg_len - 1));
+
+               if ((to_process + processed) < nbytes)
+                       NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
+               else
+                       NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
+
+               NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
+
+               rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src,
+                                       to_process, processed,
+                                       csbcpb->cpb.aes_ccm.iv_or_ctr);
+               if (rc)
+                       goto out;
+
+               rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
                           req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
-       if (rc)
-               goto out;
+               if (rc)
+                       goto out;
 
-       atomic_inc(&(nx_ctx->stats->aes_ops));
-       atomic64_add(csbcpb->csb.processed_byte_count,
-                    &(nx_ctx->stats->aes_bytes));
+               /* for partial completion, copy following for next
+                * entry into loop...
+                */
+               memcpy(desc->info, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE);
+               memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0,
+                       csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE);
+               memcpy(csbcpb->cpb.aes_ccm.in_s0,
+                       csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE);
+
+               NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
+
+               /* update stats */
+               atomic_inc(&(nx_ctx->stats->aes_ops));
+               atomic64_add(csbcpb->csb.processed_byte_count,
+                            &(nx_ctx->stats->aes_bytes));
+
+               processed += to_process;
+       } while (processed < nbytes);
 
        rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag,
                    authsize) ? -EBADMSG : 0;
@@ -325,41 +426,73 @@ static int ccm_nx_encrypt(struct aead_request   *req,
        unsigned int nbytes = req->cryptlen;
        unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
        unsigned long irq_flags;
+       unsigned int processed = 0, to_process;
+       u32 max_sg_len;
        int rc = -1;
 
        spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
-       if (nbytes > nx_ctx->ap->databytelen) {
-               rc = -EINVAL;
-               goto out;
-       }
-
        rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes,
                          csbcpb->cpb.aes_ccm.in_pat_or_b0);
        if (rc)
                goto out;
 
-       rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes, 0,
-                              csbcpb->cpb.aes_ccm.iv_or_ctr);
-       if (rc)
-               goto out;
-
-       NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
-       NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
-
-       rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
-                          req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
-       if (rc)
-               goto out;
-
-       atomic_inc(&(nx_ctx->stats->aes_ops));
-       atomic64_add(csbcpb->csb.processed_byte_count,
-                    &(nx_ctx->stats->aes_bytes));
+       /* page_limit: number of sg entries that fit on one page */
+       max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
+                          nx_ctx->ap->sglen);
+
+       do {
+               /* to process: the AES_BLOCK_SIZE data chunk to process in this
+                * update. This value is bound by sg list limits.
+                */
+               to_process = min_t(u64, nbytes - processed,
+                                  nx_ctx->ap->databytelen);
+               to_process = min_t(u64, to_process,
+                                  NX_PAGE_SIZE * (max_sg_len - 1));
+
+               if ((to_process + processed) < nbytes)
+                       NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
+               else
+                       NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
+
+               NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
+
+               rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src,
+                                       to_process, processed,
+                                      csbcpb->cpb.aes_ccm.iv_or_ctr);
+               if (rc)
+                       goto out;
+
+               rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
+                                  req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
+               if (rc)
+                       goto out;
+
+               /* for partial completion, copy following for next
+                * entry into loop...
+                */
+               memcpy(desc->info, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE);
+               memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0,
+                       csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE);
+               memcpy(csbcpb->cpb.aes_ccm.in_s0,
+                       csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE);
+
+               NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
+
+               /* update stats */
+               atomic_inc(&(nx_ctx->stats->aes_ops));
+               atomic64_add(csbcpb->csb.processed_byte_count,
+                            &(nx_ctx->stats->aes_bytes));
+
+               processed += to_process;
+
+       } while (processed < nbytes);
 
        /* copy out the auth tag */
        scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac,
                                 req->dst, nbytes, authsize,
                                 SCATTERWALK_TO_SG);
+
 out:
        spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
        return rc;
-- 
1.7.12

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