During a EEH recover, the pci_dev structure can be null, mainly if an
eeh event is detected during cpi config operation. In this case, the
pci_dev will not be known (and will be null) the kernel will crash
with the following message:

Unable to handle kernel paging request for data at address 0x000000a0
Faulting instruction address: 0xc00000000006b8b4
Oops: Kernel access of bad area, sig: 11 [#1]

NIP [c00000000006b8b4] .eeh_event_handler+0x10c/0x1a0
LR [c00000000006b8a8] .eeh_event_handler+0x100/0x1a0
Call Trace:
[c0000003a80dff00] [c00000000006b8a8] .eeh_event_handler+0x100/0x1a0
[c0000003a80dff90] [c000000000031f1c] .kernel_thread+0x54/0x70

The bug occurs because pci_name() tries to access a null pointer.
This patch just guarantee that pci_name() is not called on Null pointers.
Signed-off-by: NBreno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: NLinas Vepstas <linasvepstas@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

By default, the EEH framework on powerpc does what's known as a "hot
reset" during recovery of a PCI Express device.  We've found a case
where the device needs a "fundamental reset" to recover properly.  The
current PCI error recovery and EEH frameworks do not support this
distinction.

The attached patch makes changes to EEH to utilize the new bit field.
Signed-off-by: NMike Mason <mmlnx@us.ibm.com>
Signed-off-by: NRichard Lary <rlary@us.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

To properly fix PCI hotplug, it's useful to be able to make the fixup
passes on all devices whether they were just hot plugged or already
there.

The EEH code however used to not be very friendly with calling
eeh_add_device_late() multiple time, and not very rebust in the way it
generally tests whether a device is in the expected state vs. the EEH
code.

This improves it, along with cleaning up a couple of debug printk's.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch changes the EEH_MAX_FAILS action from panic to printing an
error message.  Panicking under under this condition is too harsh.
Although performance will be affected and the device may not recover,
the system is still running, which at the very least should allow for a
more graceful shutdown. The patch also removes the msleep() within a
spinlock, which can lead to a deadlock and is not recommended.
Signed-off-by: NMike Mason <mmlnx@us.ibm.com>
Acked-by: NLinas Vepstas <linasvepstas@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The following patch restores the PERR and SERR bits in the PCI
command register during an EEH device recovery. We have found
at least one case (an Agilent test card) where the PERR/SERR
bits are set to 1 by firmware at boot time, but are not restored
to 1 during EEH recovery.  The patch fixes the Agilent card
problem.  It has been tested on several other EEH-enabled cards
with no regressions.
Signed-off-by: NMike Mason <mmlnx@us.ibm.com>
Acked-by: NLinas Vepstas <linasvepstas@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a DEBUG config setting which turns on all (most) of the debugging
under platforms/pseries.

To have this take effect we need to remove all the #undef DEBUG's, in
various files. We leave the #undef DEBUG in platforms/pseries/lpar.c,
as this enables debugging printks from the low-level hash table routines,
and tends to make your system unusable. If you want those enabled you
still have to turn them on by hand.

Also some of the RAS code has a DEBUG block which causes a functional
change, so I've keyed this off a different (non-existant) debug #define.

This is only enabled if you have PPC_EARLY_DEBUG enabled also.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

A couple of places are duplicating the function of
of_device_is_available; convert them to use it.
Signed-off-by: NNathan Lynch <ntl@pobox.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

If an "empty" slot is failing, make sure its a permanent failure;
else process the error normally.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Perform all error checking at the "partitonable endpoint"
of the device.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Fix old buglet; a warning message should have been printed
when a hardware reset takes too long.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Bugfix: avoid crash if there's no PCI device for a given
openfirmware node.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

It seems that some versions of firmware will report a device
node status as the string "okay". As we are not expecting this
string, the device node will be ignored by the EEH subsystem.
Which means EEH will not be enabled.

