This function maps the system address to the normalized DCT address.
Document what the code does for more clarity and wrap insane bitmasks in
a more understandable macro which generates them. Also, reduce number of
arguments passed to the function. Finally, rename this function to what
it actually does.
No functional change.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cleanup and simplify f10_determine_channel(); make it more readable.
Also drop f10_map_intlv_en_to_shift() in favor of simply counting the
bits in F1x124[DramIntlvEn] which is equivalent.
There should be no functionality change resulting from this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add a struct representing the DRAM chip select base/limit register
pairs. Concentrate all CS handling in a single function. Also, add CS
looping macros for cleaner, more readable code. While at it, adjust code
to F15h. Finally, do smaller macro names cleanups (remove family names
from register macros) and debug messages clarification.
No functional change.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add a struct representing the DRAM base/limit range pairs and remove all
cached subfields. Replace them with accessor functions, which actually
saves us some space:
text data bss dec hex filename
14712 1577 336 16625 40f1 drivers/edac/amd64_edac_mod.o.after
14831 1609 336 16776 4188 drivers/edac/amd64_edac_mod.o.before
Also, it simplifies the code a lot allowing to merge the K8 and F10h
routines.
No functional change.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
F15h "multiplexes" between the configuration space of the two DRAM
controllers by toggling D18F1x10C[DctCfgSel] while F10h has a different
set of registers for DCT0, and DCT1 in extended PCI config space.
Add DCT configuration space accessors per family thus wrapping all the
different access prerequisites. Clean up code while at it, shorten
names.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
amd64_debug_display_dimm_sizes() reports the distribution of the DIMMs
on each DRAM controller and its chip select sizes. Thus, the last don't
have anything to do with whether we're running in ganged DCT mode or not
- their sizes don't change all of a sudden. Fix that by removing the
ganged-check and dump DCT0's config for DCT1 when in ganged mode since
they're identical.
Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
K8 does not allow for an atomic RMW to a cacheline as F10h does so
disable the error injection interface for it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Make the ->{get|set}_sdram_scrub_rate return the actual scrub rate
bandwidth it succeeded setting and remove superfluous arg pointer used
for that. A negative value returned still means that an error occurred
while setting the scrubrate. Document this for future reference.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Now that all prerequisites are in place, drop the two-stage driver
instances initialization in favor of the following simple init sequence:
1. Probe PCI device: we only test ECC capabilities here and if none exit
early.
2. If the hw supports ECC and it is/can be enabled, we init the per-node
instance.
Remove "amd64_" prefix from static functions touched, while at it.
There actually should be no visible functional change resulting from
this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Rework the code to check the hardware ECC capabilities at PCI probing
time. We do all further initialization only if we actually can/have ECC
enabled.
While at it:
0. Fix function naming.
1. Simplify/clarify debug output.
2. Remove amd64_ prefix from the static functions
3. Reorganize code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
This is in preparation for the init path reorganization where we want
only to
1) test whether a particular node supports ECC
2) can it be enabled
and only then do the necessary allocation/initialization. For that,
we need to decouple the ECC settings of the node from the instance's
descriptor.
The should be no functional change introduced by this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
PCI ECS is being enabled by default since 2.6.26 on AMD so this code is
just superfluous now, remove it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Remove static allocation in favor of dynamically allocating space for as
many driver instances as northbridges present on the system.
There should be no functional change resulting from this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add a macro per printk level, shorten up error messages. Add relevant
information to KERN_INFO level. No functional change.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Rename variables representing PCI devices to their BKDG names for faster
search and shorter, clearer code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Move the remaining per-family init code into the proper place and
simplify the rest of the initialization. Reorganize error handling in
amd64_init_one_instance().
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Run a per-family init function which does all the settings based on
the family this driver instance is running on. Move the scrubrate
calculation in it and simplify code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
* 'x86-amd-nb-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, cacheinfo: Cleanup L3 cache index disable support
x86, amd-nb: Cleanup AMD northbridge caching code
x86, amd-nb: Complete the rename of AMD NB and related code
When matching error address to the range contained by one memory node,
we're in valid range when node interleaving
1. is disabled, or
2. enabled and when the address bits we interleave on match the
interleave selector on this node (see the "Node Interleaving" section in
the BKDG for an enlightening example).
Thus, when we early-exit, we need to reverse the compound logic
statement properly.
Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Support more than just the "Misc Control" part of the northbridges.
