This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following race can occur with qdio devices that use the shared device
state change indicator:
Device (Shared DSCI) CPU0 CPU1
===============================================================================
1. DSCI 0 => 1,
INT pending
2. Thinint handler
* si_used = 1
* Inbound tasklet_schedule
* DSCI 1 => 0
3. DSCI 0 => 1,
INT pending
4. Thinint handler
* si_used = 1
* Inbound tasklet_schedu
le
=> NOP
5. Inbound tasklet run
6. DSCI = 1,
INT surpressed
7. DSCI 1 => 0
The race would lead to a stall where new data in the input queue is
not recognized so the device stops working in case of no further traffic.
Fix the race by resetting the DSCI before scheduling the inbound tasklet
so the device generates an interrupt if new data arrives in the above
scenario in step 6.
Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This enables pm_notifier_call_chain() to get the actual error code
in the callback rather than always assume -EINVAL by converting all
PM notifier calls to return encapsulate error code with
notifier_from_errno().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The qdio SBAL entry flag is made-up of four different values that are
independent of one another. Some of the bits are reserved by the
hardware and should not be changed by qdio. Currently all four values
are overwritten since the SBAL entry flag is defined as an u32.
Split the SBAL entry flag into four u8's as defined by the hardware
and don't touch the reserved bits.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Update affected channel path descriptors when receiving channel path
availability information.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Prevent the following compile warning for !CONFIG_64BIT:
CC drivers/s390/cio/qdio_main.o
drivers/s390/cio/qdio_main.c: In function ‘handle_outbound’:
drivers/s390/cio/qdio_main.c:1449: warning: ‘state’ may be used uninitialized in this function
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In ccw_device_set_online we basically start path verification and
wait for the device to reach a final state. If it turns out that the
device has no useable path we schedule the deregistration of the
device (which is still in an non-final state) and wake up the waiting
process. The deregistration process will set a final state, but if
the wake up happens to be prior to this, the device will hang forever
in ccw_device_set_online.
To fix this just set the final NOT_OPER state prior to the scheduled
deregistration of the device.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The qdio hardware may surpress further interrupts as long as a SBAL is in
the error state. That can lead to unnotified data in the SBALs following
the error state. To prevent this behaviour change the SBAL[s] in error
state immediately to another program owned state so interrupts are again
received for further traffic on the device.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The cio_ignore purge function is intended to only remove CCW devices
which are in the offline state. There is a time frame after the purge
function finished where a CCW device is scheduled for removal but
still accessible. When the device is set online during this time
frame, it may first appear online before it is then removed.
Fix this by preventing that CCW devices can be set online while there
is work (such as removal triggered by the purge function) for it
pending. Also ensure that the purge function does not schedule devices
for removal which are in the process of being set online.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reorder the initialization sequence of the qdio module to avoid
writing to an uninitialized debug feature entry. Also reorder
the exit function to restore a consistent cleanup path.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the owner and name members of struct
ccwgroup_driver and convert all drivers to store
this data in the embedded struct device_driver.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make ccw_bus_type static. ccw_device drivers have to
use ccw_driver_register.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the owner and name members of struct
ccw_driver and convert all drivers to store
this data in the embedded struct device_driver.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Exit do_QDIO early if the buffer count is zero to prevent side effects
in the following functions.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make css_bus_type static. Subchannel drivers have to
use css_driver_register.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the owner and name members of struct
css_driver and convert all drivers to store
this data in the embedded struct device_driver.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
All subchannel drivers use drv_data, so get rid of the
additional private pointer of struct subchannel.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the subchannels drv_data to access chsc_private
for chsc subchannels.
Note: Also set the drv_data prior to the cio_enable_subchannel
call, since we can receive an interrupt the moment we enable
the subchannel and the IRQ handler relies on this data.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the subchannels drv_data to access io_subchannel_private
for io subchannels.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the subchannels ccw device pointer from drv_data to
the private data for I/O subchannels, since it is not the
only drv_data for I/O subchannels. The next step will be
to make io_subchannel_private the new drv_data for I/O
subchannels.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the options member from struct subchannel to
io_subchannel_private since it's I/O subchannel specific.
Also remove the unused cio_get_options function.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The ssch and csch functions are not I/O subchannel specific,
thus move them from io_sch.h to ioasm.h
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the data definition for the orb union to a separate
header file. Also apply the curent codingstyle.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Don't check for the int_type if an adapter interrupt is presented.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Prevent the following compiler warning if compiling a 31 bit kernel:
drivers/s390/cio/qdio_main.c: In function ‘get_outbound_buffer_frontier’:
drivers/s390/cio/qdio_main.c:646:16: warning: ‘state’ may be used uninitialized in this function
CC lib/radix-tree.o
CC drivers/s390/scsi/zfcp_cfdc.o
drivers/s390/cio/qdio_main.c: In function ‘qdio_inbound_q_moved’:
drivers/s390/cio/qdio_main.c:479:16: warning: ‘state’ may be used uninitialized in this function
drivers/s390/cio/qdio_main.c:479:16: note: ‘state’ was declared here
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
While resuming report any found paths as new to the
device drivers.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
A race condition exists in the ccwgroup device unregistration code
which can cause a kernel panic due to a use-after-free bug. This
race condition might be triggered when all ccw devices associated with
a ccwgroup device are removed at the same time (e.g. because the
corresponding channel path becomes no longer available).
