linux.git/arch/powerpc/platforms/pseries, branch v5.4.249

powerpc/pseries/lparcfg: add missing RTAS retry status handling

2023-03-11T15:43:51+00:00

[ Upstream commit 5d08633e5f6564b60f1cbe09af3af40a74d66431 ]

The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again.

lparcfg's parse_system_parameter_string() ignores this, making it
possible to intermittently report incorrect SPLPAR characteristics.

Move the RTAS call into a coventional rtas_busy_delay()-based loop.

Signed-off-by: Nathan Lynch 
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-4-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/pseries/lpar: add missing RTAS retry status handling

2023-03-11T15:43:51+00:00

[ Upstream commit daa8ab59044610aa8ef2ee45a6c157b5e11635e9 ]

The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again.

pseries_lpar_read_hblkrm_characteristics() ignores this, making it
possible to incorrectly detect TLB block invalidation characteristics
at boot.

Move the RTAS call into a coventional rtas_busy_delay()-based loop.

Signed-off-by: Nathan Lynch 
Fixes: 1211ee61b4a8 ("powerpc/pseries: Read TLB Block Invalidate Characteristics")
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-3-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/pseries: wire up rng during setup_arch()

2022-06-29T06:58:50+00:00

commit e561e472a3d441753bd012333b057f48fef1045b upstream.

The platform's RNG must be available before random_init() in order to be
useful for initial seeding, which in turn means that it needs to be
called from setup_arch(), rather than from an init call. Fortunately,
each platform already has a setup_arch function pointer, which means
it's easy to wire this up. This commit also removes some noisy log
messages that don't add much.

Fixes: a489043f4626 ("powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Jason A. Donenfeld 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220611151015.548325-4-Jason@zx2c4.com
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix regression while building external modules

2021-08-04T10:27:40+00:00

commit 333cf507465fbebb3727f5b53e77538467df312a upstream.

With commit c9f3401313a5 ("powerpc: Always enable queued spinlocks for
64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always
enabled on ppc64le, external modules that use spinlock APIs are
failing.

  ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor'

Before the above commit, modules were able to build without any
issues. Also this problem is not seen on other architectures. This
problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in
the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by
default and only enabled in certain conditions like
CONFIG_DEBUG_SPINLOCKS is set in the kernel config.

  #include 
  spinlock_t spLock;

  static int __init spinlock_test_init(void)
  {
          spin_lock_init(&spLock);
          spin_lock(&spLock);
          spin_unlock(&spLock);
          return 0;
  }

  static void __exit spinlock_test_exit(void)
  {
  	printk("spinlock_test unloaded\n");
  }
  module_init(spinlock_test_init);
  module_exit(spinlock_test_exit);

  MODULE_DESCRIPTION ("spinlock_test");
  MODULE_LICENSE ("non-GPL");
  MODULE_AUTHOR ("Srikar Dronamraju");

Given that spin locks are one of the basic facilities for module code,
this effectively makes it impossible to build/load almost any non GPL
modules on ppc64le.

This was first reported at https://github.com/openzfs/zfs/issues/11172

Currently shared_processor is exported as GPL only symbol.
Fix this for parity with other architectures by exposing
shared_processor to non-GPL modules too.

Fixes: 14c73bd344da ("powerpc/vcpu: Assume dedicated processors as non-preempt")
Cc: stable@vger.kernel.org # v5.5+
Reported-by: marc.c.dionne@gmail.com
Signed-off-by: Srikar Dronamraju 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210729060449.292780-1-srikar@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Stop calling printk in rtas_stop_self()

2021-05-19T08:08:23+00:00

[ Upstream commit ed8029d7b472369a010a1901358567ca3b6dbb0d ]

RCU complains about us calling printk() from an offline CPU:

  =============================
  WARNING: suspicious RCU usage
  5.12.0-rc7-02874-g7cf90e481cb8 #1 Not tainted
  -----------------------------
  kernel/locking/lockdep.c:3568 RCU-list traversed in non-reader section!!

  other info that might help us debug this:

  RCU used illegally from offline CPU!
  rcu_scheduler_active = 2, debug_locks = 1
  no locks held by swapper/0/0.

  stack backtrace:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7-02874-g7cf90e481cb8 #1
  Call Trace:
    dump_stack+0xec/0x144 (unreliable)
    lockdep_rcu_suspicious+0x124/0x144
    __lock_acquire+0x1098/0x28b0
    lock_acquire+0x128/0x600
    _raw_spin_lock_irqsave+0x6c/0xc0
    down_trylock+0x2c/0x70
    __down_trylock_console_sem+0x60/0x140
    vprintk_emit+0x1a8/0x4b0
    vprintk_func+0xcc/0x200
    printk+0x40/0x54
    pseries_cpu_offline_self+0xc0/0x120
    arch_cpu_idle_dead+0x54/0x70
    do_idle+0x174/0x4a0
    cpu_startup_entry+0x38/0x40
    rest_init+0x268/0x388
    start_kernel+0x748/0x790
    start_here_common+0x1c/0x614

Which happens because by the time we get to rtas_stop_self() we are
already offline. In addition the message can be spammy, and is not that
helpful for users, so remove it.

Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210418135413.1204031-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin

powerpc/pseries: extract host bridge from pci_bus prior to bus removal

2021-05-14T07:44:30+00:00

[ Upstream commit 38d0b1c9cec71e6d0f3bddef0bbce41d05a3e796 ]

The pci_bus->bridge reference may no longer be valid after
pci_bus_remove() resulting in passing a bad value to device_unregister()
for the associated bridge device.

Store the host_bridge reference in a separate variable prior to
pci_bus_remove().

Fixes: 7340056567e3 ("powerpc/pci: Reorder pci bus/bridge unregistration during PHB removal")
Signed-off-by: Tyrel Datwyler 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210211182435.47968-1-tyreld@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/pseries: Don't enforce MSI affinity with kdump

2021-03-17T16:03:30+00:00

commit f9619d5e5174867536b7e558683bc4408eab833f upstream.

Depending on the number of online CPUs in the original kernel, it is
likely for CPU #0 to be offline in a kdump kernel. The associated IRQs
in the affinity mappings provided by irq_create_affinity_masks() are
thus not started by irq_startup(), as per-design with managed IRQs.

This can be a problem with multi-queue block devices driven by blk-mq :
such a non-started IRQ is very likely paired with the single queue
enforced by blk-mq during kdump (see blk_mq_alloc_tag_set()). This
causes the device to remain silent and likely hangs the guest at
some point.

This is a regression caused by commit 9ea69a55b3b9 ("powerpc/pseries:
Pass MSI affinity to irq_create_mapping()"). Note that this only happens
with the XIVE interrupt controller because XICS has a workaround to bypass
affinity, which is activated during kdump with the "noirqdistrib" kernel
parameter.

The issue comes from a combination of factors:
- discrepancy between the number of queues detected by the multi-queue
  block driver, that was used to create the MSI vectors, and the single
  queue mode enforced later on by blk-mq because of kdump (i.e. keeping
  all queues fixes the issue)
- CPU#0 offline (i.e. kdump always succeed with CPU#0)

Given that I couldn't reproduce on x86, which seems to always have CPU#0
online even during kdump, I'm not sure where this should be fixed. Hence
going for another approach : fine-grained affinity is for performance
and we don't really care about that during kdump. Simply revert to the
previous working behavior of ignoring affinity masks in this case only.

Fixes: 9ea69a55b3b9 ("powerpc/pseries: Pass MSI affinity to irq_create_mapping()")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Greg Kurz 
Reviewed-by: Laurent Vivier 
Reviewed-by: Cédric Le Goater 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210215094506.1196119-1-groug@kaod.org
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/dlpar: handle ibm, configure-connector delay status

2021-03-04T09:26:33+00:00

[ Upstream commit 768d70e19ba525debd571b36e6d0ab19956c63d7 ]

dlpar_configure_connector() has two problems in its handling of
ibm,configure-connector's return status:

1. When the status is -2 (busy, call again), we call
   ibm,configure-connector again immediately without checking whether
   to schedule, which can result in monopolizing the CPU.
2. Extended delay status (9900..9905) goes completely unhandled,
   causing the configuration to unnecessarily terminate.

Fix both of these issues by using rtas_busy_delay().

Fixes: ab519a011caa ("powerpc/pseries: Kernel DLPAR Infrastructure")
Signed-off-by: Nathan Lynch 
Reviewed-by: Tyrel Datwyler 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210107025900.410369-1-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/pseries/hibernation: remove redundant cacheinfo update

2020-12-30T10:51:21+00:00

[ Upstream commit b866459489fe8ef0e92cde3cbd6bbb1af6c4e99b ]

Partitions with cache nodes in the device tree can encounter the
following warning on resume:

CPU 0 already accounted in PowerPC,POWER9@0(Data)
WARNING: CPU: 0 PID: 3177 at arch/powerpc/kernel/cacheinfo.c:197 cacheinfo_cpu_online+0x640/0x820

These calls to cacheinfo_cpu_offline/online have been redundant since
commit e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo
hierarchy post-migration").

Fixes: e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration")
Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20201207215200.1785968-25-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/pseries/hibernation: drop pseries_suspend_begin() from suspend ops

2020-12-30T10:51:21+00:00

[ Upstream commit 52719fce3f4c7a8ac9eaa191e8d75a697f9fbcbc ]

There are three ways pseries_suspend_begin() can be reached:

1. When "mem" is written to /sys/power/state:

kobj_attr_store()
-> state_store()
  -> pm_suspend()
    -> suspend_devices_and_enter()
      -> pseries_suspend_begin()

This never works because there is no way to supply a valid stream id
using this interface, and H_VASI_STATE is called with a stream id of
zero. So this call path is useless at best.

2. When a stream id is written to /sys/devices/system/power/hibernate.
pseries_suspend_begin() is polled directly from store_hibernate()
until the stream is in the "Suspending" state (i.e. the platform is
ready for the OS to suspend execution):

dev_attr_store()
-> store_hibernate()
  -> pseries_suspend_begin()

3. When a stream id is written to /sys/devices/system/power/hibernate
(continued). After #2, pseries_suspend_begin() is called once again
from the pm core:

dev_attr_store()
-> store_hibernate()
  -> pm_suspend()
    -> suspend_devices_and_enter()
      -> pseries_suspend_begin()

This is redundant because the VASI suspend state is already known to
be Suspending.

The begin() callback of platform_suspend_ops is optional, so we can
simply remove that assignment with no loss of function.

Fixes: 32d8ad4e621d ("powerpc/pseries: Partition hibernation support")
Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20201207215200.1785968-18-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin