[PATCH v4 07/11] crypto: ccp: Add support for getting and setting DBC parameters

From: Mario Limonciello
Date: Thu Jun 08 2023 - 15:13:28 EST


After software has authenticated a dynamic boost control request,
it can fetch and set supported parameters using a selection of messages.

Add support for these messages and export the ability to do this to
userspace.

Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/crypto/ccp/dbc.c | 41 ++++++++++++++++++++
drivers/crypto/ccp/dbc.h | 6 +++
include/linux/psp-platform-access.h | 2 +
include/uapi/linux/psp-dbc.h | 60 +++++++++++++++++++++++++++++
4 files changed, 109 insertions(+)

diff --git a/drivers/crypto/ccp/dbc.c b/drivers/crypto/ccp/dbc.c
index ca7ec528536b..89976d6b9109 100644
--- a/drivers/crypto/ccp/dbc.c
+++ b/drivers/crypto/ccp/dbc.c
@@ -74,6 +74,30 @@ static int send_dbc_nonce(struct psp_dbc_device *dbc_dev)
return ret;
}

+static int send_dbc_parameter(struct psp_dbc_device *dbc_dev)
+{
+ dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_param);
+
+ switch (dbc_dev->mbox->dbc_param.user.msg_index) {
+ case PARAM_SET_FMAX_CAP:
+ case PARAM_SET_PWR_CAP:
+ case PARAM_SET_GFX_MODE:
+ return send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_SET_PARAMETER);
+ case PARAM_GET_FMAX_CAP:
+ case PARAM_GET_PWR_CAP:
+ case PARAM_GET_CURR_TEMP:
+ case PARAM_GET_FMAX_MAX:
+ case PARAM_GET_FMAX_MIN:
+ case PARAM_GET_SOC_PWR_MAX:
+ case PARAM_GET_SOC_PWR_MIN:
+ case PARAM_GET_SOC_PWR_CUR:
+ case PARAM_GET_GFX_MODE:
+ return send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_GET_PARAMETER);
+ }
+
+ return -EINVAL;
+}
+
void dbc_dev_destroy(struct psp_device *psp)
{
struct psp_dbc_device *dbc_dev = psp->dbc_data;
@@ -135,6 +159,23 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
goto unlock;
}
break;
+ case DBCIOCPARAM:
+ if (copy_from_user(&dbc_dev->mbox->dbc_param.user, argp,
+ sizeof(struct dbc_user_param))) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+
+ 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))) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+ break;
default:
ret = -EINVAL;

diff --git a/drivers/crypto/ccp/dbc.h b/drivers/crypto/ccp/dbc.h
index 156435100076..e963099ca38e 100644
--- a/drivers/crypto/ccp/dbc.h
+++ b/drivers/crypto/ccp/dbc.h
@@ -38,10 +38,16 @@ struct dbc_set_uid {
struct dbc_user_setuid user;
} __packed;

+struct dbc_param {
+ struct psp_req_buffer_hdr header;
+ struct dbc_user_param user;
+} __packed;
+
union dbc_buffer {
struct psp_request req;
struct dbc_nonce dbc_nonce;
struct dbc_set_uid dbc_set_uid;
+ struct dbc_param dbc_param;
};

void dbc_dev_destroy(struct psp_device *psp);
diff --git a/include/linux/psp-platform-access.h b/include/linux/psp-platform-access.h
index 18b9e0f0cb03..c1dc87fc536b 100644
--- a/include/linux/psp-platform-access.h
+++ b/include/linux/psp-platform-access.h
@@ -10,6 +10,8 @@ enum psp_platform_access_msg {
PSP_I2C_REQ_BUS_CMD = 0x64,
PSP_DYNAMIC_BOOST_GET_NONCE,
PSP_DYNAMIC_BOOST_SET_UID,
+ PSP_DYNAMIC_BOOST_GET_PARAMETER,
+ PSP_DYNAMIC_BOOST_SET_PARAMETER,
};

struct psp_req_buffer_hdr {
diff --git a/include/uapi/linux/psp-dbc.h b/include/uapi/linux/psp-dbc.h
index 7443c78ede19..b3845a9ff5fd 100644
--- a/include/uapi/linux/psp-dbc.h
+++ b/include/uapi/linux/psp-dbc.h
@@ -45,6 +45,23 @@ struct dbc_user_setuid {
__u8 signature[DBC_SIG_SIZE];
} __packed;

