[PATCH 12/39] ia64/topology: Switch over to GENERIC_CPU_DEVICES

Russell King
2023-10-24T15:18:35Z

ia64 has its own arch specific data structure for cpus: struct ia64_cpu.
This has one member, making ia64's cpu_devices the same as that
provided be GENERIC_CPU_DEVICES.
ia64 craetes a percpu struct ia64_cpu called cpu_devices, which has no
users. Instead it uses the struct ia64_cpu named sysfs_cpus allocated at
boot.

Remove the arch specific structure allocation and initialisation.
ia64's arch_register_cpu() now overrides the weak version from
GENERIC_CPU_DEVICES, and uses the percpu cpu_devices defined by
core code.

All uses of sysfs_cpus are changed to use the percpu cpu_devices.

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 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@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
Changes since RFC v2:
* Add note about initialisation order change.
---
arch/ia64/Kconfig | 1 +
arch/ia64/include/asm/cpu.h | 6 ------
arch/ia64/kernel/topology.c | 35 +++++------------------------------
3 files changed, 6 insertions(+), 36 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index a3bfd42467ab..06692e1c7c62 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -42,6 +42,7 @@ config IA64
select HAVE_FUNCTION_DESCRIPTORS
select HAVE_VIRT_CPU_ACCOUNTING
select HUGETLB_PAGE_SIZE_VARIABLE if HUGETLB_PAGE
+ select GENERIC_CPU_DEVICES
select GENERIC_IRQ_PROBE
select GENERIC_PENDING_IRQ if SMP
select GENERIC_IRQ_SHOW
diff --git a/arch/ia64/include/asm/cpu.h b/arch/ia64/include/asm/cpu.h
index 642d71675ddb..3b36c6a382bb 100644
--- a/arch/ia64/include/asm/cpu.h
+++ b/arch/ia64/include/asm/cpu.h
@@ -7,12 +7,6 @@
#include <linux/topology.h>
#include <linux/percpu.h>

-struct ia64_cpu {
- struct cpu cpu;
-};
-
-DECLARE_PER_CPU(struct ia64_cpu, cpu_devices);
-
DECLARE_PER_CPU(int, cpu_state);

#endif /* _ASM_IA64_CPU_H_ */
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 741863a187a6..8f5cafde2bc9 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -26,8 +26,6 @@
#include <asm/numa.h>
#include <asm/cpu.h>

-static struct ia64_cpu *sysfs_cpus;
-
void arch_fix_phys_package_id(int num, u32 slot)
{
#ifdef CONFIG_SMP
@@ -41,50 +39,27 @@ EXPORT_SYMBOL_GPL(arch_fix_phys_package_id);
#ifdef CONFIG_HOTPLUG_CPU
int __ref arch_register_cpu(int num)
{
+ struct cpu *cpu = &per_cpu(cpu_devices, num);
+
/*
* If CPEI can be re-targeted or if this is not
* CPEI target, then it is hotpluggable
*/
if (can_cpei_retarget() || !is_cpu_cpei_target(num))
- sysfs_cpus[num].cpu.hotpluggable = 1;
+ cpu->hotpluggable = 1;
map_cpu_to_node(num, node_cpuid[num].nid);
- return register_cpu(&sysfs_cpus[num].cpu, num);
+ return register_cpu(cpu, num);
}
EXPORT_SYMBOL(arch_register_cpu);

void __ref arch_unregister_cpu(int num)
{
- unregister_cpu(&sysfs_cpus[num].cpu);
+ unregister_cpu(&per_cpu(cpu_devices, num));
unmap_cpu_from_node(num, cpu_to_node(num));
}
EXPORT_SYMBOL(arch_unregister_cpu);
-#else
-int __init arch_register_cpu(int num)
-{
- return register_cpu(&sysfs_cpus[num].cpu, num);
-}
#endif /*CONFIG_HOTPLUG_CPU*/

-
-static int __init topology_init(void)
-{
- int i, err = 0;
-
- sysfs_cpus = kcalloc(NR_CPUS, sizeof(struct ia64_cpu), GFP_KERNEL);
- if (!sysfs_cpus)
- panic("kzalloc in topology_init failed - NR_CPUS too big?");
-
- for_each_present_cpu(i) {
- if((err = arch_register_cpu(i)))
- goto out;
- }
-out:
- return err;
-}
-
-subsys_initcall(topology_init);
-
-
/*
* Export cpu cache information through sysfs
*/
--
2.30.2