Support more flags by turning "gart_supported" into a single bit flag
that is stored in a flags member. Clean up related code by using a set
of functions (amd_nb_num(), amd_nb_has_feature() and node_to_amd_nb())
instead of accessing the NB data structures directly. Reorder the
initialization code and put the GART flush words caching in a separate
function.
Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Not only the naming of the files was confusing, it was even more so for
the function and variable names.
Renamed the K8 NB and NUMA stuff that is also used on other AMD
platforms. This also renames the CONFIG_K8_NUMA option to
CONFIG_AMD_NUMA and the related file k8topology_64.c to
amdtopology_64.c. No functional changes intended.
Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
... instead of the MCi_STATUS info only for improved handling of certain
types of errors later.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The file names are somehow misleading as the code is not specific to
AMD K8 CPUs anymore. The files accomodate code for other AMD CPU
northbridges as well.
Same is true for the config option which is valid for AMD CPU
northbridges in general and not specific to K8.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100917160343.GD4958@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
So far we only provide num_k8_northbridges. This is required in
different areas (e.g. L3 cache index disable, GART). But not all AMD
CPUs provide a GART. Thus it is useful to split off the GART handling
from the generic caching of AMD northbridge misc devices.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100917160254.GC4958@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When the Overflow MCi_STATUS bit is set, EDAC reports the lost error
with a "no information available" message which often puzzles users
parsing the dmesg. This doesn't make much sense since this error has
been lost anyway so no need for reporting it separately. Thus, report
the overflow bit setting in the MCE dump instead. While at it, remove
reporting of MiscV and ErrorEnable (en) which are superfluous.
Now it looks like this:
[ 1501.650024] MC4_STATUS: Corrected error, other errors lost: yes, CPU context corrupt: no, CECC Error
[ 1501.666887] Northbridge Error, node 2
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
EDAC MC3: CE page 0xc32281, offset 0x8a0, grain 0, syndrome 0x1, row 2, channel 1, label "": amd64_edac
EDAC MC3: CE - no information available: amd64_edacError Overflow
Add the missing space before "Error Overflow" on the second line.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Fortify the interface to not accept negative values, remove
memctrl_int_store() as a result. Also, sanitize bandwidth setting by
making the argument a simple u32 instead of strange u32 pointer being
passed around for no obvious reason. Then, fix error handling and teach
it to return proper error values. Finally, make code more readable,
simplify debug messages.
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Arthur Jones <ajones@riverbed.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
The correct check is to verify whether in high range we're below 4GB
and not to extract the DctSelBaseAddr again. See "2.8.5 Routing DRAM
Requests" in the F10h BKDG.
Cc: <stable@kernel.org> # .32.x .33.x .34.x
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Switch to reusing the mcheck core's machine check polling mechanism
instead of duplicating functionality by using the EDAC polling routine.
Correct formatting while at it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Remove the two syndrome extraction macros and add a single function
which does the same thing but with proper typechecking. While at it,
make sure to cache ECC syndrome size and dump it in debug output.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
When calculating the DCT channel from the syndrome we need to know the
syndrome type (x4 vs x8). On F10h, this is read out from extended PCI
cfg space register F3x180 while on K8 we only support x4 syndromes and
don't have extended PCI config space anyway.
Make the code accessing F3x180 F10h only and fall back to x4 syndromes
on everything else.
Cc: <stable@kernel.org> # .33.x .34.x
Reported-by: Jeffrey Merkey <jeffmerkey@gmail.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
No need for clearing ecc_enable_override and checking it in two places.
Instead, simply check it during probing and act accordingly. Also,
rename the flag bitfields according to the functionality they actually
represent. What is more, make sure original BIOS ECC settings are
restored when the module is unloaded.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add __percpu sparse annotations to places which didn't make it in one
of the previous patches. All converions are trivial.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Neil Brown <neilb@suse.de>
An unfortunate "WARNING" in the message amd64_edac dumps when the system
doesn't support DRAM ECC or ECC checking is not enabled in the BIOS
used to trigger kerneloops which qualified the message as an OOPS thus
misleading the users. See, e.g.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/422536http://bugzilla.kernel.org/show_bug.cgi?id=15238
Downgrade the message level to KERN_NOTICE and fix the formulation.
Cc: stable@kernel.org # .32.x
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Add a missing iterator variable thus fixing the conditional of the
for-loop in amd64_get_scrub_rate().
