[RFC PATCH v3 17/27] hw/loongarch: Add LoongArch ipi interrupt support(IPI)

[Xiaojuan Yang]

This patch realize the IPI interrupt controller.

Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
---
 hw/intc/Kconfig                 |   3 +
 hw/intc/loongarch_ipi.c         | 162 ++++++++++++++++++++++++++++++++
 hw/intc/meson.build             |   1 +
 hw/intc/trace-events            |   4 +
 hw/loongarch/Kconfig            |   1 +
 include/hw/intc/loongarch_ipi.h |  45 +++++++++
 target/loongarch/cpu.h          |   1 +
 7 files changed, 217 insertions(+)
 create mode 100644 hw/intc/loongarch_ipi.c
 create mode 100644 include/hw/intc/loongarch_ipi.h

diff --git a/hw/intc/Kconfig b/hw/intc/Kconfig
index 78aed93c45..511dcac537 100644
--- a/hw/intc/Kconfig
+++ b/hw/intc/Kconfig
@@ -73,3 +73,6 @@ config GOLDFISH_PIC
 
 config M68K_IRQC
     bool
+
+config LOONGARCH_IPI
+    bool
diff --git a/hw/intc/loongarch_ipi.c b/hw/intc/loongarch_ipi.c
new file mode 100644
index 0000000000..72e434c983
--- /dev/null
+++ b/hw/intc/loongarch_ipi.c
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * LoongArch ipi interrupt support
+ *
+ * Copyright (C) 2021 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "hw/intc/loongarch_ipi.h"
+#include "hw/irq.h"
+#include "qapi/error.h"
+#include "qemu/log.h"
+#include "exec/address-spaces.h"
+#include "hw/loongarch/loongarch.h"
+#include "migration/vmstate.h"
+#include "trace.h"
+
+static uint64_t loongarch_ipi_readl(void *opaque, hwaddr addr, unsigned size)
+{
+    ipi_core *s = opaque;
+    uint64_t ret = 0;
+
+    addr &= 0xff;
+    switch (addr) {
+    case CORE_STATUS_OFF:
+        ret = s->status;
+        break;
+    case CORE_EN_OFF:
+        ret = s->en;
+        break;
+    case CORE_SET_OFF:
+        ret = 0;
+        break;
+    case CORE_CLEAR_OFF:
+        ret = 0;
+        break;
+    case CORE_BUF_20 ... CORE_BUF_38:
+        if (size == 4) {
+            ret = ldl_p((void *)s->buf + (addr - CORE_BUF_20));
+        } else if (size == 8) {
+            ret = ldq_p((void *)s->buf + (addr - CORE_BUF_20));
+        }
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "invalid read: %x", (uint32_t)addr);
+        break;
+    }
+
+    trace_loongarch_ipi_read(size, (uint64_t)addr, ret);
+    return ret;
+}
+
+static void loongarch_ipi_writel(void *opaque, hwaddr addr, uint64_t val,
+                                 unsigned size)
+{
+    ipi_core *s = opaque;
+
+    addr &= 0xff;
+    trace_loongarch_ipi_write(size, (uint64_t)addr, val);
+    switch (addr) {
+    case CORE_STATUS_OFF:
+        qemu_log_mask(LOG_GUEST_ERROR, "can not be written");
+        break;
+    case CORE_EN_OFF:
+        s->en = val;
+        break;
+    case CORE_SET_OFF:
+        s->status |= val;
+        if (s->status != 0) {
+            qemu_irq_raise(s->irq);
+        }
+        break;
+    case CORE_CLEAR_OFF:
+        s->status ^= val;
+        if (s->status == 0) {
+            qemu_irq_lower(s->irq);
+        }
+        break;
+    case CORE_BUF_20 ... CORE_BUF_38:
+        if (size == 4) {
+            stl_p((void *)s->buf + (addr - CORE_BUF_20), val);
+        } else if (size == 8) {
+            stq_p((void *)s->buf + (addr - CORE_BUF_20), val);
+        }
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "invalid write: %x", (uint32_t)addr);
+        break;
+    }
+}
+
+static const MemoryRegionOps loongarch_ipi_ops = {
+    .read = loongarch_ipi_readl,
+    .write = loongarch_ipi_writel,
+    .impl.min_access_size = 4,
+    .impl.max_access_size = 8,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 8,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void loongarch_ipi_init(Object *obj)
+{
+    loongarch_ipi *s = LOONGARCH_IPI(obj);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+    int cpu;
+
+    for (cpu = 0; cpu < MACHINE(qdev_get_machine())->smp.cpus; cpu++) {
+        memory_region_init_io(&s->ipi_mmio[cpu], obj, &loongarch_ipi_ops,
+                              &s->core[cpu], "loongarch_ipi", 0x100);
+        sysbus_init_mmio(sbd, &s->ipi_mmio[cpu]);
+        qdev_init_gpio_out(DEVICE(obj), &s->core[cpu].irq, 1);
+   }
+}
+
+static const VMStateDescription vmstate_ipi_core = {
+    .name = "ipi-single",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(status, ipi_core),
