linux.git/arch/powerpc/platforms/pseries, branch v3.18.64

powerpc/pseries: Fix of_node_put() underflow during reconfig remove

2017-08-11T16:30:08+00:00

commit 4fd1bd443e80b12f0a01a45fb9a793206b41cb72 upstream.

As for commit 68baf692c435 ("powerpc/pseries: Fix of_node_put()
underflow during DLPAR remove"), the call to of_node_put() must be
removed from pSeries_reconfig_remove_node().

dlpar_detach_node() and pSeries_reconfig_remove_node() both call
of_detach_node(), and thus the node should not be released in both
cases.

Fixes: 0829f6d1f69e ("of: device_node kobject lifecycle fixes")
Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix of_node_put() underflow during DLPAR remove

2017-05-25T12:18:00+00:00

commit 68baf692c435339e6295cb470ea5545cbc28160e upstream.

Historically struct device_node references were tracked using a kref embedded as
a struct field. Commit 75b57ecf9d1d ("of: Make device nodes kobjects so they
show up in sysfs") (Mar 2014) refactored device_nodes to be kobjects such that
the device tree could by more simply exposed to userspace using sysfs.

Commit 0829f6d1f69e ("of: device_node kobject lifecycle fixes") (Mar 2014)
followed up these changes to better control the kobject lifecycle and in
particular the referecne counting via of_node_get(), of_node_put(), and
of_node_init().

A result of this second commit was that it introduced an of_node_put() call when
a dynamic node is detached, in of_node_remove(), that removes the initial kobj
reference created by of_node_init().

Traditionally as the original dynamic device node user the pseries code had
assumed responsibilty for releasing this final reference in its platform
specific DLPAR detach code.

This patch fixes a refcount underflow introduced by commit 0829f6d1f6, and
recently exposed by the upstreaming of the recount API.

Messages like the following are no longer seen in the kernel log with this
patch following DLPAR remove operations of cpus and pci devices.

  rpadlpar_io: slot PHB 72 removed
  refcount_t: underflow; use-after-free.
  ------------[ cut here ]------------
  WARNING: CPU: 5 PID: 3335 at lib/refcount.c:128 refcount_sub_and_test+0xf4/0x110

Fixes: 0829f6d1f69e ("of: device_node kobject lifecycle fixes")
Signed-off-by: Tyrel Datwyler 
[mpe: Make change log commit references more verbose]
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix PCI config address for DDW

2016-08-22T16:23:30+00:00

[ Upstream commit 8a934efe94347eee843aeea65bdec8077a79e259 ]

In commit 8445a87f7092 "powerpc/iommu: Remove the dependency on EEH
struct in DDW mechanism", the PE address was replaced with the PCI
config address in order to remove dependency on EEH. According to PAPR
spec, firmware (pHyp or QEMU) should accept "xxBBSSxx" format PCI config
address, not "xxxxBBSS" provided by the patch. Note that "BB" is PCI bus
number and "SS" is the combination of slot and function number.

This fixes the PCI address passed to DDW RTAS calls.

Fixes: 8445a87f7092 ("powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism")
Cc: stable@vger.kernel.org # v3.4+
Reported-by: Guilherme G. Piccoli 
Signed-off-by: Gavin Shan 
Tested-by: Guilherme G. Piccoli 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism

2016-08-22T16:23:29+00:00

[ Upstream commit 8445a87f7092bc8336ea1305be9306f26b846d93 ]

Commit 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn")
changed the pci_dn struct by removing its EEH-related members.
As part of this clean-up, DDW mechanism was modified to read the device
configuration address from eeh_dev struct.

As a consequence, now if we disable EEH mechanism on kernel command-line
for example, the DDW mechanism will fail, generating a kernel oops by
dereferencing a NULL pointer (which turns to be the eeh_dev pointer).

This patch just changes the configuration address calculation on DDW
functions to a manual calculation based on pci_dn members instead of
using eeh_dev-based address.

No functional changes were made. This was tested on pSeries, both
in PHyp and qemu guest.

Fixes: 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn")
Cc: stable@vger.kernel.org # v3.4+
Reviewed-by: Gavin Shan 
Signed-off-by: Guilherme G. Piccoli 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

powerpc/pseries/eeh: Handle RTAS delay requests in configure_bridge

2016-06-18T20:52:56+00:00

[ Upstream commit 871e178e0f2c4fa788f694721a10b4758d494ce1 ]

In the "ibm,configure-pe" and "ibm,configure-bridge" RTAS calls, the
spec states that values of 9900-9905 can be returned, indicating that
software should delay for 10^x (where x is the last digit, i.e. 990x)
milliseconds and attempt the call again. Currently, the kernel doesn't
know about this, and respecting it fixes some PCI failures when the
hypervisor is busy.

The delay is capped at 0.2 seconds.

