diff options
Diffstat (limited to 'arch/riscv/kernel')
| -rw-r--r-- | arch/riscv/kernel/entry.S | 30 | ||||
| -rw-r--r-- | arch/riscv/kernel/head.S | 8 | ||||
| -rw-r--r-- | arch/riscv/kernel/smp.c | 1 | ||||
| -rw-r--r-- | arch/riscv/kernel/time.c | 1 | ||||
| -rw-r--r-- | arch/riscv/kernel/traps.c | 14 |
5 files changed, 40 insertions, 14 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 74ccfd464071..8ca479831142 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -98,7 +98,26 @@ _save_context: */ .macro RESTORE_ALL REG_L a0, PT_SSTATUS(sp) - REG_L a2, PT_SEPC(sp) + /* + * The current load reservation is effectively part of the processor's + * state, in the sense that load reservations cannot be shared between + * different hart contexts. We can't actually save and restore a load + * reservation, so instead here we clear any existing reservation -- + * it's always legal for implementations to clear load reservations at + * any point (as long as the forward progress guarantee is kept, but + * we'll ignore that here). + * + * Dangling load reservations can be the result of taking a trap in the + * middle of an LR/SC sequence, but can also be the result of a taken + * forward branch around an SC -- which is how we implement CAS. As a + * result we need to clear reservations between the last CAS and the + * jump back to the new context. While it is unlikely the store + * completes, implementations are allowed to expand reservations to be + * arbitrarily large. + */ + REG_L a2, PT_SEPC(sp) + REG_SC x0, a2, PT_SEPC(sp) + csrw CSR_SSTATUS, a0 csrw CSR_SEPC, a2 @@ -166,9 +185,13 @@ ENTRY(handle_exception) move a0, sp /* pt_regs */ tail do_IRQ 1: - /* Exceptions run with interrupts enabled */ + /* Exceptions run with interrupts enabled or disabled + depending on the state of sstatus.SR_SPIE */ + andi t0, s1, SR_SPIE + beqz t0, 1f csrs CSR_SSTATUS, SR_SIE +1: /* Handle syscalls */ li t0, EXC_SYSCALL beq s4, t0, handle_syscall @@ -250,12 +273,11 @@ restore_all: resume_kernel: REG_L s0, TASK_TI_PREEMPT_COUNT(tp) bnez s0, restore_all -need_resched: REG_L s0, TASK_TI_FLAGS(tp) andi s0, s0, _TIF_NEED_RESCHED beqz s0, restore_all call preempt_schedule_irq - j need_resched + j restore_all #endif work_pending: diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 15a9189f91ad..72f89b7590dd 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -63,6 +63,11 @@ _start_kernel: li t0, SR_FS csrc CSR_SSTATUS, t0 +#ifdef CONFIG_SMP + li t0, CONFIG_NR_CPUS + bgeu a0, t0, .Lsecondary_park +#endif + /* Pick one hart to run the main boot sequence */ la a3, hart_lottery li a2, 1 @@ -154,9 +159,6 @@ relocate: .Lsecondary_start: #ifdef CONFIG_SMP - li a1, CONFIG_NR_CPUS - bgeu a0, a1, .Lsecondary_park - /* Set trap vector to spin forever to help debug */ la a3, .Lsecondary_park csrw CSR_STVEC, a3 diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 3836760d7aaf..b18cd6c8e8fb 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -206,3 +206,4 @@ void smp_send_reschedule(int cpu) { send_ipi_single(cpu, IPI_RESCHEDULE); } +EXPORT_SYMBOL_GPL(smp_send_reschedule); diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c index 541a2b885814..9dd1f2e64db1 100644 --- a/arch/riscv/kernel/time.c +++ b/arch/riscv/kernel/time.c @@ -9,6 +9,7 @@ #include <asm/sbi.h> unsigned long riscv_timebase; +EXPORT_SYMBOL_GPL(riscv_timebase); void __init time_init(void) { diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 424eb72d56b1..93742df9067f 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -124,24 +124,24 @@ static inline unsigned long get_break_insn_length(unsigned long pc) asmlinkage void do_trap_break(struct pt_regs *regs) { -#ifdef CONFIG_GENERIC_BUG if (!user_mode(regs)) { enum bug_trap_type type; type = report_bug(regs->sepc, regs); switch (type) { - case BUG_TRAP_TYPE_NONE: - break; +#ifdef CONFIG_GENERIC_BUG case BUG_TRAP_TYPE_WARN: regs->sepc += get_break_insn_length(regs->sepc); - break; + return; case BUG_TRAP_TYPE_BUG: +#endif /* CONFIG_GENERIC_BUG */ + default: die(regs, "Kernel BUG"); } + } else { + force_sig_fault(SIGTRAP, TRAP_BRKPT, + (void __user *)(regs->sepc)); } -#endif /* CONFIG_GENERIC_BUG */ - - force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc)); } #ifdef CONFIG_GENERIC_BUG |