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* Re: [PATCH (net.git) V2] stmmac: fix driver built w/ w/o both pci and platf modules
From: David Miller @ 2012-06-07 18:01 UTC (permalink / raw)
  To: peppe.cavallaro; +Cc: netdev, wfg
In-Reply-To: <1339073322-23093-1-git-send-email-peppe.cavallaro@st.com>

From: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
Date: Thu,  7 Jun 2012 14:48:42 +0200

> +	pr_err("stmmac: do not register the PCI driver\n");

This is inappropriate, since this is called unconditionally.

^ permalink raw reply

* Re: tcp wifi upload performance and lots of ACKs
From: David Miller @ 2012-06-07 18:10 UTC (permalink / raw)
  To: rick.jones2; +Cc: David.Laight, greearb, dbaluta, netdev
In-Reply-To: <4FD0EA18.3090606@hp.com>

From: Rick Jones <rick.jones2@hp.com>
Date: Thu, 07 Jun 2012 10:51:20 -0700

> This may not work well when the sender has a congestion window growth
> heuristic different from what the ACK avoidance heuristic assumes.  If
> I recall correctly, the heuristic in HP-UX assumes the sender grows
> cwnd by the number of bytes/segments ACKnowledged.

Linux violates this assumption.

^ permalink raw reply

* [PATCH] fix kernel crash in the macvlan driver
From: Ani Sinha @ 2012-06-07 18:45 UTC (permalink / raw)
  To: netdev; +Cc: Eric Biederman, Francesco Ruggeri

Hello folks :

We noticed a consistently reproducable kernel crash in the macvlan driver
when we were running our test script. I believe I have found the reason
for the crash and a patch that fixes it. I am attaching the patch for your
comments and opinions.

Cheers,
Ani



commit cd28ce3cb624ddaaf97935c1f34d44bb13ffb786
Author: Anirban Sinha <ani@aristanetworks.com>
Date:   Thu Jun 7 11:21:02 2012 -0700

    macvlan : The patch d5cd92448fded12c91f7574e49747c5f7d975a8d introduced reference
    counting for macvlan_port. This patch fixes an issue where the reference
    counts were being decremented incorrectly from macvlan_uninit() and not from
    macvlan_dellink(). This was causing the kernel crash shown below :

    BUG: unable to handle kernel paging request at 0000000100000000
    IP: [<ffffffffa031f8e5>] macvlan_addr_busy+0x58/0x8d [macvlan]
    PGD 3a2aa067 PUD 0
    Oops: 0000 [#1] SMP
    last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1/energy_full
    CPU 0
    Modules linked in: macvlan rfcomm sco bnep l2cap sunrpc ipt_REJECT iptable_filter ip6t_REJECT xt_tcpudp

    Pid: 2490, comm: ip Not tainted 2.6.38.8-705892.2012aniArora.7.fc14.x86_64 #1
    RIP: 0010:[<ffffffffa031f8e5>]  [<ffffffffa031f8e5>] macvlan_addr_busy+0x58/0x8d [macvlan]
    RSP: 0018:ffff880037d2b698  EFLAGS: 00010296
    RAX: 0000000100000000 RBX: ffff88003bf54000 RCX: 0000000000000000
    RDX: 0000111111111102 RSI: 0000000000000092 RDI: 0000000000000246
    RBP: ffff880037d2b6a8 R08: 0000000000000040 R09: ffffffff81a73f18
    R10: ffffffff81e03a20 R11: 0000000000000020 R12: ffff88003c8e33d0
    R13: ffff880037ecd000 R14: 00000000fffffff0 R15: 0000000000000001
    FS:  0000000000000000(0000) GS:ffff88003e200000(0063) knlGS:00000000f75d26c0
    CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
    CR2: 0000000100000000 CR3: 00000000377e7000 CR4: 00000000000006f0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Process ip (pid: 2490, threadinfo ffff880037d2a000, task ffff88003d1206c0)
    Stack:
     ffff88003d031000 ffff88003d031680 ffff880037d2b6d8 ffffffffa031fbcc
     ffff88003d031000 ffffffffa03211c0 ffff88003d031078 0000000000000000
     ffff880037d2b708 ffffffff81345cf7 ffff88003d031000 0000000000001003
    Call Trace:
     [<ffffffffa031fbcc>] macvlan_open+0x7e/0x116 [macvlan]
     [<ffffffff81345cf7>] __dev_open+0x90/0xc7
     [<ffffffff81345f26>] __dev_change_flags+0xa8/0x12c
     [<ffffffff81346021>] dev_change_flags+0x1c/0x52
     [<ffffffff8134fce1>] do_setlink+0x2b4/0x67d
     [<ffffffff813bc85f>] ? inet6_fill_link_af+0x1a/0x22
     [<ffffffff8134f6bf>] ? rtnl_fill_ifinfo+0x99f/0xa7d
     [<ffffffff81350d02>] rtnl_newlink+0x247/0x40d
     [<ffffffff81350b7a>] ? rtnl_newlink+0xbf/0x40d
     [<ffffffff81337ced>] ? sock_rmalloc+0x2e/0x90
     [<ffffffff810dc46c>] ? arch_local_irq_save+0x16/0x1c
     [<ffffffff810685fe>] ? arch_local_irq_save+0x18/0x1e
     [<ffffffff813508dc>] rtnetlink_rcv_msg+0x1e6/0x1fc
     [<ffffffff810af70a>] ? get_page_from_freelist+0x4dd/0x68d
     [<ffffffff813506f6>] ? rtnetlink_rcv_msg+0x0/0x1fc
     [<ffffffff81364239>] netlink_rcv_skb+0x40/0x8b
     [<ffffffff813502c7>] rtnetlink_rcv+0x21/0x28
     [<ffffffff81363d27>] netlink_unicast+0xec/0x155
     [<ffffffff81364041>] netlink_sendmsg+0x2b1/0x2cf
     [<ffffffff81332ec2>] ? __sock_recvmsg+0x75/0x84
     [<ffffffff81332d70>] __sock_sendmsg+0x66/0x72
     [<ffffffff81333521>] sock_sendmsg+0xa3/0xbc
     [<ffffffff810b25da>] ? lru_cache_add_lru+0x3c/0x3e
     [<ffffffff810cc1e3>] ? page_add_new_anon_rmap+0x5b/0x6d
     [<ffffffff810c17cb>] ? set_pte_at+0x9/0xd
     [<ffffffff810c2f31>] ? do_wp_page+0x496/0x541
     [<ffffffff81333ec0>] ? move_addr_to_kernel+0x44/0x49
     [<ffffffff813585a4>] ? verify_compat_iovec+0x6d/0xb9
     [<ffffffff81334cac>] sys_sendmsg+0x230/0x2ae
     [<ffffffff810c1965>] ? pmd_offset+0x14/0x3b
     [<ffffffff810c4c0a>] ? handle_mm_fault+0x13a/0x14f
     [<ffffffff81334756>] ? sys_sendto+0x13f/0x16c
     [<ffffffff81334d76>] ? sys_recvmsg+0x4c/0x5b
     [<ffffffff81358deb>] compat_sys_sendmsg+0xf/0x11
     [<ffffffff81359005>] compat_sys_socketcall+0x14f/0x186
     [<ffffffff8102c2b0>] sysenter_dispatch+0x7/0x2e
    Code: 0e e1 48 8b 03 4c 89 e2 48 c7 c7 6c 10 32 a0 48 8b b0 80 02 00 00 31 c0 e8 f1 17 0e e1 48 8b 03 49 8b 14 24 48 8b 80 80 02 00 00 <48> 33 10 b8 01 00 00 00 48 c1 e2 10 74 22 48 c7 c7 93 10 32 a0

    Signed-off-by: Anirban Sinha <ani@aristanetworks.com>

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 66a9bfe..d880bc8 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -481,7 +481,6 @@ static void macvlan_uninit(struct net_device *dev)

 	free_percpu(vlan->pcpu_stats);

-	port->count -= 1;
 	if (!port->count)
 		macvlan_port_destroy(port->dev);
 }
@@ -795,7 +794,9 @@ static int macvlan_newlink(struct net *src_net, struct net_device *dev,
 void macvlan_dellink(struct net_device *dev, struct list_head *head)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct macvlan_port *port = vlan->port;

+	port->count -= 1;
 	list_del(&vlan->list);
 	unregister_netdevice_queue(dev, head);
 }

^ permalink raw reply related

* Re: pull request: can-next 2012-06-07
From: David Miller @ 2012-06-07 19:02 UTC (permalink / raw)
  To: mkl; +Cc: netdev, linux-can
In-Reply-To: <4FD062D3.5010107@pengutronix.de>

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Thu, 07 Jun 2012 10:14:11 +0200

> here two patches for net-next, by AnilKumar Ch, they add support for
> Bosch's d_can hardware to the existing c_can driver.

Pulled, thanks.

^ permalink raw reply

* Re: [PATCH] fix kernel crash in the macvlan driver
From: Eric W. Biederman @ 2012-06-07 19:49 UTC (permalink / raw)
  To: Ani Sinha; +Cc: netdev, Francesco Ruggeri
In-Reply-To: <alpine.OSX.2.00.1206071137360.86561@animac.local>

Ani Sinha <ani@aristanetworks.com> writes:

> Hello folks :
>
> We noticed a consistently reproducable kernel crash in the macvlan driver
> when we were running our test script. I believe I have found the reason
> for the crash and a patch that fixes it. I am attaching the patch for your
> comments and opinions.

I don't completely follow the logic of your change.  Crashing in
macvlan_addr_busy does seem to indicate you are using a corrupted data
structure.

My compiled version of macvlan_addr_busy is much smaller than yours so I
can't guess based on your disassembly what is wrong.  But by reading the
code it must either be port->dev->dev_addr or the rcu
macvlan_hash_lookup.

Regardless all I see your patch doing is moving the decrement of
port->count earlier and possibly allowing newlink in
MACVLAN_MODE_PASSTHRU to succeed a smidge earlier.

I might just be dense today but I can't possibly see how moving that
decrement would solve the crash you have reported below.

