Currently reset methods are not specified directly in the
ata_port_operations table. If a LLD wants to use custom reset
methods, it should construct and use a error_handler which uses those
reset methods. It's done this way for two reasons.
First, the ops table already contained too many methods and adding
four more of them would noticeably increase the amount of necessary
boilerplate code all over low level drivers.
Second, as ->error_handler uses those reset methods, it can get
confusing. ie. By overriding ->error_handler, those reset ops can be
made useless making layering a bit hazy.
Now that ops table uses inheritance, the first problem doesn't exist
anymore. The second isn't completely solved but is relieved by
providing default values - most drivers can just override what it has
implemented and don't have to concern itself about higher level
callbacks. In fact, there currently is no driver which actually
modifies error handling behavior. Drivers which override
->error_handler just wraps the standard error handler only to prepare
the controller for EH. I don't think making ops layering strict has
any noticeable benefit.
This patch makes ->prereset, ->softreset, ->hardreset, ->postreset and
their PMP counterparts propoer ops. Default ops are provided in the
base ops tables and drivers are converted to override individual reset
methods instead of creating custom error_handler.
* ata_std_error_handler() doesn't use sata_std_hardreset() if SCRs
aren't accessible. sata_promise doesn't need to use separate
error_handlers for PATA and SATA anymore.
* softreset is broken for sata_inic162x and sata_sx4. As libata now
always prefers hardreset, this doesn't really matter but the ops are
forced to NULL using ATA_OP_NULL for documentation purpose.
* pata_hpt374 needs to use different prereset for the first and second
PCI functions. This used to be done by branching from
hpt374_error_handler(). The proper way to do this is to use
separate ops and port_info tables for each function. Converted.
Signed-off-by: Tejun Heo <htejun@gmail.com>
libata core layer doesn't care about sht or ->irq_handler. Those are
only of interest to the LLD during initialization. This is confusing
and has caused several drivers to have duplicate unused initializers
for these fields.
Currently only sata_nv uses these fields. Make sata_nv use
->private_data, which is supposed to carry LLD-specific information,
instead and kill ->sht and ->irq_handler. nv_pi_priv structure is
defined and struct literals are used to initialize private_data.
Notational overhead is negligible.
Signed-off-by: Tejun Heo <htejun@gmail.com>
port_info->private_data is currently used for two purposes - to record
private data about the port_info or to specify host->private_data to
use when allocating ata_host.
This overloading is confusing and counter-intuitive in that
port_info->private_data becomes host->private_data instead of
port->private_data. In addition, port_info and host don't correspond
to each other 1-to-1. Currently, the first non-NULL
port_info->private_data is used.
This patch makes port_info->private_data just be what it is -
private_data for the port_info where LLD can jot down extra info.
libata no longer sets host->private_data to the first non-NULL
port_info->private_data, @host_priv argument is added to
ata_pci_init_one() instead. LLDs which use ata_pci_init_one() can use
this argument to pass in pointer to host private data. LLDs which
don't should use init-register model anyway and can initialize
host->private_data directly.
Adding @host_priv instead of using init-register model for LLDs which
use ata_pci_init_one() is suggested by Alan Cox.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
ata_pci_init_one() is the only function which uses ops->irq_handler
and pi->sht. Other initialization functions take the same information
as arguments. This causes confusion and duplicate unused entries in
structures.
Make ata_pci_init_one() take sht as an argument and use ata_interrupt
implicitly. All current users use ata_interrupt and if different irq
handler is necessary open coding ata_pci_init_one() using
ata_prepare_sff_host() and ata_activate_sff_host can be done under ten
lines including error handling and driver which requires custom
interrupt handler is likely to require custom initialization anyway.
As ata_pci_init_one() was the last user of ops->irq_handler, this
patch also kills the field.
Signed-off-by: Tejun Heo <htejun@gmail.com>
libata lets low level drivers build ata_port_operations table and
register it with libata core layer. This allows low level drivers
high level of flexibility but also burdens them with lots of
boilerplate entries.
This becomes worse for drivers which support related similar
controllers which differ slightly. They share most of the operations
except for a few. However, the driver still needs to list all
operations for each variant. This results in large number of
duplicate entries, which is not only inefficient but also error-prone
as it becomes very difficult to tell what the actual differences are.
This duplicate boilerplates all over the low level drivers also make
updating the core layer exteremely difficult and error-prone. When
compounded with multi-branched development model, it ends up
accumulating inconsistencies over time. Some of those inconsistencies
cause immediate problems and fixed. Others just remain there dormant
making maintenance increasingly difficult.
