[char-misc-next 1/2] mei: support for dynamic clients
From: Tomas Winkler
Date: Tue Jun 16 2015 - 17:33:55 EST
HBM version 2.0 and above allows ME clients in the system to
register/unregister after the system is fully initialized.
Clients may be added or removed after enum_resp message was
received
1. To preserve backward compatibility the driver can opt-in to receive
client add messages by setting allow_add field in enum_req
2. A new client is added upon reception of MEI_HBM_ADD_CLIENT_REQ_CMD
3. A client is removed in a lazy manner when connection request
respond with MEI_HBMS_CLIENT_NOT_FOUND status
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
drivers/misc/mei/debugfs.c | 2 +
drivers/misc/mei/hbm.c | 92 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/misc/mei/hw.h | 50 ++++++++++++++++++++++++-
drivers/misc/mei/mei_dev.h | 2 +
4 files changed, 144 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/mei/debugfs.c b/drivers/misc/mei/debugfs.c
index eb868341247f..a65a1e6f386f 100644
--- a/drivers/misc/mei/debugfs.c
+++ b/drivers/misc/mei/debugfs.c
@@ -154,6 +154,8 @@ static ssize_t mei_dbgfs_read_devstate(struct file *fp, char __user *ubuf,
pos += scnprintf(buf + pos, bufsz - pos, "hbm features:\n");
pos += scnprintf(buf + pos, bufsz - pos, "\tPG: %01d\n",
dev->hbm_f_pg_supported);
+ pos += scnprintf(buf + pos, bufsz - pos, "\tDC: %01d\n",
+ dev->hbm_f_dc_supported);
}
pos += scnprintf(buf + pos, bufsz - pos, "pg: %s, %s\n",
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index a4f283165a33..d4dba639db37 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -299,6 +299,7 @@ static int mei_hbm_enum_clients_req(struct mei_device *dev)
enum_req = (struct hbm_host_enum_request *)dev->wr_msg.data;
memset(enum_req, 0, len);
enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
+ enum_req->allow_add = dev->hbm_f_dc_supported;
ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
if (ret) {
@@ -344,6 +345,64 @@ static int mei_hbm_me_cl_add(struct mei_device *dev,
}
/**
+ * mei_hbm_add_cl_resp - send response to fw on client add request
+ *
+ * @dev: the device structure
+ * @addr: me address
+ * @status: response status
+ *
+ * Return: 0 on success and < 0 on failure
+ */
+static int mei_hbm_add_cl_resp(struct mei_device *dev, u8 addr, u8 status)
+{
+ struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
+ struct hbm_add_client_response *resp;
+ const size_t len = sizeof(struct hbm_add_client_response);
+ int ret;
+
+ dev_dbg(dev->dev, "adding client response\n");
+
+ resp = (struct hbm_add_client_response *)dev->wr_msg.data;
+
+ mei_hbm_hdr(mei_hdr, len);
+ memset(resp, 0, sizeof(struct hbm_add_client_response));
+
+ resp->hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
+ resp->me_addr = addr;
+ resp->status = status;
+
+ ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+ if (ret)
+ dev_err(dev->dev, "add client response write failed: ret = %d\n",
+ ret);
+ return ret;
+}
+
+/**
+ * mei_hbm_fw_add_cl_req - request from the fw to add a client
+ *
+ * @dev: the device structure
+ * @req: add client request
+ *
+ * Return: 0 on success and < 0 on failure
+ */
+static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
+ struct hbm_add_client_request *req)
+{
+ int ret;
+ u8 status = MEI_HBMS_SUCCESS;
+
+ BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
+ sizeof(struct hbm_props_response));
+
+ ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
+ if (ret)
+ status = !MEI_HBMS_SUCCESS;
+
+ return mei_hbm_add_cl_resp(dev, req->me_addr, status);
+}
+
+/**
* mei_hbm_prop_req - request property for a single client
*
* @dev: the device structure
@@ -610,8 +669,11 @@ static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
if (rs->status == MEI_CL_CONN_SUCCESS)
cl->state = MEI_FILE_CONNECTED;
- else
+ else {
cl->state = MEI_FILE_DISCONNECT_REPLY;
+ if (rs->status == MEI_CL_CONN_NOT_FOUND)
+ mei_me_cl_del(dev, cl->me_cl);
+ }
cl->status = mei_cl_conn_status_to_errno(rs->status);
}
@@ -709,6 +771,9 @@ static void mei_hbm_config_features(struct mei_device *dev)
if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
