From: Atish Patra <atish.patra@wdc.com> To: linux-riscv@lists.infradead.org Cc: "Atish Patra" <atish.patra@wdc.com>, "Alan Kao" <alankao@andestech.com>, "Albert Ou" <aou@eecs.berkeley.edu>, "Andreas Schwab" <schwab@suse.de>, "Anup Patel" <anup@brainfault.org>, "Daniel Lezcano" <daniel.lezcano@linaro.org>, "Dmitriy Cherkasov" <dmitriy@oss-tech.org>, "Jason Cooper" <jason@lakedaemon.net>, linux-kernel@vger.kernel.org, "Marc Zyngier" <marc.zyngier@arm.com>, "Palmer Dabbelt" <palmer@sifive.com>, "Patrick Stählin" <me@packi.ch>, "Paul Walmsley" <paul.walmsley@sifive.com>, "Thomas Gleixner" <tglx@linutronix.de>, "Zong Li" <zongbox@gmail.com>, "Damien Le Moal" <Damien.LeMoal@wdc.com> Subject: [v3 PATCH 1/8] RISC-V: Do not wait indefinitely in __cpu_up Date: Thu, 7 Feb 2019 17:51:14 -0800 [thread overview] Message-ID: <1549590681-24125-2-git-send-email-atish.patra@wdc.com> (raw) In-Reply-To: <1549590681-24125-1-git-send-email-atish.patra@wdc.com> In SMP path, __cpu_up waits for other CPU to come online indefinitely. This is wrong as other CPU might be disabled in machine mode and possible CPU is set to the cpus present in DT. Introduce a completion variable and waits only for a second. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> --- arch/riscv/kernel/smpboot.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 18cda0e8..669eb332 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -39,6 +39,7 @@ void *__cpu_up_stack_pointer[NR_CPUS]; void *__cpu_up_task_pointer[NR_CPUS]; +static DECLARE_COMPLETION(cpu_running); void __init smp_prepare_boot_cpu(void) { @@ -77,6 +78,7 @@ void __init setup_smp(void) int __cpu_up(unsigned int cpu, struct task_struct *tidle) { + int ret = 0; int hartid = cpuid_to_hartid_map(cpu); tidle->thread_info.cpu = cpu; @@ -92,10 +94,16 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) task_stack_page(tidle) + THREAD_SIZE); WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle); - while (!cpu_online(cpu)) - cpu_relax(); + lockdep_assert_held(&cpu_running); + wait_for_completion_timeout(&cpu_running, + msecs_to_jiffies(1000)); - return 0; + if (!cpu_online(cpu)) { + pr_crit("CPU%u: failed to come online\n", cpu); + ret = -EIO; + } + + return ret; } void __init smp_cpus_done(unsigned int max_cpus) @@ -121,6 +129,7 @@ asmlinkage void __init smp_callin(void) * a local TLB flush right now just in case. */ local_flush_tlb_all(); + complete(&cpu_running); /* * Disable preemption before enabling interrupts, so we don't try to * schedule a CPU that hasn't actually started yet. -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Atish Patra <atish.patra@wdc.com> To: linux-riscv@lists.infradead.org Cc: "Patrick Stählin" <me@packi.ch>, "Albert Ou" <aou@eecs.berkeley.edu>, "Damien Le Moal" <Damien.LeMoal@wdc.com>, "Jason Cooper" <jason@lakedaemon.net>, "Alan Kao" <alankao@andestech.com>, "Dmitriy Cherkasov" <dmitriy@oss-tech.org>, "Anup Patel" <anup@brainfault.org>, "Daniel Lezcano" <daniel.lezcano@linaro.org>, linux-kernel@vger.kernel.org, "Zong Li" <zongbox@gmail.com>, "Atish Patra" <atish.patra@wdc.com>, "Palmer Dabbelt" <palmer@sifive.com>, "Paul Walmsley" <paul.walmsley@sifive.com>, "Andreas Schwab" <schwab@suse.de>, "Marc Zyngier" <marc.zyngier@arm.com>, "Thomas Gleixner" <tglx@linutronix.de> Subject: [v3 PATCH 1/8] RISC-V: Do not wait indefinitely in __cpu_up Date: Thu, 7 Feb 2019 17:51:14 -0800 [thread overview] Message-ID: <1549590681-24125-2-git-send-email-atish.patra@wdc.com> (raw) In-Reply-To: <1549590681-24125-1-git-send-email-atish.patra@wdc.com> In SMP path, __cpu_up waits for other CPU to come online indefinitely. This is wrong as other CPU might be disabled in machine mode and possible CPU is set to the cpus present in DT. Introduce a completion variable and waits only for a second. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> --- arch/riscv/kernel/smpboot.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 18cda0e8..669eb332 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -39,6 +39,7 @@ void *__cpu_up_stack_pointer[NR_CPUS]; void *__cpu_up_task_pointer[NR_CPUS]; +static DECLARE_COMPLETION(cpu_running); void __init smp_prepare_boot_cpu(void) { @@ -77,6 +78,7 @@ void __init setup_smp(void) int __cpu_up(unsigned int cpu, struct task_struct *tidle) { + int ret = 0; int hartid = cpuid_to_hartid_map(cpu); tidle->thread_info.cpu = cpu; @@ -92,10 +94,16 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) task_stack_page(tidle) + THREAD_SIZE); WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle); - while (!cpu_online(cpu)) - cpu_relax(); + lockdep_assert_held(&cpu_running); + wait_for_completion_timeout(&cpu_running, + msecs_to_jiffies(1000)); - return 0; + if (!cpu_online(cpu)) { + pr_crit("CPU%u: failed to come online\n", cpu); + ret = -EIO; + } + + return ret; } void __init smp_cpus_done(unsigned int max_cpus) @@ -121,6 +129,7 @@ asmlinkage void __init smp_callin(void) * a local TLB flush right now just in case. */ local_flush_tlb_all(); + complete(&cpu_running); /* * Disable preemption before enabling interrupts, so we don't try to * schedule a CPU that hasn't actually started yet. -- 2.7.4 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2019-02-08 1:51 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-02-08 1:51 [v3 PATCH 0/8] Various SMP related fixes Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 1:51 ` Atish Patra [this message] 2019-02-08 1:51 ` [v3 PATCH 1/8] RISC-V: Do not wait indefinitely in __cpu_up Atish Patra 2019-02-08 9:01 ` Christoph Hellwig 2019-02-08 9:01 ` Christoph Hellwig 2019-02-08 1:51 ` [v3 PATCH 2/8] RISC-V: Move cpuid to hartid mapping to SMP Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 9:03 ` Christoph Hellwig 2019-02-08 9:03 ` Christoph Hellwig 2019-02-08 22:56 ` Atish Patra 2019-02-08 22:56 ` Atish Patra 2019-02-08 1:51 ` [v3 PATCH 3/8] RISC-V: Remove NR_CPUs check during hartid search from DT Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 1:51 ` [v3 PATCH 4/8] RISC-V: Allow hartid-to-cpuid function to fail Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 1:51 ` [v3 PATCH 5/8] RISC-V: Compare cpuid with NR_CPUS before mapping Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 1:51 ` [v3 PATCH 6/8] clocksource/drivers/riscv: Add required checks during clock source init Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 9:04 ` Christoph Hellwig 2019-02-08 9:04 ` Christoph Hellwig 2019-02-08 22:56 ` Atish Patra 2019-02-08 22:56 ` Atish Patra 2019-02-08 1:51 ` [v3 PATCH 7/8] irqchip/irq-sifive-plic:: Check and continue in case of an invalid cpuid Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 1:51 ` [v3 PATCH 8/8] RISC-V: Assign hwcap only according to boot cpu Atish Patra 2019-02-08 1:51 ` Atish Patra 2019-02-08 9:11 ` Christoph Hellwig 2019-02-08 9:11 ` Christoph Hellwig 2019-02-08 23:02 ` Atish Patra 2019-02-08 23:02 ` Atish Patra 2019-02-09 4:26 ` David Abdurachmanov 2019-02-09 4:26 ` David Abdurachmanov 2019-02-09 16:11 ` Marc Zyngier 2019-02-09 16:11 ` Marc Zyngier 2019-02-11 19:02 ` Palmer Dabbelt 2019-02-11 19:02 ` Palmer Dabbelt 2019-02-11 20:03 ` Atish Patra 2019-02-11 20:03 ` Atish Patra 2019-02-11 22:13 ` Marc Zyngier 2019-02-11 22:13 ` Marc Zyngier 2019-02-11 22:23 ` Palmer Dabbelt 2019-02-11 22:23 ` Palmer Dabbelt 2019-02-11 23:25 ` Atish Patra 2019-02-11 23:25 ` Atish Patra 2019-02-11 13:23 ` Andreas Schwab 2019-02-11 13:23 ` Andreas Schwab
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