Eric


> commit cd28ce3cb624ddaaf97935c1f34d44bb13ffb786
> Author: Anirban Sinha <ani@aristanetworks.com>
> Date:   Thu Jun 7 11:21:02 2012 -0700
>
>     macvlan : The patch d5cd92448fded12c91f7574e49747c5f7d975a8d introduced reference
>     counting for macvlan_port. This patch fixes an issue where the reference
>     counts were being decremented incorrectly from macvlan_uninit() and not from
>     macvlan_dellink(). This was causing the kernel crash shown below :
>
>     BUG: unable to handle kernel paging request at 0000000100000000
>     IP: [<ffffffffa031f8e5>] macvlan_addr_busy+0x58/0x8d [macvlan]
>     PGD 3a2aa067 PUD 0
>     Oops: 0000 [#1] SMP
>     last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1/energy_full
>     CPU 0
>     Modules linked in: macvlan rfcomm sco bnep l2cap sunrpc ipt_REJECT iptable_filter ip6t_REJECT xt_tcpudp
>
>     Pid: 2490, comm: ip Not tainted 2.6.38.8-705892.2012aniArora.7.fc14.x86_64 #1
>     RIP: 0010:[<ffffffffa031f8e5>]  [<ffffffffa031f8e5>] macvlan_addr_busy+0x58/0x8d [macvlan]
>     RSP: 0018:ffff880037d2b698  EFLAGS: 00010296
>     RAX: 0000000100000000 RBX: ffff88003bf54000 RCX: 0000000000000000
>     RDX: 0000111111111102 RSI: 0000000000000092 RDI: 0000000000000246
>     RBP: ffff880037d2b6a8 R08: 0000000000000040 R09: ffffffff81a73f18
>     R10: ffffffff81e03a20 R11: 0000000000000020 R12: ffff88003c8e33d0
>     R13: ffff880037ecd000 R14: 00000000fffffff0 R15: 0000000000000001
>     FS:  0000000000000000(0000) GS:ffff88003e200000(0063) knlGS:00000000f75d26c0
>     CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
>     CR2: 0000000100000000 CR3: 00000000377e7000 CR4: 00000000000006f0
>     DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>     DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>     Process ip (pid: 2490, threadinfo ffff880037d2a000, task ffff88003d1206c0)
>     Stack:
>      ffff88003d031000 ffff88003d031680 ffff880037d2b6d8 ffffffffa031fbcc
>      ffff88003d031000 ffffffffa03211c0 ffff88003d031078 0000000000000000
>      ffff880037d2b708 ffffffff81345cf7 ffff88003d031000 0000000000001003
>     Call Trace:
>      [<ffffffffa031fbcc>] macvlan_open+0x7e/0x116 [macvlan]
>      [<ffffffff81345cf7>] __dev_open+0x90/0xc7
>      [<ffffffff81345f26>] __dev_change_flags+0xa8/0x12c
>      [<ffffffff81346021>] dev_change_flags+0x1c/0x52
>      [<ffffffff8134fce1>] do_setlink+0x2b4/0x67d
>      [<ffffffff813bc85f>] ? inet6_fill_link_af+0x1a/0x22
>      [<ffffffff8134f6bf>] ? rtnl_fill_ifinfo+0x99f/0xa7d
>      [<ffffffff81350d02>] rtnl_newlink+0x247/0x40d
>      [<ffffffff81350b7a>] ? rtnl_newlink+0xbf/0x40d
>      [<ffffffff81337ced>] ? sock_rmalloc+0x2e/0x90
>      [<ffffffff810dc46c>] ? arch_local_irq_save+0x16/0x1c
>      [<ffffffff810685fe>] ? arch_local_irq_save+0x18/0x1e
>      [<ffffffff813508dc>] rtnetlink_rcv_msg+0x1e6/0x1fc
>      [<ffffffff810af70a>] ? get_page_from_freelist+0x4dd/0x68d
>      [<ffffffff813506f6>] ? rtnetlink_rcv_msg+0x0/0x1fc
>      [<ffffffff81364239>] netlink_rcv_skb+0x40/0x8b
>      [<ffffffff813502c7>] rtnetlink_rcv+0x21/0x28
>      [<ffffffff81363d27>] netlink_unicast+0xec/0x155
>      [<ffffffff81364041>] netlink_sendmsg+0x2b1/0x2cf
>      [<ffffffff81332ec2>] ? __sock_recvmsg+0x75/0x84
>      [<ffffffff81332d70>] __sock_sendmsg+0x66/0x72
>      [<ffffffff81333521>] sock_sendmsg+0xa3/0xbc
>      [<ffffffff810b25da>] ? lru_cache_add_lru+0x3c/0x3e
>      [<ffffffff810cc1e3>] ? page_add_new_anon_rmap+0x5b/0x6d
>      [<ffffffff810c17cb>] ? set_pte_at+0x9/0xd
>      [<ffffffff810c2f31>] ? do_wp_page+0x496/0x541
>      [<ffffffff81333ec0>] ? move_addr_to_kernel+0x44/0x49
>      [<ffffffff813585a4>] ? verify_compat_iovec+0x6d/0xb9
>      [<ffffffff81334cac>] sys_sendmsg+0x230/0x2ae
>      [<ffffffff810c1965>] ? pmd_offset+0x14/0x3b
>      [<ffffffff810c4c0a>] ? handle_mm_fault+0x13a/0x14f
>      [<ffffffff81334756>] ? sys_sendto+0x13f/0x16c
>      [<ffffffff81334d76>] ? sys_recvmsg+0x4c/0x5b
>      [<ffffffff81358deb>] compat_sys_sendmsg+0xf/0x11
>      [<ffffffff81359005>] compat_sys_socketcall+0x14f/0x186
>      [<ffffffff8102c2b0>] sysenter_dispatch+0x7/0x2e
>     Code: 0e e1 48 8b 03 4c 89 e2 48 c7 c7 6c 10 32 a0 48 8b b0 80 02 00 00 31 c0 e8 f1 17 0e e1 48 8b 03 49 8b 14 24 48 8b 80 80 02 00 00 <48> 33 10 b8 01 00 00 00 48 c1 e2 10 74 22 48 c7 c7 93 10 32 a0
>
>     Signed-off-by: Anirban Sinha <ani@aristanetworks.com>
>
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index 66a9bfe..d880bc8 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -481,7 +481,6 @@ static void macvlan_uninit(struct net_device *dev)
>
>  	free_percpu(vlan->pcpu_stats);
>
> -	port->count -= 1;
>  	if (!port->count)
>  		macvlan_port_destroy(port->dev);
>  }
> @@ -795,7 +794,9 @@ static int macvlan_newlink(struct net *src_net, struct net_device *dev,
>  void macvlan_dellink(struct net_device *dev, struct list_head *head)
>  {
>  	struct macvlan_dev *vlan = netdev_priv(dev);
> +	struct macvlan_port *port = vlan->port;
>
> +	port->count -= 1;
>  	list_del(&vlan->list);
>  	unregister_netdevice_queue(dev, head);
>  }

^ permalink raw reply

* Re: [PATCH] net: l2tp_eth: fix kernel panic on rmmod l2tp_eth
From: David Miller @ 2012-06-07 20:02 UTC (permalink / raw)
  To: eric.dumazet; +Cc: denys, netdev, jchapman
In-Reply-To: <1339063640.26966.113.camel@edumazet-glaptop>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 07 Jun 2012 12:07:20 +0200

> From: Eric Dumazet <edumazet@google.com>
> 
> We must prevent module unloading if some devices are still attached to
> l2tp_eth driver.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
> Tested-by: Denys Fedoryshchenko <denys@visp.net.lb>
Applied.

^ permalink raw reply

* Re: [PATCH] net: neighbour: fix neigh_dump_info()
From: David Miller @ 2012-06-07 20:03 UTC (permalink / raw)
  To: eric.dumazet; +Cc: denys, netdev, shemminger
In-Reply-To: <1339081115.5083.21.camel@edumazet-glaptop>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 07 Jun 2012 16:58:35 +0200

> From: Eric Dumazet <edumazet@google.com>
> 
> Denys found out "ip neigh" output was truncated to
> about 54 neighbours.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>

Applied.

^ permalink raw reply

* Re: [PATCH] ipv6: fib: Restore NTF_ROUTER exception in fib6_age()
From: David Miller @ 2012-06-07 20:03 UTC (permalink / raw)
  To: tgraf; +Cc: netdev
In-Reply-To: <6e43964ac82665f0257ac4f53c17b3b3403edcc3.1339087863.git.tgraf@suug.ch>

From: Thomas Graf <tgraf@suug.ch>
Date: Thu,  7 Jun 2012 18:51:04 +0200

> Commit 5339ab8b1dd82 (ipv6: fib: Convert fib6_age() to
> dst_neigh_lookup().) seems to have mistakenly inverted the
> exception for cached NTF_ROUTER routes.
> 
> Signed-off-by: Thomas Graf <tgraf@suug.ch>

Thanks for fixing this, applied.

^ permalink raw reply

* Re: [V2 RFC net-next PATCH 2/2] virtio_net: export more statistics through ethtool
From: David Miller @ 2012-06-07 20:05 UTC (permalink / raw)
  To: bhutchings; +Cc: mst, netdev, linux-kernel, virtualization
In-Reply-To: <1339089306.2770.10.camel@bwh-desktop.uk.solarflarecom.com>

From: Ben Hutchings <bhutchings@solarflare.com>
Date: Thu, 7 Jun 2012 18:15:06 +0100

> I would really like to see some sort of convention for presenting
> per-queue statistics through ethtool.  At the moment we have a complete
> mess of different formats:

Indeed.  Probably ${QUEUE_TYPE}-${INDEX}-${STATISTIC} is best.
With an agreed upon list of queue types such as "rx", "tx", "rxtx"
etc.

^ permalink raw reply

* Re: [PATCH] sky2: fix checksum bit management on some chips
From: David Miller @ 2012-06-07 20:07 UTC (permalink / raw)
  To: shemminger; +Cc: kirr, mlindner, netdev
In-Reply-To: <20120606130130.5a86f94a@nehalam.linuxnetplumber.net>

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Wed, 6 Jun 2012 13:01:30 -0700

> The newer flavors of Yukon II use a different method for receive
> checksum offload. This is indicated in the driver by the SKY2_HW_NEW_LE
> flag. On these newer chips, the BMU_ENA_RX_CHKSUM should not be set.
> 
> The driver would get incorrectly toggle the bit, enabling the old
> checksum logic on these chips and cause a BUG_ON() assertion. If
> receive checksum was toggled via ethtool.
> 
> Reported-by: Kirill Smelkov <kirr@mns.spb.ru>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

Applied and queued up for -stable.

> Patch against net-next, please apply to net and stable kernels.

Stephen, please don't do this, generate your patches always
against the correct tree even if they are likely to still
apply when generated against the wrong tree.

^ permalink raw reply

* Re: [PATCH] ieee802154: verify packet size before trying to allocate it
From: David Miller @ 2012-06-07 20:10 UTC (permalink / raw)
  To: levinsasha928
  Cc: dbaryshkov, slapin, linux-zigbee-devel, netdev, linux-kernel
In-Reply-To: <1339018322-19360-1-git-send-email-levinsasha928@gmail.com>

From: Sasha Levin <levinsasha928@gmail.com>
Date: Wed,  6 Jun 2012 23:32:02 +0200

> Currently when sending data over datagram, the send function will attempt to
> allocate any size passed on from the userspace.
> 
> We should make sure that this size is checked and limited. The maximum size
> of an IP packet seemed like the safest limit here.
> 
> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>

This limit is arbitrary, I'm not applying a patch like this.

Use the actual limit, which is either the protocol limit or something
like the device mtu.

^ permalink raw reply

* Re: Remove out of date message in appletalk printk
From: David Miller @ 2012-06-07 20:12 UTC (permalink / raw)
  To: davej; +Cc: netdev, acme
In-Reply-To: <20120606184559.GA27763@redhat.com>

From: Dave Jones <davej@redhat.com>
Date: Wed, 6 Jun 2012 14:45:59 -0400

> I accidentally triggered this printk, which amused me for a few moments.
> Given we're post 2.2, we could just -EACCES, but does anyone even care about Appletalk now ?
> I figure it's better to leave sleeping dogs lie, and just update the message.
> 
> Signed-off-by: Dave Jones <davej@redhat.com>

Applied, but I made a few refinements.  I made it use pr_warn() and
also prefixed the message with "atalk_connect: " so if someone sees
this it's easier to figure out where it's coming from.

Thanks.

^ permalink raw reply

* Re: [PATCH] net: stmmac: Fix clock en-/disable calls
From: David Miller @ 2012-06-07 20:13 UTC (permalink / raw)
  To: sr; +Cc: netdev, viresh.linux, peppe.cavallaro
In-Reply-To: <1338965351-6286-1-git-send-email-sr@denx.de>

From: Stefan Roese <sr@denx.de>
Date: Wed,  6 Jun 2012 08:49:11 +0200

> Signed-off-by: Stefan Roese <sr@denx.de>

This means nothing to me.

What is fixed by using the prepare/unprepare variants vs. the
plain ones?

It is absolutely inappropriate to not describe your change
completely in your commit message.

This patch is being rejected.

^ permalink raw reply

* Re: [patch] net/ethernet: ks8851_mll unregister_netdev() before freeing
From: David Miller @ 2012-06-07 20:15 UTC (permalink / raw)
  To: dan.carpenter; +Cc: raffaele.recalcati, netdev, kernel-janitors
In-Reply-To: <20120606063129.GA26829@elgon.mountain>

From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 6 Jun 2012 09:31:29 +0300

> We added another error condition here, but if we were to hit it then
> we need to unregister_netdev() before doing the free_netdev().
> Otherwise we would hit the BUG_ON() in free_netdev():
> 
> 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Applied, but please be explicit that your patch is against one
tree or another.  This one was for net-next only, but I tried
initially to apply it to net which failed.

^ permalink raw reply

* Re: [PATCH net-next 0/3] qlcnic: Bug fixes
From: David Miller @ 2012-06-07 20:19 UTC (permalink / raw)
  To: anirban.chakraborty; +Cc: netdev, Dept_NX_Linux_NIC_Driver
In-Reply-To: <1339004108-7356-1-git-send-email-anirban.chakraborty@qlogic.com>

From: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Date: Wed,  6 Jun 2012 13:35:05 -0400

> Please apply.

All applied to net-next, thanks.

^ permalink raw reply

* Re: [PATCH net-next] net: Update kernel-doc for __alloc_skb()
From: David Miller @ 2012-06-07 20:19 UTC (permalink / raw)
  To: bhutchings; +Cc: netdev, grant.b.edwards
In-Reply-To: <1339032217.2836.61.camel@bwh-desktop.uk.solarflarecom.com>

From: Ben Hutchings <bhutchings@solarflare.com>
Date: Thu, 7 Jun 2012 02:23:37 +0100

> __alloc_skb() now extends tailroom to allow the use of padding added
> by the heap allocator.
> 
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Applied.

^ permalink raw reply

* Re: [v4 net-next PATCH 0/3] Energy Efficient Ethernet (eee) support
From: David Miller @ 2012-06-07 20:19 UTC (permalink / raw)
  To: yuvalmin; +Cc: netdev, eilong, peppe.cavallaro, bhutchings
In-Reply-To: <1339038788-3447-1-git-send-email-yuvalmin@broadcom.com>

From: "Yuval Mintz" <yuvalmin@broadcom.com>
Date: Thu, 7 Jun 2012 06:13:05 +0300

> This patch series adds energy efficient ethernet support for the
> bnx2x driver (for new chips with appropriate phys). 
> It also extends the ethtool API to enable control of the eee feature.
> 
> Another patch series has been sent to Ben to allow the ethtool application
> to use this new API.

All applied to net-next, thanks.

