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[PATCH] Fix and enable EDAC sysfs operation

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When EDAC was first introduced into the kernel it had a sysfs interface,
but due to some problems it was disabled in 2.6.16 and remained disabled in
2.6.17.

With feedback, several of the control and attribute files of that interface
had some good constructive feedback.  PCI Blacklist/Whitelist was a major
set which has design issues and it has been removed in this patch.  Instead
of storing PCI broken parity status in EDAC, it has been moved to the
pci_dev structure itself by a previous PCI patch.  A future patch will
enable that feature in EDAC by utilizing the pci_dev info.

The sysfs is now enabled in this patch, with a minimal set of control and
attribute files for examining EDAC state and for enabling/disabling the
memory and PCI operations.

The Documentation for EDAC has also been updated to reflect the new state
of EDAC operation.

Signed-off-by:Doug Thompson <norsk5@xmisson.com>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Doug Thompson 2006-07-10 04:45:19 -07:00 committed by Linus Torvalds
parent 68e3c5e3b5
commit 49c0dab7e6
2 changed files with 226 additions and 623 deletions
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152
Documentation/drivers/edac/edac.txt
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@ -35,15 +35,14 @@ the vendor should tie the parity status bits to 0 if they do not intend
to generate parity. Some vendors do not do this, and thus the parity bit
can "float" giving false positives.
The PCI Parity EDAC device has the ability to "skip" known flaky
cards during the parity scan. These are set by the parity "blacklist"
interface in the sysfs for PCI Parity. (See the PCI section in the sysfs
section below.) There is also a parity "whitelist" which is used as
an explicit list of devices to scan, while the blacklist is a list
of devices to skip.
[There are patches in the kernel queue which will allow for storage of
quirks of PCI devices reporting false parity positives. The 2.6.18
kernel should have those patches included. When that becomes available,
then EDAC will be patched to utilize that information to "skip" such
devices.]
EDAC will have future error detectors that will be added or integrated
into EDAC in the following list:
EDAC will have future error detectors that will be integrated with
EDAC or added to it, in the following list:
MCE Machine Check Exception
MCA Machine Check Architecture
@ -93,22 +92,24 @@ EDAC lives in the /sys/devices/system/edac directory. Within this directory
there currently reside 2 'edac' components:
mc memory controller(s) system
pci PCI status system
pci PCI control and status system
============================================================================
Memory Controller (mc) Model
First a background on the memory controller's model abstracted in EDAC.
Each mc device controls a set of DIMM memory modules. These modules are
Each 'mc' device controls a set of DIMM memory modules. These modules are
laid out in a Chip-Select Row (csrowX) and Channel table (chX). There can
be multiple csrows and two channels.
be multiple csrows and multiple channels.
Memory controllers allow for several csrows, with 8 csrows being a typical value.
Yet, the actual number of csrows depends on the electrical "loading"
of a given motherboard, memory controller and DIMM characteristics.
Dual channels allows for 128 bit data transfers to the CPU from memory.
Some newer chipsets allow for more than 2 channels, like Fully Buffered DIMMs
(FB-DIMMs). The following example will assume 2 channels:
Channel 0 Channel 1
@ -234,23 +235,15 @@ Polling period control file:
The time period, in milliseconds, for polling for error information.
Too small a value wastes resources. Too large a value might delay
necessary handling of errors and might loose valuable information for
locating the error. 1000 milliseconds (once each second) is about
right for most uses.
locating the error. 1000 milliseconds (once each second) is the current
default. Systems which require all the bandwidth they can get, may
increase this.
LOAD TIME: module/kernel parameter: poll_msec=[0|1]
RUN TIME: echo "1000" >/sys/devices/system/edac/mc/poll_msec
