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Bhat" Subject: [PATCH v5 37/45] mn10300: Use get/put_online_cpus_atomic() to prevent CPU offline To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org Date: Tue, 22 Jan 2013 13:13:16 +0530 Message-ID: <20130122074312.13822.41323.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> References: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-arch@vger.kernel.org, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() 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 Cc: Koichi Yasutake Cc: linux-am33-list@redhat.com Signed-off-by: Srivatsa S. Bhat --- arch/mn10300/kernel/smp.c | 2 ++ arch/mn10300/mm/cache-smp.c | 5 +++++ arch/mn10300/mm/tlb-smp.c | 15 +++++++++------ 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/mn10300/kernel/smp.c b/arch/mn10300/kernel/smp.c index 5d7e152..9dfa172 100644 --- a/arch/mn10300/kernel/smp.c +++ b/arch/mn10300/kernel/smp.c @@ -349,9 +349,11 @@ void send_IPI_allbutself(int irq) { cpumask_t cpumask; + get_online_cpus_atomic(); cpumask_copy(&cpumask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &cpumask); send_IPI_mask(&cpumask, irq); + put_online_cpus_atomic(); } void arch_send_call_function_ipi_mask(const struct cpumask *mask) diff --git a/arch/mn10300/mm/cache-smp.c b/arch/mn10300/mm/cache-smp.c index 2d23b9e..47ca1c9 100644 --- a/arch/mn10300/mm/cache-smp.c +++ b/arch/mn10300/mm/cache-smp.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -94,6 +95,8 @@ void smp_cache_call(unsigned long opr_mask, smp_cache_mask = opr_mask; smp_cache_start = start; smp_cache_end = end; + + get_online_cpus_atomic(); cpumask_copy(&smp_cache_ipi_map, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &smp_cache_ipi_map); @@ -102,4 +105,6 @@ 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..d47304d 100644 --- a/arch/mn10300/mm/tlb-smp.c +++ b/arch/mn10300/mm/tlb-smp.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -105,6 +106,7 @@ static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm, BUG_ON(cpumask_empty(&cpumask)); BUG_ON(cpumask_test_cpu(smp_processor_id(), &cpumask)); + get_online_cpus_atomic(); cpumask_and(&tmp, &cpumask, cpu_online_mask); BUG_ON(!cpumask_equal(&cpumask, &tmp)); @@ -134,6 +136,7 @@ static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm, flush_mm = NULL; flush_va = 0; spin_unlock(&tlbstate_lock); + put_online_cpus_atomic(); } /** @@ -144,7 +147,7 @@ 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 +155,7 @@ 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 +166,7 @@ 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 +174,7 @@ 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 +187,7 @@ 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 +195,7 @@ 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(); } /**