^ permalink raw reply

* Re: [PATCH net-next] macvtap: use prepare_to_wait/finish_wait to ensure mb
From: David Miller @ 2012-06-07 20:19 UTC (permalink / raw)
  To: honkiko; +Cc: netdev, arnd, zhiguo.hong, vikifang
In-Reply-To: <1339058187-6619-1-git-send-email-honkiko@gmail.com>

From: Hong Zhiguo <honkiko@gmail.com>
Date: Thu,  7 Jun 2012 16:36:27 +0800

> instead of raw assignment to current->state
> 
> Signed-off-by: Hong Zhiguo <honkiko@gmail.com>

Applied.

^ permalink raw reply

* Re: [PATCH net-next] be2net: Fix driver load for VFs for Lancer
From: David Miller @ 2012-06-07 20:19 UTC (permalink / raw)
  To: padmanabh.ratnakar; +Cc: netdev
In-Reply-To: <e4b55390-7f60-4365-9203-fde4c661e339@exht1.ad.emulex.com>

From: Padmanabh Ratnakar <padmanabh.ratnakar@emulex.com>
Date: Thu, 7 Jun 2012 20:07:08 +0530

> Permanent MAC is wrongly supplied in create iface command. Call the
> command with no MAC address and then MAC address should be later queried
> and applied.
> 
> Signed-off-by: Padmanabh Ratnakar <padmanabh.ratnakar@emulex.com>

Applied.

^ permalink raw reply

* Re: [V2 RFC net-next PATCH 2/2] virtio_net: export more statistics through ethtool
From: Ben Hutchings @ 2012-06-07 20:24 UTC (permalink / raw)
  To: David Miller; +Cc: mst, netdev, linux-kernel, virtualization
In-Reply-To: <20120607.130512.219951433412203999.davem@davemloft.net>

On Thu, 2012-06-07 at 13:05 -0700, David Miller wrote:
> From: Ben Hutchings <bhutchings@solarflare.com>
> Date: Thu, 7 Jun 2012 18:15:06 +0100
> 
> > I would really like to see some sort of convention for presenting
> > per-queue statistics through ethtool.  At the moment we have a complete
> > mess of different formats:
> 
> Indeed.  Probably ${QUEUE_TYPE}-${INDEX}-${STATISTIC} is best.
> With an agreed upon list of queue types such as "rx", "tx", "rxtx"
> etc.

I think we should leave the type names open-ended, as there are other
useful groupings like per-virtual-port.  In that case the separator
should be chosen to allow arbitrary type names without ambiguity.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

^ permalink raw reply

* Re: [PATCH] fix kernel crash in the macvlan driver
From: Ani Sinha @ 2012-06-07 20:37 UTC (permalink / raw)
  To: Eric W. Biederman; +Cc: netdev, Francesco Ruggeri
In-Reply-To: <87bokux5po.fsf@xmission.com>

Hi Eric :

On Thu, 7 Jun 2012, Eric W. Biederman wrote:

> I don't completely follow the logic of your change.  Crashing in
> macvlan_addr_busy does seem to indicate you are using a corrupted data
> structure.

The logic of my change is as follows :

As far as I can see, macvlan_newlink() pairs with macvlan_dellink(). If
you are incrementing the reference count in newlink(), the corresponding
decrement should be, in my opinion in dellink(). If you are derementing
the count in uninit(), you are asuming that for every dellink() call,
there is a corresponding uninit() call. I am not sure if this assumption
is correct. Perhaps you can shed some more lights on this.

Now since, macvlan_common_newlink() symbol has been exported but dellink() is not, it
is possible to call the common_newlink() from some GPL driver code and
increment the reference count which will not have a corresponding
decrement. I am not sure what can be done about this issue either.

>
> My compiled version of macvlan_addr_busy is much smaller than yours so I
> can't guess based on your disassembly what is wrong.  But by reading the
> code it must either be port->dev->dev_addr or the rcu
> macvlan_hash_lookup.

Yes, the corruption is in port->dev->dev_addr. The dev_addr seems to get a
bogus address value.


> I might just be dense today but I can't possibly see how moving that
> decrement would solve the crash you have reported below.

In my tests, I have confirmed that with my change, the crash I reported is
no longer reproducable with our scripts. I have also verified that when I
pull out your d5cd92448fded change, I can also no longer reproduce the
issue. So I believe that the crash is related to the above change.
However, I am not very familier with the code in the macvlan
driver, so I can not say for sure that the fix I made genuinely solves the
problem.

Cheers,
Ani

^ permalink raw reply

* Re: [PATCH v10] tilegx network driver: initial support
From: David Miller @ 2012-06-07 20:39 UTC (permalink / raw)
  To: cmetcalf; +Cc: eric.dumazet, bhutchings, arnd, linux-kernel, netdev
In-Reply-To: <201206072031.q57KV0NG029301@farm-0023.internal.tilera.com>

From: Chris Metcalf <cmetcalf@tilera.com>
Date: Fri, 6 Apr 2012 16:42:03 -0400

> Date: Fri, 6 Apr 2012 16:42:03 -0400

You did not commit this file on April 6th.

Please don't use the date emitted by the GIT tools, just
let the email use the natural correct date which is the
one at the time you send the email out.

Otherwise your patch gets misordered as automated tools like
patchwork think this file should go all the way at the back
of the patch queue because of it's old date relative to
other pending patches.

^ permalink raw reply

* Re: [V2 RFC net-next PATCH 2/2] virtio_net: export more statistics through ethtool
From: Rick Jones @ 2012-06-07 20:39 UTC (permalink / raw)
  To: Ben Hutchings; +Cc: mst, netdev, linux-kernel, virtualization, David Miller
In-Reply-To: <1339100649.2770.20.camel@bwh-desktop.uk.solarflarecom.com>

On 06/07/2012 01:24 PM, Ben Hutchings wrote:
> On Thu, 2012-06-07 at 13:05 -0700, David Miller wrote:
>> From: Ben Hutchings<bhutchings@solarflare.com>
>> Date: Thu, 7 Jun 2012 18:15:06 +0100
>>
>>> I would really like to see some sort of convention for presenting
>>> per-queue statistics through ethtool.  At the moment we have a complete
>>> mess of different formats:
>>
>> Indeed.  Probably ${QUEUE_TYPE}-${INDEX}-${STATISTIC} is best.
>> With an agreed upon list of queue types such as "rx", "tx", "rxtx"
>> etc.
>
> I think we should leave the type names open-ended, as there are other
> useful groupings like per-virtual-port.  In that case the separator
> should be chosen to allow arbitrary type names without ambiguity.

So you mean like something along the lines of the presence of say '.' 
indicating indent a level:

rx_bytes:  1234
     myqueue1.rx_bytes: 234
     myqueue2.rx_bytes: 345
     ...

rick jones

^ permalink raw reply

* Re: [PATCH v10] tilegx network driver: initial support
From: Chris Metcalf @ 2012-06-07 20:44 UTC (permalink / raw)
  To: David Miller; +Cc: eric.dumazet, bhutchings, arnd, linux-kernel, netdev
In-Reply-To: <20120607.133900.1764130639940088009.davem@davemloft.net>

On 6/7/2012 4:39 PM, David Miller wrote:
> From: Chris Metcalf <cmetcalf@tilera.com>
> Date: Fri, 6 Apr 2012 16:42:03 -0400
>
>> Date: Fri, 6 Apr 2012 16:42:03 -0400
> You did not commit this file on April 6th.
>
> Please don't use the date emitted by the GIT tools, just
> let the email use the natural correct date which is the
> one at the time you send the email out.
>
> Otherwise your patch gets misordered as automated tools like
> patchwork think this file should go all the way at the back
> of the patch queue because of it's old date relative to
> other pending patches.

Yes, when I use "git rebase" to merge changes into the earlier patch, this
is the behavior I see.  I don't know if there's some way to tell git to
take the date on the later change instead when I "squash" them.  Or if,
perhaps, there is some other workflow I should be using.  It does seem like
the git history should reflect the latest time.

The issue of the date on the email is separate.  I tend to use "git
format-patch" to start with, munge up the headers to jam in some
"In-Reply-To" and "References" lines, manually update the "Date:", then
feed it to "sendmail -t".  Perhaps there's a different workflow I should be
using there, too.  (I tried deleting the "Date", but the one time I tried
that I ended up with some surprisingly bogus date in the email that hit
LKML, so I've been avoiding that approach.)

I'll resend the patch without a Date: line and see how it ends up this time.

-- 
Chris Metcalf, Tilera Corp.
http://www.tilera.com

^ permalink raw reply

* [PATCH v10] tilegx network driver: initial support
From: Chris Metcalf @ 2012-06-07 20:45 UTC (permalink / raw)
  To: David Miller, eric.dumazet, bhutchings, arnd, linux-kernel,
	netdev
In-Reply-To: <20120606.115440.1245419453265419850.davem@davemloft.net>

This change adds support for the tilegx network driver based on the
GXIO IORPC support in the tilegx software stack, using the on-chip
mPIPE packet processing engine.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
---
This version makes the driver multi-queued and support non-zero
tx_queue_len.  I also made a couple of magic numbers into #defines.
I skimmed the tg3.c driver, but didn't see any other obvious
changes that would be appropriate.

 drivers/net/ethernet/tile/Kconfig  |    2 +
 drivers/net/ethernet/tile/Makefile |    4 +-
 drivers/net/ethernet/tile/tilegx.c | 1898 ++++++++++++++++++++++++++++++++++++
 3 files changed, 1902 insertions(+), 2 deletions(-)
 create mode 100644 drivers/net/ethernet/tile/tilegx.c

diff --git a/drivers/net/ethernet/tile/Kconfig b/drivers/net/ethernet/tile/Kconfig
index 2d9218f..098b1c4 100644
--- a/drivers/net/ethernet/tile/Kconfig
+++ b/drivers/net/ethernet/tile/Kconfig
@@ -7,6 +7,8 @@ config TILE_NET
 	depends on TILE
 	default y
 	select CRC32
+	select TILE_GXIO_MPIPE if TILEGX
+	select HIGH_RES_TIMERS if TILEGX
 	---help---
 	  This is a standard Linux network device driver for the
 	  on-chip Tilera Gigabit Ethernet and XAUI interfaces.
diff --git a/drivers/net/ethernet/tile/Makefile b/drivers/net/ethernet/tile/Makefile
index f634f14..0ef9eef 100644
--- a/drivers/net/ethernet/tile/Makefile
+++ b/drivers/net/ethernet/tile/Makefile
@@ -4,7 +4,7 @@
 
