In the kdump scenario, the first kerenl doesn't shutdown PCI devices
and the kdump kerenl clean PHB IODA table at the early probe time.
That means the kdump kerenl can't support PCI transactions piled
by the first kerenl. Otherwise, lots of EEH errors and frozen PEs
will be detected.

In order to avoid the EEH errors, the PHB is resetted to drop all
PCI transaction from the first kerenl.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The problem was initially reported by Wendy who tried pass through
IPR adapter, which was connected to PHB root port directly, to KVM
based guest. When doing that, pci_reset_bridge_secondary_bus() was
called by VFIO driver and linkDown was detected by the root port.
That caused all PEs to be frozen.

The patch fixes the issue by routing the reset for the secondary bus
of root port to underly firmware. For that, one more weak function
pci_reset_secondary_bus() is introduced so that the individual platforms
can override that and do specific reset for bridge's secondary bus.
Reported-by: NWendy Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Basically, we have 3 types of resets to fulfil PE reset: fundamental,
hot and PHB reset. For the later 2 cases, we need PCI bus reset hold
and settlement delay as specified by PCI spec. PowerNV and pSeries
platforms are running on top of different firmware and some of the
delays have been covered by underly firmware (PowerNV).

The patch makes the delays unified to be done in backend, instead of
EEH core.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Resetting root port has more stuff to do than that for PCIe switch
ports and we should have resetting root port done in firmware instead
of the kernel itself. The problem was introduced by commit 5b2e198e
("powerpc/powernv: Rework EEH reset").

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In pseries_eeh_get_state(), EEH_STATE_UNAVAILABLE is always
overwritten by EEH_STATE_NOT_SUPPORT because of the missed
"break" there. The patch fixes the issue.
Reported-by: NJoe Perches <joe@perches.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Once one specific PE has been marked as EEH_PE_ISOLATED, it's in
the middile of recovery or removed permenently. We needn't report
the frozen PE again. Otherwise, we will have endless reporting
same frozen PE.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The issue was detected in a bit complicated test case where
we have multiple hierarchical PEs shown as following figure:

                +-----------------+
                | PE#3     p2p#0  |
                |          p2p#1  |
                +-----------------+
                        |
                +-----------------+
                | PE#4     pdev#0 |
                |          pdev#1 |
                +-----------------+

PE#4 (have 2 PCI devices) is the child of PE#3, which has 2 p2p
bridges. We accidentally had less-known scenario: PE#4 was removed
permanently from the system because of permanent failure (e.g.
exceeding the max allowd failure times in last hour), then we detects
EEH errors on PE#3 and tried to recover it. However, eeh_dev instances
for pdev#0/1 were not detached from PE#4, which was still connected to
PE#3. All of that was because of the fact that we rely on count-based
pcibios_release_device(), which isn't reliable enough. When doing
recovery for PE#3, we still apply hotplug on PE#4 and pdev#0/1, which
are not valid any more. Eventually, we run into kernel crash.

The patch fixes above issue from two aspects. For unplug, we simply
skip those permanently removed PE, whose state is (EEH_PE_STATE_ISOLATED
&& !EEH_PE_STATE_RECOVERING) and its frozen count should be greater
than EEH_MAX_ALLOWED_FREEZES. For plug, we marked all permanently
removed EEH devices with EEH_DEV_REMOVED and return 0xFF's on read
its PCI config so that PCI core will omit them.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch introduces bootarg "eeh=off" to disable EEH functinality.
Also, it creates /sys/kerenl/debug/powerpc/eeh_enable to disable
or enable EEH functionality. By default, we have the functionality
enabled.

For PowerNV platform, we will restore to have the conventional
mechanism of clearing frozen PE during PCI config access if we're
going to disable EEH functionality. Conversely, we will rely on
EEH for error recovery.

The patch also fixes the issue that we missed to cover the case
of disabled EEH functionality in function ioda_eeh_event(). Those
events driven by interrupt should be cleared to avoid endless
reporting.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When calling into eeh_gather_pci_data() on pSeries platform, we
possiblly don't have pci_dev instance yet, but eeh_dev is always
ready. So we use cached capability from eeh_dev instead of pci_dev
for log dump there. In order to keep things unified, we also cache
PCI capability positions to eeh_dev for PowerNV as well.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We have suffered recrusive frozen PE a lot, which was caused
by IO accesses during the PE reset. Ben came up with the good
idea to keep frozen PE until recovery (BAR restore) gets done.
With that, IO accesses during PE reset are dropped by hardware
and wouldn't incur the recrusive frozen PE any more.

The patch implements the idea. We don't clear the frozen state
until PE reset is done completely. During the period, the EEH
core expects unfrozen state from backend to keep going. So we
have to reuse EEH_PE_RESET flag, which has been set during PE
reset, to return normal state from backend. The side effect is
we have to clear frozen state for towice (PE reset and clear it
explicitly), but that's harmless.

We have some limitations on pHyp. pHyp doesn't allow to enable
IO or DMA for unfrozen PE. So we don't enable them on unfrozen PE
in eeh_pci_enable(). We have to enable IO before grabbing logs on
pHyp. Otherwise, 0xFF's is always returned from PCI config space.
Also, we had wrong return value from eeh_pci_enable() for
EEH_OPT_THAW_DMA case. The patch fixes it too.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For EEH PowerNV backends, they need use their own PCI config
accesors as the normal one could be blocked during PE reset.
The patch also removes necessary parameter "hose" for the
function ioda_eeh_bridge_reset().
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We've observed multiple PE reset failures because of PCI-CFG
access during that period. Potentially, some device drivers
can't support EEH very well and they can't put the device to
motionless state before PE reset. So those device drivers might
produce PCI-CFG accesses during PE reset. Also, we could have
PCI-CFG access from user space (e.g. "lspci"). Since access to
frozen PE should return 0xFF's, we can block PCI-CFG access
during the period of PE reset so that we won't get recrusive EEH
errors.

The patch adds flag EEH_PE_RESET, which is kept during PE reset.
The PowerNV/pSeries PCI-CFG accessors reuse the flag to block
PCI-CFG accordingly.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For some fields (e.g. LEM, MMIO, DMA) in PHB diag-data dump, it's
meaningless to print them if they have non-zero value in the
corresponding mask registers because we always have non-zero values
in the mask registers. The patch only prints those fieds if we
have non-zero values in the primary registers (e.g. LEM, MMIO, DMA
status) so that we can save couple of lines. The patch also removes
unnecessary spare line before "brdgCtl:" and two leading spaces as
prefix in each line as Ben suggested.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The flag PNV_EEH_STATE_ENABLED is put into pnv_phb::eeh_state,
which is protected by CONFIG_EEH. We needn't that. Instead, we
can have pnv_phb::flags and maintain all flags there, which is
the purpose of the patch. The patch also renames PNV_EEH_STATE_ENABLED
to PNV_PHB_FLAG_EEH.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The PHB state PNV_EEH_STATE_REMOVED maintained in pnv_phb isn't
so useful any more and it's duplicated to EEH_PE_ISOLATED. The
patch replaces PNV_EEH_STATE_REMOVED with EEH_PE_ISOLATED.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Up until now we have been setting the runlatch bits for a busy CPU and
clearing it when a CPU enters idle state. The runlatch bit has thus
been consistent with the utilization of a CPU as long as the CPU is online.

However when a CPU is hotplugged out the runlatch bit is not cleared. It
needs to be cleared to indicate an unused CPU. Hence this patch has the
runlatch bit cleared for an offline CPU just before entering an idle state
and sets it immediately after it exits the idle state.
Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While testing memory hot-remove, I found following dead lock:

Process #1141 is drmgr, trying to remove some memory, i.e. memory499.
It holds the memory_hotplug_mutex, and blocks when trying to remove file
"online" under dir memory499, in kernfs_drain(), at
        wait_event(root->deactivate_waitq,
                   atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);

Process #1120 is trying to online memory499 by
   echo 1 > memory499/online

In .kernfs_fop_write, it uses kernfs_get_active() to increase
&kn->active, thus blocking process #1141. While itself is blocked later
when trying to acquire memory_hotplug_mutex, which is held by process

The backtrace of both processes are shown below:

