--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Secure Processor Dynamic Boost Control interface
+ *
+ * Copyright (C) 2023 Advanced Micro Devices, Inc.
+ *
+ * Author: Mario Limonciello <mario.limonciello@amd.com>
+ */
+
+#include "dbc.h"
+
+struct error_map {
+ u32 psp;
+ int ret;
+};
+
+#define DBC_ERROR_ACCESS_DENIED 0x0001
+#define DBC_ERROR_EXCESS_DATA 0x0004
+#define DBC_ERROR_BAD_PARAMETERS 0x0006
+#define DBC_ERROR_BAD_STATE 0x0007
+#define DBC_ERROR_NOT_IMPLEMENTED 0x0009
+#define DBC_ERROR_BUSY 0x000D
+#define DBC_ERROR_MESSAGE_FAILURE 0x0307
+#define DBC_ERROR_OVERFLOW 0x300F
+#define DBC_ERROR_SIGNATURE_INVALID 0x3072
+
+static struct error_map error_codes[] = {
+ {DBC_ERROR_ACCESS_DENIED, -EACCES},
+ {DBC_ERROR_EXCESS_DATA, -E2BIG},
+ {DBC_ERROR_BAD_PARAMETERS, -EINVAL},
+ {DBC_ERROR_BAD_STATE, -EAGAIN},
+ {DBC_ERROR_MESSAGE_FAILURE, -ENOENT},
+ {DBC_ERROR_NOT_IMPLEMENTED, -ENOENT},
+ {DBC_ERROR_BUSY, -EBUSY},
+ {DBC_ERROR_OVERFLOW, -ENFILE},
+ {DBC_ERROR_SIGNATURE_INVALID, -EPERM},
+ {0x0, 0x0},
+};
+
+static int send_dbc_cmd(struct psp_dbc_device *dbc_dev,
+ enum psp_platform_access_msg msg)
+{
+ int ret;
+
+ dbc_dev->mbox->req.header.status = 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);
+
+ for (i = 0; error_codes[i].psp; i++) {
+ if (dbc_dev->mbox->req.header.status == error_codes[i].psp)
+ return error_codes[i].ret;
+ }
+ }
+
+ return ret;
+}
+
+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);
+ ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_GET_NONCE);
+ if (ret == -EAGAIN) {
+ dev_dbg(dbc_dev->dev, "retrying get nonce\n");
+ ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_GET_NONCE);
+ }
+
+ return ret;
+}
+
+void dbc_dev_destroy(struct psp_device *psp)
+{
+ struct psp_dbc_device *dbc_dev = psp->dbc_data;
+
+ if (!dbc_dev)
+ return;
+
+ misc_deregister(&dbc_dev->char_dev);
+ mutex_destroy(&dbc_dev->ioctl_mutex);
+ psp->dbc_data = NULL;
+}
+
+static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct psp_device *psp_master = psp_get_master_device();
+ void __user *argp = (void __user *)arg;
+ struct psp_dbc_device *dbc_dev;
+ int ret;
+
+ if (!psp_master || !psp_master->dbc_data)
+ return -ENODEV;
+ dbc_dev = psp_master->dbc_data;
+
+ mutex_lock(&dbc_dev->ioctl_mutex);
+
+ switch (cmd) {
+ case DBCIOCNONCE:
+ if (copy_from_user(&dbc_dev->mbox->dbc_nonce.user, argp,
+ sizeof(struct dbc_user_nonce))) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+
+ ret = send_dbc_nonce(dbc_dev);
+ if (ret)
+ goto unlock;
+
+ if (copy_to_user(argp, &dbc_dev->mbox->dbc_nonce.user,
+ sizeof(struct dbc_user_nonce))) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+
+ }
+unlock:
+ mutex_unlock(&dbc_dev->ioctl_mutex);
+
+ return ret;
+}
+
+static const struct file_operations dbc_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = dbc_ioctl,
+};
+
+int dbc_dev_init(struct psp_device *psp)
+{
+ struct device *dev = psp->dev;
+ struct psp_dbc_device *dbc_dev;
+ int ret;
+
+ if (!PSP_FEATURE(psp, DBC))
+ return 0;
+
