There is a possble racing scenario.
'process_oq' is called by two routines, as shown below.
pm8001_8001_dispatch = {
.......
.isr = pm8001_chip_isr --> process_oq,// A
.isr_process_oq = process_oq, // B
.....
}
process_oq() --> process_one_iomb() --> mpi_sata_completion()
In 'mpi_sata_completion', "pm8001_ha->lock" is first released.
It means lock is taken before, which is true for
the context A, as 'pm8001_ha->lock' is taken in 'pm8001_chip_isr()'
But for context B there is no lock taken before and pm8001_ha->lock
is unlocked in 'mpi_sata_completion()'. This may unlock the lock
taken in context A. Possible racing ??
If 'pm8001_ha->lock' is taken in 'process_oq()' instead of
'pm8001_chip_isr' then the above issue can be avoided.
Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Static checker is giving following warning:
" error: calling 'spin_unlock_irqrestore()' with bogus flags"
The code flow is as shown below:
process_oq() --> process_one_iomb --> mpi_sata_completion
In 'mpi_sata_completion'
the first call for 'spin_unlock_irqrestore()' is with flags=0,
which is as good as 'spin_unlock_irq()' ( unconditional interrupt
enabling).
So for better performance 'spin_unlock_irqrestore()' can be replaced
with 'spin_unlock_irq()' and 'spin_lock_irqsave()' can be replaced by
'spin_lock_irq()'.
Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
IO_XFER_ERROR_BREAK and IO_XFER_OPEN_RETRY_TIMEOUT are deficient of the
required actions as outlined in the programming manual for the pm8001. Due to
the overlapping code requirements of these recovery responses, we found it
necessary to bundle them together into one patch.
When a break is received during the command phase (ssp_completion), this is a
result of a timeout or interruption on the bus. Logic suggests that we should
retry the command.
When a break is received during the data-phase (ssp_event), the task must be
aborted on the target or it will retain a data-phase lock turning the target
reticent to all future media commands yet will successfully respond to TUR,
INQUIRY and ABORT leading eventually to target failure through several
abort-cycle loops.
The open retry interval is exceedingly short resulting in occasional target
drop-off during expander resets or when targets push-back during bad-block
remapping. Increased effective timeout from 130ms to 1.5 seconds for each try
so as to trigger after the administrative inquiry/tur timeout in the scsi
subsystem to keep error-recovery harmonics to a minimum.
When an open retry timeout event is received, the action required by the
targets is to issue an abort for the outstanding command then logic suggests
we retry the command as this state is usually an indication of a credit block
or busy condition on the target.
We hijacked the pm8001_handle_event work queue handler so that it will handle
task as an argument instead of device for the workers in support of the
deferred handling outlined above.
Moderate to Heavy bad-path testing on a 2.6.32 vintage kernel, compile-testing
on scsi-misc-2.6 kernel ...
Signed-off-by: Mark Salyzyn <mark_salyzyn@xyratex.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Jack noticed I dropped a patch fragment associated with a flags automatic
variable in mpi_set_phys_g3_with_ssc (ooops) and that the pre-emptive locking
that piggy-backed this patch was not in-fact necessary because of underlying
atomic accesses to the hardware. Here is the updated patch fixing these two
issues.
The pm8001 driver is missing the FUNC_GET_EVENTS handler in the phy control
function. Since the pm8001_bar4_shift function was not designed to be called
at runtime, added locking surrounding the adjustment for all accesses.
Signed-off-by: Mark Salyzyn <mark_salyzyn@xyratex.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Code Inspection: found two missing break directives. First one will
result in not retrying an a task that report
IO_OPEN_CNX_ERROR_HW_RESOURCE_BUSY, the second will result in cosmetic
debug printk conflicting statement stutter. Because checkpatch.pl came
up with a warning regarding unnecessary space before a newline on one of
the fragments associated with the diff context, I took the liberty of
fixing all the cases of this issue in the pair of files touched by this
defect. These cosmetic changes hide the break changes :-(
To help focus, break changes are in pm8001_hwi.c fragment line 1649 for
the IO_OPEN_CNX_ERROR_HW_RESOURCE_BUSY case statement and pm8001_sas.c
line 1000 deals with the conflicting debug print stutter.
Signed-off-by: Mark Salyzyn <mark_salyzyn@us.xyratex.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
pm8001 manages its own list of pending works and cancel them on device
free. It is unnecessarily complex and has a race condition - the
works are canceled but not synced, so the work could still be running
during and after the data structures are freed.
This patch simplifies workqueue usage.
* A driver specific workqueue pm8001_wq is created to serve these
work items.
* To avoid confusion, the "queue" suffixes are dropped from work items
and functions.
* Delayed queueing was never used. pm8001_work now uses work_struct
instead.
* The driver no longer keeps track of pending works. All pm8001_works
are queued to pm8001_wq and the workqueue is flushed as necessary.
flush_scheduled_work() usage is removed during conversion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Return -ENOMEM if the allocations fail.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Error handling code following a kmalloc should free the allocated data.
The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
expression E;
identifier f,f1;
position p1,p2;
@@
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
<... when != x
when != if (...) { <+...x...+> }
when != (x) == NULL
when != (x) != NULL
when != (x) == 0
when != (x) != 0
(
x->f1 = E
|
(x->f1 == NULL || ...)
|
f(...,x->f1,...)
)
...>
(
return <+...x...+>;
|
return@p2 ...;
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: jack wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
We have two separate definitions for identical constants with nearly the
same name. One comes from the generic headers in scsi.h; the other is
an enum in libsas.h ... it's causing confusion about which one is
correct (fortunately they both are).
Fix this by eliminating the libsas.h duplicate
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
The region set by the call to memset is immediately overwritten by the
subsequent call to memcpy.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e1,e2,e3,e4;
@@
- memset(e1,e2,e3);
memcpy(e1,e4,e3);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Add more data to printk's, add some spaces around arithmetic ops and
improve comments.
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Enhance error handle for IO patch, when the port is down, fast return phy
down for task.
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch fix for sata IO circular lock dependency. When we call task_done
for SATA IO, we have got pm8001_ha->lock ,and in sas_ata_task_done, it will
get (dev->sata_dev.ap->lock. then cause circular lock dependency .So we
should drop pm8001_ha->lock when we call task_done for SATA task.
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Lindar Liu <lindar_liu@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
We set interupt cascading count of outbound queue to get better
performance, correct some unnecessary return values and some noisy
print messages. patch attached.
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Lindar Liu <lindar_liu@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Lindar Liu <lindar_liu@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This driver supports PMC-Sierra PCIe SAS/SATA 8x6G SPC 8001 chip based
host adapters.
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Lindar Liu <lindar_liu@usish.com>
Signed-off-by: Tom Peng <tom_peng@usish.com>
Signed-off-by: Kevin Ao <aoqingyun@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