Module Version read-only attribute file:
'mc_version'
The EDAC CORE module's version and compile date are shown here to
indicate what EDAC is running.
============================================================================
'mcX' DIRECTORIES
@ -284,35 +277,6 @@ Seconds since last counter reset control file:
DIMM capability attribute file:
'edac_capability'
The EDAC (Error Detection and Correction) capabilities/modes of
the memory controller hardware.
DIMM Current Capability attribute file:
'edac_current_capability'
The EDAC capabilities available with the hardware
configuration. This may not be the same as "EDAC capability"
if the correct memory is not used. If a memory controller is
capable of EDAC, but DIMMs without check bits are in use, then
Parity, SECDED, S4ECD4ED capabilities will not be available
even though the memory controller might be capable of those
modes with the proper memory loaded.
Memory Type supported on this controller attribute file:
'supported_mem_type'
This attribute file displays the memory type, usually
buffered and unbuffered DIMMs.
Memory Controller name attribute file:
'mc_name'
@ -321,16 +285,6 @@ Memory Controller name attribute file:
that is being utilized.
Memory Controller Module name attribute file:
'module_name'
This attribute file displays the memory controller module name,
version and date built. The name of the memory controller
hardware - some drivers work with multiple controllers and
this field shows which hardware is present.
Total memory managed by this memory controller attribute file:
'size_mb'
@ -432,6 +386,9 @@ Memory Type attribute file:
This attribute file will display what type of memory is currently
on this csrow. Normally, either buffered or unbuffered memory.
Examples:
Registered-DDR
Unbuffered-DDR
EDAC Mode of operation attribute file:
@ -446,8 +403,13 @@ Device type attribute file:
'dev_type'
This attribute file will display what type of DIMM device is
being utilized. Example: x4
This attribute file will display what type of DRAM device is
being utilized on this DIMM.
Examples:
x1
x2
x4
x8
Channel 0 CE Count attribute file:
@ -522,10 +484,10 @@ SYSTEM LOGGING
If logging for UEs and CEs are enabled then system logs will have
error notices indicating errors that have been detected:
MC0: CE page 0x283, offset 0xce0, grain 8, syndrome 0x6ec3, row 0,
EDAC MC0: CE page 0x283, offset 0xce0, grain 8, syndrome 0x6ec3, row 0,
channel 1 "DIMM_B1": amd76x_edac
MC0: CE page 0x1e5, offset 0xfb0, grain 8, syndrome 0xb741, row 0,
EDAC MC0: CE page 0x1e5, offset 0xfb0, grain 8, syndrome 0xb741, row 0,
channel 1 "DIMM_B1": amd76x_edac
@ -610,64 +572,4 @@ Parity Count:
PCI Device Whitelist:
'pci_parity_whitelist'
This control file allows for an explicit list of PCI devices to be
scanned for parity errors. Only devices found on this list will
be examined. The list is a line of hexadecimal VENDOR and DEVICE
ID tuples:
1022:7450,1434:16a6
One or more can be inserted, separated by a comma.
To write the above list doing the following as one command line:
echo "1022:7450,1434:16a6"
> /sys/devices/system/edac/pci/pci_parity_whitelist
To display what the whitelist is, simply 'cat' the same file.
PCI Device Blacklist:
'pci_parity_blacklist'
This control file allows for a list of PCI devices to be
skipped for scanning.
The list is a line of hexadecimal VENDOR and DEVICE ID tuples:
1022:7450,1434:16a6
One or more can be inserted, separated by a comma.
To write the above list doing the following as one command line:
echo "1022:7450,1434:16a6"
> /sys/devices/system/edac/pci/pci_parity_blacklist
To display what the whitelist currently contains,
simply 'cat' the same file.
=======================================================================
PCI Vendor and Devices IDs can be obtained with the lspci command. Using
the -n option lspci will display the vendor and device IDs. The system
administrator will have to determine which devices should be scanned or
skipped.
The two lists (white and black) are prioritized. blacklist is the lower
priority and will NOT be utilized when a whitelist has been set.
Turn OFF a whitelist by an empty echo command:
echo > /sys/devices/system/edac/pci/pci_parity_whitelist
and any previous blacklist will be utilized.

697
drivers/edac/edac_mc.c
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