diff mbox series

[v9,03/22] riscv: Enable interrupts during syscalls with M-Mode

Message ID 20201213081016.179192-4-damien.lemoal@wdc.com (mailing list archive)
State New, archived
Headers show
Series RISC-V Kendryte K210 support improvements | expand

Commit Message

Damien Le Moal Dec. 13, 2020, 8:09 a.m. UTC 
When running is M-Mode (no MMU config), MPIE does not get set. This
results in all syscalls being executed with interrupts disabled as
handle_exception never sets SR_IE as it always sees SR_PIE being
cleared. Fix this by always force enabling interrupts in
handle_syscall when CONFIG_RISCV_M_MODE is enabled.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 arch/riscv/kernel/entry.S | 9 +++++++++
 1 file changed, 9 insertions(+)
diff mbox series

Patch

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 524d918f3601..080eb8d78589 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -155,6 +155,15 @@  skip_context_tracking:
 	tail do_trap_unknown
 
 handle_syscall:
+#ifdef CONFIG_RISCV_M_MODE
+	/*
+	 * When running is M-Mode (no MMU config), MPIE does not get set.
+	 * As a result, we need to force enable interrupts here because
+	 * handle_exception did not do set SR_IE as it always sees SR_PIE
+	 * being cleared.
+	 */
+	csrs CSR_STATUS, SR_IE
+#endif
 #if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
 	/* Recover a0 - a7 for system calls */
 	REG_L a0, PT_A0(sp)