To rectify the problem, this patch implements ata_port_operations
inheritance. To allow LLDs to easily re-use their own ops tables
overriding only specific methods, this patch implements poor man's
class inheritance. An ops table has ->inherits field which can be set
to any ops table as long as it doesn't create a loop. When the host
is started, the inheritance chain is followed and any operation which
isn't specified is taken from the nearest ancestor which has it
specified. This operation is called finalization and done only once
per an ops table and the LLD doesn't have to do anything special about
it other than making the ops table non-const such that libata can
update it.
libata provides four base ops tables lower drivers can inherit from -
base, sata, pmp, sff and bmdma. To avoid overriding these ops
accidentaly, these ops are declared const and LLDs should always
inherit these instead of using them directly.
After finalization, all the ops table are identical before and after
the patch except for setting .irq_handler to ata_interrupt in drivers
which didn't use to. The .irq_handler doesn't have any actual effect
and the field will soon be removed by later patch.
* sata_sx4 is still using old style EH and currently doesn't take
advantage of ops inheritance.
Signed-off-by: Tejun Heo <htejun@gmail.com>
libata lets low level drivers build scsi_host_template and register it
to the SCSI layer. This allows low level drivers high level of
flexibility but also burdens them with lots of boilerplate entries.
This patch implements SHT initializers which can be used to initialize
all the boilerplate entries in a sht. Three variants of them are
implemented - BASE, BMDMA and NCQ - for different types of drivers.
Note that entries can be overriden by putting individual initializers
after the helper macro.
All sht tables are identical before and after this patch.
Signed-off-by: Tejun Heo <htejun@gmail.com>
->irq_clear() is used to clear IRQ bit of a SFF controller and isn't
useful for drivers which don't use libata SFF HSM implementation.
However, it's a required callback and many drivers implement their own
noop version as placeholder. This patch implements ata_noop_irq_clear
and use it to replace those custom placeholders.
Also, SFF drivers which don't support BMDMA don't need to use
ata_bmdma_irq_clear(). It becomes noop if BMDMA address isn't
initialized. Convert them to use ata_noop_irq_clear().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Over the time, ops in ata_port_operations has become a bit confusing.
Reorganize. SFF/BMDMA ops are separated into separate a group as they
will be taken out of ata_port_operations later.
Signed-off-by: Tejun Heo <htejun@gmail.com>
ata_ehi_schedule_probe() was created to hide details of link-resuming
reset magic. Now that all the softreset workarounds are gone,
scheduling probe is very simple - set probe_mask and request RESET.
Kill ata_ehi_schedule_probe() and open code it. This also increases
consistency as ata_ehi_schedule_probe() couldn't cover individual
device probings so they were open-coded even when the helper existed.
While at it, define ATA_ALL_DEVICES as mask of all possible devices on
a link and always use it when requesting probe on link level for
simplicity and consistency. Setting extra bits in the probe_mask
doesn't hurt anybody.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Some controllers can't reliably record the initial D2H FIS after SATA
link is brought online for whatever reason. Advanced controllers
which don't have traditional TF register based interface often have
this problem as they don't really have the TF registers to update
while the controller and link are being initialized.
SKIP_D2H_BSY works around the problem by skipping the wait for device
readiness before issuing SRST, so for such controllers libata issues
SRST blindly and hopes for the best.
Now that libata defaults to hardreset, this workaround is no longer
necessary. For controllers which have support for hardreset, SRST is
never issued by itself. It is only issued as follow-up SRST for
device classification and PMP initialization, so there's no need to
wait for it from prereset.
Kill ATA_LFLAG_SKIP_D2H_BSY.
Signed-off-by: Tejun Heo <htejun@gmail.com>
ATA_EHI_RESUME_LINK has two functions - promote reset to hardreset if
ATA_LFLAG_HRST_TO_RESUME is set and preventing EH from shortcutting
reset action when probing is requested. The former is gone now and
the latter can easily be achieved by making EH to perform at least one
reset if reset is requested, which also makes more sense than
depending on RESUME_LINK flag.
As ATA_EHI_RESUME_LINK was the only EHI reset modifier, this also
kills reset modifier handling.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Now that hardreset is the preferred method of resetting, there's no
need for ATA_LFLAG_HRST_TO_RESUME flag. Kill it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
When both soft and hard resets are available, libata preferred
softreset till now. The logic behind it was to be softer to devices;
however, this doesn't really help much. Rationales for the change:
* BIOS may freeze lock certain things during boot and softreset can't
unlock those. This by itself is okay but during operation PHY event
or other error conditions can trigger hardreset and the device may
end up with different configuration.
