Commit Graph

109 Commits (1a0f6b7ecdcd810f8991ea26c95d93ff965e8f41)

Author SHA1 Message Date
Borislav Petkov 4d7963648f amd64_edac: Fix DIMMs per DCTs output
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>
2011-02-10 14:41:49 +01:00
Linus Torvalds 128283a47e Merge branch 'mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp
* 'mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  EDAC, MCE: Fix NB error formatting
  EDAC, MCE: Use BIT_64() to eliminate warnings on 32-bit
  EDAC, MCE: Enable MCE decoding on F15h
  EDAC, MCE: Allow F15h bank 6 MCE injection
  EDAC, MCE: Shorten error report formatting
  EDAC, MCE: Overhaul error fields extraction macros
  EDAC, MCE: Add F15h FP MCE decoder
  EDAC, MCE: Add F15 EX MCE decoder
  EDAC, MCE: Add an F15h NB MCE decoder
  EDAC, MCE: No F15h LS MCE decoder
  EDAC, MCE: Add F15h CU MCE decoder
  EDAC, MCE: Add F15h IC MCE decoder
  EDAC, MCE: Add F15h DC MCE decoder
  EDAC, MCE: Select extended error code mask
2011-01-07 14:54:03 -08:00
Borislav Petkov 6245288232 EDAC, MCE: Overhaul error fields extraction macros
Make macro names shorter thus making code shorter and more clear.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2011-01-07 11:54:21 +01:00
Borislav Petkov a135cef79a amd64_edac: Disable DRAM ECC injection on K8
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>
2011-01-07 11:38:46 +01:00
Borislav Petkov 390944439f EDAC: Fixup scrubrate manipulation
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>
2011-01-07 11:38:31 +01:00
Borislav Petkov 360b7f3c60 amd64_edac: Remove two-stage initialization
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>
2011-01-07 11:34:03 +01:00
Borislav Petkov 2299ef7114 amd64_edac: Check ECC capabilities initially
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>
2011-01-07 11:34:02 +01:00
Borislav Petkov ae7bb7c679 amd64_edac: Carve out ECC-related hw settings
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>
2011-01-07 11:34:00 +01:00
Borislav Petkov f1db274e1b amd64_edac: Remove PCI ECS enabling functions
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>
2011-01-07 11:33:59 +01:00
Borislav Petkov cc4d8860fc amd64_edac: Allocate driver instances dynamically
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>
2011-01-07 11:33:57 +01:00
Borislav Petkov 24f9a7fe3f amd64_edac: Rework printk macros
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>
2011-01-07 11:33:56 +01:00
Borislav Petkov 8d5b5d9c7b amd64_edac: Rename CPU PCI devices
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>
2011-01-07 11:33:54 +01:00
Borislav Petkov b8cfa02f83 amd64_edac: Concentrate per-family init even more
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>
2011-01-07 11:33:53 +01:00
Borislav Petkov bbd0c1f675 amd64_edac: Cleanup the CPU PCI device reservation
Shorten code and clarify comments, return proper -E* values on error.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2011-01-07 11:33:52 +01:00
Borislav Petkov 0092b20d4c amd64_edac: Simplify CPU family detection
Concentrate CPU family detection in the per-family init function.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2011-01-07 11:33:51 +01:00
Borislav Petkov 395ae783b3 amd64_edac: Add per-family init function
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>
2011-01-07 11:33:50 +01:00
Borislav Petkov 9f56da0e3c amd64_edac: Use cached extended CPU model
... instead of computing it needlessly again.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2011-01-07 11:33:49 +01:00
Borislav Petkov 3ab0e7dc2e amd64_edac: Remove F11h support
F11h doesn't support DRAM ECC so whack it away.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2011-01-07 11:33:47 +01:00
Linus Torvalds 42cbd8efb0 Merge branch 'x86-amd-nb-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* '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
2011-01-06 10:50:28 -08:00
Borislav Petkov e726f3c368 amd64_edac: Fix interleaving check
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>
2010-12-08 19:52:54 +01:00
Hans Rosenfeld 9653a5c76c x86, amd-nb: Cleanup AMD northbridge caching code
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>
2010-11-18 15:53:05 +01:00
Hans Rosenfeld eec1d4fa00 x86, amd-nb: Complete the rename of AMD NB and related code
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>
2010-11-18 15:53:04 +01:00
Linus Torvalds c029e405bd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp: (21 commits)
  EDAC, MCE: Fix shift warning on 32-bit
  EDAC, MCE: Add a BIT_64() macro
  EDAC, MCE: Enable MCE decoding on F12h
  EDAC, MCE: Add F12h NB MCE decoder
  EDAC, MCE: Add F12h IC MCE decoder
  EDAC, MCE: Add F12h DC MCE decoder
  EDAC, MCE: Add support for F11h MCEs
  EDAC, MCE: Enable MCE decoding on F14h
  EDAC, MCE: Fix FR MCEs decoding
  EDAC, MCE: Complete NB MCE decoders
  EDAC, MCE: Warn about LS MCEs on F14h
  EDAC, MCE: Adjust IC decoders to F14h
  EDAC, MCE: Adjust DC decoders to F14h
  EDAC, MCE: Rename files
  EDAC, MCE: Rework MCE injection
  EDAC: Export edac sysfs class to users.
  EDAC, MCE: Pass complete MCE info to decoders
  EDAC, MCE: Sanitize error codes
  EDAC, MCE: Remove unused function parameter
  EDAC, MCE: Add HW_ERR prefix
  ...
2010-10-21 14:04:58 -07:00
Borislav Petkov 7cfd4a8744 EDAC, MCE: Pass complete MCE info to decoders
... 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>
2010-10-21 14:47:58 +02:00
Andreas Herrmann 23ac4ae827 x86, k8: Rename k8.[ch] to amd_nb.[ch] and CONFIG_K8_NB to CONFIG_AMD_NB
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>
2010-09-20 14:22:58 -07:00
Andreas Herrmann 900f9ac9f1 x86, k8-gart: Decouple handling of garts and northbridges
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>
2010-09-17 13:26:21 -07:00
Borislav Petkov 37b7370a8d amd64_edac: Do not report error overflow as a separate error
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>
2010-08-26 12:46:03 +02:00
Borislav Petkov c4799c7570 amd64_edac: Minor formatting fix
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>
2010-08-04 11:16:01 +02:00
Borislav Petkov 962b70a1eb amd64_edac: Fix operator precendence error
The bitwise AND is of higher precedence, make that explicit.

