Commit Graph

223120 Commits

Author SHA1 Message Date
David S. Miller eaa7dcde1d Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/net-next-2.6 2010-12-10 11:22:57 -08:00
David S. Miller cf78f8ee3d Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/bwh/sfc-next-2.6 2010-12-10 10:20:43 -08:00
David S. Miller 1e13f863ca Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
2010-12-10 09:50:47 -08:00
Shan Wei b7ec19af63 dccp: remove unused macros
Remove macros which have been unused since the initial implementation
(commit 7c657876b6, [DCCP]: Initial
 implementation from Tue Aug 9 20:14:34 2005 -0700).

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-10 12:49:23 +01:00
Vladislav Zolotarov f404c2fea3 bnx2x: Update version number and a date.
Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:50:02 -08:00
Vladislav Zolotarov 5cd737c2e8 bnx2x: Fixed a compilation warning
bnx2x_src_init_t2() is used only when BCM_CNIC is defined.
So, to avoid a compilation warning, we won't define it unless
BCM_CNIC is defined.

Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:50:01 -08:00
Vladislav Zolotarov d245a11112 bnx2x: Use dma_alloc_coherent() semantics for ILT memory allocation
Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:50:01 -08:00
Vladislav Zolotarov 2297a2da5a bnx2x: LSO code was broken on BE platforms
Make the LSO code work on BE platforms: parsing_data field of
a parsing BD (PBD) for 57712 was improperly composed which made FW read wrong
values for TCP header's length and offset and, as a result, the corresponding
PCI device was performing bad DMA reads triggering EEH.

Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:50:00 -08:00
Eric Dumazet 4bc65dd8d8 filter: use size of fetched data in __load_pointer()
__load_pointer() checks data we fetch from skb is included in head
portion, but assumes we fetch one byte, instead of up to four.

This wont crash because we have extra bytes (struct skb_shared_info)
after head, but this can read uninitialized bytes.

Fix this using size of the data (1, 2, 4 bytes) in the test.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:47:04 -08:00
Jozsef Kadlecsik 60d509c823 The new jhash implementation
The current jhash.h implements the lookup2() hash function by Bob Jenkins.
However, lookup2() is outdated as Bob wrote a new hash function called
lookup3(). The patch replaces the lookup2() implementation of the 'jhash*'
functions with that of lookup3().

You can read a longer comparison of the two and other hash functions at
http://burtleburtle.net/bob/hash/doobs.html.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:17:07 -08:00
Eric Dumazet 68835aba4d net: optimize INET input path further
Followup of commit b178bb3dfc (net: reorder struct sock fields)

Optimize INET input path a bit further, by :

1) moving sk_refcnt close to sk_lock.

This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).

2) moving inet_daddr & inet_rcv_saddr at the beginning of sk

(same cache line than hash / family / bound_dev_if / nulls_node)

This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.

Before patch :

offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274

After patch :

offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4

compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09 20:05:58 -08:00
David S. Miller defb3519a6 net: Abstract away all dst_entry metrics accesses.
Use helper functions to hide all direct accesses, especially writes,
to dst_entry metrics values.

This will allow us to:

1) More easily change how the metrics are stored.

2) Implement COW for metrics.

In particular this will help us put metrics into the inetpeer
cache if that is what we end up doing.  We can make the _metrics
member a pointer instead of an array, initially have it point
at the read-only metrics in the FIB, and then on the first set
grab an inetpeer entry and point the _metrics member there.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-12-09 10:46:36 -08:00
David S. Miller 84b3cdc38c can: slcan: Add missing linux/sched.h include.
drivers/net/can/slcan.c: In function 'slcan_open':
drivers/net/can/slcan.c:568: error: dereferencing pointer to incomplete type

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 18:41:03 -08:00
David S. Miller fe6c791570 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
	net/llc/af_llc.c
2010-12-08 13:47:38 -08:00
Eric Dumazet f19872575f tcp: protect sysctl_tcp_cookie_size reads
Make sure sysctl_tcp_cookie_size is read once in
tcp_cookie_size_check(), or we might return an illegal value to caller
if sysctl_tcp_cookie_size is changed by another cpu.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: William Allen Simpson <william.allen.simpson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:34:09 -08:00
Eric Dumazet ad9f4f50fe tcp: avoid a possible divide by zero
sysctl_tcp_tso_win_divisor might be set to zero while one cpu runs in
tcp_tso_should_defer(). Make sure we dont allow a divide by zero by
reading sysctl_tcp_tso_win_divisor exactly once.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:34:08 -08:00
Breno Leitao c7757fdb41 ehea: Fixing LRO configuration
In order to set LRO on ehea, the user must set a module parameter, which
is not the standard way to do so. This patch adds a way to set LRO using
the ethtool tool.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:19:14 -08:00
Tom Herbert 67631510a3 tcp: Replace time wait bucket msg by counter
Rather than printing the message to the log, use a mib counter to keep
track of the count of occurences of time wait bucket overflow.  Reduces
spam in logs.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:16:33 -08:00
Apollon Oikonomopoulos 171995e5d8 x25: decrement netdev reference counts on unload
x25 does not decrement the network device reference counts on module unload.
Thus unregistering any pre-existing interface after unloading the x25 module
hangs and results in

