[PATCH 2/3] riscv: Remove unused members from struct cpu_operations

From: Samuel Holland
Date: Tue Nov 21 2023 - 18:47:46 EST


name is not used anywhere at all. cpu_prepare and cpu_disable do nothing
and always return 0 if implemented.

Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
---

arch/riscv/include/asm/cpu_ops.h | 10 ----------
arch/riscv/kernel/cpu-hotplug.c | 9 +--------
arch/riscv/kernel/cpu_ops.c | 2 --
arch/riscv/kernel/cpu_ops_sbi.c | 19 -------------------
arch/riscv/kernel/cpu_ops_spinwait.c | 11 -----------
arch/riscv/kernel/head.S | 1 -
arch/riscv/kernel/setup.c | 1 -
arch/riscv/kernel/smpboot.c | 6 ------
8 files changed, 1 insertion(+), 58 deletions(-)

diff --git a/arch/riscv/include/asm/cpu_ops.h b/arch/riscv/include/asm/cpu_ops.h
index aa128466c4d4..18af75e6873c 100644
--- a/arch/riscv/include/asm/cpu_ops.h
+++ b/arch/riscv/include/asm/cpu_ops.h
@@ -13,26 +13,16 @@
/**
* struct cpu_operations - Callback operations for hotplugging CPUs.
*
- * @name: Name of the boot protocol.
- * @cpu_prepare: Early one-time preparation step for a cpu. If there
- * is a mechanism for doing so, tests whether it is
- * possible to boot the given HART.
* @cpu_start: Boots a cpu into the kernel.
- * @cpu_disable: Prepares a cpu to die. May fail for some
- * mechanism-specific reason, which will cause the hot
- * unplug to be aborted. Called from the cpu to be killed.
* @cpu_stop: Makes a cpu leave the kernel. Must not fail. Called from
* the cpu being stopped.
* @cpu_is_stopped: Ensures a cpu has left the kernel. Called from another
* cpu.
*/
struct cpu_operations {
- const char *name;
- int (*cpu_prepare)(unsigned int cpu);
int (*cpu_start)(unsigned int cpu,
struct task_struct *tidle);
#ifdef CONFIG_HOTPLUG_CPU
- int (*cpu_disable)(unsigned int cpu);
void (*cpu_stop)(void);
int (*cpu_is_stopped)(unsigned int cpu);
#endif
diff --git a/arch/riscv/kernel/cpu-hotplug.c b/arch/riscv/kernel/cpu-hotplug.c
index 457a18efcb11..934eb64da0d0 100644
--- a/arch/riscv/kernel/cpu-hotplug.c
+++ b/arch/riscv/kernel/cpu-hotplug.c
@@ -29,25 +29,18 @@ bool cpu_has_hotplug(unsigned int cpu)
*/
int __cpu_disable(void)
{
- int ret = 0;
unsigned int cpu = smp_processor_id();

if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_stop)
return -EOPNOTSUPP;

- if (cpu_ops[cpu]->cpu_disable)
- ret = cpu_ops[cpu]->cpu_disable(cpu);
-
- if (ret)
- return ret;
-
remove_cpu_topology(cpu);
numa_remove_cpu(cpu);
set_cpu_online(cpu, false);
riscv_ipi_disable();
irq_migrate_all_off_this_cpu();

- return ret;
+ return 0;
}

#ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/riscv/kernel/cpu_ops.c b/arch/riscv/kernel/cpu_ops.c
index eb479a88a954..5540e2880abb 100644
--- a/arch/riscv/kernel/cpu_ops.c
+++ b/arch/riscv/kernel/cpu_ops.c
@@ -18,8 +18,6 @@ const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
extern const struct cpu_operations cpu_ops_sbi;
#ifndef CONFIG_RISCV_BOOT_SPINWAIT
const struct cpu_operations cpu_ops_spinwait = {
- .name = "",
- .cpu_prepare = NULL,
.cpu_start = NULL,
};
#endif
diff --git a/arch/riscv/kernel/cpu_ops_sbi.c b/arch/riscv/kernel/cpu_ops_sbi.c
index efa0f0816634..1cc7df740edd 100644
--- a/arch/riscv/kernel/cpu_ops_sbi.c
+++ b/arch/riscv/kernel/cpu_ops_sbi.c
@@ -79,23 +79,7 @@ static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle)
return sbi_hsm_hart_start(hartid, boot_addr, hsm_data);
}

