DRA7xx has 8 GPIO banks so that there are 32x8 = 256 GPIOs.
In order for the gpiolib to detect and initialize these
and other TWL GPIOs, ARCH_NR_GPIO is set to 512 using the
kconfig default for DRA7.
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Describe minimal DT boot machine details for DRA7xx based SoC's. DRA7xx
family is based on dual core ARM CORTEX A15 using GIC as the interrupt controller.
The PRCM and timer infrastructure is reused from OMAP5 and so are the io
descriptor tables.
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
TWL6040 is used only with OMAP4/5 SoCs and they can only boot in in DT mode.
The support for pdata/legacy boot can be removed.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
All of OMAP5 timer support for clocksource and clockevent is completely
reused across DRA7.
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
The IO descriptor tables for DRA7 are a complete reuse from OMAP5.
A new dra7xx_init_early() does the base address inits.
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
The PRCM and MPUSS parts of DRA7 devices are quite identical
to OMAP5 so as to reuse all the existing infrastructure around it.
Makefile updates to do just that.
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Probably this one is quite unlikely to be triggered, but it's more safe
to do the call_rcu() at the end after we have dropped the reference on
the asoc and freed sctp packet chunks. The reason why is because in
sctp_transport_destroy_rcu() the transport is being kfree()'d, and if
we're unlucky enough we could run into corrupted pointers. Probably
that's more of theoretical nature, but it's safer to have this simple fix.
Introduced by commit 8c98653f ("sctp: sctp_close: fix release of bindings
for deferred call_rcu's"). I also did the 8c98653f regression test and
it's fine that way.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The SCTP Quick failover draft [1] section 5.1, point 5 says that the cwnd
should be 1 MTU. So, instead of 1, set it to 1 MTU.
[1] https://tools.ietf.org/html/draft-nishida-tsvwg-sctp-failover-05
Reported-by: Karl Heiss <kheiss@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In stmmac_init_rx_buffers():
* add missing handling of dma_map_single() error
* remove superfluous unlikely() optimization while at it
Add stmmac_free_rx_buffers() helper and use it in dma_free_rx_skbufs().
In init_dma_desc_rings():
* add missing handling of kmalloc_array() errors
* fix handling of dma_alloc_coherent() and stmmac_init_rx_buffers() errors
* make function return an error value on error and 0 on success
In stmmac_open():
* add handling of init_dma_desc_rings() return value
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Odd little issue, found that if you create an IPv6 portal bound to the
IN6ADDR_ANY wildcard address it will accept IPv4 connections (as long as
bindv6only isn't set globally) but respond to SendTargets requests with
an IPv4-mapped IPv6 address.
Example over loopback:
In targetcli create a wildcard IPv6 portal
/iscsi/iqn.../portals/> create ::
Which should create a portal [::]:3260
Initiate SendTargets discovery to the portal using an IPv4 address
# iscsiadm -m discovery -t st -p 127.0.0.1
The response formats TargetAddress as [::ffff:127.0.0.1]:3260,1
This still works and uses v4 on the network between two v6 sockets, but
only if the initiator supports IPv6 with v4-mapped addresses.
This change detects v4-mapped address on v6 sockets for the wildcard
case, and instead formats the TargetAddress response as an IPv4 address.
In order to not further complicate iscsit_build_sendtargets_response,
I've actually simplified it by moving the bracket wrapping of IPv6
address into iscsit_accept_np where local_ip and login_ip strings are
set. That also simplifies iscsi_stat_tgt_attr_show_attr_fail_intr_addr.
Side effect of the string format change is that
lio_target_nacl_show_info will now print login_ip bracket wrapped for
IPv6 connections, as will a few debug prints.
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Changing this attribute to 0 will mean that all initiators that login
to the target while the target has generate_node_acls=1 will see all
TPG LUNs, which may be the desired behavior in some cases.
