diff options
Diffstat (limited to 'arch/loongarch/kernel/traps.c')
| -rw-r--r-- | arch/loongarch/kernel/traps.c | 41 |
1 files changed, 38 insertions, 3 deletions
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index 89699db45cec..7ed01a7b2542 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -36,6 +36,7 @@ #include <asm/break.h> #include <asm/cpu.h> #include <asm/fpu.h> +#include <asm/lbt.h> #include <asm/inst.h> #include <asm/loongarch.h> #include <asm/mmu_context.h> @@ -966,13 +967,47 @@ out: irqentry_exit(regs, state); } +static void init_restore_lbt(void) +{ + if (!thread_lbt_context_live()) { + /* First time LBT context user */ + init_lbt(); + set_thread_flag(TIF_LBT_CTX_LIVE); + } else { + if (!is_lbt_owner()) + own_lbt_inatomic(1); + } + + BUG_ON(!is_lbt_enabled()); +} + asmlinkage void noinstr do_lbt(struct pt_regs *regs) { irqentry_state_t state = irqentry_enter(regs); - local_irq_enable(); - force_sig(SIGILL); - local_irq_disable(); + /* + * BTD (Binary Translation Disable exception) can be triggered + * during FP save/restore if TM (Top Mode) is on, which may + * cause irq_enable during 'switch_to'. To avoid this situation + * (including the user using 'MOVGR2GCSR' to turn on TM, which + * will not trigger the BTE), we need to check PRMD first. + */ + if (regs->csr_prmd & CSR_PRMD_PIE) + local_irq_enable(); + + if (!cpu_has_lbt) { + force_sig(SIGILL); + goto out; + } + BUG_ON(is_lbt_enabled()); + + preempt_disable(); + init_restore_lbt(); + preempt_enable(); + +out: + if (regs->csr_prmd & CSR_PRMD_PIE) + local_irq_disable(); irqentry_exit(regs, state); } |