linux-dev/arch/powerpc/platforms/pseries/suspend.c, branch linus/master

powerpc/pseries/hibernation: remove prepare_late() callback

2020-12-08T10:41:02Z

The pseries hibernate code no longer calls into the original join/suspend code in kernel/rtas.c, so pseries_prepare_late() and related code don't accomplish anything now. Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201207215200.1785968-27-nathanl@linux.ibm.com

powerpc/pseries/hibernation: perform post-suspend fixups later

2020-12-08T10:41:02Z

The pseries hibernate code calls post_mobility_fixup() which is sort of a dumping ground of fixups that need to run after resuming from suspend regardless of whether suspend was a hibernation or a migration. Calling post_mobility_fixup() from pseries_suspend_enable_irqs() runs this code early in resume with devices suspended and only one CPU up, while the much more commonly used migration case runs these fixups in a more typical process context. Call post_mobility_fixup() after the suspend core returns a success status to the hibernate sysfs store method and remove pseries_suspend_enable_irqs(). Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201207215200.1785968-26-nathanl@linux.ibm.com

powerpc/pseries/hibernation: remove redundant cacheinfo update

2020-12-08T10:41:02Z

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

powerpc/pseries/hibernation: switch to rtas_ibm_suspend_me()

2020-12-08T10:41:01Z

rtas_suspend_last_cpu() and related code perform a lot of work that isn't relevant to the hibernation workflow. All other CPUs are offline when called so there is no need to place them in H_JOIN or prod them on resume, nor is there need for retries or operations on shared state. Call the rtas_ibm_suspend_me() wrapper function directly from pseries_suspend_enter() instead of using rtas_suspend_last_cpu(). Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201207215200.1785968-23-nathanl@linux.ibm.com

powerpc/pseries/hibernation: remove pseries_suspend_cpu()

2020-12-08T10:41:01Z

Since commit 48f6e7f6d948 ("powerpc/pseries: remove cede offline state for CPUs"), ppc_md.suspend_disable_cpu() is no longer used and all CPUs (save one) are placed into true offline state as opposed to H_JOIN. So pseries_suspend_cpu() is effectively unused; remove it. Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201207215200.1785968-20-nathanl@linux.ibm.com

powerpc/pseries/hibernation: pass stream id via function arguments

2020-12-08T10:41:00Z

There is no need for the stream id to be a file-global variable; pass it from hibernate_store() to pseries_suspend_begin() for the H_VASI_STATE call. Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201207215200.1785968-19-nathanl@linux.ibm.com

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

2020-12-08T10:41:00Z

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

powerpc/numa: remove start/stop_topology_update()

2020-07-16T03:12:38Z

These APIs have become no-ops, so remove them and all call sites. Signed-off-by: Nathan Lynch Reviewed-by: Srikar Dronamraju Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200612051238.1007764-12-nathanl@linux.ibm.com

powerpc/rtas: don't online CPUs for partition suspend

2020-07-16T03:12:35Z

Partition suspension, used for hibernation and migration, requires that the OS place all but one of the LPAR's processor threads into one of two states prior to calling the ibm,suspend-me RTAS function: * the architected offline state (via RTAS stop-self); or * the H_JOIN hcall, which does not return until the partition resumes execution Using H_CEDE as the offline mode, introduced by commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman