For quite some time there have been problems with memory barriers and
various races with NMI on multi processor systems using the kernel
debugger. The algorithm for entering the kernel debug core and
resuming kernel execution was racy and had several known edge case
problems with attempting to debug something on a heavily loaded system
using breakpoints that are hit repeatedly and quickly.
The prior "locking" design entry worked as follows:
* The atomic counter kgdb_active was used with atomic exchange in
order to elect a master cpu out of all the cpus that may have
taken a debug exception.
* The master cpu increments all elements of passive_cpu_wait[].
* The master cpu issues the round up cpus message.
* Each "slave cpu" that enters the debug core increments its own
element in cpu_in_kgdb[].
* Each "slave cpu" spins on passive_cpu_wait[] until it becomes 0.
* The master cpu debugs the system.
The new scheme removes the two arrays of atomic counters and replaces
them with 2 single counters. One counter is used to count the number
of cpus waiting to become a master cpu (because one or more hit an
exception). The second counter is use to indicate how many cpus have
entered as slave cpus.
The new entry logic works as follows:
* One or more cpus enters via kgdb_handle_exception() and increments
the masters_in_kgdb. Each cpu attempts to get the spin lock called
dbg_master_lock.
* The master cpu sets kgdb_active to the current cpu.
* The master cpu takes the spinlock dbg_slave_lock.
* The master cpu asks to round up all the other cpus.
* Each slave cpu that is not already in kgdb_handle_exception()
will enter and increment slaves_in_kgdb. Each slave will now spin
try_locking on dbg_slave_lock.
* The master cpu waits for the sum of masters_in_kgdb and slaves_in_kgdb
to be equal to the sum of the online cpus.
* The master cpu debugs the system.
In the new design the kgdb_active can only be changed while holding
dbg_master_lock. Stress testing has not turned up any further
entry/exit races that existed in the prior locking design. The prior
locking design suffered from atomic variables not being truly atomic
(in the capacity as used by kgdb) along with memory barrier races.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dongdong Deng <dongdong.deng@windriver.com>
The kernel debug_core invokes hw breakpoint install and removal via
call backs. The architecture specific kgdb stubs only need to
implement the call backs and not actually call the functions.
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: x86@kernel.org
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: H. Peter Anvin <hpa@zytor.com>
The slave cpus do not have the hw breakpoints disabled upon entry to
the debug_core and as a result could cause unrecoverable recursive
faults on badly placed breakpoints, or get out of sync with the arch
specific hw breakpoint operations.
This patch addresses the problem by invoking kgdb_disable_hw_debug()
earlier in kgdb_enter_cpu for each cpu that enters the debug core.
The hw breakpoint dis/enable flow should be:
master_debug_cpu slave_debug_cpu
\ /
kgdb_cpu_enter
|
kgdb_disable_hw_debug --> uninstall pre-enabled hw_breakpoint
|
do add/rm dis/enable operates to hw_breakpoints on master_debug_cpu..
|
correct_hw_break --> correct/install the enabled hw_breakpoint
|
leave_kgdb
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Fix the following sparse warnings:
kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static?
kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static?
kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces)
kgdb.c:652:26: expected void const *ptr
kgdb.c:652:26: got struct perf_event *[noderef] <asn:3>*pev
The one in kgdb.c required the (void * __force) because of the return
code from register_wide_hw_breakpoint looking like:
return (void __percpu __force *)ERR_PTR(err);
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Nothing should try to use kdb_commands directly as sometimes it is
null. Instead, use the for_each_kdbcmd() iterator.
This particular problem dates back to the initial kdb merge (2.6.35),
but at that point nothing was dynamically unregistering commands from
the kdb shell.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Now that include/linux/kdb.h properly exports all the functions
required to dynamically add a kdb shell command, the reference to the
private kdb header can be removed.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
In order to allow kernel modules to dynamically add a command to the
kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and
kdb_printf need to be exported as GPL symbols.
Any kernel module that adds a dynamic kdb shell function should only
need to include linux/kdb.h.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
When returning from the kernel debugger reset the rcu jiffies_stall
value to prevent the rcu stall detector from sending NMI events which
invoke a stack dump for each cpu in the system.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Move the various clock and watch dog syncs to a single function in
advance of adding another sync for the rcu stall detector.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
HW breakpoints events stopped working correctly with kgdb as a result
of commit: 018cbffe68 (Merge commit
'v2.6.33' into perf/core), later commit:
ba773f7c51 (x86,kgdb: Fix hw breakpoint
regression) allowed breakpoints to propagate to the debugger core but
did not completely address the original regression in functionality
found in 2.6.35.