-static int sbi_cpu_prepare(unsigned int cpuid)
-{
- if (!cpu_ops_sbi.cpu_start) {
- pr_err("cpu start method not defined for CPU [%d]\n", cpuid);
- return -ENODEV;
- }
- return 0;
-}
-
#ifdef CONFIG_HOTPLUG_CPU
-static int sbi_cpu_disable(unsigned int cpuid)
-{
- if (!cpu_ops_sbi.cpu_stop)
- return -EOPNOTSUPP;
- return 0;
-}
-
static void sbi_cpu_stop(void)
{
int ret;
@@ -118,11 +102,8 @@ static int sbi_cpu_is_stopped(unsigned int cpuid)
#endif

const struct cpu_operations cpu_ops_sbi = {
- .name = "sbi",
- .cpu_prepare = sbi_cpu_prepare,
.cpu_start = sbi_cpu_start,
#ifdef CONFIG_HOTPLUG_CPU
- .cpu_disable = sbi_cpu_disable,
.cpu_stop = sbi_cpu_stop,
.cpu_is_stopped = sbi_cpu_is_stopped,
#endif
diff --git a/arch/riscv/kernel/cpu_ops_spinwait.c b/arch/riscv/kernel/cpu_ops_spinwait.c
index d98d19226b5f..613872b0a21a 100644
--- a/arch/riscv/kernel/cpu_ops_spinwait.c
+++ b/arch/riscv/kernel/cpu_ops_spinwait.c
@@ -39,15 +39,6 @@ static void cpu_update_secondary_bootdata(unsigned int cpuid,
WRITE_ONCE(__cpu_spinwait_task_pointer[hartid], tidle);
}

-static int spinwait_cpu_prepare(unsigned int cpuid)
-{
- if (!cpu_ops_spinwait.cpu_start) {
- pr_err("cpu start method not defined for CPU [%d]\n", cpuid);
- return -ENODEV;
- }
- return 0;
-}
-
static int spinwait_cpu_start(unsigned int cpuid, struct task_struct *tidle)
{
/*
@@ -64,7 +55,5 @@ static int spinwait_cpu_start(unsigned int cpuid, struct task_struct *tidle)
}

const struct cpu_operations cpu_ops_spinwait = {
- .name = "spinwait",
- .cpu_prepare = spinwait_cpu_prepare,
.cpu_start = spinwait_cpu_start,
};
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index b77397432403..0349e5cdfe1d 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -11,7 +11,6 @@
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/csr.h>
-#include <asm/cpu_ops_sbi.h>
#include <asm/hwcap.h>
#include <asm/image.h>
#include <asm/scs.h>
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 535a837de55d..2bf882804624 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -26,7 +26,6 @@
#include <asm/alternative.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
-#include <asm/cpu_ops.h>
#include <asm/early_ioremap.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 1c68e61fb852..5551945255cd 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -49,7 +49,6 @@ void __init smp_prepare_boot_cpu(void)
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int cpuid;
- int ret;
unsigned int curr_cpuid;

init_cpu_topology();
@@ -66,11 +65,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
for_each_possible_cpu(cpuid) {
if (cpuid == curr_cpuid)
continue;
- if (cpu_ops[cpuid]->cpu_prepare) {
- ret = cpu_ops[cpuid]->cpu_prepare(cpuid);
- if (ret)
- continue;
- }
set_cpu_present(cpuid, true);
numa_store_cpu_info(cpuid);
}
--
2.42.0