When EEH is not enabled, PCI errors will be converted into
Machine Check exceptions, and we'll have a very unhappy system.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Remove dead code, and a misleading comment about EEH checking
for video devices.  The removed code is a left-over from the
olden days where there was concern over how video devices
worked in Linux. We are never going to go that way again,
so kill this.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c |   17 -----------------
 1 file changed, 17 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Gather bridge-specific data on EEH events.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
----
 arch/powerpc/platforms/pseries/eeh.c |   27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Print return code to print message.  Also fix whitespace.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Twiddle the copyright notices. Per current guidelines, the use
of the (C) or (c) in source code is deprecated.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c        |    6 +++++-
 arch/powerpc/platforms/pseries/eeh_cache.c  |    3 ++-
 arch/powerpc/platforms/pseries/eeh_driver.c |    6 +++---
 3 files changed, 10 insertions(+), 5 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Remove some dead code.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Track and report the number of times we read an all-1s value (0xff,
0xffff or 0xffffffff) from each device which is valid data, not
indicating EEH isolation.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c       |    5 +++++
 arch/powerpc/platforms/pseries/eeh_sysfs.c |    3 +++
 include/asm-powerpc/pci-bridge.h           |    1 +
 3 files changed, 9 insertions(+)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add sysfs blinkenlights for EEH statistics.  Shuffle the
eeh_add_device_tree() call so that it appears in the correct
sequence.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/Makefile    |    2
 arch/powerpc/platforms/pseries/eeh.c       |    4 +
 arch/powerpc/platforms/pseries/eeh_cache.c |    2
 arch/powerpc/platforms/pseries/eeh_sysfs.c |   84 +++++++++++++++++++++++++++++
 arch/powerpc/platforms/pseries/pci_dlpar.c |    7 +-
 include/asm-powerpc/ppc-pci.h              |    3 +
 6 files changed, 98 insertions(+), 4 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Assorted minor cleanups to EEH code; -- use literals, use
kerneldoc format.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c        |   13 ++++++++++---
 arch/powerpc/platforms/pseries/eeh_driver.c |    7 ++++---
 include/asm-powerpc/ppc-pci.h               |   18 +++++++++++++++---
 3 files changed, 29 insertions(+), 9 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

When an EEH event is detected, and after the device driver
has been notified, but before the device is reset, enable
MMIO to the adapter, and grab the contents of the PCI status
and command registers, the PCI-X status and command, and the
PCI-E capability 10 and AER registers. Pass these up to the
RTAS error log, and also printk them.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

If an EEH event is observed, capture PCI config space info about
the device, wrap it up and pass it to the event logger.  This
pach just slots in the basic logging function. A later patch
will provide for more through data gathering.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Adds the pSeries platform implementation for a new PCI API
which can be used to issue various types of PCI-E reset,
including PCI-E warm reset and PCI-E hot reset. This is needed
for an ipr PCI-E adapter which does not properly implement BIST.
Running BIST on this adapter results in PCI-E errors. The only
reliable reset mechanism that exists on this hardware is PCI
Fundamental reset (warm reset).
Acked-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Rework how multi-function PCI devices are identified and traversed.
This fixes a bug with multi-function recovery on Power4 that was
introduced by a recent Power4 EEH patch.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

After requesting a state change, verify that the state change
actually ocurred, and the system ends up in the expected state.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The EEH event notification system passes around data that is
not needed or at least, not used properly. Stop passing this
data; get it in a more reliable fashion.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Modify routine that returns PCI slot status to wait for slot status
to become available. This is needed, as slots that are in some remote
card cage may go offline for extended periods of time. New users for
this routine in following patches.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Some firmware versions will return a slot reset state of "1"
when a slot is EEH frozen. Recognize this as a state that can be
handled.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Provide support for the new ibm,get-config-addr-info2 RTAS token,
whenever it is actually available.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Some drivers will attempt to perform a lot of mmio even after
an EEH event was detected. This is especially the case for fast cpu's
and PCI-E slots. Be a bit more lenient in allowing this.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Change the order in which pci error state is examined;
the "capabilites" is not valid if "reset state" is 5.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@osdl.org: sparc64 fix]
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It appears that EEH is improperly enabled for some Power4 systems.
On these systems, the ibm,set-eeh-option returns a value of success
even when EEH is not supported on the given node. Thus, an explicit
check for support is required.

During boot, on power4, without this patch, one sees messages
similar to:

EEH: event on unsupported device, rc=0 dn=/pci@400000000110/IBM,sp@1
EEH: event on unsupported device, rc=0 dn=/pci@400000000110/pci@2
EEH: event on unsupported device, rc=0 dn=/pci@400000000110/pci@2,2
etc.

The patch makes these go away.

Without this patch, EEH recovery does seem to work correctly for
at least some devices (I tested ethernet e1000), but fails to
recover others (the Emulex LightPulse LPFC, most notably).
Off the top of my head, I don't remember why some devices are
affected, but not others.

The PAPR indicates that the correct way to test for EEH is as
done in this patch; its not clear to me if this was in the PAPR
all along, or recently added; if it was there all along, its not
clear to me why this hadn't been fixed long ago. I suspect only
certain firmware levels are affected.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

If one attempts to create a device driver recovery sequence that
does not depend on a hard reset of the device, but simply just
attempts to resume processing, then one discovers that the
recovery sequence implemented on powerpc is not quite right.
This patch fixes this up.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Bug fix: when marking a slot as frozen, we forgot to mark
pci device itself as frozen. (we did manage to mark the
pci children, but forget the parent itself.)

This is needed so that some device drivers can check the
pci status in critical sections (e.g. in spin loops with
interrupts disabled).
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

On detection of an EEH error, some Power4 systems seem to occasionally
want to be reset twice before they report themselves as fully recovered.
This patch re-arranges the code to attempt additional resets if the first
one doesn't take.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add wrapper around the rtas call to enable MMIO or DMA on a frozen pci
slot.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>