 unregister_netdevice: waiting for tap0 to become free. Usage count = 1

This patch decrements the reference counts of all interfaces in x25_link_free,
the way it is already done in x25_link_device_down for NETDEV_DOWN events.

Signed-off-by: Apollon Oikonomopoulos <apollon@noc.grnet.gr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:13:44 -08:00
Joe Jin 408cc293c2 driver/net/benet: fix be_cmd_multicast_set() memcpy bug
Regarding  benet be_cmd_multicast_set() function, now using
netdev_for_each_mc_addr() helper for mac address copy, but
when copying to req->mac[] did not increase of the index.

Cc: Sathya Perla <sathyap@serverengines.com>
Cc: Subbu Seetharaman <subbus@serverengines.com>
Cc: Sarveshwar Bandi <sarveshwarb@serverengines.com>
Cc: Ajit Khaparde <ajitk@serverengines.com>
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:13:43 -08:00
Michal Marek e8d34a884e l2tp: Fix modalias of l2tp_ip
Using the SOCK_DGRAM enum results in
"net-pf-2-proto-SOCK_DGRAM-type-115", so use the numeric value like it
is done in net/dccp.

Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:13:43 -08:00
Nelson Elhage 0c62fc6dd0 econet: Do the correct cleanup after an unprivileged SIOCSIFADDR.
We need to drop the mutex and do a dev_put, so set an error code and break like
the other paths, instead of returning directly.

Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 12:13:42 -08:00
David S. Miller 0833847552 Merge branch 'sfc-2.6.37' of git://git.kernel.org/pub/scm/linux/kernel/git/bwh/sfc-2.6 2010-12-08 12:13:23 -08:00
Namhyung Kim f8bf5681cf isdn/hisax: fix compiler warning on hisax_pci_tbl
Annotate hisax_pci_tbl as '__used' to fix following warning:

  CC      drivers/isdn/hisax/config.o
drivers/isdn/hisax/config.c:1920: warning: ‘hisax_pci_tbl’ defined but not used

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:49:00 -08:00
Changli Gao 920b8d913b af_packet: fix freeing pg_vec twice on error path
It is introduced in:
        commit 0e3125c755
        Author: Neil Horman <nhorman@tuxdriver.com>
        Date:   Tue Nov 16 10:26:47 2010 -0800

        packet: Enhance AF_PACKET implementation to not require high order contiguous memory allocation (v4)

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:43:41 -08:00
Changli Gao f6dafa95d1 af_packet: eliminate pgv_to_page on some arches
Some arches don't need flush_dcache_page(), and don't implement it, so
we can eliminate pgv_to_page() calls on those arches.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:43:41 -08:00
Eric Dumazet 15c2d75f49 net: call dev_queue_xmit_nit() after skb_dst_drop()
Avoid some atomic ops on dst refcount, calling dev_queue_xmit_nit()
after skb_dst_drop() in dev_hard_start_xmit().

When queueing a packet into af_packet socket, we drop dst anyway.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:39:54 -08:00
Eric Dumazet 62ab081213 filter: constify sk_run_filter()
sk_run_filter() doesnt write on skb, change its prototype to reflect
this.

Fix two af_packet comments.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:30:34 -08:00
Roger Luethi 38f49e8801 via-rhine: hardware VLAN support
This patch adds VLAN hardware support for Rhine chips.

The driver uses up to 3 additional bytes of buffer space when extracting
802.1Q headers; PKT_BUF_SZ should still be sufficient.

The initial code was provided by David Lv. I reworked it to use standard
kernel facilities. Coding style clean up mostly follows via-velocity.

Adapted to new interface for VLAN acceleration (per request of Jesse Gross).

Signed-off-by: David Lv <DavidLv@viatech.com.cn>
Signed-off-by: Roger Luethi <rl@hellgate.ch>

 drivers/net/via-rhine.c |  326 +++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 312 insertions(+), 14 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:23:36 -08:00
Eric Dumazet 941666c2e3 net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()
Le dimanche 05 décembre 2010 à 09:19 +0100, Eric Dumazet a écrit :

> Hmm..
>
> If somebody can explain why RTNL is held in arp_ioctl() (and therefore
> in arp_req_delete()), we might first remove RTNL use in arp_ioctl() so
> that your patch can be applied.
>
> Right now it is not good, because RTNL wont be necessarly held when you
> are going to call arp_invalidate() ?

