[PATCH v4 15/18] hw/intc/loongarch_ipi: Add loongarch IPI support

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

From: Bibo Mao <maobibo@loongson.cn>

Loongarch IPI is added here, it inherits from class
TYPE_LOONGSON_IPI_COMMON, and two interfaces get_iocsr_as() and
cpu_by_arch_id() are added for Loongarch 3A5000 machine. It can
be used when ipi is emulated in userspace with KVM mode.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
[PMD: Rebased and simplified]
Co-Developed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Bibo Mao <maobibo@loongson.cn>
---
 include/hw/intc/loongarch_ipi.h | 25 ++++++++++++
 hw/intc/loongarch_ipi.c         | 68 +++++++++++++++++++++++++++++++++
 hw/intc/Kconfig                 |  4 ++
 hw/intc/meson.build             |  1 +
 4 files changed, 98 insertions(+)
 create mode 100644 include/hw/intc/loongarch_ipi.h
 create mode 100644 hw/intc/loongarch_ipi.c

diff --git a/include/hw/intc/loongarch_ipi.h b/include/hw/intc/loongarch_ipi.h
new file mode 100644
index 0000000000..d134c9d0c7
--- /dev/null
+++ b/include/hw/intc/loongarch_ipi.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Loongarch ipi interrupt header files
+ *
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#ifndef HW_LOONGARCH_IPI_H
+#define HW_LOONGARCH_IPI_H
+
+#include "qom/object.h"
+#include "hw/intc/loongson_ipi_common.h"
+
+#define TYPE_LOONGARCH_IPI  "loongarch_ipi"
+OBJECT_DECLARE_TYPE(LoongarchIPIState, LoongarchIPIClass, LOONGARCH_IPI)
+
+struct LoongarchIPIState {
+    LoongsonIPICommonState parent_obj;
+};
+
+struct LoongarchIPIClass {
+    LoongsonIPICommonClass parent_class;
+};
+
+#endif
diff --git a/hw/intc/loongarch_ipi.c b/hw/intc/loongarch_ipi.c
new file mode 100644
index 0000000000..ccbfad07b7
--- /dev/null
+++ b/hw/intc/loongarch_ipi.c
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Loongarch ipi interrupt support
+ *
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "hw/boards.h"
+#include "hw/intc/loongarch_ipi.h"
+#include "target/loongarch/cpu.h"
+
+static AddressSpace *get_iocsr_as(CPUState *cpu)
+{
+    return LOONGARCH_CPU(cpu)->env.address_space_iocsr;
+}
+
+static int archid_cmp(const void *a, const void *b)
+{
+   CPUArchId *archid_a = (CPUArchId *)a;
+   CPUArchId *archid_b = (CPUArchId *)b;
+
+   return archid_a->arch_id - archid_b->arch_id;
+}
+
+static CPUArchId *find_cpu_by_archid(MachineState *ms, uint32_t id)
+{
+    CPUArchId apic_id, *found_cpu;
+
+    apic_id.arch_id = id;
+    found_cpu = bsearch(&apic_id, ms->possible_cpus->cpus,
+                        ms->possible_cpus->len,
+                        sizeof(*ms->possible_cpus->cpus),
+                        archid_cmp);
+
+    return found_cpu;
+}
+
+static CPUState *loongarch_cpu_by_arch_id(int64_t arch_id)
+{
+    MachineState *machine = MACHINE(qdev_get_machine());
+    CPUArchId *archid;
+
+    archid = find_cpu_by_archid(machine, arch_id);
+    if (archid) {
+        return CPU(archid->cpu);
+    }
+
+    return NULL;
+}
+
+static void loongarch_ipi_class_init(ObjectClass *klass, void *data)
+{
+    LoongsonIPICommonClass *licc = LOONGSON_IPI_COMMON_CLASS(klass);
+
+    licc->get_iocsr_as = get_iocsr_as;
+    licc->cpu_by_arch_id = loongarch_cpu_by_arch_id;
+}
+
+static const TypeInfo loongarch_ipi_types[] = {
+    {
+        .name               = TYPE_LOONGARCH_IPI,
+        .parent             = TYPE_LOONGSON_IPI_COMMON,
+        .class_init         = loongson_ipi_class_init,
+    }
+};
+
+DEFINE_TYPES(loongarch_ipi_types)
diff --git a/hw/intc/Kconfig b/hw/intc/Kconfig
index a2a0fdca85..dd405bdb5d 100644
--- a/hw/intc/Kconfig
+++ b/hw/intc/Kconfig
@@ -94,6 +94,10 @@ config LOONGSON_IPI
     bool
     select LOONGSON_IPI_COMMON
 
+config LOONGARCH_IPI
+    bool
+    select LOONGSON_IPI_COMMON
+
 config LOONGARCH_PCH_PIC
     bool
     select UNIMP
diff --git a/hw/intc/meson.build b/hw/intc/meson.build
index a09a527207..f4d81eb8e4 100644
--- a/hw/intc/meson.build
+++ b/hw/intc/meson.build
@@ -71,6 +71,7 @@ specific_ss.add(when: ['CONFIG_KVM', 'CONFIG_XIVE'],
 specific_ss.add(when: 'CONFIG_M68K_IRQC', if_true: files('m68k_irqc.c'))
 specific_ss.add(when: 'CONFIG_LOONGSON_IPI_COMMON', if_true: files('loongson_ipi_common.c'))
 specific_ss.add(when: 'CONFIG_LOONGSON_IPI', if_true: files('loongson_ipi.c'))
+specific_ss.add(when: 'CONFIG_LOONGARCH_IPI', if_true: files('loongarch_ipi.c'))
 specific_ss.add(when: 'CONFIG_LOONGARCH_PCH_PIC', if_true: files('loongarch_pch_pic.c'))
 specific_ss.add(when: 'CONFIG_LOONGARCH_PCH_MSI', if_true: files('loongarch_pch_msi.c'))
 specific_ss.add(when: 'CONFIG_LOONGARCH_EXTIOI', if_true: files('loongarch_extioi.c'))
-- 
2.41.0