(nab: Apply patch without macro changes)
Reported-by: Craig Watson <craig.watson@vanguard-rugged.com>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The usage of strict_strtoul() and strict_strtoull() is not preferred,
because strict_strtoul() and strict_strtoull() are obsolete. Thus,
kstrtoul() and kstrtoull() should be used.
v2: Fix incorrect return in ft_add_tpg (Fengguang)
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes spc_emulate_inquiry_std() to add trailing ASCII
spaces for INQUIRY vendor + model fields following SPC-4 text:
"ASCII data fields described as being left-aligned shall have any
unused bytes at the end of the field (i.e., highest offset) and
the unused bytes shall be filled with ASCII space characters (20h)."
This addresses a problem with Falconstor NSS multipathing.
Reported-by: Tomas Molota <tomas.molota@lightstorm.sk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
There is a potential race condition between cpu_subsys_online()
and either acpi_processor_remove() or remove_memory() that execute
try_offline_node(). Namely, it is possible that cpu_subsys_online()
will run right after the CPUs NUMA node has been put offline and
cpu_to_node() executed by it will return NUMA_NO_NODE (-1). In
that case the CPU is gone and it doesn't make sense to call cpu_up()
for it, so make cpu_subsys_online() return -ENODEV then.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch corrects unfaithful Korean translation in Documentation/ko_KR/HOWTO.
Signed-off-by: Lee, Jae-Hong <pyrasis@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes some minor typos in Documentation/ko_KR/stable_api_nonsense.txt
Signed-off-by: Lee, Jae-Hong <pyrasis@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes some minor typos in Documentation/ko_KR/HOWTO.
Signed-off-by: Lee, Jae-Hong <pyrasis@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the full dynticks subsystem only enables the context tracking
on full dynticks CPUs, lets remove the dependency on CONTEXT_TRACKING_FORCE
This dependency was a hack to enable the context tracking widely for the
full dynticks susbsystem until the latter becomes able to enable it in a
more CPU-finegrained fashion.
Now CONTEXT_TRACKING_FORCE only stands for testing on archs that
work on support for the context tracking while full dynticks can't be
used yet due to unmet dependencies. It simulates a system where all CPUs
are full dynticks so that RCU user extended quiescent states and dynticks
cputime accounting can be tested on the given arch.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
The context tracking subsystem has the ability to selectively
enable the tracking on any defined subset of CPU. This means that
we can define a CPU range that doesn't run the context tracking
and another range that does.
Now what we want in practice is to enable the tracking on full
dynticks CPUs only. In order to perform this, we just need to pass
our full dynticks CPU range selection from the full dynticks
subsystem to the context tracking.
This way we can spare the overhead of RCU user extended quiescent
state and vtime maintainance on the CPUs that are outside the
full dynticks range. Just keep in mind the raw context tracking
itself is still necessary everywhere.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
Validate log space during log mount stage, the underlying function
will drop a warning message via syslog in critical level if the log
space is too small or too large.
[ dchinner: For CRC enable filesystems, abort the mounting of the
filesystem as mkfs should never make a log too small for the given
filesystem configuration. ]
[ dchinner: make a note of the fact that the log size limits in
block counts are in units of filesystem blocks, not basic blocks. ]
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Add source files for xfs_log_rlimit.c The new file is used for log
size calculations and validation shared with userspace.
[dchinner: xfs_log_calc_max_attrsetm_res() does not modify the
tr_attrsetm reservation, just calculates the maximum. ]
[dchinner: rework loop in xfs_log_get_max_trans_res() ]
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Refactor xlog_ticket_alloc() to extract a new helper, i.e.
xfs_log_calc_unit_res().
This helper would be used to calculate the total log reservation
size by adding extra log operation/transation headers for a new
log ticket.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Get rid of all XFS_XXX_LOG_RES() macros since they are obsoleted now.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
With the new xfs_trans_res structure has been introduced, the log
reservation size, log count as well as log flags are pre-initialized
at mount time. So it's time to refine xfs_trans_reserve() interface
to be more neat.
Also, introduce a new helper M_RES() to return a pointer to the
mp->m_resv structure to simplify the input.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
tr_writeid is defined at mp->m_resv structure, however, it does not
really being used when it should be..
