[RFC,v1,01/10] RISC-V: Clear SIP bit only when using SBI IPI operations

Commit Message

Anup Patel June 12, 2021, 4:04 p.m. UTC

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

Signed-off-by: Anup Patel <[e-mail]>
---
 arch/riscv/kernel/sbi.c | 8 +++++++-
 arch/riscv/kernel/smp.c | 2 --
 2 files changed, 7 insertions(+), 3 deletions(-)

Comments

Bin Meng June 14, 2021, 1:33 p.m. UTC | #1

On Sun, Jun 13, 2021 at 12:07 AM Anup Patel <[e-mail]> wrote:
>
> The software interrupt pending (i.e. [M|S]SIP) bit is writeable for
> S-mode but readonly for M-mode so we clear this bit only when using

nits: read-only

> SBI IPI operations.
>
> Signed-off-by: Anup Patel <[e-mail]>
> ---
>  arch/riscv/kernel/sbi.c | 8 +++++++-
>  arch/riscv/kernel/smp.c | 2 --
>  2 files changed, 7 insertions(+), 3 deletions(-)
>

Otherwise,
Reviewed-by: Bin Meng <[e-mail]>

Patch

diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 9a84f0cb5175..8aeca26198f2 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -598,8 +598,14 @@  static void sbi_send_cpumask_ipi(const struct cpumask *target)
 	sbi_send_ipi(cpumask_bits(&hartid_mask));
 }
 
+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 921d9d7df400..547dc508f7d1 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -99,8 +99,6 @@  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);