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Currently, the module does not initialize fully when the DIMMs aren't
ECC but remains still loaded. Propagate the error when no instance of
the driver is properly initialized and prevent further loading.
Reorganize and polish error handling in amd64_edac_init() while at it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Fix use-after-free errors by pushing all memory-freeing calls to the end
of amd64_remove_one_instance().
Reported-by: Darren Jenkins <darrenrjenkins@gmail.com>
LKML-Reference: <1261370306.11354.52.camel@ICE-BOX>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Fix the case when amd64_debug_display_dimm_sizes() reports only half the
amount of DRAM on it because it doesn't account for when the single DCT
operates in 128-bit mode and merges chip selects from different DIMMs.
Reported-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
LKML-Reference: <200912112202.48173.johannes.hirte@fem.tu-ilmenau.de>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The current rd/wrmsr_on_cpus helpers assume that the supplied
cpumasks are contiguous. However, there are machines out there
like some K8 multinode Opterons which have a non-contiguous core
enumeration on each node (e.g. cores 0,2 on node 0 instead of 0,1), see
http://www.gossamer-threads.com/lists/linux/kernel/1160268.
This patch fixes out-of-bounds writes (see URL above) by adding per-CPU
msr structs which are used on the respective cores.
Additionally, two helpers, msrs_{alloc,free}, are provided for use by
the callers of the MSR accessors.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20091211171440.GD31998@aftab>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
drivers/edac/amd64_edac.c: In function 'amd64_edac_init':
drivers/edac/amd64_edac.c:2840: warning: 'ret' may be used uninitialized in this function
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The routine does the reverse mapping of the error address of a CECC back
to the node id, DRAM controller and chip select of the DIMM which caused
the error. We should lookup the channel using the syndromes _only_ when
the DCTs are ganged so fix that.
Also, add an early exit when there's an error while scanning for the
csrow thus decreasing indentation levels for better readability.
Finally, fixup comments.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Instead of using the whole syndrome tables for channel decoding, use a
set of eigenvectors with which the tables can be generated to search for
the syndrome in error. The algorithm operates independently of symbol
size and can be used for both x4 and x8 syndromes.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The .probe_valid_hardware low_ops member checked whether the DCTs are in
DDR3 mode and bailed out if so. Now that all the needed changes for DDR3
support is in place, remove it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Instead of using deeply-nested conditionals for dumping the DIMM type in
debug mode, add a strings array of the supported DIMM types.
This is useful in cases where an edac driver supports multiple DRAM
types and is only defined in debug builds.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add cs mode to cs size mapping tables for DDR2 and DDR3 and F10
and all K8 flavors and remove klugdy table of pseudo values. Add a
low_ops->dbam_to_cs member which is family-specific and replaces
low_ops->dbam_map_to_pages since the pages calculation is a one liner
now.
Further cleanups, while at it:
- shorten family name defines
- align amd64_family_types struct members
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Do not read DCLR[01] again since this is done in
amd64_read_mc_registers() earlier. There can be more than two physical
DIMMs present so clamp the channels value to max 2. Also, do not report
DCT data width - it is also done earlier.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Extend f10_debug_display_dimm_sizes to dump the logical DIMMs
configuration on K8 revF too. Remove the ganged arg since we print the
DCT operating mode (ganged vs unganged) earlier.
Also, DCT csrow configuration is relevant therefore dump it as
KERN_DEBUG instead of only on debug builds. Remove misleading DIMM
output since there's no reliable way of mapping of chip selects to
actual physical DIMMs.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Carve out the register-specific debug statements into a separate
function, clarify meanings of the single bitfields in the register,
remove irrelevant output and macros.
There should be no functionality change resulting from this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Add a pci config read wrapper for signaling pci config space access
errors instead of them being visible only on a debug build. This is
important on amd64_edac since it uses all those pci config register
values to access the DRAM/DIMM configuration of the nodes.
In addition, the wrapper makes a _lot_ (look at the diffstat!) of
error handling code superfluous and improves much of the overall code
readability by removing error handling details out of the way.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Unify almost identical code into one function and remove NUMA-specific
usage (specifically cpumask_of_node()) in favor of generic topology
methods.
Remove unused defines, while at it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
cpumask_t -> struct cpumask, and don't put one on the stack. (Note: this
is actually on the stack unless CONFIG_CPUMASK_OFFSTACK=y).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Do not shift the TOP_MEM and TOP_MEM2 values by 23 but rather save the
whole 64-bit value read from the MSR. Although the TOP_MEM/TOP_MEM2 bits
are only a subset of the 64bit register, the values are correct since
the remaining bits are Read-As-Zero and no shifting is needed.
