diff options
| author | Andreas Schwab <schwab@suse.de> | 2018-12-11 11:20:40 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@sifive.com> | 2019-01-07 17:19:19 +0100 |
| commit | 37a107ff6dcd773da4dc75b62b9bf4349dd7300f (patch) | |
| tree | 3c958f7b8b007b28e3dd91aa823697458d7cab67 /arch/riscv | |
| parent | arch: riscv: support kernel command line forcing when no DTB passed (diff) | |
| download | linux-37a107ff6dcd773da4dc75b62b9bf4349dd7300f.tar.xz linux-37a107ff6dcd773da4dc75b62b9bf4349dd7300f.zip | |
riscv: don't stop itself in smp_send_stop
Add IPI_CPU_STOP message and use it in smp_send_stop to stop other cpus,
but not itself. Mark cpu offline on reception of IPI_CPU_STOP.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/kernel/smp.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 57b1383e5ef7..246635eac7bb 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -23,6 +23,7 @@ #include <linux/smp.h> #include <linux/sched.h> #include <linux/seq_file.h> +#include <linux/delay.h> #include <asm/sbi.h> #include <asm/tlbflush.h> @@ -31,6 +32,7 @@ enum ipi_message_type { IPI_RESCHEDULE, IPI_CALL_FUNC, + IPI_CPU_STOP, IPI_MAX }; @@ -66,6 +68,13 @@ int setup_profiling_timer(unsigned int multiplier) return -EINVAL; } +static void ipi_stop(void) +{ + set_cpu_online(smp_processor_id(), false); + while (1) + wait_for_interrupt(); +} + void riscv_software_interrupt(void) { unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits; @@ -94,6 +103,11 @@ void riscv_software_interrupt(void) generic_smp_call_function_interrupt(); } + if (ops & (1 << IPI_CPU_STOP)) { + stats[IPI_CPU_STOP]++; + ipi_stop(); + } + BUG_ON((ops >> IPI_MAX) != 0); /* Order data access and bit testing. */ @@ -121,6 +135,7 @@ send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation) static const char * const ipi_names[] = { [IPI_RESCHEDULE] = "Rescheduling interrupts", [IPI_CALL_FUNC] = "Function call interrupts", + [IPI_CPU_STOP] = "CPU stop interrupts", }; void show_ipi_stats(struct seq_file *p, int prec) @@ -146,15 +161,29 @@ void arch_send_call_function_single_ipi(int cpu) send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC); } -static void ipi_stop(void *unused) -{ - while (1) - wait_for_interrupt(); -} - void smp_send_stop(void) { - on_each_cpu(ipi_stop, NULL, 1); + unsigned long timeout; + + if (num_online_cpus() > 1) { + cpumask_t mask; + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &mask); + + if (system_state <= SYSTEM_RUNNING) + pr_crit("SMP: stopping secondary CPUs\n"); + send_ipi_message(&mask, IPI_CPU_STOP); + } + + /* Wait up to one second for other CPUs to stop */ + timeout = USEC_PER_SEC; + while (num_online_cpus() > 1 && timeout--) + udelay(1); + + if (num_online_cpus() > 1) + pr_warn("SMP: failed to stop secondary CPUs %*pbl\n", + cpumask_pr_args(cpu_online_mask)); } void smp_send_reschedule(int cpu) |