kernel.git/arch/powerpc/platforms/pseries/hotplug-cpu.c, branch linux-4.9.y

powerpc/pseries: Stop calling printk in rtas_stop_self()

2021-05-22T08:40:30Z

[ 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: Perform full re-add of CPU for topology update post-migration

2019-04-05T20:29:13Z

[ Upstream commit 81b61324922c67f73813d8a9c175f3c153f6a1c6 ] On pseries systems, performing a partition migration can result in altering the nodes a CPU is assigned to on the destination system. For exampl, pre-migration on the source system CPUs are in node 1 and 3, post-migration on the destination system CPUs are in nodes 2 and 3. Handling the node change for a CPU can cause corruption in the slab cache if we hit a timing where a CPUs node is changed while cache_reap() is invoked. The corruption occurs because the slab cache code appears to rely on the CPU and slab cache pages being on the same node. The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c does not prevent us from hitting this scenario. Changing the device tree property update notification handler that recognizes an affinity change for a CPU to do a full DLPAR remove and add of the CPU instead of dynamically changing its node resolves this issue. Signed-off-by: Nathan Fontenot Signed-off-by: Michael W. Bringmann Tested-by: Michael W. Bringmann Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/pseries: Remove MPIC from pseries cpu hotplug

2016-06-14T03:58:27Z

MPIC was only used by Power3 which is now unsupported, so remove MPIC code. Signed-off-by: Rashmica Gupta Signed-off-by: Michael Ellerman

param: convert some "on"/"off" users to strtobool

2016-03-17T22:09:34Z

This changes several users of manual "on"/"off" parsing to use strtobool. Some side-effects: - these uses will now parse y/n/1/0 meaningfully too - the early_param uses will now bubble up parse errors Signed-off-by: Kees Cook Acked-by: Heiko Carstens Acked-by: Michael Ellerman Cc: Amitkumar Karwar Cc: Andy Shevchenko Cc: Daniel Borkmann Cc: Joe Perches Cc: Kalle Valo Cc: Martin Schwidefsky Cc: Nishant Sarmukadam Cc: Rasmus Villemoes Cc: Steve French Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc/pseries: Add CPU dlpar add functionality

2015-12-17T11:41:02Z

Add the ability to hotplug add cpus via rtas hotplug events by either specifying the drc index of the CPU to add, or providing a count of the number of CPUs to add. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman

powerpc/pseries: Add CPU dlpar remove functionality

2015-12-17T11:41:02Z

Add the ability to dlpar remove CPUs via hotplug rtas events, either by specifying the drc-index of the CPU to remove or providing a count of cpus to remove. To remove multiple cpus in a single request we create a list of possible DR (Dynamic Reconfiguration) cpus and their drc indexes that can be removed. We can then traverse the list remove each cpu and easily clean up in any cases of failure. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman

powerpc/pseries: Update CPU hotplug error recovery

2015-12-17T11:41:02Z

Update the cpu dlpar add/remove paths to do better error recovery when a failure occurs during the add/remove operation. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman

powerpc/pseries: Factor out common cpu hotplug code

2015-12-17T11:41:01Z

Re-factor the cpu hotplug code to support doing cpu hotplug completely in the kernel and using the existing sysfs probe/release interfaces. This patch pulls out pieces of existing cpu hotplug code into common routines, dlpar_cpu_add() and dlpar_cpu_remove(), to be used by both interfaces. There are no functional changes introduced. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman

powerpc/pseries: Consolidate CPU hotplug code to hotplug-cpu.c

2015-12-17T11:41:01Z

No functional changes, this patch is simply a move of the cpu hotplug code from pseries/dlpar.c to pseries/hotplug-cpu.c. This is in an effort to consolidate all of the cpu hotplug code in a common place. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman

powerpc/pseries: Use rtas_call_unlocked() in pseries hotplug

2015-12-17T11:40:55Z

Avoid open coding the logic by using rtas_call_unlocked(). Signed-off-by: Michael Ellerman