[<c000000001b18600>] 0xc000000001b18600
[<c000000000015044>] .__switch_to+0x144/0x200
[<c000000000263ca4>] .online_pages+0x74/0x7b0
[<c00000000055b40c>] .memory_subsys_online+0x9c/0x150
[<c00000000053cbe8>] .device_online+0xb8/0x120
[<c00000000053cd04>] .online_store+0xb4/0xc0
[<c000000000538ce4>] .dev_attr_store+0x64/0xa0
[<c00000000030f4ec>] .sysfs_kf_write+0x7c/0xb0
[<c00000000030e574>] .kernfs_fop_write+0x154/0x1e0
[<c000000000268450>] .vfs_write+0xe0/0x260
[<c000000000269144>] .SyS_write+0x64/0x110
[<c000000000009ffc>] syscall_exit+0x0/0x7c

[<c000000001b18600>] 0xc000000001b18600
[<c000000000015044>] .__switch_to+0x144/0x200
[<c00000000030be14>] .__kernfs_remove+0x204/0x300
[<c00000000030d428>] .kernfs_remove_by_name_ns+0x68/0xf0
[<c00000000030fb38>] .sysfs_remove_file_ns+0x38/0x60
[<c000000000539354>] .device_remove_attrs+0x54/0xc0
[<c000000000539fd8>] .device_del+0x158/0x250
[<c00000000053a104>] .device_unregister+0x34/0xa0
[<c00000000055bc14>] .unregister_memory_section+0x164/0x170
[<c00000000024ee18>] .__remove_pages+0x108/0x4c0
[<c00000000004b590>] .arch_remove_memory+0x60/0xc0
[<c00000000026446c>] .remove_memory+0x8c/0xe0
[<c00000000007f9f4>] .pseries_remove_memblock+0xd4/0x160
[<c00000000007fcfc>] .pseries_memory_notifier+0x27c/0x290
[<c0000000008ae6cc>] .notifier_call_chain+0x8c/0x100
[<c0000000000d858c>] .__blocking_notifier_call_chain+0x6c/0xe0
[<c00000000071ddec>] .of_property_notify+0x7c/0xc0
[<c00000000071ed3c>] .of_update_property+0x3c/0x1b0
[<c0000000000756cc>] .ofdt_write+0x3dc/0x740
[<c0000000002f60fc>] .proc_reg_write+0xac/0x110
[<c000000000268450>] .vfs_write+0xe0/0x260
[<c000000000269144>] .SyS_write+0x64/0x110
[<c000000000009ffc>] syscall_exit+0x0/0x7c

This patch uses lock_device_hotplug() to protect remove_memory() called
in pseries_remove_memblock(), which is also stated before function
remove_memory():

 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
 * and online/offline operations before this call, as required by
 * try_offline_node().
 */
void __ref remove_memory(int nid, u64 start, u64 size)

With this lock held, the other process(#1120 above) trying to online the
memory block will retry the system call when calling
lock_device_hotplug_sysfs(), and finally find No such device error.
Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We have two copies of code that creates an OPAL sg list. Consolidate
these into a common set of helpers and fix the endian issues.

The flash interface embedded a version number in the num_entries
field, whereas the dump interface did did not. Since versioning
wasn't added to the flash interface and it is impossible to add
this in a backwards compatible way, just remove it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Fix little endian issues with the OPAL error log code.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Reviewed-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The bitmap in opal_poll_events and opal_handle_interrupt is
big endian, so we need to byteswap it on little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Using size_t in our APIs is asking for trouble, especially
when some OPAL calls use size_t pointers.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Reviewed-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On PowerNV platform, we are holding an unnecessary refcount on a pci_dev, which
leads to the pci_dev is not destroyed when hotplugging a pci device.

This patch release the unnecessary refcount.
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

During the EEH hotplug event, iommu_add_device() will be invoked three times
and two of them will trigger warning or error.

The three times to invoke the iommu_add_device() are:

    pci_device_add
       ...
       set_iommu_table_base_and_group   <- 1st time, fail
    device_add
       ...
       tce_iommu_bus_notifier           <- 2nd time, succees
    pcibios_add_pci_devices
       ...
       pcibios_setup_bus_devices        <- 3rd time, re-attach

The first time fails, since the dev->kobj->sd is not initialized. The
dev->kobj->sd is initialized in device_add().
The third time's warning is triggered by the re-attach of the iommu_group.

After applying this patch, the error

    iommu_tce: 0003:05:00.0 has not been added, ret=-14

and the warning

    [  204.123609] ------------[ cut here ]------------
    [  204.123645] WARNING: at arch/powerpc/kernel/iommu.c:1125
    [  204.123680] Modules linked in: xt_CHECKSUM nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT bnep bluetooth 6lowpan_iphc rfkill xt_conntrack ebtable_nat ebtable_broute bridge stp llc mlx4_ib ib_sa ib_mad ib_core ib_addr ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnx2x tg3 mlx4_core nfsd ptp mdio ses libcrc32c nfs_acl enclosure be2net pps_core shpchp lockd kvm uinput sunrpc binfmt_misc lpfc scsi_transport_fc ipr scsi_tgt
    [  204.124356] CPU: 18 PID: 650 Comm: eehd Not tainted 3.14.0-rc5yw+ #102
    [  204.124400] task: c0000027ed485670 ti: c0000027ed50c000 task.ti: c0000027ed50c000
    [  204.124453] NIP: c00000000003cf80 LR: c00000000006c648 CTR: c00000000006c5c0
    [  204.124506] REGS: c0000027ed50f440 TRAP: 0700   Not tainted  (3.14.0-rc5yw+)
    [  204.124558] MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI>  CR: 88008084  XER: 20000000
    [  204.124682] CFAR: c00000000006c644 SOFTE: 1
    GPR00: c00000000006c648 c0000027ed50f6c0 c000000001398380 c0000027ec260300
    GPR04: c0000027ea92c000 c00000000006ad00 c0000000016e41b0 0000000000000110
    GPR08: c0000000012cd4c0 0000000000000001 c0000027ec2602ff 0000000000000062
    GPR12: 0000000028008084 c00000000fdca200 c0000000000d1d90 c0000027ec281a80
    GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
    GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000001
    GPR24: 000000005342697b 0000000000002906 c000001fe6ac9800 c000001fe6ac9800
    GPR28: 0000000000000000 c0000000016e3a80 c0000027ea92c090 c0000027ea92c000
    [  204.125353] NIP [c00000000003cf80] .iommu_add_device+0x30/0x1f0
    [  204.125399] LR [c00000000006c648] .pnv_pci_ioda_dma_dev_setup+0x88/0xb0
    [  204.125443] Call Trace:
    [  204.125464] [c0000027ed50f6c0] [c0000027ed50f750] 0xc0000027ed50f750 (unreliable)
    [  204.125526] [c0000027ed50f750] [c00000000006c648] .pnv_pci_ioda_dma_dev_setup+0x88/0xb0
    [  204.125588] [c0000027ed50f7d0] [c000000000069cc8] .pnv_pci_dma_dev_setup+0x78/0x340
    [  204.125650] [c0000027ed50f870] [c000000000044408] .pcibios_setup_device+0x88/0x2f0
    [  204.125712] [c0000027ed50f940] [c000000000046040] .pcibios_setup_bus_devices+0x60/0xd0
    [  204.125774] [c0000027ed50f9c0] [c000000000043acc] .pcibios_add_pci_devices+0xdc/0x1c0
    [  204.125837] [c0000027ed50fa50] [c00000000086f970] .eeh_reset_device+0x36c/0x4f0
    [  204.125939] [c0000027ed50fb20] [c00000000003a2d8] .eeh_handle_normal_event+0x448/0x480
    [  204.126068] [c0000027ed50fbc0] [c00000000003a35c] .eeh_handle_event+0x4c/0x340
    [  204.126192] [c0000027ed50fc80] [c00000000003a74c] .eeh_event_handler+0xfc/0x1b0
    [  204.126319] [c0000027ed50fd30] [c0000000000d1ea0] .kthread+0x110/0x130
    [  204.126430] [c0000027ed50fe30] [c00000000000a460] .ret_from_kernel_thread+0x5c/0x7c
    [  204.126556] Instruction dump:
    [  204.126610] 7c0802a6 fba1ffe8 fbc1fff0 fbe1fff8 f8010010 f821ff71 7c7e1b78 60000000
    [  204.126787] 60000000 e87e0298 3143ffff 7d2a1910 <0b090000> 2fa90000 40de00c8 ebfe0218
    [  204.126966] ---[ end trace 6e7aefd80add2973 ]---

are cleared.

