[ofa-general] question regarding umad_recv

[Sumit Gaur - Sun Microsystem]

Thanks Sasha for patch I will try it and looks like it would work.

Regards
sumit

Sasha Khapyorsky wrote:
> On 04:50 Fri 12 Oct     , Hal Rosenstock wrote:
> 
>>On Fri, 2007-10-12 at 12:09 +0530, Sumit Gaur - Sun Microsystem wrote:
>>
>>>Hi ,
>>>
>>>Sean Hefty wrote:
>>>
>>>>>There is no per thread demuxing. You would need two different mad agents
>>>>>to do this with one looking at the SMI side and the other the GSI side.
>>>>>I haven't looked at libibmad in terms of using this model though.
>>>>
>>>>
>>>>umad_receive() doesn't take the mad_agent as an input parameter.  The only
>>>>possibility I see is calling umad_open_port() twice for the same port, with the
>>>>GSI/SMI registrations going to separate port_id's.
>>>
>>>I think this solution is also not possible as calling umad_open_port() twice for 
>>>the same port and ca_name is always gives error in port_alloc because 
>>>dev_to_umad_id generate same umad_id for same ca_name and portnum.
>>>
>>>ibwarn: [9634] port_alloc: umad port id 1 is already allocated for mthca0 2
>>>
>>>So looks like it is impossible to generate two separate portid for the same port.
>>
>>It might be possible to support this with some changes to libibumad.
>>Sasha ?
> 
> 
> Yes, it could be possible this way.
> 
> Sumit, could you try this patch?
> 
> Sasha
> 
> 
> diff --git a/libibumad/src/umad.c b/libibumad/src/umad.c
> index 589684c..5ccdcfb 100644
> --- a/libibumad/src/umad.c
> +++ b/libibumad/src/umad.c
> @@ -82,6 +82,7 @@ int umaddebug = 0;
>  
>  #define UMAD_DEV_NAME_SZ	32
>  #define UMAD_DEV_FILE_SZ	256
> +#define MAX_OPEN_PORTS 2048
>  
>  static char *def_ca_name = "mthca0";
>  static int def_ca_port = 1;
> @@ -94,54 +95,18 @@ typedef struct Port {
>  	int id;
>  } Port;
>  
> -static Port ports[UMAD_MAX_PORTS];
> +static Port *open_ports[MAX_OPEN_PORTS];
>  
>  /*************************************
>   * Port
>   */
>  static Port *
> -port_alloc(int portid, char *dev, int portnum)
> -{
> -	Port *port = ports + portid;
> -
> -	if (portid < 0 || portid >= UMAD_MAX_PORTS) {
> -		IBWARN("bad umad portid %d", portid);
> -		errno = EINVAL;
> -		return 0;
> -	}
> -
> -	if (port->dev_name[0]) {
> -		IBWARN("umad port id %d is already allocated for %s %d",
> -			portid, port->dev_name, port->dev_port);
> -		errno = EBUSY;
> -		return 0;
> -	}
> -
> -	strncpy(port->dev_name, dev, UMAD_CA_NAME_LEN);
> -	port->dev_port = portnum;
> -	port->id = portid;
> -
> -	return port;
> -}
> -
> -static Port *
>  port_get(int portid)
>  {
> -	Port *port = ports + portid;
> -
> -	if (portid < 0 || portid >= UMAD_MAX_PORTS)
> -		return 0;
> -
> -	if (port->dev_name[0] == 0)
> -		return 0;
> -
> -	return port;
> -}
> +	if (portid < 0 || portid >= MAX_OPEN_PORTS)
> +		return NULL;
>  
> -static void
> -port_free(Port *port)
> -{
> -	memset(port, 0, sizeof *port);
> +	return open_ports[portid];
>  }
>  
>  static int
> @@ -571,7 +536,7 @@ umad_get_ca_portguids(char *ca_name, uint64_t *portguids, int max)
>  int
>  umad_open_port(char *ca_name, int portnum)
>  {
> -	int umad_id;
> +	int umad_id, fd;
>  	Port *port;
>  
>  	TRACE("ca %s port %d", ca_name, portnum);
> @@ -584,19 +549,35 @@ umad_open_port(char *ca_name, int portnum)
>  	if ((umad_id = dev_to_umad_id(ca_name, portnum)) < 0)
>  		return -EINVAL;
>  
> -	if (!(port = port_alloc(umad_id, ca_name, portnum)))
> -		return -errno;
> +	port = malloc(sizeof(*port));
> +	if (!port)
> +		return -ENOMEM;
> +	memset(port, 0, sizeof(*port));
>  
>  	snprintf(port->dev_file, sizeof port->dev_file - 1, "%s/umad%d",
>  		 UMAD_DEV_DIR , umad_id);
>  
> -	if ((port->dev_fd = open(port->dev_file, O_RDWR|O_NONBLOCK)) < 0) {
> +	fd = open(port->dev_file, O_RDWR|O_NONBLOCK);
> +	if (fd < 0) {
>  		DEBUG("open %s failed: %s", port->dev_file, strerror(errno));
> +		free(port);
>  		return -EIO;
> +	} else if (fd >= MAX_OPEN_PORTS) {
> +		DEBUG("no ports space for %s", port->dev_file);
> +		errno = ENOMEM;
> +		free(port);
> +		return -ENOMEM;
>  	}
>  
> +	port->id = umad_id;
> +	port->dev_port = portnum;
> +	port->dev_fd = fd;
> +	strncpy(port->dev_name, ca_name, UMAD_CA_NAME_LEN);
> +
> +	open_ports[fd] = port;
> +
>  	DEBUG("opened %s fd %d portid %d", port->dev_file, port->dev_fd, port->id);
> -	return port->id;
> +	return fd;
>  }
>  
>  int
> @@ -677,7 +658,8 @@ umad_close_port(int portid)
>  
>  	close(port->dev_fd);
>  
> -	port_free(port);
> +	open_ports[portid] = NULL;
> +	free(port);
>  
>  	DEBUG("closed %s fd %d", port->dev_file, port->dev_fd);
>  	return 0;