When the DR_STEP flag is set in dr6 along with any of the DR_TRAP
bits, the kgdb exception handler will enter once from the
hw_breakpoint API call back and again from the die notifier for
do_debug(), which causes the debugger to stop twice and also for the
kgdb regression tests to fail running under kvm with:
echo V2I1 > /sys/module/kgdbts/parameters/kgdbts
To address the problem, the kgdb overflow handler needs to implement
the same logic as the ptrace overflow handler call back with respect
to updating the virtual copy of dr6. This will allow the kgdb
do_debug() die notifier to properly handle the exception and the
attached debugger, or kgdb test suite, will only receive a single
notification.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: x86@kernel.org
Start unifying the PPI/EPPI peripheral structures in one place. This
may be used by camera/video/fpga/high speed devices.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This matches all the other Blackfin ports and keep us from having to write
bf561-specific code in many places.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Now that the common 8250 serial driver supports an "irqflags" field,
we don't need to patch in a custom define into the code.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Different arches use different names, so make sure we define both so
common code (like MTD_XIP) "just works".
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Mainline version of git merged support for Blackfin parts, but we now
need to propagate the gcc arch define to make it work.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We have to use ioctl numbers that don't collide with common code.
Otherwise, these ones never even get called because the common fs
code swalled all invocations.
Reported-by: Kay Duenzer <kduenzer@maku.eu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This board has a SSM2603 codec, so make sure we have the right resources
declared for it.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The RX/TX address is always the same regardless of the size of the access.
That means there is no dedicated "16bit" or "32bit" MMR. Trying to use
these currently leads to compile errors. So change everything to use the
right MMR define.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
pcmcia: fix ni_daq_700 compilation
pcmcia: IOCARD is also required for using IRQs
* git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
asm-generic/io.h: allow people to override individual funcs
bitops: remove duplicated extern declarations
bitops: make asm-generic/bitops/find.h more generic
asm-generic: kdebug.h: Checkpatch cleanup
asm-generic: fcntl: make exported headers use strict posix types
asm-generic: cmpxchg does not handle non-long arguments
asm-generic: make atomic_add_unless a function
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
* 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits)
BKL: remove BKL from freevxfs
BKL: remove BKL from qnx4
autofs4: Only declare function when CONFIG_COMPAT is defined
autofs: Only declare function when CONFIG_COMPAT is defined
ncpfs: Lock socket in ncpfs while setting its callbacks
fs/locks.c: prepare for BKL removal
BKL: Remove BKL from ncpfs
BKL: Remove BKL from OCFS2
BKL: Remove BKL from squashfs
BKL: Remove BKL from jffs2
BKL: Remove BKL from ecryptfs
BKL: Remove BKL from afs
BKL: Remove BKL from USB gadgetfs
BKL: Remove BKL from autofs4
BKL: Remove BKL from isofs
BKL: Remove BKL from fat
BKL: Remove BKL from ext2 filesystem
BKL: Remove BKL from do_new_mount()
BKL: Remove BKL from cgroup
BKL: Remove BKL from NTFS
...
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
block: autoconvert trivial BKL users to private mutex
drivers: autoconvert trivial BKL users to private mutex
ipmi: autoconvert trivial BKL users to private mutex
mac: autoconvert trivial BKL users to private mutex
mtd: autoconvert trivial BKL users to private mutex
scsi: autoconvert trivial BKL users to private mutex
Fix up trivial conflicts (due to addition of private mutex right next to
deletion of a version string) in drivers/char/pcmcia/cm40[04]0_cs.c
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: introduce CONFIG_BKL.
dabusb: remove the BKL
sunrpc: remove the big kernel lock
init/main.c: remove BKL notations
blktrace: remove the big kernel lock
rtmutex-tester: make it build without BKL
dvb-core: kill the big kernel lock
dvb/bt8xx: kill the big kernel lock
tlclk: remove big kernel lock
fix rawctl compat ioctls breakage on amd64 and itanic
uml: kill big kernel lock
parisc: remove big kernel lock
cris: autoconvert trivial BKL users
alpha: kill big kernel lock
isapnp: BKL removal
s390/block: kill the big kernel lock
hpet: kill BKL, add compat_ioctl
Fix regression introduced by commit
f26788da3b (USB: serial: refactor generic
close) which broke driver close().
This driver uses non-standard semantics for the read urb which makes the
generic close function fail to kill it (the read urb is actually an
interrupt urb and therefore bulk_in size is zero).
Reported-by: Eric Shattow "Eprecocious" <lucent@gmail.com>
Tested-by: Eric Shattow "Eprecocious" <lucent@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In function udc_probe() call put_device() when device_register() fails.