While doing this analysis, I found a refcount bug in llc, I'll send a
patch for net-2.6

Meanwhile, here is the patch for net-next-2.6

Your patch then can be applied after mine.

Thanks

[PATCH] net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()

dev_getbyhwaddr() was called under RTNL.

Rename it to dev_getbyhwaddr_rcu() and change all its caller to now use
RCU locking instead of RTNL.

Change arp_ioctl() to use RCU instead of RTNL locking.

Note: this fix a dev refcount bug in llc

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:07:24 -08:00
David S. Miller a2d4b65d47 Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/net-next-2.6 2010-12-08 10:01:00 -08:00
Eric Dumazet 35d9b0c906 llc: fix a device refcount imbalance
Le dimanche 05 décembre 2010 à 12:23 +0100, Eric Dumazet a écrit :
> Le dimanche 05 décembre 2010 à 09:19 +0100, Eric Dumazet a écrit :
>
> > Hmm..
> >
> > If somebody can explain why RTNL is held in arp_ioctl() (and therefore
> > in arp_req_delete()), we might first remove RTNL use in arp_ioctl() so
> > that your patch can be applied.
> >
> > Right now it is not good, because RTNL wont be necessarly held when you
> > are going to call arp_invalidate() ?
>
> While doing this analysis, I found a refcount bug in llc, I'll send a
> patch for net-2.6

Oh well, of course I must first fix the bug in net-2.6, and wait David
pull the fix in net-next-2.6 before sending this rcu conversion.

Note: this patch should be sent to stable teams (2.6.34 and up)

[PATCH net-2.6] llc: fix a device refcount imbalance

commit abf9d537fe (llc: add support for SO_BINDTODEVICE) added one
refcount imbalance in llc_ui_bind(), because dev_getbyhwaddr() doesnt
take a reference on device, while dev_get_by_index() does.

Fix this using RCU locking. And since an RCU conversion will be done for
2.6.38 for dev_getbyhwaddr(), put the rcu_read_lock/unlock exactly at
their final place.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@kernel.org
Cc: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:58:44 -08:00
Thiago Farina 01b0c5cfb2 net/9p/protocol.c: Remove duplicated macros.
Use the macros already provided by kernel.h file.

Signed-off-by: Thiago Farina <tfransosi@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:56:28 -08:00
Changli Gao 75c1c82566 ifb: goto resched directly if error happens and dp->tq isn't empty
If we break the loop when there are still skbs in tq and no skb in
rq, the skbs will be left in txq until new skbs are enqueued into rq.
In rare cases, no new skb is queued, then these skbs will stay in rq
forever.

After this patch, if tq isn't empty when we break the loop, we goto
resched directly.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:45:34 -08:00
Changli Gao aa94210411 net: init ingress queue
The dev field of ingress queue is forgot to initialized, then NULL
pointer dereference happens in qdisc_alloc().

Move inits of tx queues to netif_alloc_netdev_queues().

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:43:27 -08:00
Nandita Dukkipati b1afde60f2 tcp: Bug fix in initialization of receive window.
The bug has to do with boundary checks on the initial receive window.
If the initial receive window falls between init_cwnd and the
receive window specified by the user, the initial window is incorrectly
brought down to init_cwnd. The correct behavior is to allow it to
remain unchanged.

Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:38:37 -08:00
Dimitris Michailidis ce9aeb583a cxgb4: fix MAC address hash filter
Fix the calculation of the inexact hash-based MAC address filter.
It's 64 bits but current code is missing a ULL.  Results in filtering out
some legitimate packets.

Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:36:22 -08:00
Oliver Hartkopp a1044e36e4 can: add slcan driver for serial/USB-serial CAN adapters
This patch adds support for serial/USB-serial CAN adapters implementing the
LAWICEL ASCII protocol for CAN frame transport over serial lines.

The driver implements the SLCAN line discipline and is heavily based on the
slip.c driver. Therefore the code style remains similar to slip.c to be able
to apply changes of the SLIP driver to the SLCAN driver easily.

For more details see the slcan Kconfig entry.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 09:03:32 -08:00
Andy Shevchenko 58e481f66e atm: lanai: use kernel's '%pM' format option to print MAC
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Chas Williams <chas@cmf.nrl.navy.mil>
Cc: linux-atm-general@lists.sourceforge.net
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 08:53:41 -08:00
Kim Lilliestierna XX e83293233f CAIF: Fix U5500 compile error for shared memory driver
Rearrange pr_fmt so it compiles.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 08:35:29 -08:00
David S. Miller 4f58605e6b Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-12-08 08:13:01 -08:00
Ben Hutchings e8f149924a sfc: Fix NAPI list corruption during ring reallocation
Call netif_napi_{add,del}() on the NAPI contexts in the new and
old channels, respectively.