Cc: <stable@kernel.org> # 34.x
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2010-08-04 11:15:09 +02:00
Borislav Petkov eba042a81e edac, mc: Improve scrub rate handling
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>
2010-08-03 16:14:06 +02:00
Borislav Petkov bc57117856 amd64_edac: Correct scrub rate setting
Exit early when setting scrub rate on unknown/unsupported families.

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>
2010-08-03 16:14:05 +02:00
Borislav Petkov 9975a5f22a amd64_edac: Fix DCT base address selector
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>
2010-08-03 16:14:04 +02:00
Borislav Petkov f4347553b3 amd64_edac: Remove polling mechanism
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>
2010-08-03 16:14:03 +02:00
Borislav Petkov ad6a32e969 amd64_edac: Sanitize syndrome extraction
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>
2010-08-03 16:13:31 +02:00
Borislav Petkov 41c310447f amd64_edac: Fix syndrome calculation on K8
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>
2010-07-02 17:32:34 +02:00
Linus Torvalds eaa5eec739 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  amd64_edac: Simplify ECC override handling
2010-03-03 09:25:37 -08:00
Linus Torvalds 0a135ba14d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: add __percpu sparse annotations to what's left
  percpu: add __percpu sparse annotations to fs
  percpu: add __percpu sparse annotations to core kernel subsystems
  local_t: Remove leftover local.h
  this_cpu: Remove pageset_notifier
  this_cpu: Page allocator conversion
  percpu, x86: Generic inc / dec percpu instructions
  local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c
  module: Use this_cpu_xx to dynamically allocate counters
  local_t: Remove cpu_local_xx macros
  percpu: refactor the code in pcpu_[de]populate_chunk()
  percpu: remove compile warnings caused by __verify_pcpu_ptr()
  percpu: make accessors check for percpu pointer in sparse
  percpu: add __percpu for sparse.
  percpu: make access macros universal
  percpu: remove per_cpu__ prefix.
2010-03-03 07:34:18 -08:00
Borislav Petkov d95cf4de6a amd64_edac: Simplify ECC override handling
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>
2010-03-01 19:25:12 +01:00
Tejun Heo a29d8b8e2d percpu: add __percpu sparse annotations to what's left
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>
2010-02-17 11:17:38 +09:00
Borislav Petkov cab4d27764 amd64_edac: Do not falsely trigger kerneloops
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/422536
http://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>
2010-02-11 20:32:14 +01:00
Roel Kluin 926311fd7d amd64_edac: Ensure index stays within bounds in amd64_get_scrub_rate
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>
2010-01-15 10:45:58 +01:00
Borislav Petkov 92389102b6 amd64_edac: restrict PCI config space access
Do not access F2x19[0,4] on K8 since they're undefined there.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2009-12-24 11:07:08 +01:00
Borislav Petkov 43f5e68733 amd64_edac: fix forcing module load/unload
Clear the override flag after force-loading the module.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2009-12-24 11:07:08 +01:00
Borislav Petkov 56b34b91e2 amd64_edac: make driver loading more robust
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>
2009-12-24 11:07:07 +01:00
Borislav Petkov 8f68ed9728 amd64_edac: fix driver instance freeing
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>
2009-12-24 11:07:07 +01:00
Borislav Petkov 603adaf6b3 amd64_edac: fix K8 chip select reporting
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>
2009-12-24 11:07:07 +01:00
Borislav Petkov 505422517d x86, msr: Add support for non-contiguous cpumasks
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>
2009-12-11 10:59:21 -08:00
Andrew Morton 18ba54ac12 amd64_edac: fix use-uninitialised bug
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>
2009-12-08 13:38:13 +01:00
Borislav Petkov bdc30a0c8c amd64_edac: correct sys address to chip select mapping
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>
2009-12-08 13:38:12 +01:00
Borislav Petkov bfc04aec7d amd64_edac: add a leaner syndrome decoding algorithm
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>
2009-12-08 13:37:59 +01:00