 obj-$(CONFIG_TILE_NET) += tile_net.o
 ifdef CONFIG_TILEGX
-tile_net-objs := tilegx.o mpipe.o iorpc_mpipe.o dma_queue.o
+tile_net-y := tilegx.o
 else
-tile_net-objs := tilepro.o
+tile_net-y := tilepro.o
 endif
diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c
new file mode 100644
index 0000000..ee7556a
--- /dev/null
+++ b/drivers/net/ethernet/tile/tilegx.c
@@ -0,0 +1,1898 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>      /* printk() */
+#include <linux/slab.h>        /* kmalloc() */
+#include <linux/errno.h>       /* error codes */
+#include <linux/types.h>       /* size_t */
+#include <linux/interrupt.h>
+#include <linux/in.h>
+#include <linux/irq.h>
+#include <linux/netdevice.h>   /* struct device, and other headers */
+#include <linux/etherdevice.h> /* eth_type_trans */
+#include <linux/skbuff.h>
+#include <linux/ioctl.h>
+#include <linux/cdev.h>
+#include <linux/hugetlb.h>
+#include <linux/in6.h>
+#include <linux/timer.h>
+#include <linux/hrtimer.h>
+#include <linux/ktime.h>
+#include <linux/io.h>
+#include <linux/ctype.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+
+#include <asm/checksum.h>
+#include <asm/homecache.h>
+#include <gxio/mpipe.h>
+#include <arch/sim.h>
+
+/* Default transmit lockup timeout period, in jiffies. */
+#define TILE_NET_TIMEOUT (5 * HZ)
+
+/* The maximum number of distinct channels (idesc.channel is 5 bits). */
+#define TILE_NET_CHANNELS 32
+
+/* Maximum number of idescs to handle per "poll". */
+#define TILE_NET_BATCH 128
+
+/* Maximum number of packets to handle per "poll". */
+#define TILE_NET_WEIGHT 64
+
+/* Number of entries in each iqueue. */
+#define IQUEUE_ENTRIES 512
+
+/* Number of entries in each equeue. */
+#define EQUEUE_ENTRIES 2048
+
+/* Total header bytes per equeue slot.  Must be big enough for 2 bytes
+ * of NET_IP_ALIGN alignment, plus 14 bytes (?) of L2 header, plus up to
+ * 60 bytes of actual TCP header.  We round up to align to cache lines.
+ */
+#define HEADER_BYTES 128
+
+/* Maximum completions per cpu per device (must be a power of two).
+ * ISSUE: What is the right number here?  If this is too small, then
+ * egress might block waiting for free space in a completions array.
+ * ISSUE: At the least, allocate these only for initialized echannels.
+ */
+#define TILE_NET_MAX_COMPS 64
+
+#define MAX_FRAGS (MAX_SKB_FRAGS + 1)
+
+/* Size of completions data to allocate.
+ * ISSUE: Probably more than needed since we don't use all the channels.
+ */
+#define COMPS_SIZE (TILE_NET_CHANNELS * sizeof(struct tile_net_comps))
+
+/* Size of NotifRing data to allocate. */
+#define NOTIF_RING_SIZE (IQUEUE_ENTRIES * sizeof(gxio_mpipe_idesc_t))
+
+/* Timeout to wake the per-device TX timer after we stop the queue.
+ * We don't want the timeout too short (adds overhead, and might end
+ * up causing stop/wake/stop/wake cycles) or too long (affects performance).
+ * For the 10 Gb NIC, 30 usec means roughly 30+ 1500-byte packets.
+ */
+#define TX_TIMER_DELAY_USEC 30
+
+/* Timeout to wake the per-cpu egress timer to free completions. */
+#define EGRESS_TIMER_DELAY_USEC 1000
+
+MODULE_AUTHOR("Tilera Corporation");
+MODULE_LICENSE("GPL");
+
+/* A "packet fragment" (a chunk of memory). */
+struct frag {
+	void *buf;
+	size_t length;
+};
+
+/* A single completion. */
+struct tile_net_comp {
+	/* The "complete_count" when the completion will be complete. */
+	s64 when;
+	/* The buffer to be freed when the completion is complete. */
+	struct sk_buff *skb;
+};
+
+/* The completions for a given cpu and echannel. */
+struct tile_net_comps {
+	/* The completions. */
+	struct tile_net_comp comp_queue[TILE_NET_MAX_COMPS];
+	/* The number of completions used. */
+	unsigned long comp_next;
+	/* The number of completions freed. */
+	unsigned long comp_last;
+};
+
+/* The transmit wake timer for a given cpu and echannel. */
+struct tile_net_tx_wake {
+	struct hrtimer timer;
+	struct net_device *dev;
+};
+	
+/* Info for a specific cpu. */
+struct tile_net_info {
+	/* The NAPI struct. */
+	struct napi_struct napi;
+	/* Packet queue. */
+	gxio_mpipe_iqueue_t iqueue;
+	/* Our cpu. */
+	int my_cpu;
+	/* True if iqueue is valid. */
+	bool has_iqueue;
+	/* NAPI flags. */
+	bool napi_added;
+	bool napi_enabled;
+	/* Number of small sk_buffs which must still be provided. */
+	unsigned int num_needed_small_buffers;
+	/* Number of large sk_buffs which must still be provided. */
+	unsigned int num_needed_large_buffers;
+	/* A timer for handling egress completions. */
+	struct hrtimer egress_timer;
+	/* True if "egress_timer" is scheduled. */
+	bool egress_timer_scheduled;
+	/* Comps for each egress channel. */
+	struct tile_net_comps *comps_for_echannel[TILE_NET_CHANNELS];
+	/* Transmit wake timer for each egress channel. */
+	struct tile_net_tx_wake tx_wake[TILE_NET_CHANNELS];
+};
+
+/* Info for egress on a particular egress channel. */
+struct tile_net_egress {
+	/* The "equeue". */
+	gxio_mpipe_equeue_t *equeue;
+	/* The headers for TSO. */
+	unsigned char *headers;
+};
+
+/* Info for a specific device. */
+struct tile_net_priv {
+	/* Our network device. */
+	struct net_device *dev;
+	/* The primary link. */
+	gxio_mpipe_link_t link;
+	/* The primary channel, if open, else -1. */
+	int channel;
+	/* The "loopify" egress link, if needed. */
+	gxio_mpipe_link_t loopify_link;
+	/* The "loopify" egress channel, if open, else -1. */
+	int loopify_channel;
+	/* The egress channel (channel or loopify_channel). */
+	int echannel;
+	/* Total stats. */
+	struct net_device_stats stats;
+};
+
+/* Egress info, indexed by "priv->echannel" (lazily created as needed). */
+static struct tile_net_egress egress_for_echannel[TILE_NET_CHANNELS];
+
+/* Devices currently associated with each channel.
+ * NOTE: The array entry can become NULL after ifconfig down, but
+ * we do not free the underlying net_device structures, so it is
+ * safe to use a pointer after reading it from this array.
+ */
+static struct net_device *tile_net_devs_for_channel[TILE_NET_CHANNELS];
+
+/* A mutex for "tile_net_devs_for_channel". */
+static DEFINE_MUTEX(tile_net_devs_for_channel_mutex);
+
+/* The per-cpu info. */
+static DEFINE_PER_CPU(struct tile_net_info, per_cpu_info);
+
+/* The "context" for all devices. */
+static gxio_mpipe_context_t context;
+
+/* Buffer sizes and mpipe enum codes for buffer stacks.
+ * See arch/tile/include/gxio/mpipe.h for the set of possible values.
+ */
+#define BUFFER_SIZE_SMALL_ENUM GXIO_MPIPE_BUFFER_SIZE_128
+#define BUFFER_SIZE_SMALL 128
+#define BUFFER_SIZE_LARGE_ENUM GXIO_MPIPE_BUFFER_SIZE_1664
+#define BUFFER_SIZE_LARGE 1664
+
+/* The small/large "buffer stacks". */
+static int small_buffer_stack = -1;
+static int large_buffer_stack = -1;
+
+/* Amount of memory allocated for each buffer stack. */
+static size_t buffer_stack_size;
+
+/* The actual memory allocated for the buffer stacks. */
+static void *small_buffer_stack_va;
+static void *large_buffer_stack_va;
+
+/* The buckets. */
+static int first_bucket = -1;
+static int num_buckets = 1;
+
+/* The ingress irq. */
+static int ingress_irq = -1;
+
+/* Text value of tile_net.cpus if passed as a module parameter. */
+static char *network_cpus_string;
+
+/* The actual cpus in "network_cpus". */
+static struct cpumask network_cpus_map;
+
+/* If "loopify=LINK" was specified, this is "LINK". */
+static char *loopify_link_name;
+
+/* If "tile_net.custom" was specified, this is non-NULL. */
+static char *custom_str;
+
+/* The "tile_net.cpus" argument specifies the cpus that are dedicated
+ * to handle ingress packets.
+ *
+ * The parameter should be in the form "tile_net.cpus=m-n[,x-y]", where
+ * m, n, x, y are integer numbers that represent the cpus that can be
+ * neither a dedicated cpu nor a dataplane cpu.
+ */
+static bool network_cpus_init(void)
+{
+	char buf[1024];
+	int rc;
+
+	if (network_cpus_string == NULL)
+		return false;
+
+	rc = cpulist_parse_crop(network_cpus_string, &network_cpus_map);
+	if (rc != 0) {
+		pr_warn("tile_net.cpus=%s: malformed cpu list\n",
+			network_cpus_string);
+		return false;
+	}
+
+	/* Remove dedicated cpus. */
+	cpumask_and(&network_cpus_map, &network_cpus_map, cpu_possible_mask);
+
+	if (cpumask_empty(&network_cpus_map)) {
+		pr_warn("Ignoring empty tile_net.cpus='%s'.\n",
+			network_cpus_string);
+		return false;
+	}
+
+	cpulist_scnprintf(buf, sizeof(buf), &network_cpus_map);
+	pr_info("Linux network CPUs: %s\n", buf);
+	return true;
+}
+
+module_param_named(cpus, network_cpus_string, charp, 0444);
+MODULE_PARM_DESC(cpus, "cpulist of cores that handle network interrupts");
+
+/* The "tile_net.loopify=LINK" argument causes the named device to
+ * actually use "loop0" for ingress, and "loop1" for egress.  This
+ * allows an app to sit between the actual link and linux, passing
+ * (some) packets along to linux, and forwarding (some) packets sent
+ * out by linux.
+ */
+module_param_named(loopify, loopify_link_name, charp, 0444);
+MODULE_PARM_DESC(loopify, "name the device to use loop0/1 for ingress/egress");
+
+/* The "tile_net.custom" argument causes us to ignore the "conventional"
+ * classifier metadata, in particular, the "l2_offset".
+ */
+module_param_named(custom, custom_str, charp, 0444);
+MODULE_PARM_DESC(custom, "indicates a (heavily) customized classifier");
+
+/* Atomically update a statistics field.
+ * Note that on TILE-Gx, this operation is fire-and-forget on the
+ * issuing core (single-cycle dispatch) and takes only a few cycles
+ * longer than a regular store when the request reaches the home cache.
+ * No expensive bus management overhead is required.
+ */
+static void tile_net_stats_add(unsigned long value, unsigned long *field)
+{
+	BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(unsigned long));
+	atomic_long_add(value, (atomic_long_t *)field);
+}
+
+/* Allocate and push a buffer. */
+static bool tile_net_provide_buffer(bool small)
+{
+	int stack = small ? small_buffer_stack : large_buffer_stack;
+	const unsigned long buffer_alignment = 128;
+	struct sk_buff *skb;
+	int len;
+
+	len = sizeof(struct sk_buff **) + buffer_alignment;
+	len += (small ? BUFFER_SIZE_SMALL : BUFFER_SIZE_LARGE);
+	skb = dev_alloc_skb(len);
+	if (skb == NULL)
+		return false;
+
+	/* Make room for a back-pointer to 'skb' and guarantee alignment. */
+	skb_reserve(skb, sizeof(struct sk_buff **));
+	skb_reserve(skb, -(long)skb->data & (buffer_alignment - 1));
+
+	/* Save a back-pointer to 'skb'. */
+	*(struct sk_buff **)(skb->data - sizeof(struct sk_buff **)) = skb;
+
+	/* Make sure "skb" and the back-pointer have been flushed. */
+	wmb();
+
+	gxio_mpipe_push_buffer(&context, stack,
+			       (void *)va_to_tile_io_addr(skb->data));
+
+	return true;
+}
+
+/* Convert a raw mpipe buffer to its matching skb pointer. */
+static struct sk_buff *mpipe_buf_to_skb(void *va)
+{
+	/* Acquire the associated "skb". */
+	struct sk_buff **skb_ptr = va - sizeof(*skb_ptr);
+	struct sk_buff *skb = *skb_ptr;
+
+	/* Paranoia. */
+	if (skb->data != va) {
+		/* Panic here since there's a reasonable chance
+		 * that corrupt buffers means generic memory