+/**
+ * struct dbc_user_param - Parameter exchange structure (input/output).
+ * @msg_index: Message indicating what parameter to set or get (input)
+ * @param: 4 byte parameter, units are message specific. (input/output)
+ * @signature: 32 byte signature.
+ * - When sending a message this is to be created by software
+ * using a previous nonce (input)
+ * - For interpreting results, this signature is updated by the
+ * PSP to allow software to validate the authenticity of the
+ * results.
+ */
+struct dbc_user_param {
+ __u32 msg_index;
+ __u32 param;
+ __u8 signature[DBC_SIG_SIZE];
+} __packed;
+
/**
* Dynamic Boost Control (DBC) IOC
*
@@ -84,4 +101,47 @@ struct dbc_user_setuid {
*/
#define DBCIOCUID _IOW(DBC_IOC_TYPE, 0x2, struct dbc_user_setuid)

+/**
+ * DBCIOCPARAM - Set or get a parameter from the PSP.
+ * This request will only work after DBCIOCUID has successfully
+ * set the UID of the calling process.
+ * Whether the parameter is set or get is controlled by the
+ * message ID in the request.
+ * This command must be sent using a 32 byte signature built
+ * using the nonce fetched from DBCIOCNONCE.
+ * When the command succeeds, the 32 byte signature will be
+ * updated by the PSP for software to authenticate the results.
+ */
+#define DBCIOCPARAM _IOWR(DBC_IOC_TYPE, 0x3, struct dbc_user_param)
+
+/**
+ * enum dbc_cmd_msg - Messages utilized by DBCIOCPARAM
+ * @PARAM_GET_FMAX_CAP: Get frequency cap (MHz)
+ * @PARAM_SET_FMAX_CAP: Set frequency cap (MHz)
+ * @PARAM_GET_PWR_CAP: Get socket power cap (mW)
+ * @PARAM_SET_PWR_CAP: Set socket power cap (mW)
+ * @PARAM_GET_GFX_MODE: Get graphics mode (0/1)
+ * @PARAM_SET_GFX_MODE: Set graphics mode (0/1)
+ * @PARAM_GET_CURR_TEMP: Get current temperature (degrees C)
+ * @PARAM_GET_FMAX_MAX: Get maximum allowed value for frequency (MHz)
+ * @PARAM_GET_FMAX_MIN: Get minimum allowed value for frequency (MHz)
+ * @PARAM_GET_SOC_PWR_MAX: Get maximum allowed value for SoC power (mw)
+ * @PARAM_GET_SOC_PWR_MIN: Get minimum allowed value for SoC power (mw)
+ * @PARAM_GET_SOC_PWR_CUR: Get current value for SoC Power (mW)
+ */
+enum dbc_cmd_msg {
+ PARAM_GET_FMAX_CAP = 0x3,
+ PARAM_SET_FMAX_CAP = 0x4,
+ PARAM_GET_PWR_CAP = 0x5,
+ PARAM_SET_PWR_CAP = 0x6,
+ PARAM_GET_GFX_MODE = 0x7,
+ PARAM_SET_GFX_MODE = 0x8,
+ PARAM_GET_CURR_TEMP = 0x9,
+ PARAM_GET_FMAX_MAX = 0xA,
+ PARAM_GET_FMAX_MIN = 0xB,
+ PARAM_GET_SOC_PWR_MAX = 0xC,
+ PARAM_GET_SOC_PWR_MIN = 0xD,
+ PARAM_GET_SOC_PWR_CUR = 0xE,
+};
+
#endif /* __PSP_DBC_USER_H__ */
--
2.34.1