From 79b1feba54558bfb7df7c516dab29a7c9dba093c Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 15 Jul 2020 16:30:06 -0700 Subject: RISC-V: Setup exception vector early The trap vector is set only in trap_init which may be too late in some cases. Early ioremap/efi spits many warning messages which may be useful. Setup the trap vector early so that any warning/bug can be handled before generic code invokes trap_init. Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/head.S | 10 ++++++++-- arch/riscv/kernel/smpboot.c | 2 +- arch/riscv/kernel/traps.c | 8 +------- 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 7ed1b22950fd..d0c5c316e9bb 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -77,10 +77,16 @@ relocate: csrw CSR_SATP, a0 .align 2 1: - /* Set trap vector to spin forever to help debug */ - la a0, .Lsecondary_park + /* Set trap vector to exception handler */ + la a0, handle_exception csrw CSR_TVEC, a0 + /* + * Set sup0 scratch register to 0, indicating to exception vector that + * we are presently executing in kernel. + */ + csrw CSR_SCRATCH, zero + /* Reload the global pointer */ .option push .option norelax diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 403bd93412a4..47404d4ad721 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -154,10 +154,10 @@ asmlinkage __visible void smp_callin(void) mmgrab(mm); current->active_mm = mm; - trap_init(); notify_cpu_starting(curr_cpuid); update_siblings_masks(curr_cpuid); set_cpu_online(curr_cpuid, 1); + /* * Remote TLB flushes are ignored while the CPU is offline, so emit * a local TLB flush right now just in case. diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 7d95cce5e47c..ad14f4466d92 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -174,13 +174,7 @@ int is_valid_bugaddr(unsigned long pc) } #endif /* CONFIG_GENERIC_BUG */ +/* stvec & scratch is already set from head.S */ void trap_init(void) { - /* - * Set sup0 scratch register to 0, indicating to exception vector - * that we are presently executing in the kernel - */ - csr_write(CSR_SCRATCH, 0); - /* Set the exception vector address */ - csr_write(CSR_TVEC, &handle_exception); } -- cgit v1.2.3