netdev - Re: [PATCH] Netpoll support for Sibyte MAC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <45FFF0D9.4020905@ru.mvista.com>
Date:	Tue, 20 Mar 2007 17:34:01 +0300
From:	Sergei Shtylyov <sshtylyov@...mvista.com>
To:	dsaxena@...xity.net
Cc:	netdev@...r.kernel.org, ralf@...ux-mips.org, jeff@...zik.org,
	linux-mips@...ux-mips.org, Manish Lachwani <mlachwani@...sta.com>
Subject: Re: [PATCH] Netpoll support for Sibyte MAC

Hello.

Deepak Saxena wrote:

> NETPOLL support for Sibyte MAC

> Index: linux-2.6.18/drivers/net/sb1250-mac.c
> ===================================================================
> --- linux-2.6.18.orig/drivers/net/sb1250-mac.c
> +++ linux-2.6.18/drivers/net/sb1250-mac.c
> @@ -1128,6 +1128,26 @@ static void sbdma_fillring(sbmacdma_t *d
>  	}
>  }
>  
> +#ifdef CONFIG_NET_POLL_CONTROLLER
> +static void sbmac_netpoll(struct net_device *netdev)
> +{
> +	struct sbmac_softc *sc = netdev_priv(netdev);
> +	int irq = sc->sbm_dev->irq;
> +
> +	__raw_writeq(0, sc->sbm_imr);
> +

    Thinking about it again, I'm not sure that blindly writing to the chip 
reg. to mask interrupts is SMP-safe enough (versus disable_irq()).  I know why 
it was done this way -- to quell the BUG emitted in the realtime mode on SMP 
-- because of scheduling with disabled interrupts in synchoronize_irq(), but 
after having spent much time on netpoll, I'm no longer sure that anything but 
disable_irq() is safe enough for SMP since -- otherwise there's no warranty 
that sbmac_intr() is not running on another CPU...

> +	sbmac_intr(irq, netdev, NULL);
> +
> +#ifdef CONFIG_SBMAC_COALESCE
> +	__raw_writeq(((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) |
> +	((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_RX_CH0),
> +	sc->sbm_imr);
> +#else
> +	__raw_writeq((M_MAC_INT_CHANNEL << S_MAC_TX_CH0) | 
> +	(M_MAC_INT_CHANNEL << S_MAC_RX_CH0), sc->sbm_imr);
> +#endif
> +}
> +#endif

WBR, Sergei
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html