+ dbc_dev = devm_kzalloc(dev, sizeof(*dbc_dev), GFP_KERNEL);
+ if (!dbc_dev)
+ return -ENOMEM;
+
+ BUILD_BUG_ON(sizeof(union dbc_buffer) > PAGE_SIZE);
+ dbc_dev->mbox = (void *)devm_get_free_pages(dev, GFP_KERNEL, 0);
+ if (!dbc_dev->mbox) {
+ ret = -ENOMEM;
+ goto cleanup_dev;
+ }
+
+ psp->dbc_data = dbc_dev;
+ dbc_dev->dev = dev;
+
+ ret = send_dbc_nonce(dbc_dev);
+ if (ret == -EACCES) {
+ dev_dbg(dbc_dev->dev,
+ "dynamic boost control was previously authenticated\n");
+ ret = 0;
+ }
+ dev_dbg(dbc_dev->dev, "dynamic boost control is %savailable\n",
+ ret ? "un" : "");
+ if (ret) {
+ ret = 0;
+ goto cleanup_mbox;
+ }
+
+ dbc_dev->char_dev.minor = MISC_DYNAMIC_MINOR;
+ dbc_dev->char_dev.name = "dbc";
+ dbc_dev->char_dev.fops = &dbc_fops;
+ dbc_dev->char_dev.mode = 0600;
+ ret = misc_register(&dbc_dev->char_dev);
+ if (ret)
+ goto cleanup_mbox;
+
+ mutex_init(&dbc_dev->ioctl_mutex);
+
+ return 0;
+
+cleanup_mbox:
+ devm_free_pages(dev, (unsigned long)dbc_dev->mbox);
+
+cleanup_dev:
+ psp->dbc_data = NULL;
+ devm_kfree(dev, dbc_dev);
+
+ return ret;
+}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
+/*
+ * Userspace interface for AMD Dynamic Boost Control (DBC)
+ *
+ * Copyright (C) 2023 Advanced Micro Devices, Inc.
+ *
+ * Author: Mario Limonciello <mario.limonciello@amd.com>
+ */
+
+#ifndef __PSP_DBC_USER_H__
+#define __PSP_DBC_USER_H__
+
+#include <linux/types.h>
+
+/**
+ * DOC: AMD Dynamic Boost Control (DBC) interface
+ */
+
+#define DBC_NONCE_SIZE 16
+#define DBC_SIG_SIZE 32
+
+/**
+ * struct dbc_user_nonce - Nonce exchange structure (input/output).
+ * @auth_needed: Whether the PSP should authenticate this request (input).
+ * 0: no authentication, PSP will return single use nonce.
+ * 1: authentication: PSP will return multi-use nonce.
+ * @nonce: 8 byte value used for future authentication (output).
+ * @signature: Optional 32 byte signature created by software using a
+ * previous nonce (input).
+ */
+struct dbc_user_nonce {
+ __u32 auth_needed;
+ __u8 nonce[DBC_NONCE_SIZE];
+ __u8 signature[DBC_SIG_SIZE];
+} __packed;
+
+/**
+ * Dynamic Boost Control (DBC) IOC
+ *
+ * possible return codes for all DBC IOCTLs:
+ * 0: success
+ * -EINVAL: invalid input
+ * -E2BIG: excess data passed
+ * -EFAULT: failed to copy to/from userspace
+ * -EBUSY: mailbox in recovery or in use
+ * -ENODEV: driver not bound with PSP device
+ * -EACCES: request isn't authorized
+ * -EINVAL: invalid parameter
+ * -ETIMEDOUT: request timed out
+ * -EAGAIN: invalid request for state machine
+ * -ENOENT: not implemented
+ * -ENFILE: overflow
+ * -EPERM: invalid signature
+ * -EIO: unknown error
+ */
+#define DBC_IOC_TYPE 'D'
+
+/**
+ * DBCIOCNONCE - Fetch a nonce from the PSP for authenticating commands.
+ * If a nonce is fetched without authentication it can only
+ * be utilized for one command.
+ * If a nonce is fetched with authentication it can be used
+ * for multiple requests.
+ */
+#define DBCIOCNONCE _IOWR(DBC_IOC_TYPE, 0x1, struct dbc_user_nonce)
+
+#endif /* __PSP_DBC_USER_H__ */
projects / linux-2.6-block.git / commitdiff