crypto: ccp - Add a communication path abstraction for DBC

DBC is currently accessed only from the platform access mailbox and
a lot of that implementation's communication path is intertwined
with DBC. Add an abstraction layer for pointers into the mailbox.

No intended functional changes.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/dbc.c

@@ -42,17 +42,17 @@ static int send_dbc_cmd(struct psp_dbc_device *dbc_dev,
 {
 	int ret;
 
-	dbc_dev->mbox->req.header.status = 0;
+	*dbc_dev->result = 0;
 	ret = psp_send_platform_access_msg(msg, (struct psp_request *)dbc_dev->mbox);
 	if (ret == -EIO) {
 		int i;
 
 		dev_dbg(dbc_dev->dev,
 			 "msg 0x%x failed with PSP error: 0x%x\n",
-			 msg, dbc_dev->mbox->req.header.status);
+			 msg, *dbc_dev->result);
 
 		for (i = 0; error_codes[i].psp; i++) {
-			if (dbc_dev->mbox->req.header.status == error_codes[i].psp)
+			if (*dbc_dev->result == error_codes[i].psp)
 				return error_codes[i].ret;
 		}
 	}
@@ -64,7 +64,7 @@ static int send_dbc_nonce(struct psp_dbc_device *dbc_dev)
 {
 	int ret;
 
-	dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_nonce);
+	*dbc_dev->payload_size = dbc_dev->header_size + sizeof(struct dbc_user_nonce);
 	ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_GET_NONCE);
 	if (ret == -EAGAIN) {
 		dev_dbg(dbc_dev->dev, "retrying get nonce\n");
@@ -76,9 +76,9 @@ static int send_dbc_nonce(struct psp_dbc_device *dbc_dev)
 
 static int send_dbc_parameter(struct psp_dbc_device *dbc_dev)
 {
-	dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_param);
+	struct dbc_user_param *user_param = (struct dbc_user_param *)dbc_dev->payload;
 
-	switch (dbc_dev->mbox->dbc_param.user.msg_index) {
+	switch (user_param->msg_index) {
 	case PARAM_SET_FMAX_CAP:
 	case PARAM_SET_PWR_CAP:
 	case PARAM_SET_GFX_MODE:
@@ -125,8 +125,7 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 
 	switch (cmd) {
 	case DBCIOCNONCE:
-		if (copy_from_user(&dbc_dev->mbox->dbc_nonce.user, argp,
-				   sizeof(struct dbc_user_nonce))) {
+		if (copy_from_user(dbc_dev->payload, argp, sizeof(struct dbc_user_nonce))) {
 			ret = -EFAULT;
 			goto unlock;
 		}
@@ -135,43 +134,39 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		if (ret)
 			goto unlock;
 
-		if (copy_to_user(argp, &dbc_dev->mbox->dbc_nonce.user,
-				 sizeof(struct dbc_user_nonce))) {
+		if (copy_to_user(argp, dbc_dev->payload, sizeof(struct dbc_user_nonce))) {
 			ret = -EFAULT;
 			goto unlock;
 		}
 		break;
 	case DBCIOCUID:
-		dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_set_uid);
-		if (copy_from_user(&dbc_dev->mbox->dbc_set_uid.user, argp,
-				   sizeof(struct dbc_user_setuid))) {
+		if (copy_from_user(dbc_dev->payload, argp, sizeof(struct dbc_user_setuid))) {
 			ret = -EFAULT;
 			goto unlock;
 		}
 
+		*dbc_dev->payload_size = dbc_dev->header_size + sizeof(struct dbc_user_setuid);
 		ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_SET_UID);
 		if (ret)
 			goto unlock;
 
-		if (copy_to_user(argp, &dbc_dev->mbox->dbc_set_uid.user,
-				 sizeof(struct dbc_user_setuid))) {
+		if (copy_to_user(argp, dbc_dev->payload, sizeof(struct dbc_user_setuid))) {
 			ret = -EFAULT;
 			goto unlock;
 		}
 		break;
 	case DBCIOCPARAM:
-		if (copy_from_user(&dbc_dev->mbox->dbc_param.user, argp,
-				   sizeof(struct dbc_user_param))) {
+		if (copy_from_user(dbc_dev->payload, argp, sizeof(struct dbc_user_param))) {
 			ret = -EFAULT;
 			goto unlock;
 		}
 
+		*dbc_dev->payload_size = dbc_dev->header_size + sizeof(struct dbc_user_param);
 		ret = send_dbc_parameter(dbc_dev);
 		if (ret)
 			goto unlock;
 
-		if (copy_to_user(argp, &dbc_dev->mbox->dbc_param.user,
-				 sizeof(struct dbc_user_param)))  {
+		if (copy_to_user(argp, dbc_dev->payload, sizeof(struct dbc_user_param)))  {
 			ret = -EFAULT;
 			goto unlock;
 		}
@@ -213,6 +208,10 @@ int dbc_dev_init(struct psp_device *psp)
 
 	psp->dbc_data = dbc_dev;
 	dbc_dev->dev = dev;
+	dbc_dev->payload_size = &dbc_dev->mbox->pa_req.header.payload_size;
+	dbc_dev->result = &dbc_dev->mbox->pa_req.header.status;
+	dbc_dev->payload = &dbc_dev->mbox->pa_req.buf;
+	dbc_dev->header_size = sizeof(struct psp_req_buffer_hdr);
 
 	ret = send_dbc_nonce(dbc_dev);
 	if (ret == -EACCES) {

drivers/crypto/ccp/dbc.h

@@ -26,28 +26,17 @@ struct psp_dbc_device {
 	struct mutex ioctl_mutex;
 
 	struct miscdevice char_dev;
-};
-
-struct dbc_nonce {
-	struct psp_req_buffer_hdr	header;
-	struct dbc_user_nonce		user;
-} __packed;
 
-struct dbc_set_uid {
-	struct psp_req_buffer_hdr	header;
-	struct dbc_user_setuid		user;
-} __packed;
-
-struct dbc_param {
-	struct psp_req_buffer_hdr	header;
-	struct dbc_user_param		user;
-} __packed;
+	/* used to abstract communication path */
+	bool	use_ext;
+	u32	header_size;
+	u32	*payload_size;
+	u32	*result;
+	void	*payload;
+};
 
 union dbc_buffer {
-	struct psp_request		req;
-	struct dbc_nonce		dbc_nonce;
-	struct dbc_set_uid		dbc_set_uid;
-	struct dbc_param		dbc_param;
+	struct psp_request		pa_req;
 };
 
 void dbc_dev_destroy(struct psp_device *psp);