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  1. 11 Jun, 2012 4 commits
    • Mauro Carvalho Chehab's avatar
      edac: rewrite the sysfs code to use struct device · 7a623c03
      Mauro Carvalho Chehab authored 
      The EDAC subsystem uses the old struct sysdev approach,
creating all nodes using the raw sysfs API. This is bad,
as the API is deprecated.

As we'll be changing the EDAC API, let's first port the existing
code to struct device.

There's one drawback on this patch: driver-specific sysfs
nodes, used by mpc85xx_edac, amd64_edac and i7core_edac
 won't be created anymore. While it would be possible to
also port the device-specific code, that would mix kobj with
struct device, with is not recommended. Also, it is easier and nicer
to move the code to the drivers, instead, as the core can get rid
of some complex logic that just emulates what the device_add()
and device_create_file() already does.

The next patches will convert the driver-specific code to use
the device-specific calls. Then, the remaining bits of the old
sysfs API will be removed.

NOTE: a per-MC bus is required, otherwise devices with more than
one memory controller will hit a bug like the one below:

[  819.094946] EDAC DEBUG: find_mci_by_dev: find_mci_by_dev()
[  819.094948] EDAC DEBUG: edac_create_sysfs_mci_device: edac_create_sysfs_mci_device() idx=1
[  819.094952] EDAC DEBUG: edac_create_sysfs_mci_device: edac_create_sysfs_mci_device(): creating device mc1
[  819.094967] EDAC DEBUG: edac_create_sysfs_mci_device: edac_create_sysfs_mci_device creating dimm0, located at channel 0 slot 0
[  819.094984] ------------[ cut here ]------------
[  819.100142] WARNING: at fs/sysfs/dir.c:481 sysfs_add_one+0xc1/0xf0()
[  819.107282] Hardware name: S2600CP
[  819.111078] sysfs: cannot create duplicate filename '/bus/edac/devices/dimm0'
[  819.119062] Modules linked in: sb_edac(+) edac_core ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle iptable_filter ip_tables bridge stp llc sunrpc binfmt_misc dm_mirror dm_region_hash dm_log vhost_net macvtap macvlan tun kvm microcode pcspkr iTCO_wdt iTCO_vendor_support igb i2c_i801 i2c_core sg ioatdma dca sr_mod cdrom sd_mod crc_t10dif ahci libahci isci libsas libata scsi_transport_sas scsi_mod wmi dm_mod [last unloaded: scsi_wait_scan]
[  819.175748] Pid: 10902, comm: modprobe Not tainted 3.3.0-0.11.el7.v12.2.x86_64 #1
[  819.184113] Call Trace:
[  819.186868]  [<ffffffff8105adaf>] warn_slowpath_common+0x7f/0xc0
[  819.193573]  [<ffffffff8105aea6>] warn_slowpath_fmt+0x46/0x50
[  819.200000]  [<ffffffff811f53d1>] sysfs_add_one+0xc1/0xf0
[  819.206025]  [<ffffffff811f5cf5>] sysfs_do_create_link+0x135/0x220
[  819.212944]  [<ffffffff811f7023>] ? sysfs_create_group+0x13/0x20
[  819.219656]  [<ffffffff811f5df3>] sysfs_create_link+0x13/0x20
[  819.226109]  [<ffffffff813b04f6>] bus_add_device+0xe6/0x1b0
[  819.232350]  [<ffffffff813ae7cb>] device_add+0x2db/0x460
[  819.238300]  [<ffffffffa0325634>] edac_create_dimm_object+0x84/0xf0 [edac_core]
[  819.246460]  [<ffffffffa0325e18>] edac_create_sysfs_mci_device+0xe8/0x290 [edac_core]
[  819.255215]  [<ffffffffa0322e2a>] edac_mc_add_mc+0x5a/0x2c0 [edac_core]
[  819.262611]  [<ffffffffa03412df>] sbridge_register_mci+0x1bc/0x279 [sb_edac]
[  819.270493]  [<ffffffffa03417a3>] sbridge_probe+0xef/0x175 [sb_edac]
[  819.277630]  [<ffffffff813ba4e8>] ? pm_runtime_enable+0x58/0x90
[  819.284268]  [<ffffffff812f430c>] local_pci_probe+0x5c/0xd0
[  819.290508]  [<ffffffff812f5ba1>] __pci_device_probe+0xf1/0x100
[  819.297117]  [<ffffffff812f5bea>] pci_device_probe+0x3a/0x60
[  819.303457]  [<ffffffff813b1003>] really_probe+0x73/0x270
[  819.309496]  [<ffffffff813b138e>] driver_probe_device+0x4e/0xb0
[  819.316104]  [<ffffffff813b149b>] __driver_attach+0xab/0xb0
[  819.322337]  [<ffffffff813b13f0>] ? driver_probe_device+0xb0/0xb0
[  819.329151]  [<ffffffff813af5d6>] bus_for_each_dev+0x56/0x90
[  819.335489]  [<ffffffff813b0d7e>] driver_attach+0x1e/0x20
[  819.341534]  [<ffffffff813b0980>] bus_add_driver+0x1b0/0x2a0
[  819.347884]  [<ffffffffa0347000>] ? 0xffffffffa0346fff
[  819.353641]  [<ffffffff813b19f6>] driver_register+0x76/0x140
[  819.359980]  [<ffffffff8159f18b>] ? printk+0x51/0x53
[  819.365524]  [<ffffffffa0347000>] ? 0xffffffffa0346fff
[  819.371291]  [<ffffffff812f5896>] __pci_register_driver+0x56/0xd0
[  819.378096]  [<ffffffffa0347054>] sbridge_init+0x54/0x1000 [sb_edac]
[  819.385231]  [<ffffffff8100203f>] do_one_initcall+0x3f/0x170
[  819.391577]  [<ffffffff810bcd2e>] sys_init_module+0xbe/0x230
[  819.397926]  [<ffffffff815bb529>] system_call_fastpath+0x16/0x1b
[  819.404633] ---[ end trace 1654fdd39556689f ]---

This happens because the bus is not being properly initialized.
Instead of putting the memory sub-devices inside the memory controller,
it is putting everything under the same directory:

$ tree /sys/bus/edac/
/sys/bus/edac/
├── devices
│   ├── all_channel_counts -> ../../../devices/system/edac/mc/mc0/all_channel_counts
│   ├── csrow0 -> ../../../devices/system/edac/mc/mc0/csrow0
│   ├── csrow1 -> ../../../devices/system/edac/mc/mc0/csrow1
│   ├── csrow2 -> ../../../devices/system/edac/mc/mc0/csrow2
│   ├── dimm0 -> ../../../devices/system/edac/mc/mc0/dimm0
│   ├── dimm1 -> ../../../devices/system/edac/mc/mc0/dimm1
│   ├── dimm3 -> ../../../devices/system/edac/mc/mc0/dimm3
│   ├── dimm6 -> ../../../devices/system/edac/mc/mc0/dimm6
│   ├── inject_addrmatch -> ../../../devices/system/edac/mc/mc0/inject_addrmatch
│   ├── mc -> ../../../devices/system/edac/mc
│   └── mc0 -> ../../../devices/system/edac/mc/mc0
├── drivers
├── drivers_autoprobe
├── drivers_probe
└── uevent

On a multi-memory controller system, the names "csrow%d" and "dimm%d"
should be under "mc%d", and not at the main hierarchy level.