+		 * corruption, with unpredictable system effects.
+		 */
+		panic("Corrupt linux buffer! va=%p, skb=%p, skb->data=%p",
+		      va, skb, skb->data);
+	}
+
+	return skb;
+}
+
+static void tile_net_pop_all_buffers(int stack)
+{
+	for (;;) {
+		tile_io_addr_t addr =
+			(tile_io_addr_t)gxio_mpipe_pop_buffer(&context, stack);
+		if (addr == 0)
+			break;
+		dev_kfree_skb_irq(mpipe_buf_to_skb(tile_io_addr_to_va(addr)));
+	}
+}
+
+/* Provide linux buffers to mPIPE. */
+static void tile_net_provide_needed_buffers(void)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+
+	while (info->num_needed_small_buffers != 0) {
+		if (!tile_net_provide_buffer(true))
+			goto oops;
+		info->num_needed_small_buffers--;
+	}
+
+	while (info->num_needed_large_buffers != 0) {
+		if (!tile_net_provide_buffer(false))
+			goto oops;
+		info->num_needed_large_buffers--;
+	}
+
+	return;
+
+oops:
+	/* Add a description to the page allocation failure dump. */
+	pr_notice("Tile %d still needs some buffers\n", info->my_cpu);
+}
+
+static inline bool filter_packet(struct net_device *dev, void *buf)
+{
+	/* Filter packets received before we're up. */
+	if (dev == NULL || !(dev->flags & IFF_UP))
+		return true;
+
+	/* Filter out packets that aren't for us. */
+	if (!(dev->flags & IFF_PROMISC) &&
+	    !is_multicast_ether_addr(buf) &&
+	    compare_ether_addr(dev->dev_addr, buf) != 0)
+		return true;
+
+	return false;
+}
+
+static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb,
+				 gxio_mpipe_idesc_t *idesc, unsigned long len)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_priv *priv = netdev_priv(dev);
+
+	/* Encode the actual packet length. */
+	skb_put(skb, len);
+
+	skb->protocol = eth_type_trans(skb, dev);
+
+	/* Acknowledge "good" hardware checksums. */
+	if (idesc->cs && idesc->csum_seed_val == 0xFFFF)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	netif_receive_skb(skb);
+
+	/* Update stats. */
+	tile_net_stats_add(1, &priv->stats.rx_packets);
+	tile_net_stats_add(len, &priv->stats.rx_bytes);
+
+	/* Need a new buffer. */
+	if (idesc->size == BUFFER_SIZE_SMALL_ENUM)
+		info->num_needed_small_buffers++;
+	else
+		info->num_needed_large_buffers++;
+}
+
+/* Handle a packet.  Return true if "processed", false if "filtered". */
+static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct net_device *dev = tile_net_devs_for_channel[idesc->channel];
+	uint8_t l2_offset;
+	void *va;
+	void *buf;
+	unsigned long len;
+	bool filter;
+
+	/* Drop packets for which no buffer was available.
+	 * NOTE: This happens under heavy load.
+	 */
+	if (idesc->be) {
+		struct tile_net_priv *priv = netdev_priv(dev);
+		tile_net_stats_add(1, &priv->stats.rx_dropped);
+		gxio_mpipe_iqueue_consume(&info->iqueue, idesc);
+		if (net_ratelimit())
+			pr_info("Dropping packet (insufficient buffers).\n");
+		return false;
+	}
+
+	/* Get the "l2_offset", if allowed. */
+	l2_offset = custom_str ? 0 : gxio_mpipe_idesc_get_l2_offset(idesc);
+
+	/* Get the raw buffer VA (includes "headroom"). */
+	va = tile_io_addr_to_va((unsigned long)(long)idesc->va);
+
+	/* Get the actual packet start/length. */
+	buf = va + l2_offset;
+	len = idesc->l2_size - l2_offset;
+
+	/* Point "va" at the raw buffer. */
+	va -= NET_IP_ALIGN;
+
+	filter = filter_packet(dev, buf);
+	if (filter) {
+		gxio_mpipe_iqueue_drop(&info->iqueue, idesc);
+	} else {
+		struct sk_buff *skb = mpipe_buf_to_skb(va);
+
+		/* Skip headroom, and any custom header. */
+		skb_reserve(skb, NET_IP_ALIGN + l2_offset);
+
+		tile_net_receive_skb(dev, skb, idesc, len);
+	}
+
+	gxio_mpipe_iqueue_consume(&info->iqueue, idesc);
+	return !filter;
+}
+
+/* Handle some packets for the current CPU.
+ *
+ * This function handles up to TILE_NET_BATCH idescs per call.
+ *
+ * ISSUE: Since we do not provide new buffers until this function is
+ * complete, we must initially provide enough buffers for each network
+ * cpu to fill its iqueue and also its batched idescs.
+ *
+ * ISSUE: The "rotting packet" race condition occurs if a packet
+ * arrives after the queue appears to be empty, and before the
+ * hypervisor interrupt is re-enabled.
+ */
+static int tile_net_poll(struct napi_struct *napi, int budget)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	unsigned int work = 0;
+	gxio_mpipe_idesc_t *idesc;
+	int i, n;
+
+	/* Process packets. */
+	while ((n = gxio_mpipe_iqueue_try_peek(&info->iqueue, &idesc)) > 0) {
+		for (i = 0; i < n; i++) {
+			if (i == TILE_NET_BATCH)
+				goto done;
+			if (tile_net_handle_packet(idesc + i)) {
+				if (++work >= budget)
+					goto done;
+			}
+		}
+	}
+
+	/* There are no packets left. */
+	napi_complete(&info->napi);
+
+	/* Re-enable hypervisor interrupts. */
+	gxio_mpipe_enable_notif_ring_interrupt(&context, info->iqueue.ring);
+
+	/* HACK: Avoid the "rotting packet" problem. */
+	if (gxio_mpipe_iqueue_try_peek(&info->iqueue, &idesc) > 0)
+		napi_schedule(&info->napi);
+
+	/* ISSUE: Handle completions? */
+
+done:
+	tile_net_provide_needed_buffers();
+
+	return work;
+}
+
+/* Handle an ingress interrupt on the current cpu. */
+static irqreturn_t tile_net_handle_ingress_irq(int irq, void *unused)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	napi_schedule(&info->napi);
+	return IRQ_HANDLED;
+}
+
+/* Free some completions.  This must be called with interrupts blocked. */
+static int tile_net_free_comps(gxio_mpipe_equeue_t *equeue,
+				struct tile_net_comps *comps,
+				int limit, bool force_update)
+{
+	int n = 0;
+	while (comps->comp_last < comps->comp_next) {
+		unsigned int cid = comps->comp_last % TILE_NET_MAX_COMPS;
+		struct tile_net_comp *comp = &comps->comp_queue[cid];
+		if (!gxio_mpipe_equeue_is_complete(equeue, comp->when,
+						   force_update || n == 0))
+			break;
+		dev_kfree_skb_irq(comp->skb);
+		comps->comp_last++;
+		if (++n == limit)
+			break;
+	}
+	return n;
+}
+
+/* Add a completion.  This must be called with interrupts blocked.
+ * tile_net_equeue_try_reserve() will have ensured a free completion entry.
+ */
+static void add_comp(gxio_mpipe_equeue_t *equeue,
+		     struct tile_net_comps *comps,
+		     uint64_t when, struct sk_buff *skb)
+{
+	int cid = comps->comp_next % TILE_NET_MAX_COMPS;
+	comps->comp_queue[cid].when = when;
+	comps->comp_queue[cid].skb = skb;
+	comps->comp_next++;
+}
+
+static void tile_net_schedule_tx_wake_timer(struct net_device *dev)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_priv *priv = netdev_priv(dev);
+
+	hrtimer_start(&info->tx_wake[priv->echannel].timer,
+		      ktime_set(0, TX_TIMER_DELAY_USEC * 1000UL),
+		      HRTIMER_MODE_REL_PINNED);
+}
+
+static enum hrtimer_restart tile_net_handle_tx_wake_timer(struct hrtimer *t)
+{
+	struct tile_net_tx_wake *tx_wake =
+		container_of(t, struct tile_net_tx_wake, timer);
+	netif_wake_subqueue(tx_wake->dev, smp_processor_id());
+	return HRTIMER_NORESTART;
+}
+
+/* Make sure the egress timer is scheduled. */
+static void tile_net_schedule_egress_timer(void)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+
+	if (!info->egress_timer_scheduled) {
+		hrtimer_start(&info->egress_timer,
+			      ktime_set(0, EGRESS_TIMER_DELAY_USEC * 1000UL),
+			      HRTIMER_MODE_REL_PINNED);
+		info->egress_timer_scheduled = true;
+	}
+}
+
+/* The "function" for "info->egress_timer".
+ *
+ * This timer will reschedule itself as long as there are any pending
+ * completions expected for this tile.
+ */
+static enum hrtimer_restart tile_net_handle_egress_timer(struct hrtimer *t)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	unsigned long irqflags;
+	bool pending = false;
+	int i;
+
+	local_irq_save(irqflags);
+
+	/* The timer is no longer scheduled. */
+	info->egress_timer_scheduled = false;
+
+	/* Free all possible comps for this tile. */
+	for (i = 0; i < TILE_NET_CHANNELS; i++) {
+		struct tile_net_egress *egress = &egress_for_echannel[i];
+		struct tile_net_comps *comps = info->comps_for_echannel[i];
+		if (comps->comp_last >= comps->comp_next)
+			continue;
+		tile_net_free_comps(egress->equeue, comps, -1, true);
+		pending = pending || (comps->comp_last < comps->comp_next);
+	}
+
+	/* Reschedule timer if needed. */
+	if (pending)
+		tile_net_schedule_egress_timer();
+
+	local_irq_restore(irqflags);
+
+	return HRTIMER_NORESTART;
+}
+
+/* Helper function for "tile_net_update()".
+ * "dev" (i.e. arg) is the device being brought up or down,
+ * or NULL if all devices are now down.
+ */
+static void tile_net_update_cpu(void *arg)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct net_device *dev = arg;
+
+	if (!info->has_iqueue)
+		return;
+
+	if (dev != NULL) {
+		if (!info->napi_added) {
+			netif_napi_add(dev, &info->napi,
+				       tile_net_poll, TILE_NET_WEIGHT);
+			info->napi_added = true;
+		}
+		if (!info->napi_enabled) {
+			napi_enable(&info->napi);
+			info->napi_enabled = true;
+		}
+		enable_percpu_irq(ingress_irq, 0);
+	} else {
+		disable_percpu_irq(ingress_irq);
+		if (info->napi_enabled) {
+			napi_disable(&info->napi);
+			info->napi_enabled = false;
+		}
+		/* FIXME: Drain the iqueue. */
+	}
+}
+
+/* Helper function for tile_net_open() and tile_net_stop().
+ * Always called under tile_net_devs_for_channel_mutex.
+ */
+static int tile_net_update(struct net_device *dev)
+{
+	static gxio_mpipe_rules_t rules;  /* too big to fit on the stack */
+	bool saw_channel = false;
+	int channel;
+	int rc;
+	int cpu;
+
+	gxio_mpipe_rules_init(&rules, &context);
+
+	for (channel = 0; channel < TILE_NET_CHANNELS; channel++) {
+		if (tile_net_devs_for_channel[channel] == NULL)
+			continue;
+		if (!saw_channel) {
+			saw_channel = true;
+			gxio_mpipe_rules_begin(&rules, first_bucket,
+					       num_buckets, NULL);
+			gxio_mpipe_rules_set_headroom(&rules, NET_IP_ALIGN);
+		}
+		gxio_mpipe_rules_add_channel(&rules, channel);
+	}
+
+	/* NOTE: This can fail if there is no classifier.
+	 * ISSUE: Can anything else cause it to fail?
+	 */
+	rc = gxio_mpipe_rules_commit(&rules);
+	if (rc != 0) {
+		netdev_warn(dev, "gxio_mpipe_rules_commit failed: %d\n", rc);
+		return -EIO;
+	}
+
+	/* Update all cpus, sequentially (to protect "netif_napi_add()"). */
+	for_each_online_cpu(cpu)
+		smp_call_function_single(cpu, tile_net_update_cpu,
+					 (saw_channel ? dev : NULL), 1);
+
+	/* HACK: Allow packets to flow in the simulator. */
+	if (saw_channel)
+		sim_enable_mpipe_links(0, -1);
+
+	return 0;
+}
+
+/* Allocate and initialize mpipe buffer stacks, and register them in
+ * the mPIPE TLBs, for both small and large packet sizes.
+ * This routine supports tile_net_init_mpipe(), below.
+ */
+static int init_buffer_stacks(struct net_device *dev, int num_buffers)
+{
+	pte_t hash_pte = pte_set_home((pte_t) { 0 }, PAGE_HOME_HASH);
+	int rc;
+
+	/* Compute stack bytes; we round up to 64KB and then use
+	 * alloc_pages() so we get the required 64KB alignment as well.
+	 */
+	buffer_stack_size =
+		ALIGN(gxio_mpipe_calc_buffer_stack_bytes(num_buffers),
+		      64 * 1024);
+
+	/* Allocate two buffer stack indices. */
+	rc = gxio_mpipe_alloc_buffer_stacks(&context, 2, 0, 0);