This patch changes it to tr_writeid to fetch the correct log
reservation size.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
vma_count is used write-only and so fails to be useful. So remove it.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This makes it possible to let gdb access mappings of the process that is
being debugged.
uio_mmap_logical was moved and uio_vm_ops renamed to group related code
and differentiate to new stuff.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the next commit this function will be used in the uio subsystem
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A preparation step.
For now fsync_ts transaction use the pre-calculated log reservation
size of tr_swrite. This patch introduce a new item tr_fsyncts to
mp->m_reservations structure so that we can fetch the log
reservation value for it in a same manner to others.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Both H_IS and H_IE needs to be set to receive H_RDY
interrupt
1. Assert H_IS to clear the interrupts during hw reset
and use mei_me_reg_write instead of mei_hcsr_set as the later
strips down the H_IS
2. fix interrupt disablement embarrassing typo
hcsr |= ~H_IE -> hcsr &= ~H_IE;
this will remove the unwanted interrupt on power down
3. remove useless debug print outs
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a new structure xfs_trans_res to hold transaction
reservation item info per log ticket.
We also need to improve xfs_trans_resv_calc() by initializing the
log count as well as log flags for permanent log reservation.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
This local symbol is used only in this file.
Fix the following sparse warnings:
drivers/fmc/fmc-write-eeprom.c:106:5: warning: symbol 'fwe_probe' was not declared. Should it be static?
drivers/fmc/fmc-write-eeprom.c:147:5: warning: symbol 'fwe_remove' was not declared. Should it be static?
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need to have a nlmsghdr pointer to another temporary buffer.
Instead use a full struct nlmsghdr.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netlink_send is supposed to send just the cn_msg+hv_kvp_msg via netlink.
Currently it sets an incorrect iovec size, as reported by valgrind.
In the case of registering with the kernel the allocated buffer is large
enough to hold nlmsghdr+cn_msg+hv_kvp_msg, no overrun happens. In the
case of responding to the kernel the cn_msg is located in the middle of
recv_buffer, after the nlmsghdr. Currently the code in netlink_send adds
also the size of nlmsghdr to the payload. But nlmsghdr is a separate
iovec. This leads to an (harmless) out-of-bounds access when the kernel
processes the iovec. Correct the iovec size of the cn_msg to be just
cn_msg + its payload.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The struct xfs_perag has many kernel-only definitions in it,
requiring a __KERNEL__ guard so userspace can use it to. Move it to
xfs_mount.h so that it it kernel-only, and let userspace redefine
it's own version of the structure containing only what it needs.
This gets rid of another __KERNEL__ check in the XFS header files.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
I've found some new datasheets which describe some additionally
supported standard baud rates and I've verified them with my HX
(rev. 3A) device. But adding support for individual (chip type
specific) baud rates would add a good amount of extra code (especially
when support for further chips will be added to the driver one day),
which makes no sense as long as we are not using the direct baud rate
encoding method for newer chips.
So for now, just drop a comment about these additionally supported baud
rates.
The second comment is about the baud rate differences between the two
encoding methods. In theory, we could optimize the code a bit by
comparing the resulting baud rates of both methods and selecting the
one which is closer to the requested baud rate. But that seems to be a
bit overkill, because the differences are very small and the device
likely uses the same baud rate generator for both methods so that the
resulting baud rate would be the same.
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the divisor based baud rate encoding method has been fixed and
extended, it can also be used for baud rates < 115200 baud with HX
chips.
This makes it possible to adjust the baud rate almost continuously
instead of just beeing able to select between 16 fixed standard values.
Tested with a PL2303HX 04463A (week 46, 2004, rev 3A).
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reinhard Max has done some tests with a PL2303HX (rev A) and a logic
analyzer and it seems, that although the PL2303HX is specified for baud
rates from 75 to 6M baud, the full divisor range can be used with the
divisor based baud rate encoding method. This corresponds to baud rates
from 46 to 24M baud.
Baud rates down to 46 baud (max. divisor) have been confirmed to work
even under heavy/permanent load, so remove the lower limit.
Baud rates up to 24M baud should really be tested carefully in "real
life" scenarios before removing the upper limit completely.
