diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/include/asm/processor.h | 3 | ||||
| -rw-r--r-- | arch/riscv/include/asm/simd.h | 6 | ||||
| -rw-r--r-- | arch/riscv/kernel/kernel_mode_vector.c | 14 |
3 files changed, 19 insertions, 4 deletions
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 4809f20a2053..55ace554f202 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -78,7 +78,8 @@ struct pt_regs; * following meaning: * * - bit 0: indicates whether the in-kernel Vector context is active. The - * activation of this state disables the preemption. + * activation of this state disables the preemption. On a non-RT kernel, it + * also disable bh. */ #define RISCV_KERNEL_MODE_V 0x1 diff --git a/arch/riscv/include/asm/simd.h b/arch/riscv/include/asm/simd.h index ef8af413a9fc..4d699e16c9a9 100644 --- a/arch/riscv/include/asm/simd.h +++ b/arch/riscv/include/asm/simd.h @@ -28,8 +28,12 @@ static __must_check inline bool may_use_simd(void) /* * RISCV_KERNEL_MODE_V is only set while preemption is disabled, * and is clear whenever preemption is enabled. + * + * Kernel-mode Vector temporarily disables bh. So we must not return + * true on irq_disabled(). Otherwise we would fail the lockdep check + * calling local_bh_enable() */ - return !in_hardirq() && !in_nmi() && !(riscv_v_flags() & RISCV_KERNEL_MODE_V); + return !in_hardirq() && !in_nmi() && !irqs_disabled() && !(riscv_v_flags() & RISCV_KERNEL_MODE_V); } #else /* ! CONFIG_RISCV_ISA_V */ diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c index 114cf4f0a0eb..2fc145edae3d 100644 --- a/arch/riscv/kernel/kernel_mode_vector.c +++ b/arch/riscv/kernel/kernel_mode_vector.c @@ -46,7 +46,14 @@ static inline void riscv_v_stop(u32 flags) */ void get_cpu_vector_context(void) { - preempt_disable(); + /* + * disable softirqs so it is impossible for softirqs to nest + * get_cpu_vector_context() when kernel is actively using Vector. + */ + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + local_bh_disable(); + else + preempt_disable(); riscv_v_start(RISCV_KERNEL_MODE_V); } @@ -62,7 +69,10 @@ void put_cpu_vector_context(void) { riscv_v_stop(RISCV_KERNEL_MODE_V); - preempt_enable(); + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + local_bh_enable(); + else + preempt_enable(); } /* |