+	if (rc < 0) {
+		netdev_err(dev, "gxio_mpipe_alloc_buffer_stacks failed: %d\n",
+			   rc);
+		return rc;
+	}
+	small_buffer_stack = rc;
+	large_buffer_stack = rc + 1;
+
+	/* Allocate the small memory stack. */
+	small_buffer_stack_va =
+		alloc_pages_exact(buffer_stack_size, GFP_KERNEL);
+	if (small_buffer_stack_va == NULL) {
+		netdev_err(dev,
+			   "Could not alloc %zd bytes for buffer stacks\n",
+			   buffer_stack_size);
+		return -ENOMEM;
+	}
+	rc = gxio_mpipe_init_buffer_stack(&context, small_buffer_stack,
+					  BUFFER_SIZE_SMALL_ENUM,
+					  small_buffer_stack_va,
+					  buffer_stack_size, 0);
+	if (rc != 0) {
+		netdev_err(dev, "gxio_mpipe_init_buffer_stack: %d\n", rc);
+		return rc;
+	}
+	rc = gxio_mpipe_register_client_memory(&context, small_buffer_stack,
+					       hash_pte, 0);
+	if (rc != 0) {
+		netdev_err(dev,
+			   "gxio_mpipe_register_buffer_memory failed: %d\n",
+			   rc);
+		return rc;
+	}
+
+	/* Allocate the large buffer stack. */
+	large_buffer_stack_va =
+		alloc_pages_exact(buffer_stack_size, GFP_KERNEL);
+	if (large_buffer_stack_va == NULL) {
+		netdev_err(dev,
+			   "Could not alloc %zd bytes for buffer stacks\n",
+			   buffer_stack_size);
+		return -ENOMEM;
+	}
+	rc = gxio_mpipe_init_buffer_stack(&context, large_buffer_stack,
+					  BUFFER_SIZE_LARGE_ENUM,
+					  large_buffer_stack_va,
+					  buffer_stack_size, 0);
+	if (rc != 0) {
+		netdev_err(dev, "gxio_mpipe_init_buffer_stack failed: %d\n",
+			   rc);
+		return rc;
+	}
+	rc = gxio_mpipe_register_client_memory(&context, large_buffer_stack,
+					       hash_pte, 0);
+	if (rc != 0) {
+		netdev_err(dev,
+			   "gxio_mpipe_register_buffer_memory failed: %d\n",
+			   rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+/* Allocate per-cpu resources (memory for completions and idescs).
+ * This routine supports tile_net_init_mpipe(), below.
+ */
+static int alloc_percpu_mpipe_resources(struct net_device *dev,
+					int cpu, int ring)
+{
+	struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
+	int order, i, rc;
+	struct page *page;
+	void *addr;
+
+	/* Allocate the "comps". */
+	order = get_order(COMPS_SIZE);
+	page = homecache_alloc_pages(GFP_KERNEL, order, cpu);
+	if (page == NULL) {
+		netdev_err(dev, "Failed to alloc %zd bytes comps memory\n",
+			   COMPS_SIZE);
+		return -ENOMEM;
+	}
+	addr = pfn_to_kaddr(page_to_pfn(page));
+	memset(addr, 0, COMPS_SIZE);
+	for (i = 0; i < TILE_NET_CHANNELS; i++)
+		info->comps_for_echannel[i] =
+			addr + i * sizeof(struct tile_net_comps);
+
+	/* If this is a network cpu, create an iqueue. */
+	if (cpu_isset(cpu, network_cpus_map)) {
+		order = get_order(NOTIF_RING_SIZE);
+		page = homecache_alloc_pages(GFP_KERNEL, order, cpu);
+		if (page == NULL) {
+			netdev_err(dev,
+				   "Failed to alloc %zd bytes iqueue memory\n",
+				   NOTIF_RING_SIZE);
+			return -ENOMEM;
+		}
+		addr = pfn_to_kaddr(page_to_pfn(page));
+		rc = gxio_mpipe_iqueue_init(&info->iqueue, &context, ring++,
+					    addr, NOTIF_RING_SIZE, 0);
+		if (rc < 0) {
+			netdev_err(dev,
+				   "gxio_mpipe_iqueue_init failed: %d\n", rc);
+			return rc;
+		}
+		info->has_iqueue = true;
+	}
+
+	return ring;
+}
+
+/* Initialize NotifGroup and buckets.
+ * This routine supports tile_net_init_mpipe(), below.
+ */
+static int init_notif_group_and_buckets(struct net_device *dev,
+					int ring, int network_cpus_count)
+{
+	int group, rc;
+
+	/* Allocate one NotifGroup. */
+	rc = gxio_mpipe_alloc_notif_groups(&context, 1, 0, 0);
+	if (rc < 0) {
+		netdev_err(dev, "gxio_mpipe_alloc_notif_groups failed: %d\n",
+			   rc);
+		return rc;
+	}
+	group = rc;
+
+	/* Initialize global num_buckets value. */
+	if (network_cpus_count > 4)
+		num_buckets = 256;
+	else if (network_cpus_count > 1)
+		num_buckets = 16;
+
+	/* Allocate some buckets, and set global first_bucket value. */
+	rc = gxio_mpipe_alloc_buckets(&context, num_buckets, 0, 0);
+	if (rc < 0) {
+		netdev_err(dev, "gxio_mpipe_alloc_buckets failed: %d\n", rc);
+		return rc;
+	}
+	first_bucket = rc;
+
+	/* Init group and buckets. */
+	rc = gxio_mpipe_init_notif_group_and_buckets(
+		&context, group, ring, network_cpus_count,
+		first_bucket, num_buckets,
+		GXIO_MPIPE_BUCKET_STICKY_FLOW_LOCALITY);
+	if (rc != 0) {
+		netdev_err(
+			dev,
+			"gxio_mpipe_init_notif_group_and_buckets failed: %d\n",
+			rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+/* Create an irq and register it, then activate the irq and request
+ * interrupts on all cores.  Note that "ingress_irq" being initialized
+ * is how we know not to call tile_net_init_mpipe() again.
+ * This routine supports tile_net_init_mpipe(), below.
+ */
+static int tile_net_setup_interrupts(struct net_device *dev)
+{
+	int cpu, rc;
+
+	rc = create_irq();
+	if (rc < 0) {
+		netdev_err(dev, "create_irq failed: %d\n", rc);
+		return rc;
+	}
+	ingress_irq = rc;
+	tile_irq_activate(ingress_irq, TILE_IRQ_PERCPU);
+	rc = request_irq(ingress_irq, tile_net_handle_ingress_irq,
+			 0, NULL, NULL);
+	if (rc != 0) {
+		netdev_err(dev, "request_irq failed: %d\n", rc);
+		destroy_irq(ingress_irq);
+		ingress_irq = -1;
+		return rc;
+	}
+
+	for_each_online_cpu(cpu) {
+		struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
+		if (info->has_iqueue) {
+			gxio_mpipe_request_notif_ring_interrupt(
+				&context, cpu_x(cpu), cpu_y(cpu),
+				1, ingress_irq, info->iqueue.ring);
+		}
+	}
+
+	return 0;
+}
+
+/* Undo any state set up partially by a failed call to tile_net_init_mpipe. */
+static void tile_net_init_mpipe_fail(void)
+{
+	int cpu;
+
+	/* Do cleanups that require the mpipe context first. */
+	if (small_buffer_stack >= 0)
+		tile_net_pop_all_buffers(small_buffer_stack);
+	if (large_buffer_stack >= 0)
+		tile_net_pop_all_buffers(large_buffer_stack);
+
+	/* Destroy mpipe context so the hardware no longer owns any memory. */
+	gxio_mpipe_destroy(&context);
+
+	for_each_online_cpu(cpu) {
+		struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
+		free_pages((unsigned long)(info->comps_for_echannel[0]),
+			   get_order(COMPS_SIZE));
+		info->comps_for_echannel[0] = NULL;
+		free_pages((unsigned long)(info->iqueue.idescs),
+			   get_order(NOTIF_RING_SIZE));
+		info->iqueue.idescs = NULL;
+	}
+
+	if (small_buffer_stack_va)
+		free_pages_exact(small_buffer_stack_va, buffer_stack_size);
+	if (large_buffer_stack_va)
+		free_pages_exact(large_buffer_stack_va, buffer_stack_size);
+
+	small_buffer_stack_va = NULL;
+	large_buffer_stack_va = NULL;
+	large_buffer_stack = -1;
+	small_buffer_stack = -1;
+	first_bucket = -1;
+}
+
+/* The first time any tilegx network device is opened, we initialize
+ * the global mpipe state.  If this step fails, we fail to open the
+ * device, but if it succeeds, we never need to do it again, and since
+ * tile_net can't be unloaded, we never undo it.
+ *
+ * Note that some resources in this path (buffer stack indices,
+ * bindings from init_buffer_stack, etc.) are hypervisor resources
+ * that are freed implicitly by gxio_mpipe_destroy().
+ */
+static int tile_net_init_mpipe(struct net_device *dev)
+{
+	int i, num_buffers, rc;
+	int cpu;
+	int first_ring, ring;
+	int network_cpus_count = cpus_weight(network_cpus_map);
+
+	if (!hash_default) {
+		netdev_err(dev, "Networking requires hash_default!\n");
+		return -EIO;
+	}
+
+	rc = gxio_mpipe_init(&context, 0);
+	if (rc != 0) {
+		netdev_err(dev, "gxio_mpipe_init failed: %d\n", rc);
+		return -EIO;
+	}
+
+	/* Set up the buffer stacks. */
+	num_buffers =
+		network_cpus_count * (IQUEUE_ENTRIES + TILE_NET_BATCH);
+	rc = init_buffer_stacks(dev, num_buffers);
+	if (rc != 0)
+		goto fail;
+
+	/* Provide initial buffers. */
+	rc = -ENOMEM;
+	for (i = 0; i < num_buffers; i++) {
+		if (!tile_net_provide_buffer(true)) {
+			netdev_err(dev, "Cannot allocate initial sk_bufs!\n");
+			goto fail;
+		}
+	}
+	for (i = 0; i < num_buffers; i++) {
+		if (!tile_net_provide_buffer(false)) {
+			netdev_err(dev, "Cannot allocate initial sk_bufs!\n");
+			goto fail;
+		}
+	}
+
+	/* Allocate one NotifRing for each network cpu. */
+	rc = gxio_mpipe_alloc_notif_rings(&context, network_cpus_count, 0, 0);
+	if (rc < 0) {
+		netdev_err(dev, "gxio_mpipe_alloc_notif_rings failed %d\n",
+			   rc);
+		goto fail;
+	}
+
+	/* Init NotifRings per-cpu. */
+	first_ring = rc;
+	ring = first_ring;
+	for_each_online_cpu(cpu) {
+		rc = alloc_percpu_mpipe_resources(dev, cpu, ring);
+		if (rc < 0)
+			goto fail;
+		ring = rc;
+	}
+
+	/* Initialize NotifGroup and buckets. */
+	rc = init_notif_group_and_buckets(dev, first_ring, network_cpus_count);
+	if (rc != 0)
+		goto fail;
+
+	/* Create and enable interrupts. */
+	rc = tile_net_setup_interrupts(dev);
+	if (rc != 0)
+		goto fail;
+
+	return 0;
+
+fail:
+	tile_net_init_mpipe_fail();
+	return rc;
+}
+
+/* Create persistent egress info for a given egress channel.
+ * Note that this may be shared between, say, "gbe0" and "xgbe0".
+ * ISSUE: Defer header allocation until TSO is actually needed?
+ */
+static int tile_net_init_egress(struct net_device *dev, int echannel)
+{
+	struct page *headers_page, *edescs_page, *equeue_page;
+	gxio_mpipe_edesc_t *edescs;
+	gxio_mpipe_equeue_t *equeue;
+	unsigned char *headers;
+	int headers_order, edescs_order, equeue_order;
+	size_t edescs_size;
+	int edma;
+	int rc = -ENOMEM;
+
+	/* Only initialize once. */
+	if (egress_for_echannel[echannel].equeue != NULL)
+		return 0;
+
+	/* Allocate memory for the "headers". */
+	headers_order = get_order(EQUEUE_ENTRIES * HEADER_BYTES);
+	headers_page = alloc_pages(GFP_KERNEL, headers_order);
+	if (headers_page == NULL) {
+		netdev_warn(dev,
+			    "Could not alloc %zd bytes for TSO headers.\n",
+			    PAGE_SIZE << headers_order);
+		goto fail;
+	}
+	headers = pfn_to_kaddr(page_to_pfn(headers_page));
+
+	/* Allocate memory for the "edescs". */
+	edescs_size = EQUEUE_ENTRIES * sizeof(*edescs);
+	edescs_order = get_order(edescs_size);
+	edescs_page = alloc_pages(GFP_KERNEL, edescs_order);
+	if (edescs_page == NULL) {
+		netdev_warn(dev,
+			    "Could not alloc %zd bytes for eDMA ring.\n",
+			    edescs_size);
+		goto fail_headers;
+	}
+	edescs = pfn_to_kaddr(page_to_pfn(edescs_page));
+
+	/* Allocate memory for the "equeue". */
+	equeue_order = get_order(sizeof(*equeue));
+	equeue_page = alloc_pages(GFP_KERNEL, equeue_order);
+	if (equeue_page == NULL) {
+		netdev_warn(dev,
+			    "Could not alloc %zd bytes for equeue info.\n",
+			    PAGE_SIZE << equeue_order);
+		goto fail_edescs;
+	}
+	equeue = pfn_to_kaddr(page_to_pfn(equeue_page));
+
+	/* Allocate an edma ring.  Note that in practice this can't
+	 * fail, which is good, because we will leak an edma ring if so.
+	 */
+	rc = gxio_mpipe_alloc_edma_rings(&context, 1, 0, 0);
+	if (rc < 0) {
+		netdev_warn(dev, "gxio_mpipe_alloc_edma_rings failed: %d\n",
+			    rc);
+		goto fail_equeue;
+	}
+	edma = rc;
+
+	/* Initialize the equeue. */
+	rc = gxio_mpipe_equeue_init(equeue, &context, edma, echannel,
+				    edescs, edescs_size, 0);
+	if (rc != 0) {
+		netdev_err(dev, "gxio_mpipe_equeue_init failed: %d\n", rc);