For example, after a hardreset, previously unlockable HPA can be
unlocked resulting in different device size and thus revalidation
failure. Similar condition can occur during or after resume.
* Certain ATAPI devices require hardreset to recover after certain
error conditions. On PATA, this is done by issuing the DEVICE RESET
command. On SATA, COMRESET has equivalent effect. The problem is
that DEVICE RESET needs its own execution protocol.
For SFF controllers with bare TF access, it can be easily
implemented but more advanced controllers (e.g. ahci and sata_sil24)
require specialized implementations. Simply using hardreset solves
the problem nicely.
* COMRESET initialization sequence is the norm in SATA land and many
SATA devices don't work properly if only SRST is used. For example,
some PMPs behave this way and libata works around by always issuing
hardreset if the host supports PMP.
Like the above example, libata has developed a number of mechanisms
aiming to promote softreset to hardreset if softreset is not going
to work. This approach is time consuming and error prone.
Also, note that, dependingon how you read the specs, it could be
argued that PMP fan-out ports require COMRESET to start operation.
In fact, all the PMPs on the market except one don't work properly
if COMRESET is not issued to fan-out ports after PMP reset.
* COMRESET is an integral part of SATA connection and any working
device should be able to handle COMRESET properly. After all, it's
the way to signal hardreset during reboot. This is the most used
and recommended (at least by the ahci spec) method of resetting
devices.
So, this patch makes libata prefer hardreset over softreset by making
the following changes.
* Rename ATA_EH_RESET_MASK to ATA_EH_RESET and use it whereever
ATA_EH_{SOFT|HARD}RESET used to be used. ATA_EH_{SOFT|HARD}RESET is
now only used to tell prereset whether soft or hard reset will be
issued.
* Strip out now unneeded promote-to-hardreset logics from
ata_eh_reset(), ata_std_prereset(), sata_pmp_std_prereset() and
other places.
Signed-off-by: Tejun Heo <htejun@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
it821x: do not describe noraid parameter with its value
Pb1200/DBAu1200: fix bad IDE resource size
Au1200: IDE driver build fix
Au1200: kill IDE driver function prototypes
avr32 mustn't select HAVE_IDE
The header files for the Pb1200/DBAu1200 boards have wrong definition for the
IDE interface's decoded range length -- it should be 512 bytes according to
what the IDE driver does. In addition, the IDE platform device claims 1 byte
too many for its memory resource -- fix the platform code and the IDE driver
in accordance.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Fix these warnings emitted when compiling drivers/ide/mips/au1xxx-ide.c:
include/asm/mach-au1x00/au1xxx_ide.h:137: warning: 'auide_tune_drive' declared
`static' but never defined
include/asm/mach-au1x00/au1xxx_ide.h:138: warning: 'auide_tune_chipset' declared
`static' but never defined
by wiping out the whole "function prototyping" section from the header file
<asm-mips/mach-au1x00/au1xxx_ide.h> as it mostly declared functions that are
already dead in the IDE driver; move the only useful prototype into the driver.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
[TCP]: Add return value indication to tcp_prune_ofo_queue().
PS3: gelic: fix the oops on the broken IE returned from the hypervisor
b43legacy: fix DMA mapping leakage
mac80211: remove message on receiving unexpected unencrypted frames
Update rt2x00 MAINTAINERS entry
Add rfkill to MAINTAINERS file
rfkill: Fix device type check when toggling states
b43legacy: Fix usage of struct device used for DMAing
ssb: Fix usage of struct device used for DMAing
MAINTAINERS: move to generic repository for iwlwifi
b43legacy: fix initvals loading on bcm4303
rtl8187: Add missing priv->vif assignments
netconsole: only set CON_PRINTBUFFER if the user specifies a netconsole
[CAN]: Update documentation of struct sockaddr_can
MAINTAINERS: isdn4linux@listserv.isdn4linux.de is subscribers-only
[TCP]: Fix never pruned tcp out-of-order queue.
