mailbox: Add common header for RPMI messages sent via mailbox

The RPMI based mailbox controller drivers and mailbox clients need to
share defines related to RPMI messages over mailbox interface so add
a common header for this purpose.

Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Co-developed-by: Rahul Pathak <rpathak@ventanamicro.com>
Signed-off-by: Rahul Pathak <rpathak@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Link: https://lore.kernel.org/r/20250818040920.272664-5-apatel@ventanamicro.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>

diff --git a/include/linux/mailbox/riscv-rpmi-message.h b/include/linux/mailbox/riscv-rpmi-message.h
new file mode 100644 (file)
index 0000000..c3a98fc
--- /dev/null
+++ b/include/linux/mailbox/riscv-rpmi-message.h
@@ -0,0 +1,214 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2025 Ventana Micro Systems Inc. */
+
+#ifndef _LINUX_RISCV_RPMI_MESSAGE_H_
+#define _LINUX_RISCV_RPMI_MESSAGE_H_
+
+#include <linux/errno.h>
+#include <linux/mailbox_client.h>
+#include <linux/types.h>
+#include <linux/wordpart.h>
+
+/* RPMI version encode/decode macros */
+#define RPMI_VER_MAJOR(__ver)          upper_16_bits(__ver)
+#define RPMI_VER_MINOR(__ver)          lower_16_bits(__ver)
+#define RPMI_MKVER(__maj, __min)       (((u32)(__maj) << 16) | (u16)(__min))
+
+/* RPMI message header */
+struct rpmi_message_header {
+       __le16 servicegroup_id;
+       u8 service_id;
+       u8 flags;
+       __le16 datalen;
+       __le16 token;
+};
+
+/* RPMI message */
+struct rpmi_message {
+       struct rpmi_message_header header;
+       u8 data[];
+};
+
+/* RPMI notification event */
+struct rpmi_notification_event {
+       __le16 event_datalen;
+       u8 event_id;
+       u8 reserved;
+       u8 event_data[];
+};
+
+/* RPMI error codes */
+enum rpmi_error_codes {
+       RPMI_SUCCESS                    = 0,
+       RPMI_ERR_FAILED                 = -1,
+       RPMI_ERR_NOTSUPP                = -2,
+       RPMI_ERR_INVALID_PARAM          = -3,
+       RPMI_ERR_DENIED                 = -4,
+       RPMI_ERR_INVALID_ADDR           = -5,
+       RPMI_ERR_ALREADY                = -6,
+       RPMI_ERR_EXTENSION              = -7,
+       RPMI_ERR_HW_FAULT               = -8,
+       RPMI_ERR_BUSY                   = -9,
+       RPMI_ERR_INVALID_STATE          = -10,
+       RPMI_ERR_BAD_RANGE              = -11,
+       RPMI_ERR_TIMEOUT                = -12,
+       RPMI_ERR_IO                     = -13,
+       RPMI_ERR_NO_DATA                = -14,
+       RPMI_ERR_RESERVED_START         = -15,
+       RPMI_ERR_RESERVED_END           = -127,
+       RPMI_ERR_VENDOR_START           = -128,
+};
+
+static inline int rpmi_to_linux_error(int rpmi_error)
+{
+       switch (rpmi_error) {
+       case RPMI_SUCCESS:
+               return 0;
+       case RPMI_ERR_INVALID_PARAM:
+       case RPMI_ERR_BAD_RANGE:
+       case RPMI_ERR_INVALID_STATE:
+               return -EINVAL;
+       case RPMI_ERR_DENIED:
+               return -EPERM;
+       case RPMI_ERR_INVALID_ADDR:
+       case RPMI_ERR_HW_FAULT:
+               return -EFAULT;
+       case RPMI_ERR_ALREADY:
+               return -EALREADY;
+       case RPMI_ERR_BUSY:
+               return -EBUSY;
+       case RPMI_ERR_TIMEOUT:
+               return -ETIMEDOUT;
+       case RPMI_ERR_IO:
+               return -ECOMM;
+       case RPMI_ERR_FAILED:
+       case RPMI_ERR_NOTSUPP:
+       case RPMI_ERR_NO_DATA:
+       case RPMI_ERR_EXTENSION:
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
+/* RPMI Linux mailbox attribute IDs */
+enum rpmi_mbox_attribute_id {
+       RPMI_MBOX_ATTR_SPEC_VERSION,
+       RPMI_MBOX_ATTR_MAX_MSG_DATA_SIZE,
+       RPMI_MBOX_ATTR_SERVICEGROUP_ID,
+       RPMI_MBOX_ATTR_SERVICEGROUP_VERSION,
+       RPMI_MBOX_ATTR_IMPL_ID,
+       RPMI_MBOX_ATTR_IMPL_VERSION,
+       RPMI_MBOX_ATTR_MAX_ID
+};
+
+/* RPMI Linux mailbox message types */
