diff options
| -rw-r--r-- | arch/arm64/include/asm/Kbuild | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/percpu.h | 41 | ||||
| -rw-r--r-- | arch/arm64/kernel/setup.c | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/smp.c | 6 |
4 files changed, 55 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 519f89f5b6a3..d0ff25de67ca 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -26,7 +26,6 @@ generic-y += mman.h generic-y += msgbuf.h generic-y += mutex.h generic-y += pci.h -generic-y += percpu.h generic-y += poll.h generic-y += posix_types.h generic-y += resource.h diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h new file mode 100644 index 000000000000..13fb0b3efc5f --- /dev/null +++ b/arch/arm64/include/asm/percpu.h @@ -0,0 +1,41 @@ +/* + * Copyright (C) 2013 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_PERCPU_H +#define __ASM_PERCPU_H + +static inline void set_my_cpu_offset(unsigned long off) +{ + asm volatile("msr tpidr_el1, %0" :: "r" (off) : "memory"); +} + +static inline unsigned long __my_cpu_offset(void) +{ + unsigned long off; + register unsigned long *sp asm ("sp"); + + /* + * We want to allow caching the value, so avoid using volatile and + * instead use a fake stack read to hazard against barrier(). + */ + asm("mrs %0, tpidr_el1" : "=r" (off) : "Q" (*sp)); + + return off; +} +#define __my_cpu_offset __my_cpu_offset() + +#include <asm-generic/percpu.h> + +#endif /* __ASM_PERCPU_H */ diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index bd9bbd0e44ed..97d90840a7fd 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -108,6 +108,16 @@ void __init early_print(const char *str, ...) printk("%s", buf); } +void __init smp_setup_processor_id(void) +{ + /* + * clear __my_cpu_offset on boot CPU to avoid hang caused by + * using percpu variable early, for example, lockdep will + * access percpu variable inside lock_release + */ + set_my_cpu_offset(0); +} + bool arch_match_cpu_phys_id(int cpu, u64 phys_id) { return phys_id == cpu_logical_map(cpu); diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index a0c2ca602cf8..b5d2031c12c6 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -122,8 +122,6 @@ asmlinkage void secondary_start_kernel(void) struct mm_struct *mm = &init_mm; unsigned int cpu = smp_processor_id(); - printk("CPU%u: Booted secondary processor\n", cpu); - /* * All kernel threads share the same mm context; grab a * reference and switch to it. @@ -132,6 +130,9 @@ asmlinkage void secondary_start_kernel(void) current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); + set_my_cpu_offset(per_cpu_offset(smp_processor_id())); + printk("CPU%u: Booted secondary processor\n", cpu); + /* * TTBR0 is only used for the identity mapping at this stage. Make it * point to zero page to avoid speculatively fetching new entries. @@ -271,6 +272,7 @@ void __init smp_cpus_done(unsigned int max_cpus) void __init smp_prepare_boot_cpu(void) { + set_my_cpu_offset(per_cpu_offset(smp_processor_id())); } static void (*smp_cross_call)(const struct cpumask *, unsigned int); |