crypto: nx - fix limits to sg lists for AES-CBC

This patch updates the nx-aes-cbc implementation to perform several
hyper calls if needed in order to always respect the length limits for
scatter/gather lists.

Two different limits are considered:

 - "ibm,max-sg-len": maximum number of bytes of each scatter/gather
   list.

 - "ibm,max-sync-cop":
    - The total number of bytes that a scatter/gather list can hold.
    - The maximum number of elements that a scatter/gather list can have.

Reviewed-by: Joy Latten <jmlatten@linux.vnet.ibm.com>
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/nx/nx-aes-cbc.c b/drivers/crypto/nx/nx-aes-cbc.c
index a9e76c6..cc00b52 100644 (file)
--- a/drivers/crypto/nx/nx-aes-cbc.c
+++ b/drivers/crypto/nx/nx-aes-cbc.c
@@ -71,39 +71,49 @@ static int cbc_aes_nx_crypt(struct blkcipher_desc *desc,
        struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
        struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
        unsigned long irq_flags;
+       unsigned int processed = 0, to_process;
+       u32 max_sg_len;
        int rc;
 
        spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
-       if (nbytes > nx_ctx->ap->databytelen) {
-               rc = -EINVAL;
-               goto out;
-       }
+       max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
+                          nx_ctx->ap->sglen);
 
        if (enc)
                NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
        else
                NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 
-       rc = nx_build_sg_lists(nx_ctx, desc, dst, src, nbytes, 0,
-                              csbcpb->cpb.aes_cbc.iv);
-       if (rc)
-               goto out;
-
-       if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
-               rc = -EINVAL;
-               goto out;
-       }
-
-       rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
-                          desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
-       if (rc)
-               goto out;
-
-       memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
-       atomic_inc(&(nx_ctx->stats->aes_ops));
-       atomic64_add(csbcpb->csb.processed_byte_count,
-                    &(nx_ctx->stats->aes_bytes));
+       do {
+               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));
+               to_process = to_process & ~(AES_BLOCK_SIZE - 1);
+
+               rc = nx_build_sg_lists(nx_ctx, desc, dst, src, to_process,
+                                      processed, csbcpb->cpb.aes_cbc.iv);
+               if (rc)
+                       goto out;
+
+               if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
+                       rc = -EINVAL;
+                       goto out;
+               }
+
+               rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
+                                  desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
+               if (rc)
+                       goto out;
+
+               memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
+               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);
 out:
        spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
        return rc;