Signed-off-by: Rahul Ruikar <rahul.ruikar@gmail.com>
Acked-by: Thomas Dahlmann <dahlmann.thomas@arcor.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
warning: (USB_MUSB_HDRC_HCD && USB_SUPPORT && USB_MUSB_HDRC &&
(USB_MUSB_HOST || USB_MUSB_OTG) && USB_GADGET_MUSB_HDRC || USB_MUSB_OTG
&& <choice> && USB && USB_GADGET && PM && EXPERIMENTAL) selects USB_OTG
which has unmet direct dependencies (USB_GADGET_OMAP && ARCH_OMAP_OTG &&
USB_OHCI_HCD)
This doesn't seem to happen on 2.6.36-rc8, but still doesn't make sense
to keep this duplicated config that is already defined in usb/core.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When USB was removed, this patch prepares for the next insertion.
Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
this patch gives the possibility to workaround bug ENGcm09152
on i.MX35 when the hardware workaround is also implemented on
the board.
It covers the workaround described on page 25 of the following Errata :
http://cache.freescale.com/files/dsp/doc/errata/IMX35CE.pdf
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds the requested device ids to the ftdi_sio driver.
Reported-by: Ewan Bingham <ewan@auc.co.uk>
Cc: Kuba Ober <kuba@mareimbrium.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
AM35x supports only 32bit read operations so we need to have
workaround for 8bit and 16bit read operations.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
AM35x has musb interface and uses CPPI4.1 DMA engine.
Current patch supports only PIO mode. DMA support can be
added later once basic CPPI4.1 DMA patch is accepted.
Also added USB_MUSB_AM35X which is required to differentiate musb ips
between OMAP3x and AM35x. This config would be used to for below
purposes,
- Select am35x.c instead of omap2430.c for compilation
at drivers/usb/musb directory. Please note there are
significant differneces in these two files as musb ip
in quite different on AM35x.
Please note that in multi omap configuration only omap2430.c
file will get compiled and we would require to select only
AM35x based board config to compile am35x.c
- Select workaround codes applicable for AM35x musb issues.
one such workaround is for bytewise read issue on AM35x.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
AM35x has musb interface (version 1.8) and uses CPPI41 DMA engine.
It has USB phy built inside the IP itself.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix this error when CONFIG_PM is not enabled:
drivers/usb/host/xhci.c:675: error: implicit declaration of function 'usb_root_hub_lost_power'
Wrap xhci_suspend() and xhci_resume() into an ifdef CONFIG_PM, along with
the functions that only they call -- xhci_save_registers() and
xhci_restore_registers().
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A few devices (such as the RCA VR5220 voice recorder) are so
non-compliant with the USB spec that they have invalid maxpacket sizes
for endpoint 0. Nevertheless, as long as we can safely use them, we
may as well do so.
This patch (as1432) softens our acceptance criterion by allowing
high-speed devices to have ep0-maxpacket sizes other than 64. A
warning is printed in the system log when this happens, and the
existing error message is clarified.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: James <bjlockie@lockie.ca>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch implements the PCI suspend/resume.
Please refer to xHCI spec for doing the suspend/resume operation.
For S3, CSS/SRS in USBCMD is used to save/restore the internal state.
However, an error maybe occurs while restoring the internal state.
In this case, it means that HC internal state is wrong and HC will be
re-initialized.
Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Dong Nguyen <dong.nguyen@amd.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch implements xHCI bus suspend/resume function hook.
In the patch it goes through all the ports and suspend/resume
the ports if needed.
If any port is in remote wakeup, abort bus suspend as what ehci/ohci do.
Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit implements port remote wakeup.
When a port is in U3 state and resume signaling is detected from a device,
the port transitions to the Resume state, and the xHC generates a Port Status
Change Event.
For USB3 port, software write a '0' to the PLS field to complete the resume
signaling. For USB2 port, the resume should be signaling for at least 20ms,
irq handler set a timer for port remote wakeup, and then finishes process in
hub_control GetPortStatus.
Some codes are borrowed from EHCI code.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add software trigger USB device suspend resume function hook.
Do port suspend & resume in terms of xHCI spec.
Port Suspend:
Stop all endpoints via Stop Endpoint Command with Suspend (SP) flag set.
Place individual ports into suspend mode by writing '3' for Port Link State
(PLS) field into PORTSC register. This can only be done when the port is in
Enabled state. When writing, the Port Link State Write Strobe (LWS) bit shall
be set to '1'.
Allocate an xhci_command and stash it in xhci_virt_device to wait completion for
the last Stop Endpoint Command. Use the Suspend bit in TRB to indicate the Stop
Endpoint Command is for port suspend. Based on Sarah's suggestion.
Port Resume:
Write '0' in PLS field, device will transition to running state.
Ring an endpoints' doorbell to restart it.
Ref: USB device remote wake need another patch to implement. For details of
how USB subsystem do power management, please see:
Documentation/usb/power-management.txt
Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