+enum rpmi_mbox_message_type {
+       RPMI_MBOX_MSG_TYPE_GET_ATTRIBUTE,
+       RPMI_MBOX_MSG_TYPE_SET_ATTRIBUTE,
+       RPMI_MBOX_MSG_TYPE_SEND_WITH_RESPONSE,
+       RPMI_MBOX_MSG_TYPE_SEND_WITHOUT_RESPONSE,
+       RPMI_MBOX_MSG_TYPE_NOTIFICATION_EVENT,
+       RPMI_MBOX_MSG_MAX_TYPE
+};
+
+/* RPMI Linux mailbox message instance */
+struct rpmi_mbox_message {
+       enum rpmi_mbox_message_type type;
+       union {
+               struct {
+                       enum rpmi_mbox_attribute_id id;
+                       u32 value;
+               } attr;
+
+               struct {
+                       u32 service_id;
+                       void *request;
+                       unsigned long request_len;
+                       void *response;
+                       unsigned long max_response_len;
+                       unsigned long out_response_len;
+               } data;
+
+               struct {
+                       u16 event_datalen;
+                       u8 event_id;
+                       u8 *event_data;
+               } notif;
+       };
+       int error;
+};
+
+/* RPMI Linux mailbox message helper routines */
+static inline void rpmi_mbox_init_get_attribute(struct rpmi_mbox_message *msg,
+                                               enum rpmi_mbox_attribute_id id)
+{
+       msg->type = RPMI_MBOX_MSG_TYPE_GET_ATTRIBUTE;
+       msg->attr.id = id;
+       msg->attr.value = 0;
+       msg->error = 0;
+}
+
+static inline void rpmi_mbox_init_set_attribute(struct rpmi_mbox_message *msg,
+                                               enum rpmi_mbox_attribute_id id,
+                                               u32 value)
+{
+       msg->type = RPMI_MBOX_MSG_TYPE_SET_ATTRIBUTE;
+       msg->attr.id = id;
+       msg->attr.value = value;
+       msg->error = 0;
+}
+
+static inline void rpmi_mbox_init_send_with_response(struct rpmi_mbox_message *msg,
+                                                    u32 service_id,
+                                                    void *request,
+                                                    unsigned long request_len,
+                                                    void *response,
+                                                    unsigned long max_response_len)
+{
+       msg->type = RPMI_MBOX_MSG_TYPE_SEND_WITH_RESPONSE;
+       msg->data.service_id = service_id;
+       msg->data.request = request;
+       msg->data.request_len = request_len;
+       msg->data.response = response;
+       msg->data.max_response_len = max_response_len;
+       msg->data.out_response_len = 0;
+       msg->error = 0;
+}
+
+static inline void rpmi_mbox_init_send_without_response(struct rpmi_mbox_message *msg,
+                                                       u32 service_id,
+                                                       void *request,
+                                                       unsigned long request_len)
+{
+       msg->type = RPMI_MBOX_MSG_TYPE_SEND_WITHOUT_RESPONSE;
+       msg->data.service_id = service_id;
+       msg->data.request = request;
+       msg->data.request_len = request_len;
+       msg->data.response = NULL;
+       msg->data.max_response_len = 0;
+       msg->data.out_response_len = 0;
+       msg->error = 0;
+}
+
+static inline void *rpmi_mbox_get_msg_response(struct rpmi_mbox_message *msg)
+{
+       return msg ? msg->data.response : NULL;
+}
+
+static inline int rpmi_mbox_send_message(struct mbox_chan *chan,
+                                        struct rpmi_mbox_message *msg)
+{
+       int ret;
+
+       /* Send message for the underlying mailbox channel */
+       ret = mbox_send_message(chan, msg);
+       if (ret < 0)
+               return ret;
+
+       /* Explicitly signal txdone for mailbox channel */
+       ret = msg->error;
+       mbox_client_txdone(chan, ret);
+       return ret;
+}
+
+#endif /* _LINUX_RISCV_RPMI_MESSAGE_H_ */