Fix this race condition by clearing the references from the associated
ccw devices to the ccw group device during unregistration of the
ccw group device.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Any list of indirect data adresses (TIDAL) used by a TCW must not
cross a page boundary. The original itcw implementation complies with
this restriction by allocating allmost twice as much memory as
actually needed, so that in any case there is enough room for the full
TIDAL, either above or below the page boundary.
This patch implements an alternative method, by using a TTIC TIDAW to
connect TIDAL parts below and above a page boundary.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Update the subchannel descriptor if we receive a
"Installed parameters modified" crw.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support to accumulate the number of 64K-bytes blocks all paths
to a device at least support for a transport command.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Simplify the SIGA sync code and add unlikely annotations. In polling mode
SBALs may be accessed without interrupt, so call SIGA sync before every scan.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
HiperSocket devices only use one SBAL per qdio call without the enhanced SIGA
feature. Since that feature is currently not used remove it from the qdio code
so the compiler can generate better code for the HiperSocket outbound path.
While at it mark the SIGA error conditions as unlikely.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If QIOASSIST is enabled for a qdio device the SIGA instruction requires
a modified function code. This function code modifier was missing for
SIGA-R and SIGA-S which can lead to a kernel panic caused by an
operand exception.
Cc: stable@kernel.org
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a counter for outbound queue full events to the qdio statistics.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce a scan treshold for the qdio outbound queues. By setting the
threshold the driver can tell qdio after how much used SBALs qdio
should schedule the outbound tasklet that scans the queue for finished
SBALs. The threshold is specific by the drivers because a
Hipersockets device is much faster in utilizing outbound buffers than a
ZFCP or OSA device.
The default values after how many used SBALs the tasklet should run are:
OSA: > 31 SBALs
Hipersockets: > 7 SBALs
zfcp: > 55 SBALs
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the shared indicator is used the following race leads to
an inbound stall:
Device CPU0 CPU1
========================================================
non-shared DSCI =>1
ALSI => 1
Thin INT
ALSI => 0
non-shared DSCI
tasklets scheduled
shared DSCI => 1
ALSI => 1
shared DSCI => 0
ALSI ? -> set
Thin INT
ALSI => 0
ALSI was set,
shared DSCI => 1
After that no more interrupts occur because the DSCI is still set.
Fix that race by only resetting the shared DSCI if it was actually
set so the tasklets for all shared devices are scheduled and will
run after the interrupt.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Count traditional qdio interrupts and adapter interrupts for qdio
in the interrupt statistics.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
__get_cpu_var() can be replaced with this_cpu_read and will then use a single
read instruction with implied address calculation to access the correct per cpu
instance.
However, the address of a per cpu variable passed to __this_cpu_read() cannot be
determed (since its an implied address conversion through segment prefixes).
Therefore apply this only to uses of __get_cpu_var where the addres of the
variable is not used.
V3->V4:
- Move one instance of this_cpu_inc_return to a later patch
so that this one can go in without percpu infrastructrure
changes.
Sedat: fixed compile failure caused by an extra ')'.
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Use correct bit positions of rsid field.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The qdio device indicator is freed before the device is notified that
the indicator is reset. This sequence contains a race when the freed
indicator is used by a new device while the reset of the indicator is
still pending. Do the reset operation before freeing the indicator to
avoid that potential race.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If device recognition is interrupted by a subchannel event
indicating that the device is gone, ccw_device_init_count
is not correctly decreased.
Fix this by reporting the corresponding event to the device
recognition callback via the state machine.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Function ccw_device_cancel_halt_clear may cause an unexpected kernel
panic if a clear function is currently active at the subchannel for
which it is called. In that case, the iretry counter used to determine
the number of retries is never initialized, leading to an immediate
failure of the function which results in a kernel panic.
Fix this by initializing the iretry counter when the function is
first called. Also replace the kernel panic with a return code: a
single malfunctioning I/O device should not automatically cause a
system-wide kernel panic.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds a notification mechanism to inform ccw drivers
about changes to channel paths, which occured while the device
is online.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Update the subchannel descriptor while resuming from hibernate
in order to obtain current link addresses.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Update the channel path descriptors after hibernation.
This is done unlocked, since we are the only active
task at this time.
Note: chsc_determine_base_channel_path_desc is changed
to use spin_lock_irqsave, since it's called with
interrupts disabled in this case.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Arun Sharma
Jan Glauber
Akinobu Mita
Sebastian Ott
Heiko Carstens
Linus Torvalds
Peter Oberparleiter
Lucas De Marchi
Stefan Weinhuber
Tejun Heo
Christoph Lameter