[NET_SCHED] sch_api: fix qdisc_tree_decrease_qlen() loop
The THERMAL_MAX_TRIPS value is set to 10. It is too few for the Compaq AP550
machine which has 12 trip points.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The SPI core now expects num_chipselect to be set correctly as due to added
checks on the chip being selected before an transfer is allowed. This patch
adds a num_cs field to the platform data which needs to be set correctly
before adding the SPI platform device.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mb_cache_entry_alloc() was allocating cache entries with GFP_KERNEL. But
filesystems are calling this function while holding xattr_sem so possible
recursion into the fs violates locking ordering of xattr_sem and transaction
start / i_mutex for ext2-4. Change mb_cache_entry_alloc() so that filesystems
can specify desired gfp mask and use GFP_NOFS from all of them.
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Dave Jones <davej@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes this error:
In file included from /home/wangcong/projects/linux-2.6/arch/um/kernel/smp.c:9:
include2/asm/tlb.h: In function `tlb_remove_page':
include2/asm/tlb.h:101: error: implicit declaration of function `page_cache_release'
And since including <linux/pagemap.h> in <linux/swap.h> will break sparc,
we add this #include in uml's own header.
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes DMA on architectures where DMA is nontrivial, like PPC64.
We must use the host-device's (PCI) struct device for any DMA
operation instead of the SSB device. For this we add a new
struct device pointer to the SSB device structure that will always
point to the right device for DMAing.
Without this patch b43 and b44 drivers won't work on complex-DMA
architectures, that for example need dev->archdata for DMA operations.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (31 commits)
[BRIDGE]: Fix crash in __ip_route_output_key with bridge netfilter
[NETFILTER]: ipt_CLUSTERIP: fix race between clusterip_config_find_get and _entry_put
[IPV6] ADDRCONF: Don't generate temporary address for ip6-ip6 interface.
[IPV6] ADDRCONF: Ensure disabling multicast RS even if privacy extensions are disabled.
[IPV6]: Use appropriate sock tclass setting for routing lookup.
[IPV6]: IPv6 extension header structures need to be packed.
[IPV6]: Fix ipv6 address fetching in raw6_icmp_error().
[NET]: Return more appropriate error from eth_validate_addr().
[ISDN]: Do not validate ISDN net device address prior to interface-up
[NET]: Fix kernel-doc for skb_segment
[SOCK] sk_stamp: should be initialized to ktime_set(-1L, 0)
net: check for underlength tap writes
net: make struct tun_struct private to tun.c
[SCTP]: IPv4 vs IPv6 addresses mess in sctp_inet[6]addr_event.
[SCTP]: Fix compiler warning about const qualifiers
[SCTP]: Fix protocol violation when receiving an error lenght INIT-ACK
[SCTP]: Add check for hmac_algo parameter in sctp_verify_param()
[NET_SCHED] cls_u32: refcounting fix for u32_delete()
[DCCP]: Fix skb->cb conflicts with IP
[AX25]: Potential ax25_uid_assoc-s leaks on module unload.
...
struct ipv6_opt_hdr is the common structure for IPv6 extension
headers, and it is common to increment the pointer to get
the real content. On the other hand, since the structure
consists only of 1-byte next-header field and 1-byte length
field, size of that structure depends on architecture; 2 or 4.
Add "packed" attribute to get 2.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There's no reason for this to be in the header, and it just hurts
recompile time.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Max Krasnyanskiy <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix 3 warnings about discarding const qualifiers:
net/sctp/ulpevent.c:862: warning: passing argument 1 of 'sctp_event2skb' discards qualifiers from pointer target type
net/sctp/sm_statefuns.c:4393: warning: passing argument 1 of 'SCTP_ASOC' discards qualifiers from pointer target type
net/sctp/socket.c:5874: warning: passing argument 1 of 'cmsg_nxthdr' discards qualifiers from pointer target type
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When receiving an error length INIT-ACK during COOKIE-WAIT,
a 0-vtag ABORT will be responsed. This action violates the
protocol apparently. This patch achieves the following things.
1 If the INIT-ACK contains all the fixed parameters, use init-tag
recorded from INIT-ACK as vtag.
2 If the INIT-ACK doesn't contain all the fixed parameters,
just reflect its vtag.
Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'docs' of git://git.lwn.net/linux-2.6:
Add additional examples in Documentation/spinlocks.txt
Move sched-rt-group.txt to scheduler/
Documentation: move rpc-cache.txt to filesystems/
Documentation: move nfsroot.txt to filesystems/
Spell out behavior of atomic_dec_and_lock() in kerneldoc
Fix a typo in highres.txt
Fixes to the seq_file document
Fill out information on patch tags in SubmittingPatches
Add the seq_file documentation
git commit 54a0151041 ("asmlinkage_protect
replaces prevent_tail_call") causes this build failure on s390:
AS arch/s390/kernel/entry64.o
In file included from arch/s390/kernel/entry64.S:14:
include/linux/linkage.h:34: error: syntax error in macro parameter list
make[1]: *** [arch/s390/kernel/entry64.o] Error 1
make: *** [arch/s390/kernel] Error 2
and some other architectures. The reason is that some architectures add
the "-traditional" flag to the invocation of $(AS), which disables
variadic macro argument support.
