crypto: ccp - Enable support for AES GCM on v5 CCPs

A version 5 device provides the primitive commands
required for AES GCM. This patch adds support for
en/decryption.

Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 252 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
index 0de961a22ab4..c0dfdacbdff5 100644
--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -601,6 +601,255 @@ e_key:
 	return ret;
 }
 
+static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q,
+			       struct ccp_cmd *cmd)
+{
+	struct ccp_aes_engine *aes = &cmd->u.aes;
+	struct ccp_dm_workarea key, ctx, final_wa, tag;
+	struct ccp_data src, dst;
+	struct ccp_data aad;
+	struct ccp_op op;
+
+	unsigned long long *final;
+	unsigned int dm_offset;
+	unsigned int ilen;
+	bool in_place = true; /* Default value */
+	int ret;
+
+	struct scatterlist *p_inp, sg_inp[2];
+	struct scatterlist *p_tag, sg_tag[2];
+	struct scatterlist *p_outp, sg_outp[2];
+	struct scatterlist *p_aad;
+
+	if (!aes->iv)
+		return -EINVAL;
+
+	if (!((aes->key_len == AES_KEYSIZE_128) ||
+		(aes->key_len == AES_KEYSIZE_192) ||
+		(aes->key_len == AES_KEYSIZE_256)))
+		return -EINVAL;
+
+	if (!aes->key) /* Gotta have a key SGL */
+		return -EINVAL;
+
+	/* First, decompose the source buffer into AAD & PT,
+	 * and the destination buffer into AAD, CT & tag, or
+	 * the input into CT & tag.
+	 * It is expected that the input and output SGs will
+	 * be valid, even if the AAD and input lengths are 0.
+	 */
+	p_aad = aes->src;
+	p_inp = scatterwalk_ffwd(sg_inp, aes->src, aes->aad_len);
+	p_outp = scatterwalk_ffwd(sg_outp, aes->dst, aes->aad_len);
+	if (aes->action == CCP_AES_ACTION_ENCRYPT) {
+		ilen = aes->src_len;
+		p_tag = scatterwalk_ffwd(sg_tag, p_outp, ilen);
+	} else {
+		/* Input length for decryption includes tag */
+		ilen = aes->src_len - AES_BLOCK_SIZE;
+		p_tag = scatterwalk_ffwd(sg_tag, p_inp, ilen);
+	}
+
+	memset(&op, 0, sizeof(op));
+	op.cmd_q = cmd_q;
+	op.jobid = CCP_NEW_JOBID(cmd_q->ccp);
+	op.sb_key = cmd_q->sb_key; /* Pre-allocated */
+	op.sb_ctx = cmd_q->sb_ctx; /* Pre-allocated */
+	op.init = 1;
+	op.u.aes.type = aes->type;
+
+	/* Copy the key to the LSB */
+	ret = ccp_init_dm_workarea(&key, cmd_q,
+				   CCP_AES_CTX_SB_COUNT * CCP_SB_BYTES,
+				   DMA_TO_DEVICE);
+	if (ret)
+		return ret;
+
+	dm_offset = CCP_SB_BYTES - aes->key_len;
+	ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	ret = ccp_copy_to_sb(cmd_q, &key, op.jobid, op.sb_key,
+			     CCP_PASSTHRU_BYTESWAP_256BIT);
+	if (ret) {
+		cmd->engine_error = cmd_q->cmd_error;
+		goto e_key;
+	}
+
+	/* Copy the context (IV) to the LSB.
+	 * There is an assumption here that the IV is 96 bits in length, plus
+	 * a nonce of 32 bits. If no IV is present, use a zeroed buffer.
+	 */
+	ret = ccp_init_dm_workarea(&ctx, cmd_q,
+				   CCP_AES_CTX_SB_COUNT * CCP_SB_BYTES,
+				   DMA_BIDIRECTIONAL);
+	if (ret)
+		goto e_key;
+
+	dm_offset = CCP_AES_CTX_SB_COUNT * CCP_SB_BYTES - aes->iv_len;
+	ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+
+	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
+			     CCP_PASSTHRU_BYTESWAP_256BIT);
+	if (ret) {
+		cmd->engine_error = cmd_q->cmd_error;
+		goto e_ctx;
+	}
+
+	op.init = 1;
+	if (aes->aad_len > 0) {
+		/* Step 1: Run a GHASH over the Additional Authenticated Data */
+		ret = ccp_init_data(&aad, cmd_q, p_aad, aes->aad_len,
+				    AES_BLOCK_SIZE,
+				    DMA_TO_DEVICE);
+		if (ret)
+			goto e_ctx;
+
+		op.u.aes.mode = CCP_AES_MODE_GHASH;
+		op.u.aes.action = CCP_AES_GHASHAAD;
+
+		while (aad.sg_wa.bytes_left) {
+			ccp_prepare_data(&aad, NULL, &op, AES_BLOCK_SIZE, true);
+
+			ret = cmd_q->ccp->vdata->perform->aes(&op);
+			if (ret) {
+				cmd->engine_error = cmd_q->cmd_error;
+				goto e_aad;
+			}
+