+		goto fail_equeue;
+	}
+
+	/* Done. */
+	egress_for_echannel[echannel].equeue = equeue;
+	egress_for_echannel[echannel].headers = headers;
+	return 0;
+
+fail_equeue:
+	__free_pages(equeue_page, equeue_order);
+
+fail_edescs:
+	__free_pages(edescs_page, edescs_order);
+
+fail_headers:
+	__free_pages(headers_page, headers_order);
+
+fail:
+	return rc;
+}
+
+/* Return channel number for a newly-opened link. */
+static int tile_net_link_open(struct net_device *dev, gxio_mpipe_link_t *link,
+			      const char *link_name)
+{
+	int rc = gxio_mpipe_link_open(link, &context, link_name, 0);
+	if (rc < 0) {
+		netdev_err(dev, "Failed to open '%s'\n", link_name);
+		return rc;
+	}
+	rc = gxio_mpipe_link_channel(link);
+	if (rc < 0 || rc >= TILE_NET_CHANNELS) {
+		netdev_err(dev, "gxio_mpipe_link_channel bad value: %d\n", rc);
+		gxio_mpipe_link_close(link);
+		return -EINVAL;
+	}
+	return rc;
+}
+
+/* Help the kernel activate the given network interface. */
+static int tile_net_open(struct net_device *dev)
+{
+	struct tile_net_priv *priv = netdev_priv(dev);
+	int cpu, rc;
+
+	mutex_lock(&tile_net_devs_for_channel_mutex);
+
+	/* Do one-time initialization the first time any device is opened. */
+	if (ingress_irq < 0) {
+		rc = tile_net_init_mpipe(dev);
+		if (rc != 0)
+			goto fail;
+	}
+
+	/* Determine if this is the "loopify" device. */
+	if (unlikely((loopify_link_name != NULL) &&
+		     !strcmp(dev->name, loopify_link_name))) {
+		rc = tile_net_link_open(dev, &priv->link, "loop0");
+		if (rc < 0)
+			goto fail;
+		priv->channel = rc;
+		rc = tile_net_link_open(dev, &priv->loopify_link, "loop1");
+		if (rc < 0)
+			goto fail;
+		priv->loopify_channel = rc;
+		priv->echannel = rc;
+	} else {
+		rc = tile_net_link_open(dev, &priv->link, dev->name);
+		if (rc < 0)
+			goto fail;
+		priv->channel = rc;
+		priv->echannel = rc;
+	}
+
+	/* Initialize egress info (if needed).  Once ever, per echannel. */
+	rc = tile_net_init_egress(dev, priv->echannel);
+	if (rc != 0)
+		goto fail;
+
+	tile_net_devs_for_channel[priv->channel] = dev;
+
+	rc = tile_net_update(dev);
+	if (rc != 0)
+		goto fail;
+
+	mutex_unlock(&tile_net_devs_for_channel_mutex);
+
+	/* Initialize the transmit wake timer for this device for each cpu. */
+	for_each_online_cpu(cpu) {
+		struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
+		struct tile_net_tx_wake *tx_wake =
+			&info->tx_wake[priv->echannel];
+
+		hrtimer_init(&tx_wake->timer, CLOCK_MONOTONIC,
+			     HRTIMER_MODE_REL);
+		tx_wake->timer.function = tile_net_handle_tx_wake_timer;
+		tx_wake->dev = dev;
+	}
+
+	for_each_online_cpu(cpu)
+		netif_start_subqueue(dev, cpu);
+	netif_carrier_on(dev);
+	return 0;
+
+fail:
+	if (priv->loopify_channel >= 0) {
+		if (gxio_mpipe_link_close(&priv->loopify_link) != 0)
+			netdev_warn(dev, "Failed to close loopify link!\n");
+		priv->loopify_channel = -1;
+	}
+	if (priv->channel >= 0) {
+		if (gxio_mpipe_link_close(&priv->link) != 0)
+			netdev_warn(dev, "Failed to close link!\n");
+		priv->channel = -1;
+	}
+	priv->echannel = -1;
+	tile_net_devs_for_channel[priv->channel] = NULL;
+	mutex_unlock(&tile_net_devs_for_channel_mutex);
+
+	/* Don't return raw gxio error codes to generic Linux. */
+	return (rc > -512) ? rc : -EIO;
+}
+
+/* Help the kernel deactivate the given network interface. */
+static int tile_net_stop(struct net_device *dev)
+{
+	struct tile_net_priv *priv = netdev_priv(dev);
+	int cpu;
+
+	for_each_online_cpu(cpu) {
+		struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
+		struct tile_net_tx_wake *tx_wake =
+			&info->tx_wake[priv->echannel];
+
+		hrtimer_cancel(&tx_wake->timer);
+		netif_stop_subqueue(dev, cpu);
+	}
+
+	mutex_lock(&tile_net_devs_for_channel_mutex);
+	tile_net_devs_for_channel[priv->channel] = NULL;
+	(void)tile_net_update(dev);
+	if (priv->loopify_channel >= 0) {
+		if (gxio_mpipe_link_close(&priv->loopify_link) != 0)
+			netdev_warn(dev, "Failed to close loopify link!\n");
+		priv->loopify_channel = -1;
+	}
+	if (priv->channel >= 0) {
+		if (gxio_mpipe_link_close(&priv->link) != 0)
+			netdev_warn(dev, "Failed to close link!\n");
+		priv->channel = -1;
+	}
+	priv->echannel = -1;
+	mutex_unlock(&tile_net_devs_for_channel_mutex);
+
+	return 0;
+}
+
+/* Determine the VA for a fragment. */
+static inline void *tile_net_frag_buf(skb_frag_t *f)
+{
+	unsigned long pfn = page_to_pfn(skb_frag_page(f));
+	return pfn_to_kaddr(pfn) + f->page_offset;
+}
+
+/* Acquire a completion entry and an egress slot, or if we can't,
+ * stop the queue and schedule the tx_wake timer.
+ */
+static s64 tile_net_equeue_try_reserve(struct net_device *dev,
+				       struct tile_net_comps *comps,
+				       gxio_mpipe_equeue_t *equeue,
+				       int num_edescs)
+{
+	/* Try to acquire a completion entry. */
+	if (comps->comp_next - comps->comp_last < TILE_NET_MAX_COMPS - 1 ||
+	    tile_net_free_comps(equeue, comps, 32, false) != 0) {
+
+		/* Try to acquire an egress slot. */
+		s64 slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs);
+		if (slot >= 0)
+			return slot;
+
+		/* Freeing some completions gives the equeue time to drain. */
+		tile_net_free_comps(equeue, comps, TILE_NET_MAX_COMPS, false);
+
+		slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs);
+		if (slot >= 0)
+			return slot;
+	}
+
+	/* Still nothing; give up and stop the queue for a short while. */
+	netif_stop_subqueue(dev, smp_processor_id());
+	tile_net_schedule_tx_wake_timer(dev);
+	return -1;
+}
+
+/* Determine how many edesc's are needed for TSO.
+ *
+ * Sometimes, if "sendfile()" requires copying, we will be called with
+ * "data" containing the header and payload, with "frags" being empty.
+ * Sometimes, for example when using NFS over TCP, a single segment can
+ * span 3 fragments.  This requires special care.
+ */
+static int tso_count_edescs(struct sk_buff *skb)
+{
+	struct skb_shared_info *sh = skb_shinfo(skb);
+	unsigned int data_len = skb->data_len;
+	unsigned int p_len = sh->gso_size;
+	long f_id = -1;    /* id of the current fragment */
+	long f_size = -1;  /* size of the current fragment */
+	long f_used = -1;  /* bytes used from the current fragment */
+	long n;            /* size of the current piece of payload */
+	int num_edescs = 0;
+	int segment;
+
+	for (segment = 0; segment < sh->gso_segs; segment++) {
+
+		unsigned int p_used = 0;
+
+		/* One edesc for header and for each piece of the payload. */
+		for (num_edescs++; p_used < p_len; num_edescs++) {
+
+			/* Advance as needed. */
+			while (f_used >= f_size) {
+				f_id++;
+				f_size = sh->frags[f_id].size;
+				f_used = 0;
+			}
+
+			/* Use bytes from the current fragment. */
+			n = p_len - p_used;
+			if (n > f_size - f_used)
+				n = f_size - f_used;
+			f_used += n;
+			p_used += n;
+		}
+
+		/* The last segment may be less than gso_size. */
+		data_len -= p_len;
+		if (data_len < p_len)
+			p_len = data_len;
+	}
+
+	return num_edescs;
+}
+
+/* Prepare modified copies of the skbuff headers.
+ * FIXME: add support for IPv6.
+ */
+static void tso_headers_prepare(struct sk_buff *skb, unsigned char *headers,
+				s64 slot)
+{
+	struct skb_shared_info *sh = skb_shinfo(skb);
+	struct iphdr *ih;
+	struct tcphdr *th;
+	unsigned int data_len = skb->data_len;
+	unsigned char *data = skb->data;
+	unsigned int ih_off, th_off, sh_len, p_len;
+	unsigned int isum_seed, tsum_seed, id, seq;
+	long f_id = -1;    /* id of the current fragment */
+	long f_size = -1;  /* size of the current fragment */
+	long f_used = -1;  /* bytes used from the current fragment */
+	long n;            /* size of the current piece of payload */
+	int segment;
+
+	/* Locate original headers and compute various lengths. */
+	ih = ip_hdr(skb);
+	th = tcp_hdr(skb);
+	ih_off = skb_network_offset(skb);
+	th_off = skb_transport_offset(skb);
+	sh_len = th_off + tcp_hdrlen(skb);
+	p_len = sh->gso_size;
+
+	/* Set up seed values for IP and TCP csum and initialize id and seq. */
+	isum_seed = ((0xFFFF - ih->check) +
+		     (0xFFFF - ih->tot_len) +
+		     (0xFFFF - ih->id));
+	tsum_seed = th->check + (0xFFFF ^ htons(skb->len));
+	id = ntohs(ih->id);
+	seq = ntohl(th->seq);
+
+	/* Prepare all the headers. */
+	for (segment = 0; segment < sh->gso_segs; segment++) {
+		unsigned char *buf;
+		unsigned int p_used = 0;
+
+		/* Copy to the header memory for this segment. */
+		buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES +
+			NET_IP_ALIGN;
+		memcpy(buf, data, sh_len);
+
+		/* Update copied ip header. */
+		ih = (struct iphdr *)(buf + ih_off);
+		ih->tot_len = htons(sh_len + p_len - ih_off);
+		ih->id = htons(id);
+		ih->check = csum_long(isum_seed + ih->tot_len +
+				      ih->id) ^ 0xffff;
+
+		/* Update copied tcp header. */
+		th = (struct tcphdr *)(buf + th_off);
+		th->seq = htonl(seq);
+		th->check = csum_long(tsum_seed + htons(sh_len + p_len));
+		if (segment != sh->gso_segs - 1) {
+			th->fin = 0;
+			th->psh = 0;
+		}
+
+		/* Skip past the header. */
+		slot++;
+
+		/* Skip past the payload. */
+		while (p_used < p_len) {
+
+			/* Advance as needed. */
+			while (f_used >= f_size) {
+				f_id++;
+				f_size = sh->frags[f_id].size;
+				f_used = 0;
+			}
+
+			/* Use bytes from the current fragment. */
+			n = p_len - p_used;
+			if (n > f_size - f_used)
+				n = f_size - f_used;
+			f_used += n;
+			p_used += n;
+
+			slot++;
+		}
+
+		id++;
+		seq += p_len;
+
+		/* The last segment may be less than gso_size. */
+		data_len -= p_len;
+		if (data_len < p_len)
+			p_len = data_len;
+	}
+
+	/* Flush the headers so they are ready for hardware DMA. */
+	wmb();
+}
+
+/* Pass all the data to mpipe for egress. */
+static void tso_egress(struct net_device *dev, gxio_mpipe_equeue_t *equeue,
+		       struct sk_buff *skb, unsigned char *headers, s64 slot)
+{
+	struct tile_net_priv *priv = netdev_priv(dev);
+	struct skb_shared_info *sh = skb_shinfo(skb);
+	unsigned int data_len = skb->data_len;
+	unsigned int p_len = sh->gso_size;
+	gxio_mpipe_edesc_t edesc_head = { { 0 } };
+	gxio_mpipe_edesc_t edesc_body = { { 0 } };
+	long f_id = -1;    /* id of the current fragment */
+	long f_size = -1;  /* size of the current fragment */
+	long f_used = -1;  /* bytes used from the current fragment */
+	long n;            /* size of the current piece of payload */
+	unsigned long tx_packets = 0, tx_bytes = 0;
+	unsigned int csum_start, sh_len;
+	int segment;
+
+	/* Prepare to egress the headers: set up header edesc. */
+	csum_start = skb_checksum_start_offset(skb);
+	sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
+	edesc_head.csum = 1;
+	edesc_head.csum_start = csum_start;
+	edesc_head.csum_dest = csum_start + skb->csum_offset;
+	edesc_head.xfer_size = sh_len;
+
+	/* This is only used to specify the TLB. */
+	edesc_head.stack_idx = large_buffer_stack;
+	edesc_body.stack_idx = large_buffer_stack;
+
+	/* Egress all the edescs. */
+	for (segment = 0; segment < sh->gso_segs; segment++) {
+		void *va;
+		unsigned char *buf;
+		unsigned int p_used = 0;
+
+		/* Egress the header. */
+		buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES +
