Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.
Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.
Cc: David Howells <dhowe...@redhat.com>
Cc: Koichi Yasutake <yasutake.koi...@jp.panasonic.com>
Cc: linux-am33-l...@redhat.com
Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
---
arch/mn10300/mm/cache-smp.c | 3 +++
arch/mn10300/mm/tlb-smp.c | 17 +++++++++--------
2 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/mn10300/mm/cache-smp.c b/arch/mn10300/mm/cache-smp.c
index 2d23b9e..406357d 100644
--- a/arch/mn10300/mm/cache-smp.c
+++ b/arch/mn10300/mm/cache-smp.c
@@ -13,6 +13,7 @@
#include <linux/mman.h>
#include <linux/threads.h>
#include <linux/interrupt.h>
+#include <linux/cpu.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
@@ -91,6 +92,7 @@ void smp_cache_interrupt(void)
void smp_cache_call(unsigned long opr_mask,
unsigned long start, unsigned long end)
{
+ get_online_cpus_atomic();
smp_cache_mask = opr_mask;
smp_cache_start = start;
smp_cache_end = end;
@@ -102,4 +104,5 @@ void smp_cache_call(unsigned long opr_mask,
while (!cpumask_empty(&smp_cache_ipi_map))
/* nothing. lockup detection does not belong here */
mb();
+ put_online_cpus_atomic();
}
diff --git a/arch/mn10300/mm/tlb-smp.c b/arch/mn10300/mm/tlb-smp.c
index 3e57faf..8856fd3 100644
--- a/arch/mn10300/mm/tlb-smp.c
+++ b/arch/mn10300/mm/tlb-smp.c
@@ -23,6 +23,7 @@
#include <linux/sched.h>
#include <linux/profile.h>
#include <linux/smp.h>
+#include <linux/cpu.h>
#include <asm/tlbflush.h>
#include <asm/bitops.h>
#include <asm/processor.h>
@@ -61,7 +62,7 @@ void smp_flush_tlb(void *unused)
{
unsigned long cpu_id;
- cpu_id = get_cpu();
+ cpu_id = get_online_cpus_atomic();
if (!cpumask_test_cpu(cpu_id, &flush_cpumask))
/* This was a BUG() but until someone can quote me the line
@@ -82,7 +83,7 @@ void smp_flush_tlb(void *unused)
cpumask_clear_cpu(cpu_id, &flush_cpumask);
smp_mb__after_clear_bit();
out:
- put_cpu();
+ put_online_cpus_atomic();
}
/**
@@ -144,7 +145,7 @@ void flush_tlb_mm(struct mm_struct *mm)
{
cpumask_t cpu_mask;
- preempt_disable();
+ get_online_cpus_atomic();
cpumask_copy(&cpu_mask, mm_cpumask(mm));
cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
@@ -152,7 +153,7 @@ void flush_tlb_mm(struct mm_struct *mm)
if (!cpumask_empty(&cpu_mask))
flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
- preempt_enable();
+ put_online_cpus_atomic();
}
/**
@@ -163,7 +164,7 @@ void flush_tlb_current_task(void)
struct mm_struct *mm = current->mm;
cpumask_t cpu_mask;
- preempt_disable();
+ get_online_cpus_atomic();
cpumask_copy(&cpu_mask, mm_cpumask(mm));
cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
@@ -171,7 +172,7 @@ void flush_tlb_current_task(void)
if (!cpumask_empty(&cpu_mask))
flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
- preempt_enable();
+ put_online_cpus_atomic();
}
/**
@@ -184,7 +185,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned
long va)
struct mm_struct *mm = vma->vm_mm;
cpumask_t cpu_mask;
- preempt_disable();
+ get_online_cpus_atomic();
cpumask_copy(&cpu_mask, mm_cpumask(mm));
cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
@@ -192,7 +193,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned
long va)
if (!cpumask_empty(&cpu_mask))
flush_tlb_others(cpu_mask, mm, va);
- preempt_enable();
+ put_online_cpus_atomic();
}
/**
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