+        VMSTATE_UINT32(en, ipi_core),
+        VMSTATE_UINT32(set, ipi_core),
+        VMSTATE_UINT32(clear, ipi_core),
+        VMSTATE_UINT64_ARRAY(buf, ipi_core, MAX_IPI_MBX_NUM),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_loongarch_ipi = {
+    .name = TYPE_LOONGARCH_IPI,
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_STRUCT_ARRAY(core, loongarch_ipi, MAX_IPI_CORE_NUM, 0,
+                             vmstate_ipi_core, ipi_core),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void loongarch_ipi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->vmsd = &vmstate_loongarch_ipi;
+}
+
+static const TypeInfo loongarch_ipi_info = {
+    .name          = TYPE_LOONGARCH_IPI,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(loongarch_ipi),
+    .instance_init = loongarch_ipi_init,
+    .class_init    = loongarch_ipi_class_init,
+};
+
+static void loongarch_ipi_register_types(void)
+{
+    type_register_static(&loongarch_ipi_info);
+}
+
+type_init(loongarch_ipi_register_types)
diff --git a/hw/intc/meson.build b/hw/intc/meson.build
index c89d2ca180..51f0c3988a 100644
--- a/hw/intc/meson.build
+++ b/hw/intc/meson.build
@@ -57,3 +57,4 @@ specific_ss.add(when: ['CONFIG_KVM', 'CONFIG_XIVE'],
                if_true: files('spapr_xive_kvm.c'))
 specific_ss.add(when: 'CONFIG_GOLDFISH_PIC', if_true: files('goldfish_pic.c'))
 specific_ss.add(when: 'CONFIG_M68K_IRQC', if_true: files('m68k_irqc.c'))
+specific_ss.add(when: 'CONFIG_LOONGARCH_IPI', if_true: 
files('loongarch_ipi.c'))
diff --git a/hw/intc/trace-events b/hw/intc/trace-events
index 9aba7e3a7a..124608e51f 100644
--- a/hw/intc/trace-events
+++ b/hw/intc/trace-events
@@ -246,3 +246,7 @@ sh_intc_register(const char *s, int id, unsigned short v, 
int c, int m) "%s %u -
 sh_intc_read(unsigned size, uint64_t offset, unsigned long val) "size %u 0x%" 
PRIx64 " -> 0x%lx"
 sh_intc_write(unsigned size, uint64_t offset, unsigned long val) "size %u 0x%" 
PRIx64 " <- 0x%lx"
 sh_intc_set(int id, int enable) "setting interrupt group %d to %d"
+
+# loongarch_ipi.c
+loongarch_ipi_read(unsigned size, uint32_t addr, unsigned long val) "size: %u 
addr: 0x%"PRIx32 "val: 0x%"PRIx64
+loongarch_ipi_write(unsigned size, uint32_t addr, unsigned long val) "size: %u 
addr: 0x%"PRIx32 "val: 0x%"PRIx64
diff --git a/hw/loongarch/Kconfig b/hw/loongarch/Kconfig
index ae8498de6a..1591574397 100644
--- a/hw/loongarch/Kconfig
+++ b/hw/loongarch/Kconfig
@@ -1,3 +1,4 @@
 config LOONGSON3_LS7A
     bool
     select PCI_EXPRESS_7A
+    select LOONGARCH_IPI
diff --git a/include/hw/intc/loongarch_ipi.h b/include/hw/intc/loongarch_ipi.h
new file mode 100644
index 0000000000..d2397e53e7
--- /dev/null
+++ b/include/hw/intc/loongarch_ipi.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * LoongArch ipi interrupt header files
+ *
+ * Copyright (C) 2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef HW_LOONGARCH_IPI_H
+#define HW_LOONGARCH_IPI_H
+
+/* Mainy used by iocsr read and write */
+#define SMP_IPI_MAILBOX      0x1000ULL
+#define CORE_STATUS_OFF       0x0
+#define CORE_EN_OFF           0x4
+#define CORE_SET_OFF          0x8
+#define CORE_CLEAR_OFF        0xc
+#define CORE_BUF_20           0x20
+#define CORE_BUF_28           0x28
+#define CORE_BUF_30           0x30
+#define CORE_BUF_38           0x38
+
+#define MAX_IPI_CORE_NUM      16
+#define MAX_IPI_MBX_NUM       4
+
+#define TYPE_LOONGARCH_IPI "loongarch_ipi"
+DECLARE_INSTANCE_CHECKER(struct loongarch_ipi, LOONGARCH_IPI,
+                         TYPE_LOONGARCH_IPI)
+
+
+typedef struct ipi_core {
+    uint32_t status;
+    uint32_t en;
+    uint32_t set;
+    uint32_t clear;
+    uint64_t buf[MAX_IPI_MBX_NUM];
+    qemu_irq irq;
+} ipi_core;
+
+typedef struct loongarch_ipi {
+    SysBusDevice parent_obj;
+    ipi_core core[MAX_IPI_CORE_NUM];
+    MemoryRegion ipi_mmio[MAX_IPI_CORE_NUM];
+} loongarch_ipi;
+
+#endif
diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index 01bed0786c..b287d7fca8 100644
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -153,6 +153,7 @@ extern const char * const fregnames[];
 
 #define N_IRQS      14
 #define IRQ_TIMER   11
+#define IRQ_IPI     12
 
 #define LOONGARCH_TLB_MAX      (2048 + 64) /* 2048 STLB + 64 MTLB */
 
-- 
2.27.0