Also, cleanup DRAM base/limit debug output.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Make debug info formulations about the DRAM and DCT configuration of the
machine more human readable.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
In amd64_edac_init(void) in amd64_edac.c, cache_k8_northbridges() is
called before pci_register_driver. If it fails, should exit with err
directly.
Signed-off-by: Li Hong <lihong.hi@gmail.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
On Fam10h and above, F1x[1, 0][7C:40] are DRAM Base/Limit registers
which specify the destination node of a DRAM address. Those address
boundaries are being extracted into ->dram_base[] and ->dram_limit[].
Correct the extraction masks to match the respective address bits.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Different processor families support a different number of chip selects.
Handle this in a family-dependent way with the proper values assigned at
init time (see amd64_set_dct_base_and_mask).
Remove _DCSM_COUNT defines since they're used at one place and originate
from public documentation.
CC: Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
This allows the errors to be further decoded and mapped to csrows.
Tested with ECC debug dimms and an Rev F cpu based system.
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The check when DRAM interleaving is enabled should be done against the
pvt->dram_IntlvSel field and not against the ->dram_limit.
Simplify first loop and fixup printk formatting while at it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The pvt->dram_IntlvEn saves the 3 "Interleave Enable" bits already
right-shifted by 8 so the check in find_mc_by_sys_addr() by shifting the
values to the left 8 bits is wrong.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
K8 DRAM base and limit addresses from F1x40 +8*i and F1x44 + 8*i, where
i in (0..7) are both bits 39-24 and therefore the shifting should be
done by 24 and not by 8.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Allocate memory statically for 8-node machines max for simplicity
instead of relying on MAX_NUMNODES which is 0 on !CONFIG_NUMA builds.
Spotted by Jan Beulich.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The old code was using smp_call_function_many which skips the current
cpu if it is in the supplied cpumask. Switch to the rdmsr_on_cpus()
interface which takes care of that.
In addition, add get_cpus_on_this_dct_cpumask helper which computes a
cpumask of all the cores on a node and thus on a DCT.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Simplify the procedure by checking if there is any DIMM in each channel.
This patch will fix the bugs such as when there is no DIMMs under
certain node, two DIMMs in the same channel, and only one DIMM in each
channel of the node.
Borislav: minor fixups
Signed-off-by: Wan Wei <wanwei@mail.dawning.com.cn>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Simplify code flow and make sure return value is always valid since
further driver init depends on it. Carve out long warning string and
make code more readable. Shorten some names, while at it.
There should be no functional change resulting from this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
This is the MCE error code from the MCi_STATUS banks, bits [15:0] which
describe what type of error was encountered: GART TLB, Memory or Bus
error. The semantics of those bits are identical across all MCE banks so
decode those separately, irrespectively of MCE type.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The MCi_STATUS registers have most field definitions in common so decode
them in the general path. Do not pass ecc_type along and compute it in
__amd64_decode_bus_error instead.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Move NB decoder along with required defines to EDAC MCE core. Add
registration routines for further decoding of the MCE info in the AMD64
EDAC module.
CC: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
This is in preparation of adding AMD-specific MCE decoding functionality
to the EDAC core. The error decoding macros originate from the AMD64
EDAC driver albeit in a simplified and cleaned up version here.
While at it, add macros to generate the error description strings and
use them in the error type decoders directly which removes a bunch of
code and makes the decoding functions much more readable. Also, fix
strings and shorten macro names.
Remove superfluous htlink_msgs.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
On the good path of BIOS enabled ECC and no override, the value returned
is 1 by omission and thus is deemed failing by the probe-function.
Allow proper module initialization by clearing the retval explicitly.
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
amd64_check_ecc_enabled() returns non-zero status when ECC
checking/correcting is disabled and this fails further loading of the
driver even when 'ecc_enable_override' boot param is used.
Fix that by clearing return status in that case.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Checking whether the machine is using ECC enabled DRAM is done through
testing the DimmEccEn bit in the DRAM Cfg Low register (F2x[1,0]90). Do
that instead of testing all bits from the DimmEccEn upwards.
Also, remove mci->edac_cap assignment and use value returned from
amd64_determine_edac_cap().
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov