lib: sbi: Add a simple external interrupt handling framework

Currently, the external interrupt handling is scattered between
sbi_init and sbi_trap. This patch moves all external interrupt
handling into a simple framework called sbi_irqchip.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/lib/sbi/sbi_irqchip.c b/lib/sbi/sbi_irqchip.c
new file mode 100644
index 0000000..24128be
--- /dev/null
+++ b/lib/sbi/sbi_irqchip.c
@@ -0,0 +1,54 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ *
+ * Authors:
+ *   Anup Patel <apatel@ventanamicro.com>
+ */
+
+#include <sbi/sbi_irqchip.h>
+#include <sbi/sbi_platform.h>
+
+static int default_irqfn(struct sbi_trap_regs *regs)
+{
+	return SBI_ENODEV;
+}
+
+static int (*ext_irqfn)(struct sbi_trap_regs *regs) = default_irqfn;
+
+void sbi_irqchip_set_irqfn(int (*fn)(struct sbi_trap_regs *regs))
+{
+	if (fn)
+		ext_irqfn = fn;
+}
+
+int sbi_irqchip_process(struct sbi_trap_regs *regs)
+{
+	return ext_irqfn(regs);
+}
+
+int sbi_irqchip_init(struct sbi_scratch *scratch, bool cold_boot)
+{
+	int rc;
+	const struct sbi_platform *plat = sbi_platform_ptr(scratch);
+
+	rc = sbi_platform_irqchip_init(plat, cold_boot);
+	if (rc)
+		return rc;
+
+	if (ext_irqfn != default_irqfn)
+		csr_set(CSR_MIE, MIP_MEIP);
+
+	return 0;
+}
+
+void sbi_irqchip_exit(struct sbi_scratch *scratch)
+{
+	const struct sbi_platform *plat = sbi_platform_ptr(scratch);
+
+	if (ext_irqfn != default_irqfn)
+		csr_clear(CSR_MIE, MIP_MEIP);
+
+	sbi_platform_irqchip_exit(plat);
+}