On ARM all divisions have to be performed "manually". For 64-bit
divisions that may take more than a hundred cycles in many cases.
With 32-bit divisions gcc already use the recyprocal of constant
divisors to perform a multiplication, but not with 64-bit divisions.
Since the kernel is increasingly relying upon 64-bit divisions it is
worth optimizing at least those cases where the divisor is a constant.
This is what this patch does using plain C code that gets optimized away
at compile time.
For example, despite the amount of added C code, do_div(x, 10000) now
produces the following assembly code (where x is assigned to r0-r1):
adr r4, .L0
ldmia r4, {r4-r5}
umull r2, r3, r4, r0
mov r2, #0
umlal r3, r2, r5, r0
umlal r3, r2, r4, r1
mov r3, #0
umlal r2, r3, r5, r1
mov r0, r2, lsr #11
orr r0, r0, r3, lsl #21
mov r1, r3, lsr #11
...
.L0:
.word 948328779
.word 879609302
which is the fastest that can be done for any value of x in that case,
many times faster than the __do_div64 code (except for the small x value
space for which the result ends up being zero or a single bit).
The fact that this code is generated inline produces a tiny increase in
.text size, but not significant compared to the needed code around each
__do_div64 call site this code is replacing.
The algorithm used has been validated on a 16-bit scale for all possible
values, and then recodified for 64-bit values. Furthermore I've been
running it with the final BUG_ON() uncommented for over two months now
with no problem.
Note that this new code is compiled with gcc versions 4.0 or later.
Earlier gcc versions proved themselves too problematic and only the
original code is used with them.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add support for the Cirrus Logic EDB9302A Evaluation Board. Confirmed
to work by Chase Douglas.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Do not assume that the ARM GCC toolchain defaults to building for the
32-bit ARM ISA (-marm) case. Instead, explicitly select -marm in CFLAGS
since the toolchain default can be for the 16-bit Thumb ISA (-mthumb) in
some odd/rare cases.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This fixes up most of the things pointed out by akpm and Pavel Machek
with comments below indicating why some things have been left:
Andrew Morton wrote:
>
>> +static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
>> +{
>> + struct nodeinfo *ni;
>> + int r;
>> + int n;
>> +
>> + down_read(&nodeinfo_lock);
>
> Given that this function can sleep, I wonder if `alloc' is useful.
>
> I see lots of callers passing in a literal "0" for `alloc'. That's in fact
> a secret (GFP_ATOMIC & ~__GFP_HIGH). I doubt if that's what you really
> meant. Particularly as the code could at least have used __GFP_WAIT (aka
> GFP_NOIO) which is much, much more reliable than "0". In fact "0" is the
> least reliable mode possible.
>
> IOW, this is all bollixed up.
When 0 is passed into nodeid2nodeinfo the function does not try to allocate a
new structure at all. it's an indication that the caller only wants the nodeinfo
struct for that nodeid if there actually is one in existance.
I've tidied the function itself so it's more obvious, (and tidier!)
>> +/* Data received from remote end */
>> +static int receive_from_sock(void)
>> +{
>> + int ret = 0;
>> + struct msghdr msg;
>> + struct kvec iov[2];
>> + unsigned len;
>> + int r;
>> + struct sctp_sndrcvinfo *sinfo;
>> + struct cmsghdr *cmsg;
>> + struct nodeinfo *ni;
>> +
>> + /* These two are marginally too big for stack allocation, but this
>> + * function is (currently) only called by dlm_recvd so static should be
>> + * OK.
>> + */
>> + static struct sockaddr_storage msgname;
>> + static char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
>
> whoa. This is globally singly-threaded code??
Yes. it is only ever run in the context of dlm_recvd.
>>
>> +static void initiate_association(int nodeid)
>> +{
>> + struct sockaddr_storage rem_addr;
>> + static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
>
> Another static buffer to worry about. Globally singly-threaded code?
Yes. Only ever called by dlm_sendd.
>> +
>> +/* Send a message */
>> +static int send_to_sock(struct nodeinfo *ni)
>> +{
>> + int ret = 0;
>> + struct writequeue_entry *e;
>> + int len, offset;
>> + struct msghdr outmsg;
>> + static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
>
> Singly-threaded?
Yep.
>>
>> +static void dealloc_nodeinfo(void)
>> +{
>> + int i;
>> +
>> + for (i=1; i<=max_nodeid; i++) {
>> + struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
>> + if (ni) {
>> + idr_remove(&nodeinfo_idr, i);
>
> Didn't that need locking?
Not. it's only ever called at DLM shutdown after all the other threads
have been stopped.