So just surround the new define with an #ifndef __ASSEMBLY__ to prevent
any side effects on asm code.
Cc: Roland McGrath <roland@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
[NETNS][IPV6] tcp - assign the netns for timewait sockets
[IPV4]: Fix byte value boundary check in do_ip_getsockopt().
BNX2X: Correct bringing chip out of reset
[NETFILTER]: nf_nat: autoload IPv4 connection tracking
[NETFILTER]: xt_hashlimit: fix mask calculation
[XFRM]: xfrm_user: fix selector family initialization
rt61pci: rt61pci_beacon_update do not free skb twice
ssb-mipscore: Fix interrupt vectors
ssb-pcicore: Fix IRQ TPS flag handling
mac80211: use short_preamble mode from capability if ERP IE not present
[NET]: Undo code bloat in hot paths due to print_mac().
[TCP]: Don't allow FRTO to take place while MTU is being probed
[TCP]: tcp_simple_retransmit can cause S+L
[TCP]: Fix NewReno's fast rexmit/recovery problems with GSOed skb
[TCP]: Restore 2.6.24 mark_head_lost behavior for newreno/fack
nl80211: fix STA AID bug
b43legacy: fix bcm4303 crash
iwlwifi: fix n-band association problem
ipw2200: set MAC address on radiotap interface
libertas: fix mode initialization problem
Increase the PNP "number of devices" limit. We currently use an unsigned
char, which limits us to 256 devices per protocol. This patch changes that to
an unsigned int.
Not all backends can take advantage of this: we limit ISAPNP to 10 devices in
isapnp_cfg_begin(), and PNPBIOS is limited to 256 devices because the BIOS
interfaces use a one-byte device node number.
But there is no limit on the number of PNPACPI devices we may have. Large HP
Integrity machines have more than 256, which causes the current "unsigned char
number" to wrap around. This causes errors like this:
pnp: PnP ACPI init
kobject_add failed for 00:00 with -EEXIST, don't try to register things with the same name in the same directory.
Call Trace:
[<a000000100010720>] show_stack+0x40/0xa0
[<a0000001000107b0>] dump_stack+0x30/0x60
[<a0000001001dbdf0>] kobject_add+0x290/0x2c0
[<a0000001002bfd40>] device_add+0x160/0x860
[<a0000001002c0470>] device_register+0x30/0x60
[<a00000010026ba70>] __pnp_add_device+0x130/0x180
[<a00000010026bb70>] pnp_add_device+0xb0/0xe0
[<a0000001007f2730>] pnpacpi_add_device+0x510/0x5a0
[<a0000001007f2810>] pnpacpi_add_device_handler+0x50/0x80
This patch increases the limit to fix this PNPACPI problem. It should not
have any adverse effect on ISAPNP or PNPBIOS because their limits are still
enforced in the backends.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's really a pretty ugly thing to need, and some day it will hopefully
be obviated by teaching gcc about the magic calling conventions for the
low-level system call code, but in the meantime we can at least add big
honking comments about why we need these insane and strange macros.
I took my comments from my version of the macro, but I ended up deciding
to just pick Roland's version of the actual code instead (with his
prettier syntax that uses vararg macros). Thus the previous two commits
that actually implement it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The prevent_tail_call() macro works around the problem of the compiler
clobbering argument words on the stack, which for asmlinkage functions
is the caller's (user's) struct pt_regs. The tail/sibling-call
optimization is not the only way that the compiler can decide to use
stack argument words as scratch space, which we have to prevent.
Other optimizations can do it too.
Until we have new compiler support to make "asmlinkage" binding on the
compiler's own use of the stack argument frame, we have work around all
the manifestations of this issue that crop up.
More cases seem to be prevented by also keeping the incoming argument
variables live at the end of the function. This makes their original
stack slots attractive places to leave those variables, so the compiler
tends not clobber them for something else. It's still no guarantee, but
it handles some observed cases that prevent_tail_call() did not.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't make smp_{r,w,}mb() interpolate a MEMBAR instruction when CONFIG_SMP=n as
SMP memory barries on UP systems should interpolate a compiler barrier only.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB-
and ADD-to-memory operations for userspace.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move STACK_TOP_MAX up so that we don't try moving the stack above it as that
causes setup_arg_pages() to malfunction.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Handle update_mmu_cache() being called when current->mm is NULL.
