diff options
| -rw-r--r-- | arch/riscv/include/asm/smp.h | 7 | ||||
| -rw-r--r-- | arch/riscv/lib/smp.c | 16 |
2 files changed, 21 insertions, 2 deletions
diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h index 1b428856b26..2dae0800ce2 100644 --- a/arch/riscv/include/asm/smp.h +++ b/arch/riscv/include/asm/smp.h @@ -18,14 +18,21 @@ * IPI data structure. The hart ID is inserted by the hart handling the IPI and * calling the function. * + * @valid is used to determine whether a sent IPI originated from U-Boot. It is + * initialized to zero by board_init_f_alloc_reserve. When U-Boot sends its + * first IPI, it is set to 1. This prevents already-pending IPIs not sent by + * U-Boot from being taken. + * * @addr: Address of function * @arg0: First argument of function * @arg1: Second argument of function + * @valid: Whether this IPI is valid */ struct ipi_data { ulong addr; ulong arg0; ulong arg1; + unsigned int valid; }; /** diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c index ab6d8bd7fa4..8f33ce1fe36 100644 --- a/arch/riscv/lib/smp.c +++ b/arch/riscv/lib/smp.c @@ -54,7 +54,13 @@ static int send_ipi_many(struct ipi_data *ipi, int wait) gd->arch.ipi[reg].arg0 = ipi->arg0; gd->arch.ipi[reg].arg1 = ipi->arg1; - __smp_mb(); + /* + * Ensure valid only becomes set when the IPI parameters are + * set. An IPI may already be pending on other harts, so we + * need a way to signal that the IPI device has been + * initialized, and that it is ok to call the function. + */ + __smp_store_release(&gd->arch.ipi[reg].valid, 1); ret = riscv_send_ipi(reg); if (ret) { @@ -83,7 +89,13 @@ void handle_ipi(ulong hart) if (hart >= CONFIG_NR_CPUS) return; - __smp_mb(); + /* + * If valid is not set, then U-Boot has not requested the IPI. The + * IPI device may not be initialized, so all we can do is wait for + * U-Boot to initialize it and send an IPI + */ + if (!__smp_load_acquire(&gd->arch.ipi[hart].valid)) + return; smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr; invalidate_icache_all(); |