[RFC PATCH 1/6] smp: Remove smp_call_function() and on_each_cpu() return values

Nadav Amit
2019-05-25T08:22:13Z

The return value is fixed. Remove it and amend the callers.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
---
arch/alpha/kernel/smp.c | 19 +++++--------------
arch/alpha/oprofile/common.c | 6 +++---
arch/ia64/kernel/perfmon.c | 12 ++----------
arch/ia64/kernel/uncached.c | 8 ++++----
arch/x86/lib/cache-smp.c | 3 ++-
drivers/char/agp/generic.c | 3 +--
include/linux/smp.h | 7 +++----
kernel/smp.c | 10 +++-------
kernel/up.c | 3 +--
9 files changed, 24 insertions(+), 47 deletions(-)

diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index d0dccae53ba9..5f90df30be20 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -614,8 +614,7 @@ void
smp_imb(void)
{
/* Must wait other processors to flush their icache before continue. */
- if (on_each_cpu(ipi_imb, NULL, 1))
- printk(KERN_CRIT "smp_imb: timed out\n");
+ on_each_cpu(ipi_imb, NULL, 1);
}
EXPORT_SYMBOL(smp_imb);

@@ -630,9 +629,7 @@ flush_tlb_all(void)
{
/* Although we don't have any data to pass, we do want to
synchronize with the other processors. */
- if (on_each_cpu(ipi_flush_tlb_all, NULL, 1)) {
- printk(KERN_CRIT "flush_tlb_all: timed out\n");
- }
+ on_each_cpu(ipi_flush_tlb_all, NULL, 1);
}

#define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
@@ -667,9 +664,7 @@ flush_tlb_mm(struct mm_struct *mm)
}
}

- if (smp_call_function(ipi_flush_tlb_mm, mm, 1)) {
- printk(KERN_CRIT "flush_tlb_mm: timed out\n");
- }
+ smp_call_function(ipi_flush_tlb_mm, mm, 1);

preempt_enable();
}
@@ -720,9 +715,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
data.mm = mm;
data.addr = addr;

- if (smp_call_function(ipi_flush_tlb_page, &data, 1)) {
- printk(KERN_CRIT "flush_tlb_page: timed out\n");
- }
+ smp_call_function(ipi_flush_tlb_page, &data, 1);

preempt_enable();
}
@@ -772,9 +765,7 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
}
}

- if (smp_call_function(ipi_flush_icache_page, mm, 1)) {
- printk(KERN_CRIT "flush_icache_page: timed out\n");
- }
+ smp_call_function(ipi_flush_icache_page, mm, 1);

preempt_enable();
}
diff --git a/arch/alpha/oprofile/common.c b/arch/alpha/oprofile/common.c
index 310a4ce1dccc..1b1259c7d7d1 100644
--- a/arch/alpha/oprofile/common.c
+++ b/arch/alpha/oprofile/common.c
@@ -65,7 +65,7 @@ op_axp_setup(void)
model->reg_setup(&reg, ctr, &sys);

/* Configure the registers on all cpus. */
- (void)smp_call_function(model->cpu_setup, &reg, 1);
+ smp_call_function(model->cpu_setup, &reg, 1);
model->cpu_setup(&reg);
return 0;
}
@@ -86,7 +86,7 @@ op_axp_cpu_start(void *dummy)
static int
op_axp_start(void)
{
- (void)smp_call_function(op_axp_cpu_start, NULL, 1);
+ smp_call_function(op_axp_cpu_start, NULL, 1);
op_axp_cpu_start(NULL);
return 0;
}
@@ -101,7 +101,7 @@ op_axp_cpu_stop(void *dummy)
static void
op_axp_stop(void)
{
- (void)smp_call_function(op_axp_cpu_stop, NULL, 1);
+ smp_call_function(op_axp_cpu_stop, NULL, 1);
op_axp_cpu_stop(NULL);
}

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index 7a969f4c3534..6cf7db1daba2 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -6389,11 +6389,7 @@ pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
}

/* save the current system wide pmu states */
- ret = on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);
- if (ret) {
- DPRINT(("on_each_cpu() failed: %d\n", ret));
- goto cleanup_reserve;
- }
+ on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);

/* officially change to the alternate interrupt handler */
pfm_alt_intr_handler = hdl;
@@ -6420,7 +6416,6 @@ int
pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
{
int i;
- int ret;

if (hdl == NULL) return -EINVAL;

@@ -6434,10 +6429,7 @@ pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)

pfm_alt_intr_handler = NULL;

- ret = on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);
- if (ret) {
- DPRINT(("on_each_cpu() failed: %d\n", ret));
- }
+ on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);

for_each_online_cpu(i) {
pfm_unreserve_session(NULL, 1, i);
diff --git a/arch/ia64/kernel/uncached.c b/arch/ia64/kernel/uncached.c
index 583f7ff6b589..c618d0745e22 100644
--- a/arch/ia64/kernel/uncached.c
+++ b/arch/ia64/kernel/uncached.c
@@ -124,8 +124,8 @@ static int uncached_add_chunk(struct uncached_pool *uc_pool, int nid)
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
if (status == PAL_VISIBILITY_OK_REMOTE_NEEDED) {
atomic_set(&uc_pool->status, 0);
- status = smp_call_function(uncached_ipi_visibility, uc_pool, 1);
- if (status || atomic_read(&uc_pool->status))
+ smp_call_function(uncached_ipi_visibility, uc_pool, 1);
+ if (atomic_read(&uc_pool->status))
goto failed;
} else if (status != PAL_VISIBILITY_OK)
goto failed;
@@ -146,8 +146,8 @@ static int uncached_add_chunk(struct uncached_pool *uc_pool, int nid)
if (status != PAL_STATUS_SUCCESS)
goto failed;
atomic_set(&uc_pool->status, 0);
- status = smp_call_function(uncached_ipi_mc_drain, uc_pool, 1);
- if (status || atomic_read(&uc_pool->status))
+ smp_call_function(uncached_ipi_mc_drain, uc_pool, 1);
+ if (atomic_read(&uc_pool->status))
goto failed;

/*
diff --git a/arch/x86/lib/cache-smp.c b/arch/x86/lib/cache-smp.c
index 1811fa4a1b1a..7c48ff4ae8d1 100644
--- a/arch/x86/lib/cache-smp.c
+++ b/arch/x86/lib/cache-smp.c
@@ -15,6 +15,7 @@ EXPORT_SYMBOL(wbinvd_on_cpu);

int wbinvd_on_all_cpus(void)
{
- return on_each_cpu(__wbinvd, NULL, 1);
+ on_each_cpu(__wbinvd, NULL, 1);
+ return 0;
}
EXPORT_SYMBOL(wbinvd_on_all_cpus);
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 658664a5a5aa..df1edb5ec0ad 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -1311,8 +1311,7 @@ static void ipi_handler(void *null)

void global_cache_flush(void)
{
- if (on_each_cpu(ipi_handler, NULL, 1) != 0)
- panic(PFX "timed out waiting for the other CPUs!\n");
+ on_each_cpu(ipi_handler, NULL, 1);
}
EXPORT_SYMBOL(global_cache_flush);

diff --git a/include/linux/smp.h b/include/linux/smp.h
index a56f08ff3097..bb8b451ab01f 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -35,7 +35,7 @@ int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
/*
* Call a function on all processors
*/
-int on_each_cpu(smp_call_func_t func, void *info, int wait);
+void on_each_cpu(smp_call_func_t func, void *info, int wait);

/*
* Call a function on processors specified by mask, which might include
@@ -101,7 +101,7 @@ extern void smp_cpus_done(unsigned int max_cpus);
/*
* Call a function on all other processors
*/
-int smp_call_function(smp_call_func_t func, void *info, int wait);
+void smp_call_function(smp_call_func_t func, void *info, int wait);
void smp_call_function_many(const struct cpumask *mask,
smp_call_func_t func, void *info, bool wait);

@@ -144,9 +144,8 @@ static inline void smp_send_stop(void) { }
* These macros fold the SMP functionality into a single CPU system
*/
#define raw_smp_processor_id() 0
-static inline int up_smp_call_function(smp_call_func_t func, void *info)
+static inline void up_smp_call_function(smp_call_func_t func, void *info)
{
- return 0;
}
#define smp_call_function(func, info, wait) \
(up_smp_call_function(func, info))
diff --git a/kernel/smp.c b/kernel/smp.c
index f4cf1b0bb3b8..e0b05ac53108 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -486,13 +486,11 @@ EXPORT_SYMBOL(smp_call_function_many);
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
-int smp_call_function(smp_call_func_t func, void *info, int wait)
+void smp_call_function(smp_call_func_t func, void *info, int wait)
{
preempt_disable();
smp_call_function_many(cpu_online_mask, func, info, wait);
preempt_enable();
-
- return 0;
}
EXPORT_SYMBOL(smp_call_function);

@@ -593,18 +591,16 @@ void __init smp_init(void)
* early_boot_irqs_disabled is set. Use local_irq_save/restore() instead
* of local_irq_disable/enable().
*/
-int on_each_cpu(void (*func) (void *info), void *info, int wait)
+void on_each_cpu(void (*func) (void *info), void *info, int wait)
{
unsigned long flags;
- int ret = 0;

preempt_disable();
- ret = smp_call_function(func, info, wait);
+ smp_call_function(func, info, wait);
local_irq_save(flags);
func(info);
local_irq_restore(flags);
preempt_enable();
- return ret;
}
EXPORT_SYMBOL(on_each_cpu);

diff --git a/kernel/up.c b/kernel/up.c
index ff536f9cc8a2..378551e79894 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -34,14 +34,13 @@ int smp_call_function_single_async(int cpu, call_single_data_t *csd)
}
EXPORT_SYMBOL(smp_call_function_single_async);

-int on_each_cpu(smp_call_func_t func, void *info, int wait)
+void on_each_cpu(smp_call_func_t func, void *info, int wait)
{
unsigned long flags;

local_irq_save(flags);
func(info);
local_irq_restore(flags);
- return 0;
}
EXPORT_SYMBOL(on_each_cpu);

--
2.20.1