Anyway, the Windows driver allows maximum baud rates of 110% of the
specified limit, so for now, increase the upper limit to this value.
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Reinhard Max <max@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 0c967e7e "USB: serial: pl2303 works at 500kbps" added 500000
baud to the list of supported standard baud rates.
But the reason why the driver works with this baud rate is, that since
commit 8d48fdf6 "USB: PL2303: correctly handle baudrates above 115200"
a second (divisor based) baud rate encoding method is used for values
above 115200 baud, which is not limited to a fixed set of standard baud
rates.
Remove the 500000 baud value from the list of standard baud rates
again, because this list is only used with the direct baud rate
encoding method and 500000 baud is not supported with this method.
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In opposition to the direct baud rate encoding method, the divisor
based method is not limited to a fixed set of standard baud rates.
Hence, there is no need to round to the next nearest standard value.
Reported-by: Mastro Gippo <gipmad@gmail.com>
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Reinhard Max <max@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on the formula in the code description, Reinhard Max and me have
investigated the devices behavior / functional principle of the divisor
based baud rate encoding method.
It turned out, that (although beeing a good starting point) the current
code has some flaws. It doesn't work correctly for a wide range of baud
rates and the divisor resolution can be improved. It also doesn't
report the actually set baud rate.
This patch fixes and improves the code for the divisor based baud rate
encoding method a lot. It can now be used for the whole range of baud
rates from 46 baud to 24M baud with a very good divisor resolution and
userspace can read back the resulting baud rate.
It also documents the formula used for encoding and the hardware
behavior (including special cases).
The basic algorithm, rounding and several code comments/explanations
are provided by Reinhard Max.
I've added some minor fixes, the handling of the special cases and
further code/algorithm descriptions.
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Reinhard Max <max@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the disconnect routine for the hwa_hc interface, it calls
uwb_pal_unregister to unregister itself from the UWB subsystem. This
function attempts to clean up the link to the host controller directory in
the device's UWB radio control interface directory. If the disconnect
routine for the radio control interface has already run, the uwb directory
will be gone so the call to sysfs_remove_link generates a warning.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent the USB core from suspending the HWA root hub since bus_suspend
and bus_resume are not yet supported. Otherwise the PM system will chew
up CPU time constantly attempting to suspend and resume the root hub but
never succeeding.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a kernel panic that can occur when unplugging the HWA
dongle while a downstream device is in the process of disconnecting.
This involved 2 changes. First, call usb_lock_device_for_reset before
usb_reset_device to synchronize the HWA's post_rest and disconnect
routines. Second, set the hwarc->neep_urb and hwarc->rd_buffer to NULL
when they are freed in the error path in the post_reset routine. This
prevents a double free when the disconnect routine is called and attempts
to free those resources again.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both could want to submit the same URB. Some checks of the flag
intended to prevent that were missing.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
CC: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As long as the context tracking is enabled on any CPU, even
a single one, all other CPUs need to keep track of their
user <-> kernel boundaries cross as well.
This is because a task can sleep while servicing an exception
that happened in the kernel or in userspace. Then when the task
eventually wakes up and return from the exception, the CPU needs
to know if we resume in userspace or in the kernel. exception_exit()
get this information from exception_enter() that saved the previous
state.
If the CPU where the exception happened didn't keep track of
these informations, exception_exit() doesn't know which state
tracking to restore on the CPU where the task got migrated
and we may return to userspace with the context tracking
subsystem thinking that we are in kernel mode.
This can be fixed in the long term if we move our context tracking
probes on very low level arch fast path user <-> kernel boundary,
although even that is worrisome as an exception can still happen
in the few instructions between the probe and the actual iret.
Also we are not yet ready to set these probes in the fast path given
the potential overhead problem it induces.
So let's fix this by always enable context tracking even on CPUs
that are not in the full dynticks range. OTOH we can spare the
rcu_user_*() and vtime_user_*() calls there because the tick runs
on these CPUs and we can handle RCU state machine and cputime
accounting through it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
Update a stale comment from the old vtime era and document some
locking that might be non obvious.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
