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Bhat" Subject: [PATCH v3 38/45] MIPS: 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, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com, David.Laight@aculab.com Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, fweisbec@gmail.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Ralf Baechle , David Daney , Yong Zhang , Thomas Gleixner , Sanjay Lal , "Steven J. Hill" , John Crispin , Florian Fainelli , linux-mips@linux-mips.org, "Srivatsa S. Bhat" Date: Fri, 28 Jun 2013 01:29:28 +0530 Message-ID: <20130627195927.29830.84671.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> References: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062719-8878-0000-0000-000007B9C02A Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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: Ralf Baechle Cc: David Daney Cc: Yong Zhang Cc: Thomas Gleixner Cc: Sanjay Lal Cc: "Steven J. Hill" Cc: John Crispin Cc: Florian Fainelli Cc: linux-mips@linux-mips.org Signed-off-by: Srivatsa S. Bhat --- arch/mips/kernel/cevt-smtc.c | 7 +++++++ arch/mips/kernel/smp.c | 16 ++++++++-------- arch/mips/kernel/smtc.c | 12 ++++++++++++ arch/mips/mm/c-octeon.c | 4 ++-- arch/mips/mm/c-r4k.c | 5 +++-- 5 files changed, 32 insertions(+), 12 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/mips/kernel/cevt-smtc.c b/arch/mips/kernel/cevt-smtc.c index 9de5ed7..2e6c0cd 100644 --- a/arch/mips/kernel/cevt-smtc.c +++ b/arch/mips/kernel/cevt-smtc.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -84,6 +85,8 @@ static int mips_next_event(unsigned long delta, unsigned long nextcomp = 0L; int vpe = current_cpu_data.vpe_id; int cpu = smp_processor_id(); + + get_online_cpus_atomic(); local_irq_save(flags); mtflags = dmt(); @@ -164,6 +167,7 @@ static int mips_next_event(unsigned long delta, } emt(mtflags); local_irq_restore(flags); + put_online_cpus_atomic(); return 0; } @@ -177,6 +181,7 @@ void smtc_distribute_timer(int vpe) unsigned long nextstamp; unsigned long reference; + get_online_cpus_atomic(); repeat: nextstamp = 0L; @@ -229,6 +234,8 @@ repeat: > (unsigned long)LONG_MAX) goto repeat; } + + put_online_cpus_atomic(); } diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 6e7862a..be152b6 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -250,12 +250,12 @@ static inline void smp_on_other_tlbs(void (*func) (void *info), void *info) static inline void smp_on_each_tlb(void (*func) (void *info), void *info) { - preempt_disable(); + get_online_cpus_atomic(); smp_on_other_tlbs(func, info); func(info); - preempt_enable(); + put_online_cpus_atomic(); } /* @@ -273,7 +273,7 @@ static inline void smp_on_each_tlb(void (*func) (void *info), void *info) void flush_tlb_mm(struct mm_struct *mm) { - preempt_disable(); + get_online_cpus_atomic(); if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) { smp_on_other_tlbs(flush_tlb_mm_ipi, mm); @@ -287,7 +287,7 @@ void flush_tlb_mm(struct mm_struct *mm) } local_flush_tlb_mm(mm); - preempt_enable(); + put_online_cpus_atomic(); } struct flush_tlb_data { @@ -307,7 +307,7 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned l { struct mm_struct *mm = vma->vm_mm; - preempt_disable(); + get_online_cpus_atomic(); if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) { struct flush_tlb_data fd = { .vma = vma, @@ -325,7 +325,7 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned l } } local_flush_tlb_range(vma, start, end); - preempt_enable(); + put_online_cpus_atomic(); } static void flush_tlb_kernel_range_ipi(void *info) @@ -354,7 +354,7 @@ static void flush_tlb_page_ipi(void *info) void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) { - preempt_disable(); + get_online_cpus_atomic(); if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) { struct flush_tlb_data fd = { .vma = vma, @@ -371,7 +371,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) } } local_flush_tlb_page(vma, page); - preempt_enable(); + put_online_cpus_atomic(); } static void flush_tlb_one_ipi(void *info) diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c index 75a4fd7..3cda8eb 100644 --- a/arch/mips/kernel/smtc.c +++ b/arch/mips/kernel/smtc.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -1143,6 +1144,8 @@ static irqreturn_t ipi_interrupt(int irq, void *dev_idm) * for the current TC, so we ought not to have to do it explicitly here. */ + get_online_cpus_atomic(); + for_each_online_cpu(cpu) { if (cpu_data[cpu].vpe_id != my_vpe) continue; @@ -1180,6 +1183,8 @@ static irqreturn_t ipi_interrupt(int irq, void *dev_idm) } } + put_online_cpus_atomic(); + return IRQ_HANDLED; } @@ -1383,6 +1388,7 @@ void smtc_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu) * them, let's be really careful... */ + get_online_cpus_atomic(); local_irq_save(flags); if (smtc_status & SMTC_TLB_SHARED) { mtflags = dvpe(); @@ -1438,6 +1444,7 @@ void smtc_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu) else emt(mtflags); local_irq_restore(flags); + put_online_cpus_atomic(); } /* @@ -1496,6 +1503,7 @@ void smtc_cflush_lockdown(void) { int cpu; + get_online_cpus_atomic(); for_each_online_cpu(cpu) { if (cpu != smp_processor_id()) { settc(cpu_data[cpu].tc_id); @@ -1504,6 +1512,7 @@ void smtc_cflush_lockdown(void) } } mips_ihb(); + put_online_cpus_atomic(); } /* It would be cheating to change the cpu_online states during a flush! */ @@ -1512,6 +1521,8 @@ void smtc_cflush_release(void) { int cpu; + get_online_cpus_atomic(); + /* * Start with a hazard barrier to ensure * that all CACHE ops have played through. @@ -1525,4 +1536,5 @@ void smtc_cflush_release(void) } } mips_ihb(); + put_online_cpus_atomic(); } diff --git a/arch/mips/mm/c-octeon.c b/arch/mips/mm/c-octeon.c index 8557fb5..8e1bcf6 100644 --- a/arch/mips/mm/c-octeon.c +++ b/arch/mips/mm/c-octeon.c @@ -73,7 +73,7 @@ static void octeon_flush_icache_all_cores(struct vm_area_struct *vma) mb(); octeon_local_flush_icache(); #ifdef CONFIG_SMP - preempt_disable(); + get_online_cpus_atomic(); cpu = smp_processor_id(); /* @@ -88,7 +88,7 @@ static void octeon_flush_icache_all_cores(struct vm_area_struct *vma) for_each_cpu(cpu, &mask) octeon_send_ipi_single(cpu, SMP_ICACHE_FLUSH); - preempt_enable(); + put_online_cpus_atomic(); #endif } diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 21813be..86c8b3e 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -46,13 +47,13 @@ */ static inline void r4k_on_each_cpu(void (*func) (void *info), void *info) { - preempt_disable(); + get_online_cpus_atomic(); #if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC) smp_call_function(func, info, 1); #endif func(info); - preempt_enable(); + put_online_cpus_atomic(); } #if defined(CONFIG_MIPS_CMP)