diff options
Diffstat (limited to 'arch/riscv/kernel/smpboot.c')
| -rw-r--r-- | arch/riscv/kernel/smpboot.c | 46 |
1 files changed, 32 insertions, 14 deletions
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 56abab6a9812..18cda0e8cf94 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -30,6 +30,7 @@ #include <linux/irq.h> #include <linux/of.h> #include <linux/sched/task_stack.h> +#include <linux/sched/mm.h> #include <asm/irq.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> @@ -50,25 +51,33 @@ void __init smp_prepare_cpus(unsigned int max_cpus) void __init setup_smp(void) { struct device_node *dn = NULL; - int hart, im_okay_therefore_i_am = 0; + int hart; + bool found_boot_cpu = false; + int cpuid = 1; while ((dn = of_find_node_by_type(dn, "cpu"))) { - hart = riscv_of_processor_hart(dn); - if (hart >= 0) { - set_cpu_possible(hart, true); - set_cpu_present(hart, true); - if (hart == smp_processor_id()) { - BUG_ON(im_okay_therefore_i_am); - im_okay_therefore_i_am = 1; - } + hart = riscv_of_processor_hartid(dn); + if (hart < 0) + continue; + + if (hart == cpuid_to_hartid_map(0)) { + BUG_ON(found_boot_cpu); + found_boot_cpu = 1; + continue; } + + cpuid_to_hartid_map(cpuid) = hart; + set_cpu_possible(cpuid, true); + set_cpu_present(cpuid, true); + cpuid++; } - BUG_ON(!im_okay_therefore_i_am); + BUG_ON(!found_boot_cpu); } int __cpu_up(unsigned int cpu, struct task_struct *tidle) { + int hartid = cpuid_to_hartid_map(cpu); tidle->thread_info.cpu = cpu; /* @@ -79,8 +88,9 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) * the spinning harts that they can continue the boot process. */ smp_mb(); - __cpu_up_stack_pointer[cpu] = task_stack_page(tidle) + THREAD_SIZE; - __cpu_up_task_pointer[cpu] = tidle; + WRITE_ONCE(__cpu_up_stack_pointer[hartid], + task_stack_page(tidle) + THREAD_SIZE); + WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle); while (!cpu_online(cpu)) cpu_relax(); @@ -100,14 +110,22 @@ asmlinkage void __init smp_callin(void) struct mm_struct *mm = &init_mm; /* All kernel threads share the same mm context. */ - atomic_inc(&mm->mm_count); + mmgrab(mm); current->active_mm = mm; trap_init(); notify_cpu_starting(smp_processor_id()); set_cpu_online(smp_processor_id(), 1); + /* + * Remote TLB flushes are ignored while the CPU is offline, so emit + * a local TLB flush right now just in case. + */ local_flush_tlb_all(); - local_irq_enable(); + /* + * Disable preemption before enabling interrupts, so we don't try to + * schedule a CPU that hasn't actually started yet. + */ preempt_disable(); + local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } |