On 11/7/23 20:30, Russell King (Oracle) wrote:
From: James Morse <james.morse@xxxxxxx>
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.
This allows topology_init() to be removed.
This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.
This is a subtle change. Originally:
- on boot, topology_init() would have marked present CPUs that
io_master() is true for as hotplug-incapable.
- if a CPU is hotplugged that is an io_master(), it can later be
hot-unplugged.
The new behaviour is that any CPU that io_master() is true for will
now always be marked as hotplug-incapable, thus even if it was
hotplugged, it can no longer be hot-unplugged.
This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
---
Changes since RFC v2:
* Explain the change in behaviour in the patch description
(highlighted by Jonathan Cameron - thanks.) Add note about
initialisation order change.
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/kernel/topology.c | 29 ++---------------------------
2 files changed, 3 insertions(+), 27 deletions(-)
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
