Commit 70ef835c authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman
Browse files

mei: support for dynamic clients 



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: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6009595a

drivers/misc/mei/debugfs.c

+2 −0
Original line number Diff line number Diff line
@@ -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",

drivers/misc/mei/hbm.c

+91 −1
Original line number Diff line number Diff line
@@ -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) {
@@ -343,6 +344,64 @@ static int mei_hbm_me_cl_add(struct mei_device *dev, 
	return 0;

}



/**

 * 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

 *
@@ -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;

drivers/misc/mei/hw.h

+49 −1
Original line number Diff line number Diff line
@@ -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 {
@@ -247,6 +263,38 @@ struct hbm_props_response { 
	struct mei_client_properties client_properties;

} __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

 *

drivers/misc/mei/mei_dev.h

+2 −0
Original line number Diff line number Diff line
@@ -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;

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