>>
>> +static int write_list_empty(void)
>> +{
>> + int status;
>> +
>> + spin_lock_bh(&write_nodes_lock);
>> + status = list_empty(&write_nodes);
>> + spin_unlock_bh(&write_nodes_lock);
>> +
>> + return status;
>> +}
>
> This function's return value is meaningless. As soon as the lock gets
> dropped, the return value can get out of sync with reality.
>
> Looking at the caller, this _might_ happen to be OK, but it's a nasty and
> dangerous thing. Really the locking should be moved into the caller.
It's just an optimisation to allow the caller to schedule if there is no work
to do. if something arrives immediately afterwards then it will get picked up
when the process re-awakes (and it will be woken by that arrival).
The 'accepting' atomic has gone completely. as Andrew pointed out it didn't
really achieve much anyway. I suspect it was a plaster over some other
startup or shutdown bug to be honest.
Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Pavel Machek <pavel@ucw.cz>
This is a bit better than the previous version of gfs2_fsync()
although it would be better still if we were able to call a
function which only wrote the inode & metadata. Its no big deal
though that this will potentially write the data as well since
the VFS has already done that before calling gfs2_fsync(). I've
also added a comment to explain whats going on here.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
The ata timing computation code makes some mistakes in PIO5/6 because a
check was not updated correctly when I put this support into the kernel.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch converts sata_promise to use new-style libata error
handling on Promise SATA chips, for both SATA and PATA ports.
* ATA_FLAG_SRST is no longer set
* ->phy_reset is no longer set as it is unused when ->error_handler
is present, and pdc_sata_phy_reset() has been removed
* pdc_freeze() masks interrupts and halts DMA via PDC_CTLSTAT
* pdc_thaw() clears interrupt status in PDC_INT_SEQMASK and then
unmasks interrupts in PDC_CTLSTAT
* pdc_error_handler() reinitialises the port if it isn't frozen,
and then invokes ata_do_eh() with standard {s,}ata reset methods
* pdc_post_internal_cmd() resets the port in case of errors
* the PATA-only 20619 chip continues to use old-style EH:
not by necessity but simply because I don't have documentation
for it or any way to test it
Since the previous version pdc_error_handler() has been rewritten
and it now mostly matches ahci and sata_sil24. In case anyone
wonders: the call to pdc_reset_port() isn't a heavy-duty reset,
it's a light-weight reset to quickly put a port into a sane state.
The discussion about the PCI flushes in pdc_freeze() and pdc_thaw()
seemed to end with a consensus that the flushes are OK and not
obviously redundant, so I decided to keep them for now.
This patch was prepared against 2.6.19-git7, but it also applies
to 2.6.19 + libata #upstream, with or without the revised sata_promise
cleanup patch I recently submitted.
This patch does conflict with the #promise-sata-pata patch:
this patch removes pdc_sata_phy_reset() while #promise-sata-pata
modifies it. The correct patch resolution is to remove the function.
Tested on 2037x and 2057x chips, with PATA patches on top and disks
on both SATA and PATA ports.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Even if ATA_FLAG_PIO_POLLING is set, libata uses irq pio for the ATA_PROT_NODATA protocol.
This patch let ATA_FLAG_PIO_POLLING use polling pio for the ATA_PROT_NODATA protocol.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch performs two simple cleanups of sata_promise.
* Remove board_20771 and map device id 0x3577 to board_2057x.
After the recent corrections for SATAII chips, board_20771 and
board_2057x were equivalent in the driver.
* Remove hp->hotplug_offset and use hp->flags & PDC_FLAG_GEN_II
to compute hotplug_offset in pdc_host_init(). hp->hotplug_offset
was used to distinguish 1st and 2nd generation chips in one
particular case, but now we have that information in a more
general form in hp->flags, so hp->hotplug_offset is redundant.
Changes since previous submission: rebased on libata-dev #upstream,
cleaned up hotplug_offset computation based on Tejun's comments,
expanded hotplug_offset removal rationale.
This patch does not depend on the pending new EH conversion patch.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Get rid of sparse warnings in sky2 driver because of mixed enum
usage.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Fix sparse warnings from using enum as part of arithmetic
expression, and comment indentation fixes
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
In the myri10ge_submit_8rx() routine, write the 64 byte request block as
2 32-byte blocks so that it is handled by the hardware pio write handler
if write-combining is enabled.
Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch makes the receive performance on some systems go from
714MB/s to 941MB/s. It adjusts the watermark of the receive queue
to be lower, thereby avoiding excess hardware flow control. This is
most important on the systems which have little/no additional buffering.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Different chips have different sizes of ram buffers, and some versions have
no ram buffer at all!. Be more careful about sizing the ram usage because
it maybe a problem if vendor keeps changing sizes.
There is the (unlikely) possibility that some of the errors on some of the
chips have been caused by partitioning not on a 1K boundary.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add comments to sky2 driver to show relationship between PCI id and
hardware.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Use dev_alloc_skb() instead of alloc_skb().
It is also not necessary to adjust skb->len manually since that's
already done by skb_put().
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Adds netpoll / netconsole support.
Original patch from Bill Gatliff.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Move the global 'check_timer' variable into the private data structure.
Also now use mod_timer().
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Remove the global 'at91_dev' variable.
Use netdev_priv() instead of casting dev->priv directly.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Fix non-ANSI function declaration:
net/netfilter/nf_conntrack_core.c:1096:25: warning: non-ANSI function declaration of function 'nf_conntrack_flush'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change the message to more clearly identify Serdes devices.
Update version to 3.70.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change some udelay() in some eeprom functions to msleep(). Eeprom
related functions are always called from sleepable context.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use netif_msg_* to turn on or off some messages.
Based on Stephen Hemminger's initial patch.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Honor the advertisement bitmask from ethtool. We used to always
advertise the full capability when autoneg was set to on.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add Tg3_FLG2_IS_NIC flag to unambiguously determine whether the
device is NIC or onboard. Previously, the EEPROM_WRITE_PROT flag was
overloaded to also mean onboard. With the separation, we can
support some devices that are onboard but do not use eeprom write
protect.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Phy loopback on most 10/100 devices need to be run in 1Gbps mode in
GMII mode.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As per Ralf Baechle's observations, the schedule_work() call
should give enough of a memory barrier, so the explicit one
here is totally unnecessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
I believe all the below memory barriers only matter on SMP so
therefore the smp_* variant of the barrier should be used.
I'm wondering if the barrier in net/ipv4/inet_timewait_sock.c should be
dropped entirely. schedule_work's implementation currently implies a
memory barrier and I think sane semantics of schedule_work() should imply
a memory barrier, as needed so the caller shouldn't have to worry.
It's not quite obvious why the barrier in net/packet/af_packet.c is
needed; maybe it should be implied through flush_dcache_page?
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We grab a reference to the route's inetpeer entry but
forget to release it in xfrm4_dst_destroy().
Bug discovered by Kazunori MIYAZAWA <kazunori@miyazawa.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Disables auditing in ipsec when CONFIG_AUDITSYSCALL is
disabled in the kernel.
Also includes a bug fix for xfrm_state.c as a result of
original ipsec audit patch.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
An audit message occurs when an ipsec SA
or ipsec policy is created/deleted.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/irda/irlan_filter.h:31: warning: 'struct seq_file' declared inside parameter list
include/net/irda/irlan_filter.h:31: warning: its scope is only this definition or declaration, which is probably not what you want
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We must reserve SAR + MAX_HEADER bytes for IrLMP to fit in.
Patch from Jeet Chaudhuri <jeetlinux@yahoo.co.in>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
pxaficp_ir.c was not converted to the device model framework.
Signed-off-by: Paul Sokolovsky <pmiscml@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The command flags for dump and do were swapped..
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a pointer to the OSDL wiki page on Generic Netlink.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When user builds IPv6 header and send it through raw socket, kernel
tries to release unlocked sock. (Kernel log shows
"BUG: bad unlock balance detected" with enabled debug option.)
The lock is held only for non-hdrincl sock in this function
then this patch fix to do nothing about lock for hdrincl one.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit "[IPV6]: Use kmemdup" (commit-id:
af879cc704) broke IPv6 fragments.
Bug was spotted by Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the first fw classifier is initialized, there is a small window
between the ->init() and ->change() calls, during which the classifier
is active but not entirely set up and tp->root is still NULL (->init()
does nothing).
When a packet is queued during this window a NULL pointer dereference
occurs in fw_classify() when trying to dereference head->mask;
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The attached patch resolves an issue where a IP DNATed packet with a
martian source is forwarded while it's better to drop it. It also
resolves messages complaining about ip forwarding being disabled while
it's actually enabled. Thanks to lepton <ytht.net@gmail.com> for
reporting this problem.
This is probably a candidate for the -stable release.
Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The original code continues loop to find expectation in list if the master
conntrack of the found expectation is unconfirmed. But it never success
in that case, because nf_conntrack_expect_related() never insert
clashed expectation to the list.
This stops loop in that case.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
