Commit graph

11 commits

Author SHA1 Message Date
Aneesh Kumar K.V
7844663a31 powerpc/eeh: Don't release eeh_mutex in eeh_phb_pe_get
Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>

=====================================
[ BUG: bad unlock balance detected! ]
3.6.0-rc5-00338-gcaa1d63-dirty #6 Not tainted
-------------------------------------
swapper/0/1 is trying to release lock (eeh_mutex) at:
[<c000000000058218>] .eeh_add_to_parent_pe+0x318/0x410
but there are no more locks to release!

other info that might help us debug this:
no locks held by swapper/0/1.

stack backtrace:
Call Trace:
[c00000003e483870] [c000000000013310] .show_stack+0x70/0x1c0 (unreliable)
[c00000003e483920] [c0000000000d8310] .print_unlock_inbalance_bug+0x110/0x120
[c00000003e4839b0] [c0000000000d9a50] .lock_release+0x1d0/0x240
[c00000003e483a60] [c000000000778064] .__mutex_unlock_slowpath+0xb4/0x250
[c00000003e483b10] [c000000000058218] .eeh_add_to_parent_pe+0x318/0x410
[c00000003e483bc0] [c00000000005a118] .pseries_eeh_of_probe+0x258/0x2f0
[c00000003e483cc0] [c000000000032528] .traverse_pci_devices+0xa8/0x150
[c00000003e483d70] [c000000000aa7288] .eeh_init+0xd4/0x140
[c00000003e483e00] [c00000000000abc4] .do_one_initcall+0x64/0x1e0
[c00000003e483ec0] [c000000000a90418] .kernel_init+0x1e8/0x2bc
[c00000003e483f90] [c00000000002048c] .kernel_thread+0x54/0x70
EEH: PCI Enhanced I/O Error Handling Enabled

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-27 12:51:07 +10:00
Gavin Shan
ea81245cf4 powerpc/eeh: Global mutex to protect PE tree
We have missed lots of situations where the PE hierarchy tree need
protection through the EEH global mutex. The patch fixes that for
those public APIs implemented in eeh_pe.c. The only exception is
eeh_pe_restore_bars() because it calls eeh_pe_dev_traverse(), which
has been protected by the mutex.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-18 15:32:33 +10:00
Gavin Shan
20ee6a9708 powerpc/eeh: Remove EEH PE for normal PCI hotplug
Function eeh_rmv_from_parent_pe() could be called by the path of
either normal PCI hotplug, or EEH recovery. For the former case,
we need purge the corresponding PE on removal of the associated
PE bus.

The patch tries to cover that by passing more information to function
pcibios_remove_pci_devices() so that we know if the corresponding PE
needs to be purged or be marked as "invalid".

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-18 15:32:23 +10:00
Gavin Shan
5efc3ad732 powerpc/eeh: Introduce EEH_PE_INVALID type PE
When EEH error happens on the PE whose PCI devices don't have
attached drivers. In function eeh_handle_event(), the default
value PCI_ERS_RESULT_NONE will be returned after iterating all
drivers of those PCI devices belonging to the PE. Actually, we
don't have installed drivers for the PCI devices. Under the
circumstance, we will remove the corresponding PCI bus of the PE,
including the associated EEH devices and PE instance. However,
we still need the information stored in the PE instance to do PE
reset after that. So it's unsafe to free the PE instance.

The patch introduces EEH_PE_INVALID type PE to address the issue.
When the PCI bus and the corresponding attached EEH devices are
removed, we will mark the PE as EEH_PE_INVALID. At later point,
the PE will be changed to EEH_PE_DEVICE or EEH_PE_BUS when the
corresponding EEH devices are attached again.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-18 15:02:49 +10:00
Gavin Shan
9b3c76f081 powerpc/eeh: Handle EEH error based on PE
The patch reworks the current implementation so that the eeh errors
will be handled basing on PE instead of eeh device.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:43 +10:00
Gavin Shan
9e6d2cf65e powerpc/eeh: Device bars restore based on PE
The patch introduces the function to traverse the devices of the
specified PE and its child PEs. Also, the restore on device bars
is implemented based on the traverse function.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:41 +10:00
Gavin Shan
5b66352944 powerpc/eeh: Trace EEH state based on PE
Since we've introduced dedicated struct to trace individual PEs,
it's reasonable to trace its state through the dedicated struct
instead of using "eeh_dev" any more.

The patches implements the state tracing based on PE. It's notable
that the PE state will be applied to the specified PE as well as
its child PEs. That complies with the rule that problematic parent
PE will prevent those child PEs from working properly.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:32 +10:00
Gavin Shan
82e8882f7f powerpc/eeh: Remove PE at appropriate time
During PCI hotplug and EEH recovery, the PE hierarchy tree might be
changed due to the PCI topology changes. At later point when the
PCI device is added, the PE will be created dynamically again.

The patch introduces new function to remove EEH devices from the
associated PE. That also can cause that the parent PE is removed
from the PE tree if the parent PE doesn't include valid EEH devices
and child PEs.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:32 +10:00
Gavin Shan
9b84348c92 powerpc/eeh: Create PEs duing EEH initialization
The patch creates PEs and associated the newly created PEs with
it parent/silbing as well as EEH devices. It would become more
straight to trace EEH errors and recover them accordingly.

Once the EEH functionality on one PCI IOA has been enabled, we
tries to create PE against it. If there's existing PE, to which
the current PCI IOA should be attached, the existing PE will be
converted from "device" type to "bus" type accordingly.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:31 +10:00
Gavin Shan
22f4ab123f powerpc/eeh: Search PE based on requirement
The patch implements searching PE based on the following
requirements:

 * Search PE according to PE address, which is traditional
   PE address that is composed of PCI bus/device/function
   number, or unified PE address assigned by firmware or
   platform.
 * Search parent PE according to the given EEH device. It's
   useful when creating new PE and put it into right position.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:31 +10:00
Gavin Shan
55037d1761 powerpc/eeh: Create PEs for PHBs
For one particular PE, it's only meaningful in the ancestor PHB
domain. Therefore, each PHB should have its own PE hierarchy tree
to trace those PEs created against the PHB.

The patch creates PEs for the PHBs and put those PEs into the
global link list traced by "eeh_phb_pe". The link list of PEs
would be first level of overall PE hierarchy tree across the
system.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10 09:35:30 +10:00