[PATCH 5.5 109/176] RISC-V: Dont enable all interrupts in trap_init()

Greg Kroah-Hartman
2020-03-03T18:10:56Z

From: Anup Patel <anup.patel@wdc.com>

commit 6a1ce99dc4bde564e4a072936f9d41f4a439140e upstream.

Historically, we have been enabling all interrupts for each
HART in trap_init(). Ideally, we should only enable M-mode
interrupts for M-mode kernel and S-mode interrupts for S-mode
kernel in trap_init().

Currently, we get suprious S-mode interrupts on Kendryte K210
board running M-mode NO-MMU kernel because we are enabling all
interrupts in trap_init(). To fix this, we only enable software
and external interrupt in trap_init(). In future, trap_init()
will only enable software interrupt and PLIC driver will enable
external interrupt using CPU notifiers.

Fixes: a4c3733d32a7 ("riscv: abstract out CSR names for supervisor vs machine mode")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Palmer Dabbelt <palmerdabbelt@google.com> [QMEU virt machine with SMP]
[Palmer: Move the Fixes up to a newer commit]
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/riscv/kernel/traps.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -156,6 +156,6 @@ void __init trap_init(void)
csr_write(CSR_SCRATCH, 0);
/* Set the exception vector address */
csr_write(CSR_TVEC, &handle_exception);
- /* Enable all interrupts */
- csr_write(CSR_IE, -1);
+ /* Enable interrupts */
+ csr_write(CSR_IE, IE_SIE | IE_EIE);
}