+			NET_IP_ALIGN;
+		edesc_head.va = va_to_tile_io_addr(buf);
+		gxio_mpipe_equeue_put_at(equeue, edesc_head, slot);
+		slot++;
+
+		/* Egress the payload. */
+		while (p_used < p_len) {
+
+			/* Advance as needed. */
+			while (f_used >= f_size) {
+				f_id++;
+				f_size = sh->frags[f_id].size;
+				f_used = 0;
+			}
+
+			va = tile_net_frag_buf(&sh->frags[f_id]) + f_used;
+
+			/* Use bytes from the current fragment. */
+			n = p_len - p_used;
+			if (n > f_size - f_used)
+				n = f_size - f_used;
+			f_used += n;
+			p_used += n;
+
+			/* Egress a piece of the payload. */
+			edesc_body.va = va_to_tile_io_addr(va);
+			edesc_body.xfer_size = n;
+			edesc_body.bound = !(p_used < p_len);
+			gxio_mpipe_equeue_put_at(equeue, edesc_body, slot);
+			slot++;
+		}
+
+		tx_packets++;
+		tx_bytes += sh_len + p_len;
+
+		/* The last segment may be less than gso_size. */
+		data_len -= p_len;
+		if (data_len < p_len)
+			p_len = data_len;
+	}
+
+	/* Update stats. */
+	tile_net_stats_add(tx_packets, &priv->stats.tx_packets);
+	tile_net_stats_add(tx_bytes, &priv->stats.tx_bytes);
+}
+
+/* Do "TSO" handling for egress.
+ *
+ * Normally drivers set NETIF_F_TSO only to support hardware TSO;
+ * otherwise the stack uses scatter-gather to implement GSO in software.
+ * On our testing, enabling GSO support (via NETIF_F_SG) drops network
+ * performance down to around 7.5 Gbps on the 10G interfaces, although
+ * also dropping cpu utilization way down, to under 8%.  But
+ * implementing "TSO" in the driver brings performance back up to line
+ * rate, while dropping cpu usage even further, to less than 4%.  In
+ * practice, profiling of GSO shows that skb_segment() is what causes
+ * the performance overheads; we benefit in the driver from using
+ * preallocated memory to duplicate the TCP/IP headers.
+ */
+static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_priv *priv = netdev_priv(dev);
+	int channel = priv->echannel;
+	struct tile_net_egress *egress = &egress_for_echannel[channel];
+	struct tile_net_comps *comps = info->comps_for_echannel[channel];
+	gxio_mpipe_equeue_t *equeue = egress->equeue;
+	unsigned long irqflags;
+	int num_edescs;
+	s64 slot;
+
+	/* Determine how many mpipe edesc's are needed. */
+	num_edescs = tso_count_edescs(skb);
+
+	local_irq_save(irqflags);
+
+	/* Try to acquire a completion entry and an egress slot. */
+	slot = tile_net_equeue_try_reserve(dev, comps, equeue, num_edescs);
+	if (slot < 0) {
+		local_irq_restore(irqflags);
+		return NETDEV_TX_BUSY;
+	}
+
+	/* Set up copies of header data properly. */
+	tso_headers_prepare(skb, egress->headers, slot);
+
+	/* Actually pass the data to the network hardware. */
+	tso_egress(dev, equeue, skb, egress->headers, slot);
+
+	/* Add a completion record. */
+	add_comp(equeue, comps, slot + num_edescs - 1, skb);
+
+	local_irq_restore(irqflags);
+
+	/* Make sure the egress timer is scheduled. */
+	tile_net_schedule_egress_timer();
+
+	return NETDEV_TX_OK;
+}
+
+/* Analyze the body and frags for a transmit request. */
+static unsigned int tile_net_tx_frags(struct frag *frags,
+				       struct sk_buff *skb,
+				       void *b_data, unsigned int b_len)
+{
+	unsigned int i, n = 0;
+
+	struct skb_shared_info *sh = skb_shinfo(skb);
+
+	if (b_len != 0) {
+		frags[n].buf = b_data;
+		frags[n++].length = b_len;
+	}
+
+	for (i = 0; i < sh->nr_frags; i++) {
+		skb_frag_t *f = &sh->frags[i];
+		frags[n].buf = tile_net_frag_buf(f);
+		frags[n++].length = skb_frag_size(f);
+	}
+
+	return n;
+}
+
+/* Help the kernel transmit a packet. */
+static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_priv *priv = netdev_priv(dev);
+	struct tile_net_egress *egress = &egress_for_echannel[priv->echannel];
+	gxio_mpipe_equeue_t *equeue = egress->equeue;
+	struct tile_net_comps *comps =
+		info->comps_for_echannel[priv->echannel];
+	unsigned int len = skb->len;
+	unsigned char *data = skb->data;
+	unsigned int num_edescs;
+	struct frag frags[MAX_FRAGS];
+	gxio_mpipe_edesc_t edescs[MAX_FRAGS];
+	unsigned long irqflags;
+	gxio_mpipe_edesc_t edesc = { { 0 } };
+	unsigned int i;
+	s64 slot;
+
+	if (skb_is_gso(skb))
+		return tile_net_tx_tso(skb, dev);
+
+	num_edescs = tile_net_tx_frags(frags, skb, data, skb_headlen(skb));
+
+	/* This is only used to specify the TLB. */
+	edesc.stack_idx = large_buffer_stack;
+
+	/* Prepare the edescs. */
+	for (i = 0; i < num_edescs; i++) {
+		edesc.xfer_size = frags[i].length;
+		edesc.va = va_to_tile_io_addr(frags[i].buf);
+		edescs[i] = edesc;
+	}
+
+	/* Mark the final edesc. */
+	edescs[num_edescs - 1].bound = 1;
+
+	/* Add checksum info to the initial edesc, if needed. */
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		unsigned int csum_start = skb_checksum_start_offset(skb);
+		edescs[0].csum = 1;
+		edescs[0].csum_start = csum_start;
+		edescs[0].csum_dest = csum_start + skb->csum_offset;
+	}
+
+	local_irq_save(irqflags);
+
+	/* Try to acquire a completion entry and an egress slot. */
+	slot = tile_net_equeue_try_reserve(dev, comps, equeue, num_edescs);
+	if (slot < 0) {
+		local_irq_restore(irqflags);
+		return NETDEV_TX_BUSY;
+	}
+
+	for (i = 0; i < num_edescs; i++)
+		gxio_mpipe_equeue_put_at(equeue, edescs[i], slot++);
+
+	/* Add a completion record. */
+	add_comp(equeue, comps, slot - 1, skb);
+
+	/* NOTE: Use ETH_ZLEN for short packets (e.g. 42 < 60). */
+	tile_net_stats_add(1, &priv->stats.tx_packets);
+	tile_net_stats_add(max_t(unsigned int, len, ETH_ZLEN),
+			   &priv->stats.tx_bytes);
+
+	local_irq_restore(irqflags);
+
+	/* Make sure the egress timer is scheduled. */
+	tile_net_schedule_egress_timer();
+
+	return NETDEV_TX_OK;
+}
+
+/* Return subqueue id on this core (one per core). */
+static u16 tile_net_select_queue(struct net_device *dev, struct sk_buff *skb)
+{
+	return smp_processor_id();
+}
+
+/* Deal with a transmit timeout. */
+static void tile_net_tx_timeout(struct net_device *dev)
+{
+	int cpu;
+
+	for_each_online_cpu(cpu)
+		netif_wake_subqueue(dev, cpu);
+}
+
+/* Ioctl commands. */
+static int tile_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+	return -EOPNOTSUPP;
+}
+
+/* Get system network statistics for device. */
+static struct net_device_stats *tile_net_get_stats(struct net_device *dev)
+{
+	struct tile_net_priv *priv = netdev_priv(dev);
+	return &priv->stats;
+}
+
+/* Change the MTU. */
+static int tile_net_change_mtu(struct net_device *dev, int new_mtu)
+{
+	if ((new_mtu < 68) || (new_mtu > 1500))
+		return -EINVAL;
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+/* Change the Ethernet address of the NIC.
+ *
+ * The hypervisor driver does not support changing MAC address.  However,
+ * the hardware does not do anything with the MAC address, so the address
+ * which gets used on outgoing packets, and which is accepted on incoming
+ * packets, is completely up to us.
+ *
+ * Returns 0 on success, negative on failure.
+ */
+static int tile_net_set_mac_address(struct net_device *dev, void *p)
+{
+	struct sockaddr *addr = p;
+
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EINVAL;
+	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
+	return 0;
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+/* Polling 'interrupt' - used by things like netconsole to send skbs
+ * without having to re-enable interrupts. It's not called while
+ * the interrupt routine is executing.
+ */
+static void tile_net_netpoll(struct net_device *dev)
+{
+	disable_percpu_irq(ingress_irq);
+	tile_net_handle_ingress_irq(ingress_irq, NULL);
+	enable_percpu_irq(ingress_irq, 0);
+}
+#endif
+
+static const struct net_device_ops tile_net_ops = {
+	.ndo_open = tile_net_open,
+	.ndo_stop = tile_net_stop,
+	.ndo_start_xmit = tile_net_tx,
+	.ndo_select_queue = tile_net_select_queue,
+	.ndo_do_ioctl = tile_net_ioctl,
+	.ndo_get_stats = tile_net_get_stats,
+	.ndo_change_mtu = tile_net_change_mtu,
+	.ndo_tx_timeout = tile_net_tx_timeout,
+	.ndo_set_mac_address = tile_net_set_mac_address,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller = tile_net_netpoll,
+#endif
+};
+
+/* The setup function.
+ *
+ * This uses ether_setup() to assign various fields in dev, including
+ * setting IFF_BROADCAST and IFF_MULTICAST, then sets some extra fields.
+ */
+static void tile_net_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+	dev->netdev_ops = &tile_net_ops;
+	dev->watchdog_timeo = TILE_NET_TIMEOUT;
+	dev->features |= NETIF_F_LLTX;
+	dev->features |= NETIF_F_HW_CSUM;
+	dev->features |= NETIF_F_SG;
+	dev->features |= NETIF_F_TSO;
+	dev->mtu = 1500;
+}
+
+/* Allocate the device structure, register the device, and obtain the
+ * MAC address from the hypervisor.
+ */
+static void tile_net_dev_init(const char *name, const uint8_t *mac)
+{
+	int ret;
+	int i;
+	int nz_addr = 0;
+	struct net_device *dev;
+	struct tile_net_priv *priv;
+
+	/* HACK: Ignore "loop" links. */
+	if (strncmp(name, "loop", 4) == 0)
+		return;
+
+	/* Allocate the device structure.  Normally, "name" is a
+	 * template, instantiated by register_netdev(), but not for us.
+	 */
+	dev = alloc_netdev_mqs(sizeof(*priv), name, tile_net_setup,
+			       NR_CPUS, 1);
+	if (!dev) {
+		pr_err("alloc_netdev_mqs(%s) failed\n", name);
+		return;
+	}
+
+	/* Initialize "priv". */
+	priv = netdev_priv(dev);
+	memset(priv, 0, sizeof(*priv));
+	priv->dev = dev;
+	priv->channel = -1;
+	priv->loopify_channel = -1;
+	priv->echannel = -1;
+
+	/* Get the MAC address and set it in the device struct; this must
+	 * be done before the device is opened.  If the MAC is all zeroes,
+	 * we use a random address, since we're probably on the simulator.
+	 */
+	for (i = 0; i < 6; i++)
+		nz_addr |= mac[i];
+
+	if (nz_addr) {
+		memcpy(dev->dev_addr, mac, 6);
+		dev->addr_len = 6;
+	} else {
+		random_ether_addr(dev->dev_addr);
+	}
+
+	/* Register the network device. */
+	ret = register_netdev(dev);
+	if (ret) {
+		netdev_err(dev, "register_netdev failed %d\n", ret);
+		free_netdev(dev);
+		return;
+	}
+}
+
+/* Per-cpu module initialization. */
+static void tile_net_init_module_percpu(void *unused)
+{
+	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	int my_cpu = smp_processor_id();
+
+	info->has_iqueue = false;
+
+	info->my_cpu = my_cpu;
+
+	/* Initialize the egress timer. */
+	hrtimer_init(&info->egress_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	info->egress_timer.function = tile_net_handle_egress_timer;
+}
+
+/* Module initialization. */
+static int __init tile_net_init_module(void)
+{
+	int i;
+	char name[GXIO_MPIPE_LINK_NAME_LEN];
+	uint8_t mac[6];
+
+	pr_info("Tilera Network Driver\n");
+
+	mutex_init(&tile_net_devs_for_channel_mutex);
+
+	/* Initialize each CPU. */
+	on_each_cpu(tile_net_init_module_percpu, NULL, 1);
+
+	/* Find out what devices we have, and initialize them. */
+	for (i = 0; gxio_mpipe_link_enumerate_mac(i, name, mac) >= 0; i++)
+		tile_net_dev_init(name, mac);
+
+	if (!network_cpus_init())
+		network_cpus_map = *cpu_online_mask;
+
+	return 0;
+}
+
+module_init(tile_net_init_module);
-- 
1.6.5.2

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