linux_dsm_epyc7002/arch/powerpc
Gautham R. Shenoy f3b3f28493 powerpc/powernv/idle: Don't override default/deepest directly in kernel
Currently during idle-init on power9, if we don't find suitable stop
states in the device tree that can be used as the
default_stop/deepest_stop, we set stop0 (ESL=1,EC=1) as the default
stop state psscr to be used by power9_idle and deepest stop state
which is used by CPU-Hotplug.

However, if the platform firmware has not configured or enabled a stop
state, the kernel should not make any assumptions and fallback to a
default choice.

If the kernel uses a stop state that is not configured by the platform
firmware, it may lead to further failures which should be avoided.

In this patch, we modify the init code to ensure that the kernel uses
only the stop states exposed by the firmware through the device
tree. When a suitable default stop state isn't found, we disable
ppc_md.power_save for power9. Similarly, when a suitable
deepest_stop_state is not found in the device tree exported by the
firmware, fall back to the default busy-wait loop in the CPU-Hotplug
code.

[Changelog written with inputs from svaidy@linux.vnet.ibm.com]
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-11 08:45:09 +10:00
..
boot powerpc/boot: Fix zImage TOC alignment 2017-03-08 10:39:32 +11:00
configs powerpc/configs: Re-enable POWER8 crc32c 2017-03-28 10:52:04 +11:00
crypto crypto: powerpc - Fix initialisation of crc32c context 2017-03-08 14:01:08 +08:00
include powerpc/powernv: Move CPU-Offline idle state invocation from smp.c to idle.c 2017-04-11 08:45:09 +10:00
kernel powerpc: Remove unnecessary includes of asm/debug.h 2017-04-11 07:46:04 +10:00
kvm powerpc: Remove unnecessary includes of asm/debug.h 2017-04-11 07:46:04 +10:00
lib powerpc fixes for 4.11 #3 2017-03-07 10:46:10 -08:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm powerpc/mm: Remove reduntant initmem information from log 2017-04-11 07:46:05 +10:00
net powerpc updates for 4.11 part 1. 2017-02-22 10:30:38 -08:00
oprofile ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
perf powerpc/perf: Handle sdar_mode for marked event in power9 2017-03-09 13:34:54 +11:00
platforms powerpc/powernv/idle: Don't override default/deepest directly in kernel 2017-04-11 08:45:09 +10:00
purgatory kexec, x86/purgatory: Unbreak it and clean it up 2017-03-10 20:55:09 +01:00
scripts
sysdev powerpc: Create asm/debugfs.h and move powerpc_debugfs_root there 2017-04-11 07:46:03 +10:00
xmon powerpc: Create asm/debugfs.h and move powerpc_debugfs_root there 2017-04-11 07:46:03 +10:00
Kconfig powerpc: Make sparsemem the default on 64-bit Book3S 2017-04-11 07:46:05 +10:00
Kconfig.debug powerpc/xmon: Enable disassembly files (compilation changes) 2017-02-15 20:02:42 +11:00
Makefile powerpc: Fix compiling a BE kernel with a powerpc64le toolchain 2017-03-03 11:24:50 +11:00
relocs_check.sh