So, we need to create a per-MC bus, in order to have its own namespace.
Reviewed-by: default avatarAristeu Rozanski <arozansk@redhat.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Greg K H <gregkh@linuxfoundation.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
      7a623c03
    • Mauro Carvalho Chehab's avatar
      edac: use Documentation-nano format for some data structs · b0610bb8
      Mauro Carvalho Chehab authored 
      No functional changes. Just comment improvements.
Reviewed-by: default avatarAristeu Rozanski <arozansk@redhat.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
      b0610bb8
    • Mauro Carvalho Chehab's avatar
      edac: Rename the parent dev to pdev · fd687502
      Mauro Carvalho Chehab authored 
      As EDAC doesn't use struct device itself, it created a parent dev
pointer called as "pdev".  Now that we'll be converting it to use
struct device, instead of struct devsys, this needs to be fixed.

No functional changes.
Reviewed-by: default avatarAristeu Rozanski <arozansk@redhat.com>
Acked-by: default avatarChris Metcalf <cmetcalf@tilera.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Mark Gross <mark.gross@intel.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Cc: Tim Small <tim@buttersideup.com>
Cc: Ranganathan Desikan <ravi@jetztechnologies.com>
Cc: "Arvind R." <arvino55@gmail.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Egor Martovetsky <egor@pasemi.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Joe Perches <joe@perches.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Niklas Söderlund" <niklas.soderlund@ericsson.com>
Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
      fd687502
    • Mauro Carvalho Chehab's avatar
      RAS: Add a tracepoint for reporting memory controller events · 53f2d028
      Mauro Carvalho Chehab authored 
      Add a new tracepoint-based hardware events report method for
reporting Memory Controller events.

Part of the description bellow is shamelessly copied from Tony
Luck's notes about the Hardware Error BoF during LPC 2010 [1].
Tony, thanks for your notes and discussions to generate the
h/w error reporting requirements.

[1] http://lwn.net/Articles/416669/

    We have several subsystems & methods for reporting hardware errors:

    1) EDAC ("Error Detection and Correction").  In its original form
    this consisted of a platform specific driver that read topology
    information and error counts from chipset registers and reported
    the results via a sysfs interface.

    2) mcelog - x86 specific decoding of machine check bank registers
    reporting in binary form via /dev/mcelog. Recent additions make use
    of the APEI extensions that were documented in version 4.0a of the
    ACPI specification to acquire more information about errors without
    having to rely reading chipset registers directly. A user level
    programs decodes into somewhat human readable format.

    3) drivers/edac/mce_amd.c - this driver hooks into the mcelog path and
    decodes errors reported via machine check bank registers in AMD
    processors to the console log using printk();

    Each of these mechanisms has a band of followers ... and none
    of them appear to meet all the needs of all users.

As part of a RAS subsystem, let's encapsulate the memory error hardware
events into a trace facility.

The tracepoint printk will be displayed like:

mc_event: [quant] (Corrected|Uncorrected|Fatal) error:[error msg] on [label] ([location] [edac_mc detail] [driver_detail]

Where:
       	[quant] is the quantity of errors
	[error msg] is the driver-specific error message
		    (e. g. "memory read", "bus error", ...);
	[location] is the location in terms of memory controller and
		   branch/channel/slot, channel/slot or csrow/channel;
	[label] is the memory stick label;
	[edac_mc detail] describes the address location of the error
			 and the syndrome;
	[driver detail] is driver-specifig error message details,
			when needed/provided (e. g. "area:DMA", ...)

For example:

mc_event: 1 Corrected error:memory read on memory stick DIMM_1A (mc:0 location:0:0:0 page:0x586b6e offset:0xa66 grain:32 syndrome:0x0 area:DMA)

Of course, any userspace tools meant to handle errors should not parse
the above data. They should, instead, use the binary fields provided by
the tracepoint, mapping them directly into their Management Information
Base.

NOTE: The original patch was providing an additional mechanism for
MCA-based trace events that also contained MCA error register data.
However, as no agreement was reached so far for the MCA-based trace
events, for now, let's add events only for memory errors.
A latter patch is planned to change the tracepoint, for those types
of event.

Cc: Aristeu Rozanski <arozansk@redhat.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
      53f2d028
  3. 28 May, 2012 36 commits
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