[PATCH v16 1/9] RISC-V: Clear SIP bit only when using SBI IPI operations

From: Anup Patel
Date: Tue Jan 03 2023 - 09:12:56 EST


The software interrupt pending (i.e. [M|S]SIP) bit is writeable for
S-mode but read-only for M-mode so we clear this bit only when using
SBI IPI operations.

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
Reviewed-by: Bin Meng <bmeng.cn@xxxxxxxxx>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
---
arch/riscv/kernel/sbi.c | 8 +++++++-
arch/riscv/kernel/smp.c | 2 --
2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 5c87db8fdff2..ac99a70ead6a 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -646,8 +646,14 @@ static void sbi_send_cpumask_ipi(const struct cpumask *target)
sbi_send_ipi(target);
}

+static void sbi_ipi_clear(void)
+{
+ csr_clear(CSR_IP, IE_SIE);
+}
+
static const struct riscv_ipi_ops sbi_ipi_ops = {
- .ipi_inject = sbi_send_cpumask_ipi
+ .ipi_inject = sbi_send_cpumask_ipi,
+ .ipi_clear = sbi_ipi_clear
};

void __init sbi_init(void)
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 8c3b59f1f9b8..8a12768c09ee 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -112,8 +112,6 @@ void riscv_clear_ipi(void)
{
if (ipi_ops && ipi_ops->ipi_clear)
ipi_ops->ipi_clear();
-
- csr_clear(CSR_IP, IE_SIE);
}
EXPORT_SYMBOL_GPL(riscv_clear_ipi);

--
2.34.1