This patch removes iommu_add_device() in pnv_pci_ioda_dma_dev_setup(), which
revert part of the change in commit d905c5df(PPC: POWERNV: move
iommu_add_device earlier).
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

With this patch I was able to update firmware on an LE kernel.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We have a subtle race when sending CPUs back to OPAL on kexec.

We mark them as "in real mode" right before we send them down. Once
we've booted the new kernel, it might try to call opal_reinit_cpus()
to change endianness, and that requires all CPUs to be spinning inside
OPAL.

However there is no synchronization here and we've observed cases
where the returning CPUs hadn't established their new state inside
OPAL before opal_reinit_cpus() is called, causing it to fail.

The proper fix is to actually wait for them to go down all the way
from the kexec'ing kernel.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The size of the sysparam sysfs files is determined from the device tree
at boot. However the buffer is hard coded to 64 bytes. If we encounter a
parameter that is larger than 64, or miss-parse the device tree, the
buffer will overflow when reading or writing to the parameter.

Check it at discovery time, and if the parameter is too large, do not
create a sysfs entry for it.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The sysparam code currently uses the userspace supplied number of
bytes when memcpy()ing in to a local 64-byte buffer.

Limit the maximum number of bytes by the size of the buffer.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The OPAL calls are returning int64_t values, which the sysparam code
stores in an int, and the sysfs callback returns ssize_t. Make code a
easier to read by consistently using ssize_t.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When a sysparam query in OPAL returned a negative value (error code),
sysfs would spew out a decent chunk of memory; almost 64K more than
expected. This was traced to a sign/unsigned mix up in the OPAL sysparam
sysfs code at sys_param_show.

The return value of sys_param_show is a ssize_t, calculated using

  return ret ? ret : attr->param_size;

Alan Modra explains:

  "attr->param_size" is an unsigned int, "ret" an int, so the overall
  expression has type unsigned int.  Result is that ret is cast to
  unsigned int before being cast to ssize_t.

Instead of using the ternary operator, set ret to the param_size if an
error is not detected. The same bug exists in the sysfs write callback;
this patch fixes it in the same way.

A note on debugging this next time: on my system gcc will warn about
this if compiled with -Wsign-compare, which is not enabled by -Wall,
only -Wextra.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

commit 41dd03a9 may cause Oops in rtas_stop_self().

The reason is that the rtas_args was moved into stack space. For a box
with more that 4GB RAM, the stack could easily be outside 32bit range,
but RTAS is 32bit.

So the patch moves rtas_args away from stack by adding static before
it.
Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We are currently using sysfs_schedule_callback() which is deprecated
and about to be removed. Switch to the new interface instead.
Signed-off-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Here rcu_assign_pointer() is ensuring that the
initialization of a structure is carried out before storing a pointer
to that structure.
So, rcu_assign_pointer(p, NULL) can always safely be converted to
RCU_INIT_POINTER(p, NULL).
Signed-off-by: NMonam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Just about all of these have been converted to __func__,
so convert the last uses.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This call will not be understood by OPAL, and cause it to add an error
to it's log. Among other things, this is useful for testing the
behaviour of the log as it fills up.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL provides an in-memory circular buffer containing a message log
populated with various runtime messages produced by the firmware.

Provide a sysfs interface /sys/firmware/opal/msglog for userspace to
view the messages.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we wrongly allocate mc_recoverable_range buffer (to hold
recoverable ranges) based on size of the property "mcheck-recoverable-ranges".
This results in allocating less memory to hold available recoverable range
entries from /proc/device-tree/ibm,opal/mcheck-recoverable-ranges.

This patch fixes this issue by allocating mc_recoverable_range buffer based
on number of entries of recoverable ranges instead of device property size.
Without this change we end up allocating less memory and run into memory
corruption issue.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

One OPAL call and one device tree property needed byte swapping.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

arch/powerpc/kernel/mce.c, compiled in for PPC_BOOK3S_64, calls
functions only built when IRQ_WORK, so select it.  Fixes the following
build error:

  arch/powerpc/kernel/built-in.o: In function `.machine_check_queue_event':
  (.text+0x11260): undefined reference to `.irq_work_queue'
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>