linux-kernel - Re: [PATCH] drivers: ipmi: Support for both IPMB Req and Resp

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Message-ID: <E2EAF8D1-1C16-4468-A34E-5DC3E0CE5224@fb.com>
Date:   Wed, 6 Nov 2019 17:58:15 +0000
From:   Vijay Khemka <vijaykhemka@...com>
To:     Asmaa Mnebhi <Asmaa@...lanox.com>,
        "minyard@....org" <minyard@....org>
CC:     Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "openipmi-developer@...ts.sourceforge.net" 
        <openipmi-developer@...ts.sourceforge.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "cminyard@...sta.com" <cminyard@...sta.com>,
        "joel@....id.au" <joel@....id.au>,
        "linux-aspeed@...ts.ozlabs.org" <linux-aspeed@...ts.ozlabs.org>,
        Sai Dasari <sdasari@...com>
Subject: Re: [PATCH] drivers: ipmi: Support for both IPMB Req and Resp

Thanks Asmaa,
I will have v2 soon.

Regards
-Vijay

On 11/6/19, 7:01 AM, "Asmaa Mnebhi" <Asmaa@...lanox.com> wrote:

    
    
    -----Original Message-----
    From: Vijay Khemka <vijaykhemka@...com> 
    Sent: Wednesday, November 6, 2019 1:58 AM
    To: minyard@....org
    Cc: Arnd Bergmann <arnd@...db.de>; Greg Kroah-Hartman <gregkh@...uxfoundation.org>; openipmi-developer@...ts.sourceforge.net; linux-kernel@...r.kernel.org; cminyard@...sta.com; Asmaa Mnebhi <Asmaa@...lanox.com>; joel@....id.au; linux-aspeed@...ts.ozlabs.org; Sai Dasari <sdasari@...com>
    Subject: Re: [PATCH] drivers: ipmi: Support for both IPMB Req and Resp
    
    
    
    On 11/5/19, 4:54 PM, "Corey Minyard" <tcminyard@...il.com on behalf of minyard@....org> wrote:
    
        On Tue, Nov 05, 2019 at 11:47:31AM -0800, Vijay Khemka wrote:
        > Removed check for request or response in IPMB packets coming from
        > device as well as from host. Now it supports both way communication
        > to device via IPMB. Both request and response will be passed to
        > application.
        > 
        > Signed-off-by: Vijay Khemka <vijaykhemka@...com>
        > ---
        >  drivers/char/ipmi/ipmb_dev_int.c | 29 +----------------------------
        >  1 file changed, 1 insertion(+), 28 deletions(-)
        > 
        > diff --git a/drivers/char/ipmi/ipmb_dev_int.c b/drivers/char/ipmi/ipmb_dev_int.c
        > index 285e0b8f9a97..7201fdb533d8 100644
        > --- a/drivers/char/ipmi/ipmb_dev_int.c
        > +++ b/drivers/char/ipmi/ipmb_dev_int.c
        > @@ -133,9 +133,6 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
        >  	rq_sa = GET_7BIT_ADDR(msg[RQ_SA_8BIT_IDX]);
        >  	netf_rq_lun = msg[NETFN_LUN_IDX];
        >  
        > -	if (!(netf_rq_lun & NETFN_RSP_BIT_MASK))
        > -		return -EINVAL;
        > -
        >  	/*
        >  	 * subtract rq_sa and netf_rq_lun from the length of the msg passed to
        >  	 * i2c_smbus_xfer
        > @@ -203,28 +200,6 @@ static u8 ipmb_verify_checksum1(struct ipmb_dev *ipmb_dev, u8 rs_sa)
        >  		ipmb_dev->request.checksum1);
        >  }
        >  
        > -static bool is_ipmb_request(struct ipmb_dev *ipmb_dev, u8 rs_sa)
        > -{
        > -	if (ipmb_dev->msg_idx >= IPMB_REQUEST_LEN_MIN) {
        > -		if (ipmb_verify_checksum1(ipmb_dev, rs_sa))
        > -			return false;
        
        You still need to check the message length and checksum, you just need
        to ignore the req/resp bit.
    Yes you are right, I was looking for checksum code after removing it __. I will modify it.
    
    Besides Corey's comment, looks good to me. The logic should be something like this:
    static bool is_ipmb_msg(struct ipmb_dev *ipmb_dev, u8 rs_sa)
     {
             if (ipmb_dev->msg_idx >= IPMB_REQUEST_LEN_MIN) {
                     if (ipmb_verify_checksum1(ipmb_dev, rs_sa))
                             return false;
             } else {
                     return false;
             }
             return true;
    }
        
        -corey
        
        > -
        > -		/*
        > -		 * Check whether this is an IPMB request or
        > -		 * response.
        > -		 * The 6 MSB of netfn_rs_lun are dedicated to the netfn
        > -		 * while the remaining bits are dedicated to the lun.
        > -		 * If the LSB of the netfn is cleared, it is associated
        > -		 * with an IPMB request.
        > -		 * If the LSB of the netfn is set, it is associated with
        > -		 * an IPMB response.
        > -		 */
        > -		if (!(ipmb_dev->request.netfn_rs_lun & NETFN_RSP_BIT_MASK))
        > -			return true;
        > -	}
        > -	return false;
        > -}
        > -
        >  /*
        >   * The IPMB protocol only supports I2C Writes so there is no need
        >   * to support I2C_SLAVE_READ* events.
        > @@ -273,9 +248,7 @@ static int ipmb_slave_cb(struct i2c_client *client,
        >  
        >  	case I2C_SLAVE_STOP:
        >  		ipmb_dev->request.len = ipmb_dev->msg_idx;
        > -
        > -		if (is_ipmb_request(ipmb_dev, GET_8BIT_ADDR(client->addr)))
        > -			ipmb_handle_request(ipmb_dev);
        > +		ipmb_handle_request(ipmb_dev);
    
    Keep this line.
        >  		break;
        >  
        >  	default:
        > -- 
        > 2.17.1
        >