Since efx_init_napi() cannot fail, make its return type void.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2010-12-07 20:04:22 +00:00
Ben Hutchings 94dec6a2d2 sfc: Fix crash in legacy onterrupt handler during ring reallocation
If we are using a legacy interrupt, our IRQ may be shared and our
interrupt handler may be called even though interrupts are disabled on
the NIC. When we change ring sizes, we reallocate the event queue and
the interrupt handler may use an invalid pointer when called for
another device's interrupt.

Maintain a legacy_irq_enabled flag and test that at the top of the
interrupt handler.  Note that this problem results from the need to
work around broken INT_ISR0 reads, and does not affect the legacy
interrupt handler for Falcon A1.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2010-12-07 19:30:19 +00:00
Ben Hutchings c39d35ebff sfc: Generalise filter spec initialisation
Move search_depth arrays into per-table state.

Define initialisation function efx_filter_init_rx() which sets
everything apart from the match fields.

Define efx_filter_set_{ipv4_local,ipv4_full,eth_local}() to set the
match fields.  This allows some simplification of callers and later
support for additional protocols and more flexible matching using
multiple calls to these functions.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2010-12-07 19:11:26 +00:00
Ben Hutchings 8891681af9 sfc: Remove filter table IDs from filter functions
The separation between filter tables is largely an internal detail
and it may be removed in future hardware.  To prepare for that:

- Merge table ID with filter index to make an opaque filter ID
- Wrap efx_filter_table_clear() with a function that clears filters
  from both RX tables, which is all that the current caller requires

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2010-12-07 19:02:50 +00:00
Ben Hutchings ac33ac610d sfc: Log start and end of ethtool self-test at INFO level
Add message at start of self-test and increase log level of message at
end of self-test, so that any other messages produced during the
test are clearly associated with it.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2010-12-07 18:31:48 +00:00
Tomasz Grobelny 0491026507 dccp qpolicy: Parameter checking of cmsg qpolicy parameters
Ensure that cmsg->cmsg_type value is valid for qpolicy
that is currently in use.

Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-07 13:47:12 +01:00
Tomasz Grobelny 871a2c16c2 dccp: Policy-based packet dequeueing infrastructure
This patch adds a generic infrastructure for policy-based dequeueing of
TX packets and provides two policies:
 * a simple FIFO policy (which is the default) and
 * a priority based policy (set via socket options).
Both policies honour the tx_qlen sysctl for the maximum size of the write
queue (can be overridden via socket options).

The priority policy uses skb->priority internally to assign an u32 priority
identifier, using the same ranking as SO_PRIORITY. The skb->priority field
is set to 0 when the packet leaves DCCP. The priority is supplied as ancillary
data using cmsg(3), the patch also provides the requisite parsing routines.

Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-07 13:47:12 +01:00
David S. Miller cfa969e385 Revert "ehea: Use the standard logging functions"
This reverts commit 539995d186.

As reported by Stephen Rothwell, this breaks the build.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-06 20:45:28 -08:00
Ben Hutchings cd38557d78 sfc: Use TX push whenever adding descriptors to an empty queue
Whenever we add DMA descriptors to a TX ring and update the ring
pointer, the TX DMA engine must first read the new DMA descriptors and
then start reading packet data.  However, all released Solarflare 10G
controllers have a 'TX push' feature that allows us to reduce latency
by writing the first new DMA descriptor along with the pointer update.
This is only useful when the queue is empty.  The hardware should
ignore the pushed descriptor if the queue is not empty, but this check
is buggy, so we must do it in software.

In order to tell whether a TX queue is empty, we need to compare the
previous transmission count (write_count) and completion count
(read_count).  However, if we do that every time we update the ring
pointer then read_count may ping-pong between the caches of two CPUs
running the transmission and completion paths for the queue.
Therefore, we split the check for an empty queue between the
completion path and the transmission path:

- Add an empty_read_count field representing a point at which the
  completion path saw the TX queue as empty.
- Add an old_write_count field for use on the completion path.
- On the completion path, whenever read_count reaches or passes
  old_write_count the TX queue may be empty.  We then read
  write_count, set empty_read_count if read_count == write_count,
  and update old_write_count.
- On the transmission path, we read empty_read_count.  If it's set, we
  compare it with the value of write_count before the current set of
  descriptors was added.  If they match, the queue really is empty and
  we can use TX push.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2010-12-06 23:00:07 +00:00