Cc:  # 3.10+
Signed-off-by: Russell Currey 
Acked-by: Gavin Shan 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

powerpc/rtas: Introduce rtas_get_sensor_fast() for IRQ handlers

2015-10-07T14:14:09+00:00

[ Upstream commit 1c2cb594441d02815d304cccec9742ff5c707495 ]

The EPOW interrupt handler uses rtas_get_sensor(), which in turn
uses rtas_busy_delay() to wait for RTAS becoming ready in case it
is necessary. But rtas_busy_delay() is annotated with might_sleep()
and thus may not be used by interrupts handlers like the EPOW handler!
This leads to the following BUG when CONFIG_DEBUG_ATOMIC_SLEEP is
enabled:

 BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:496
 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.2.0-rc2-thuth #6
 Call Trace:
 [c00000007ffe7b90] [c000000000807670] dump_stack+0xa0/0xdc (unreliable)
 [c00000007ffe7bc0] [c0000000000e1f14] ___might_sleep+0x134/0x180
 [c00000007ffe7c20] [c00000000002aec0] rtas_busy_delay+0x30/0xd0
 [c00000007ffe7c50] [c00000000002bde4] rtas_get_sensor+0x74/0xe0
 [c00000007ffe7ce0] [c000000000083264] ras_epow_interrupt+0x44/0x450
 [c00000007ffe7d90] [c000000000120260] handle_irq_event_percpu+0xa0/0x300
 [c00000007ffe7e70] [c000000000120524] handle_irq_event+0x64/0xc0
 [c00000007ffe7eb0] [c000000000124dbc] handle_fasteoi_irq+0xec/0x260
 [c00000007ffe7ef0] [c00000000011f4f0] generic_handle_irq+0x50/0x80
 [c00000007ffe7f20] [c000000000010f3c] __do_irq+0x8c/0x200
 [c00000007ffe7f90] [c0000000000236cc] call_do_irq+0x14/0x24
 [c00000007e6f39e0] [c000000000011144] do_IRQ+0x94/0x110
 [c00000007e6f3a30] [c000000000002594] hardware_interrupt_common+0x114/0x180

Fix this issue by introducing a new rtas_get_sensor_fast() function
that does not use rtas_busy_delay() - and thus can only be used for
sensors that do not cause a BUSY condition - known as "fast" sensors.

The EPOW sensor is defined to be "fast" in sPAPR - mpe.

Fixes: 587f83e8dd50 ("powerpc/pseries: Use rtas_get_sensor in RAS code")
Signed-off-by: Thomas Huth 
Reviewed-by: Nathan Fontenot 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

powerpc/pseries: Little endian fixes for post mobility device tree update

2015-04-17T00:13:17+00:00

[ Upstream commit f6ff04149637723261aa4738958b0098b929ee9e ]

We currently use the device tree update code in the kernel after resuming
from a suspend operation to re-sync the kernels view of the device tree with
that of the hypervisor. The code as it stands is not endian safe as it relies
on parsing buffers returned by RTAS calls that thusly contains data in big
endian format.

This patch annotates variables and structure members with __be types as well
as performing necessary byte swaps to cpu endian for data that needs to be
parsed.

Signed-off-by: Tyrel Datwyler 
Cc: Nathan Fontenot 
Cc: Cyril Bur 
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

powerpc/pseries: Honor the generic "no_64bit_msi" flag

2014-11-24T03:36:02+00:00

Instead of the arch specific quirk which we are deprecating

Signed-off-by: Benjamin Herrenschmidt 
CC:

powerpc: use device_online/offline() instead of cpu_up/down()

2014-11-01T23:55:56+00:00

In powerpc pseries platform dlpar operations, use device_online() and
device_offline() instead of cpu_up() and cpu_down().

Calling cpu_up/down() directly does not update the cpu device offline
field, which is used to online/offline a cpu from sysfs. Calling
device_online/offline() instead keeps the sysfs cpu online value
correct. The hotplug lock, which is required to be held when calling
device_online/offline(), is already held when dlpar_online/offline_cpu()
are called, since they are called only from cpu_probe|release_store().

This patch fixes errors on phyp (PowerVM) systems that have cpu(s)
added/removed using dlpar operations; without this patch, the
/sys/devices/system/cpu/cpuN/online nodes do not correctly show the
online state of added/removed cpus.

Signed-off-by: Dan Streetman 
Cc: Nathan Fontenot 
Fixes: 0902a9044fa5 ("Driver core: Use generic offline/online for CPU offline/online")
Signed-off-by: Michael Ellerman

powerpc/fadump: Fix endianess issues in firmware assisted dump handling

2014-10-30T05:52:46+00:00

Firmware-assisted dump (fadump) kernel code is not endian safe. The
below patch fixes this issue. Tested this patch with upstream kernel.
Below output shows crash tool successfully opening LE fadump vmcore.

    # crash vmlinux vmcore
    GNU gdb (GDB) 7.6
    This GDB was configured as "powerpc64le-unknown-linux-gnu"...

          KERNEL: vmlinux
        DUMPFILE: vmcore
    	CPUS: 16
    	DATE: Wed Dec 31 19:00:00 1969
          UPTIME: 00:03:28
    LOAD AVERAGE: 0.46, 0.86, 0.41
           TASKS: 268
        NODENAME: linux-dhr2
         RELEASE: 3.17.0-rc5-7-default
         VERSION: #6 SMP Tue Sep 30 01:06:34 EDT 2014
         MACHINE: ppc64le  (4116 Mhz)
          MEMORY: 40 GB
           PANIC: "Oops: Kernel access of bad area, sig: 11 [#1]" (check log for details)
    	 PID: 6223
         COMMAND: "bash"
    	TASK: c0000009661b2500  [THREAD_INFO: c000000967ac0000]
    	 CPU: 2
           STATE: TASK_RUNNING (PANIC)

Signed-off-by: Hari Bathini 
[mpe: Make the comment in pSeries_lpar_hptab_clear() clearer]
Signed-off-by: Michael Ellerman