[PATCH v1 4/4] xen/riscv: introduce intc_preinit()

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

Currently, only the device tree method is available to locate and perform
pre-initialization steps for the interrupt controller. When `acpi_disabled`
is true, the system will scan for a node with the "interrupt-controller"
property and then call `device_init()` to validate if it is an expected
interrupt controller and if yes then save this node for further usage.

If `acpi_disabled` is false, the system will panic, as ACPI support is not
yet implemented for RISC-V.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
 xen/arch/riscv/Makefile           |  1 +
 xen/arch/riscv/include/asm/intc.h |  2 ++
 xen/arch/riscv/intc.c             | 14 ++++++++++++++
 xen/arch/riscv/setup.c            |  3 +++
 4 files changed, 20 insertions(+)
 create mode 100644 xen/arch/riscv/intc.c

diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
index dd5fd25c7d..0c6c4a38a3 100644
--- a/xen/arch/riscv/Makefile
+++ b/xen/arch/riscv/Makefile
@@ -2,6 +2,7 @@ obj-y += aplic.o
 obj-y += cpufeature.o
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
 obj-y += entry.o
+obj-y += intc.o
 obj-y += mm.o
 obj-y += pt.o
 obj-$(CONFIG_RISCV_64) += riscv64/
diff --git a/xen/arch/riscv/include/asm/intc.h 
b/xen/arch/riscv/include/asm/intc.h
index ff9bb33896..52ba196d87 100644
--- a/xen/arch/riscv/include/asm/intc.h
+++ b/xen/arch/riscv/include/asm/intc.h
@@ -17,4 +17,6 @@ struct intc_info {
     const struct dt_device_node *node;
 };
 
+void intc_preinit(void);
+
 #endif /* ASM__RISCV__INTERRUPT_CONTOLLER_H */
diff --git a/xen/arch/riscv/intc.c b/xen/arch/riscv/intc.c
new file mode 100644
index 0000000000..4061a3c457
--- /dev/null
+++ b/xen/arch/riscv/intc.c
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <xen/acpi.h>
+#include <xen/device_tree.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+
+void __init intc_preinit(void)
+{
+    if ( acpi_disabled )
+        intc_dt_preinit();
+    else
+        panic("ACPI interrupt controller preinit() isn't implemented\n");
+}
diff --git a/xen/arch/riscv/setup.c b/xen/arch/riscv/setup.c
index 836ad16fed..4e416f6e44 100644
--- a/xen/arch/riscv/setup.c
+++ b/xen/arch/riscv/setup.c
@@ -16,6 +16,7 @@
 #include <asm/cpufeature.h>
 #include <asm/early_printk.h>
 #include <asm/fixmap.h>
+#include <asm/intc.h>
 #include <asm/sbi.h>
 #include <asm/setup.h>
 #include <asm/smp.h>
@@ -128,6 +129,8 @@ void __init noreturn start_xen(unsigned long bootcpu_id,
 
     preinit_xen_time();
 
+    intc_preinit();
+
     printk("All set up\n");
 
     machine_halt();
-- 
2.48.1