dev->version.minor_version >= HBM_MINOR_VERSION_PGI)
dev->hbm_f_pg_supported = 1;
+
+ if (dev->version.major_version >= HBM_MAJOR_VERSION_DC)
+ dev->hbm_f_dc_supported = 1;
}
/**
@@ -740,6 +805,8 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
struct hbm_host_version_response *version_res;
struct hbm_props_response *props_res;
struct hbm_host_enum_response *enum_res;
+ struct hbm_add_client_request *add_cl_req;
+ int ret;
struct mei_hbm_cl_cmd *cl_cmd;
struct hbm_client_connect_request *disconnect_req;
@@ -937,6 +1004,29 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
return -EIO;
}
break;
+
+ case MEI_HBM_ADD_CLIENT_REQ_CMD:
+ dev_dbg(dev->dev, "hbm: add client request received\n");
+ /*
+ * after the host receives the enum_resp
+ * message clients may be added or removed
+ */
+ if (dev->hbm_state <= MEI_HBM_ENUM_CLIENTS &&
+ dev->hbm_state >= MEI_HBM_STOPPED) {
+ dev_err(dev->dev, "hbm: add client: state mismatch, [%d, %d]\n",
+ dev->dev_state, dev->hbm_state);
+ return -EPROTO;
+ }
+ add_cl_req = (struct hbm_add_client_request *)mei_msg;
+ ret = mei_hbm_fw_add_cl_req(dev, add_cl_req);
+ if (ret) {
+ dev_err(dev->dev, "hbm: add client: failed to send response %d\n",
+ ret);
+ return -EIO;
+ }
+ dev_dbg(dev->dev, "hbm: add client request processed\n");
+ break;
+
default:
BUG();
break;
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index 16fef6dc4dd7..815f40a604b9 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -46,6 +46,12 @@
#define HBM_MINOR_VERSION_PGI 1
#define HBM_MAJOR_VERSION_PGI 1
+/*
+ * MEI version with Dynamic clients support
+ */
+#define HBM_MINOR_VERSION_DC 0
+#define HBM_MAJOR_VERSION_DC 2
+
/* Host bus message command opcode */
#define MEI_HBM_CMD_OP_MSK 0x7f
/* Host bus message command RESPONSE */
@@ -81,6 +87,8 @@
#define MEI_PG_ISOLATION_EXIT_REQ_CMD 0x0b
#define MEI_PG_ISOLATION_EXIT_RES_CMD 0x8b
+#define MEI_HBM_ADD_CLIENT_REQ_CMD 0x0f
+#define MEI_HBM_ADD_CLIENT_RES_CMD 0x8f
/*
* MEI Stop Reason
* used by hbm_host_stop_request.reason
@@ -213,9 +221,17 @@ struct hbm_me_stop_request {
u8 reserved[2];
} __packed;
+/**
+ * struct hbm_host_enum_request - enumeration request from host to fw
+ *
+ * @hbm_cmd: bus message command header
+ * @allow_add: allow dynamic clients add HBM version >= 2.0
+ * @reserved: reserved
+ */
struct hbm_host_enum_request {
u8 hbm_cmd;
- u8 reserved[3];
+ u8 allow_add;
+ u8 reserved[2];
} __packed;
struct hbm_host_enum_response {
@@ -248,6 +264,38 @@ struct hbm_props_response {
} __packed;
/**
+ * struct hbm_add_client_request - request to add a client
+ * might be sent by fw after enumeration has already completed
+ *
+ * @hbm_cmd: bus message command header
+ * @me_addr: address of the client in ME
+ * @reserved: reserved
+ * @client_properties: client properties
+ */
+struct hbm_add_client_request {
+ u8 hbm_cmd;
+ u8 me_addr;
+ u8 reserved[2];
+ struct mei_client_properties client_properties;
+} __packed;
+
+/**
+ * struct hbm_add_client_response - response to add a client
+ * sent by the host to report client addition status to fw
+ *
+ * @hbm_cmd: bus message command header
+ * @me_addr: address of the client in ME
+ * @status: if HBMS_SUCCESS then the client can now accept connections.
+ * @reserved: reserved
+ */
+struct hbm_add_client_response {
+ u8 hbm_cmd;
+ u8 me_addr;
+ u8 status;
+ u8 reserved[1];
+} __packed;
+
+/**
* struct hbm_power_gate - power gate request/response
*
* @hbm_cmd: bus message command header
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 71c55f4cabb4..33823f4a1cf2 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -408,6 +408,7 @@ const char *mei_pg_state_str(enum mei_pg_state state);
*
* @version : HBM protocol version in use
* @hbm_f_pg_supported : hbm feature pgi protocol
+ * @hbm_f_dc_supported : hbm feature dynamic clients
*
* @me_clients_rwsem: rw lock over me_clients list
* @me_clients : list of FW clients
@@ -501,6 +502,7 @@ struct mei_device {
struct hbm_version version;
unsigned int hbm_f_pg_supported:1;
+ unsigned int hbm_f_dc_supported:1;
struct rw_semaphore me_clients_rwsem;
struct list_head me_clients;
--
2.4.3
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