Message-ID: <20120608125219.GA31359@aftab.osrc.amd.com>
Date:	Fri, 8 Jun 2012 14:52:19 +0200
From:	Borislav Petkov <borislav.petkov@....com>
To:	Mauro Carvalho Chehab <mchehab@...hat.com>
CC:	edac-devel <linux-edac@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] edac: rewrite the sysfs code to use struct device

>From c0d119126e1b6daf9fe71614971233ffc90a873a Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab@...hat.com>
Date: Mon, 16 Apr 2012 16:41:11 -0300
Subject: [PATCH] edac: rewrite the sysfs code to use struct device
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

> 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

tree's output is utf8 and could cause problems like below when conversion fails:

    $ tree /sys/bus/edac/
    /sys/bus/edac/
    �<94><9C>�<94><80>�<94><80> devices
    �<94><82>   �<94><9C>�<94><80>�<94><80> all_channel_counts -> ../../../devices/system/edac/mc/mc0/all_channel_counts
    �<94><82>   �<94><9C>�<94><80>�<94><80> csrow0 -> ../../../devices/system/edac/mc/mc0/csrow0
    �<94><82>   �<94><9C>�<94><80>�<94><80> csrow1 -> ../../../devices/system/edac/mc/mc0/csrow1
    �<94><82>   �<94><9C>�<94><80>�<94><80> csrow2 -> ../../../devices/system/edac/mc/mc0/csrow2
    �<94><82>   �<94><9C>�<94><80>�<94><80> dimm0 -> ../../../devices/system/edac/mc/mc0/dimm0
    �<94><82>   �<94><9C>�<94><80>�<94><80> dimm1 -> ../../../devices/system/edac/mc/mc0/dimm1
    �<94><82>   �<94><9C>�<94><80>�<94><80> dimm3 -> ../../../devices/system/edac/mc/mc0/dimm3
    �<94><82>   �<94><9C>�<94><80>�<94><80> dimm6 -> ../../../devices/system/edac/mc/mc0/dimm6
    �<94><82>   �<94><9C>�<94><80>�<94><80> inject_addrmatch -> ../../../devices/system/edac/mc/mc0/inject_addrmatch
    �<94><82>   �<94><9C>�<94><80>�<94><80> mc -> ../../../devices/system/edac/mc
    �<94><82>   �<94><94>�<94><80>�<94><80> mc0 -> ../../../devices/system/edac/mc/mc0
    �<94><9C>�<94><80>�<94><80> drivers
    �<94><9C>�<94><80>�<94><80> drivers_autoprobe
    �<94><9C>�<94><80>�<94><80> drivers_probe
    �<94><94>�<94><80>�<94><80> uevent

This is after I've cherry-picked that patch.

What you could do is convert the output to ascii like that:

http://marc.info/?l=linux-kernel&m=133907329021320

> 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: Aristeu Rozanski <arozansk@...hat.com>
> Cc: Doug Thompson <norsk5@...oo.com>
> Cc: Greg K H <gregkh@...uxfoundation.org>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@...hat.com>

Hrrm,

this patch doesn't build here, ontop of 3.5-rc1, config attached.

In file included from arch/x86/kernel/nmi.c:23:0:
include/linux/edac.h:452:16: error: field ‘dev’ has incomplete type
include/linux/edac.h:488:16: error: field ‘dev’ has incomplete type
include/linux/edac.h:498:16: error: field ‘dev’ has incomplete type
include/linux/edac.h:553:18: error: field ‘dev’ has incomplete type
include/linux/edac.h:554:20: error: field ‘bus’ has incomplete type
make[2]: *** [arch/x86/kernel/nmi.o] Error 1
make[1]: *** [arch/x86/kernel] Error 2
make[1]: *** Waiting for unfinished jobs....
In file included from drivers/edac/edac_stub.c:16:0:
include/linux/edac.h:452:16: error: field ‘dev’ has incomplete type
include/linux/edac.h:488:16: error: field ‘dev’ has incomplete type
include/linux/edac.h:498:16: error: field ‘dev’ has incomplete type
include/linux/edac.h:553:18: error: field ‘dev’ has incomplete type
include/linux/edac.h:554:20: error: field ‘bus’ has incomplete type
make[2]: *** [drivers/edac/edac_stub.o] Error 1
make[1]: *** [drivers/edac] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [arch/x86] Error 2
make: *** Waiting for unfinished jobs....

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
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