riscv: add functions for reading the IPI status

Add the function riscv_get_ipi() for reading the pending status of IPIs.
The supported controllers are Andes' Platform Level Interrupt Controller
(PLIC), the Supervisor Binary Interface (SBI), and SiFive's Core Local
Interruptor (CLINT).

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Rick Chen <rick@andestech.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/riscv/lib/andes_plic.c b/arch/riscv/lib/andes_plic.c
index 42394b9b6e..3868569a65 100644
--- a/arch/riscv/lib/andes_plic.c
+++ b/arch/riscv/lib/andes_plic.c
@@ -117,6 +117,17 @@ int riscv_clear_ipi(int hart)
 	return 0;
 }
 
+int riscv_get_ipi(int hart, int *pending)
+{
+	PLIC_BASE_GET();
+
+	*pending = readl((void __iomem *)PENDING_REG(gd->arch.plic,
+						     gd->arch.boot_hart));
+	*pending = !!(*pending & SEND_IPI_TO_HART(hart));
+
+	return 0;
+}
+
 static const struct udevice_id andes_plic_ids[] = {
 	{ .compatible = "riscv,plic1", .data = RISCV_SYSCON_PLIC },
 	{ }