+			ccp_process_data(&aad, NULL, &op);
+			op.init = 0;
+		}
+	}
+
+	op.u.aes.mode = CCP_AES_MODE_GCTR;
+	op.u.aes.action = aes->action;
+
+	if (ilen > 0) {
+		/* Step 2: Run a GCTR over the plaintext */
+		in_place = (sg_virt(p_inp) == sg_virt(p_outp)) ? true : false;
+
+		ret = ccp_init_data(&src, cmd_q, p_inp, ilen,
+				    AES_BLOCK_SIZE,
+				    in_place ? DMA_BIDIRECTIONAL
+					     : DMA_TO_DEVICE);
+		if (ret)
+			goto e_ctx;
+
+		if (in_place) {
+			dst = src;
+		} else {
+			ret = ccp_init_data(&dst, cmd_q, p_outp, ilen,
+					    AES_BLOCK_SIZE, DMA_FROM_DEVICE);
+			if (ret)
+				goto e_src;
+		}
+
+		op.soc = 0;
+		op.eom = 0;
+		op.init = 1;
+		while (src.sg_wa.bytes_left) {
+			ccp_prepare_data(&src, &dst, &op, AES_BLOCK_SIZE, true);
+			if (!src.sg_wa.bytes_left) {
+				unsigned int nbytes = aes->src_len
+						      % AES_BLOCK_SIZE;
+
+				if (nbytes) {
+					op.eom = 1;
+					op.u.aes.size = (nbytes * 8) - 1;
+				}
+			}
+
+			ret = cmd_q->ccp->vdata->perform->aes(&op);
+			if (ret) {
+				cmd->engine_error = cmd_q->cmd_error;
+				goto e_dst;
+			}
+
+			ccp_process_data(&src, &dst, &op);
+			op.init = 0;
+		}
+	}
+
+	/* Step 3: Update the IV portion of the context with the original IV */
+	ret = ccp_copy_from_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
+			       CCP_PASSTHRU_BYTESWAP_256BIT);
+	if (ret) {
+		cmd->engine_error = cmd_q->cmd_error;
+		goto e_dst;
+	}
+
+	ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+
+	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
+			     CCP_PASSTHRU_BYTESWAP_256BIT);
+	if (ret) {
+		cmd->engine_error = cmd_q->cmd_error;
+		goto e_dst;
+	}
+
+	/* Step 4: Concatenate the lengths of the AAD and source, and
+	 * hash that 16 byte buffer.
+	 */
+	ret = ccp_init_dm_workarea(&final_wa, cmd_q, AES_BLOCK_SIZE,
+				   DMA_BIDIRECTIONAL);
+	if (ret)
+		goto e_dst;
+	final = (unsigned long long *) final_wa.address;
+	final[0] = cpu_to_be64(aes->aad_len * 8);
+	final[1] = cpu_to_be64(ilen * 8);
+
+	op.u.aes.mode = CCP_AES_MODE_GHASH;
+	op.u.aes.action = CCP_AES_GHASHFINAL;
+	op.src.type = CCP_MEMTYPE_SYSTEM;
+	op.src.u.dma.address = final_wa.dma.address;
+	op.src.u.dma.length = AES_BLOCK_SIZE;
+	op.dst.type = CCP_MEMTYPE_SYSTEM;
+	op.dst.u.dma.address = final_wa.dma.address;
+	op.dst.u.dma.length = AES_BLOCK_SIZE;
+	op.eom = 1;
+	op.u.aes.size = 0;
+	ret = cmd_q->ccp->vdata->perform->aes(&op);
+	if (ret)
+		goto e_dst;
+
+	if (aes->action == CCP_AES_ACTION_ENCRYPT) {
+		/* Put the ciphered tag after the ciphertext. */
+		ccp_get_dm_area(&final_wa, 0, p_tag, 0, AES_BLOCK_SIZE);
+	} else {
+		/* Does this ciphered tag match the input? */
+		ret = ccp_init_dm_workarea(&tag, cmd_q, AES_BLOCK_SIZE,
+					   DMA_BIDIRECTIONAL);
+		if (ret)
+			goto e_tag;
+		ccp_set_dm_area(&tag, 0, p_tag, 0, AES_BLOCK_SIZE);
+
+		ret = memcmp(tag.address, final_wa.address, AES_BLOCK_SIZE);
+		ccp_dm_free(&tag);
+	}
+
+e_tag:
+	ccp_dm_free(&final_wa);
+
+e_dst:
+	if (aes->src_len && !in_place)
+		ccp_free_data(&dst, cmd_q);
+
+e_src:
+	if (aes->src_len)
+		ccp_free_data(&src, cmd_q);
+
+e_aad:
+	if (aes->aad_len)
+		ccp_free_data(&aad, cmd_q);
+
+e_ctx:
+	ccp_dm_free(&ctx);
+
+e_key:
+	ccp_dm_free(&key);
+
+	return ret;
+}
+
 static int ccp_run_aes_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 {
 	struct ccp_aes_engine *aes = &cmd->u.aes;
@@ -614,6 +863,9 @@ static int ccp_run_aes_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
 	if (aes->mode == CCP_AES_MODE_CMAC)
 		return ccp_run_aes_cmac_cmd(cmd_q, cmd);
 
+	if (aes->mode == CCP_AES_MODE_GCM)
+		return ccp_run_aes_gcm_cmd(cmd_q, cmd);
+
 	if (!((aes->key_len == AES_KEYSIZE_128) ||
 	      (aes->key_len == AES_KEYSIZE_192) ||
 	      (aes->key_len == AES_KEYSIZE_256)))