We cache static TLB mappings for the current page table in DAMPR4 and DAMPR5
on the theory that the next data lookup is likely to be in the same general
region, and thus is likely to be mapped by the same page table. However, we
can't get this information if we can't access the appropriate mm_struct.
If current->mm is NULL, we just clear the cache in the knowledge that the TLB
miss handlers will load it.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes Bugzilla #10384
tcp_simple_retransmit does L increment without any checking
whatsoever for overflowing S+L when Reno is in use.
The simplest scenario I can currently think of is rather
complex in practice (there might be some more straightforward
cases though). Ie., if mss is reduced during mtu probing, it
may end up marking everything lost and if some duplicate ACKs
arrived prior to that sacked_out will be non-zero as well,
leading to S+L > packets_out, tcp_clean_rtx_queue on the next
cumulative ACK or tcp_fastretrans_alert on the next duplicate
ACK will fix the S counter.
More straightforward (but questionable) solution would be to
just call tcp_reset_reno_sack() in tcp_simple_retransmit but
it would negatively impact the probe's retransmission, ie.,
the retransmissions would not occur if some duplicate ACKs
had arrived.
So I had to add reno sacked_out reseting to CA_Loss state
when the first cumulative ACK arrives (this stale sacked_out
might actually be the explanation for the reports of left_out
overflows in kernel prior to 2.6.23 and S+L overflow reports
of 2.6.24). However, this alone won't be enough to fix kernel
before 2.6.24 because it is building on top of the commit
1b6d427bb7 ([TCP]: Reduce sacked_out with reno when purging
write_queue) to keep the sacked_out from overflowing.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Reported-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
flush_cache_vmap / flush_cache_vunmap were calling flush_cache_all which -
having been deprecated - turned into a nop ...
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
x86: fix 64-bit asm NOPS for CONFIG_GENERIC_CPU
x86: fix call to set_cyc2ns_scale() from time_cpufreq_notifier()
revert "x86: tsc prevent time going backwards"
The 'disable_cb' callback is designed as an optimization to tell the host
we don't need callbacks now. As it is not reliable, the debug check is
overzealous: it can happen on two CPUs at the same time. Document this.
Even if it were reliable, the virtio_net driver doesn't disable
callbacks on transmit so the START_USE/END_USE debugging reentrance
protection can be easily tripped even on UP.
Thanks to Balaji Rao for the bug report and testing.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The effects of cgroup_disable=foo are:
- foo isn't auto-mounted if you mount all cgroups in a single hierarchy
- foo isn't visible as an individually mountable subsystem
As a result there will only ever be one call to foo->create(), at init time;
all processes will stay in this group, and the group will never be mounted on
a visible hierarchy. Any additional effects (e.g. not allocating metadata)
are up to the foo subsystem.
This doesn't handle early_init subsystems (their "disabled" bit isn't set be,
but it could easily be extended to do so if any of the early_init systems
wanted it - I think it would just involve some nastier parameter processing
since it would occur before the command-line argument parser had been run.
Hugh said:
Ballpark figures, I'm trying to get this question out rather than
processing the exact numbers: CONFIG_CGROUP_MEM_RES_CTLR adds 15% overhead
to the affected paths, booting with cgroup_disable=memory cuts that back to
1% overhead (due to slightly bigger struct page).
I'm no expert on distros, they may have no interest whatever in
CONFIG_CGROUP_MEM_RES_CTLR=y; and the rest of us can easily build with or
without it, or apply the cgroup_disable=memory patches.
Unix bench's execl test result on x86_64 was
== just after boot without mounting any cgroup fs.==
mem_cgorup=off : Execl Throughput 43.0 3150.1 732.6
mem_cgroup=on : Execl Throughput 43.0 2932.6 682.0
==
[lizf@cn.fujitsu.com: fix boot option parsing]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tejun Heo
Linus Torvalds
Sergei Shtylyov
Krzysztof Helt
Ben Dooks
Jan Kara
WANG Cong
Michael Buesch
Jens Axboe
YOSHIFUJI Hideaki
Rusty Russell
Vlad Yasevich
Gui Jianfeng
J. Bruce Fields
Heiko Carstens
Bjorn Helgaas
Roland McGrath
David Howells
Ilpo Järvinen
Ralf Baechle
Suresh Siddha
Paul Menage