crypto: ccp - Add support for fetching a nonce for dynamic boost control

Dynamic Boost Control is a feature offered on AMD client platforms that
allows software to request and set power or frequency limits.

Only software that has authenticated with the PSP can retrieve or set
these limits.

Create a character device and ioctl for fetching the nonce. This ioctl
supports optionally passing authentication information which will influence
how many calls the nonce is valid for.

Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/dbc.h b/drivers/crypto/ccp/dbc.h
new file mode 100644
index 000000000000..1c3a0a078d15
--- /dev/null
+++ b/drivers/crypto/ccp/dbc.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * AMD Platform Security Processor (PSP) Dynamic Boost Control support
+ *
+ * Copyright (C) 2023 Advanced Micro Devices, Inc.
+ *
+ * Author: Mario Limonciello <mario.limonciello@amd.com>
+ */
+
+#ifndef __DBC_H__
+#define __DBC_H__
+
+#include <uapi/linux/psp-dbc.h>
+
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/psp-platform-access.h>
+
+#include "psp-dev.h"
+
+struct psp_dbc_device {
+	struct device *dev;
+
+	union dbc_buffer *mbox;
+
+	struct mutex ioctl_mutex;
+
+	struct miscdevice char_dev;
+};
+
+struct dbc_nonce {
+	struct psp_req_buffer_hdr	header;
+	struct dbc_user_nonce		user;
+} __packed;
+
+union dbc_buffer {
+	struct psp_request		req;
+	struct dbc_nonce		dbc_nonce;
+};
+
+void dbc_dev_destroy(struct psp_device *psp);
+int dbc_dev_init(struct psp_device *psp);
+
+#endif /* __DBC_H */