LoongArch: KVM: Add EXTIOI device support

Upstream: no

Added device model for EXTIOI interrupt controller,
implemented basic create destroy interface,
and registered device model to kvm device table.

Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>

arch/loongarch/include/asm/kvm_extioi.h

@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#ifndef LOONGARCH_EXTIOI_H
+#define LOONGARCH_EXTIOI_H
+
+#include <kvm/iodev.h>
+
+#define EXTIOI_IRQS			256
+#define EXTIOI_ROUTE_MAX_VCPUS		256
+#define EXTIOI_IRQS_U8_NUMS		(EXTIOI_IRQS / 8)
+#define EXTIOI_IRQS_U32_NUMS		(EXTIOI_IRQS_U8_NUMS / 4)
+#define EXTIOI_IRQS_U64_NUMS		(EXTIOI_IRQS_U32_NUMS / 2)
+/* map to ipnum per 32 irqs */
+#define EXTIOI_IRQS_NODETYPE_COUNT	16
+
+#define EXTIOI_BASE			0x1400
+#define EXTIOI_SIZE			0x900
+
+#define LS3A_INTC_IP			8
+
+struct loongarch_extioi {
+	spinlock_t lock;
+	struct kvm *kvm;
+	struct kvm_io_device device;
+	/* hardware state */
+	union nodetype {
+		u64 reg_u64[EXTIOI_IRQS_NODETYPE_COUNT / 4];
+		u32 reg_u32[EXTIOI_IRQS_NODETYPE_COUNT / 2];
+		uint16_t reg_u16[EXTIOI_IRQS_NODETYPE_COUNT];
+		u8 reg_u8[EXTIOI_IRQS_NODETYPE_COUNT * 2];
+	} nodetype;
+
+	/* one bit shows the state of one irq */
+	union bounce {
+		u64 reg_u64[EXTIOI_IRQS_U64_NUMS];
+		u32 reg_u32[EXTIOI_IRQS_U32_NUMS];
+		u8 reg_u8[EXTIOI_IRQS_U8_NUMS];
+	} bounce;
+
+	union isr {
+		u64 reg_u64[EXTIOI_IRQS_U64_NUMS];
+		u32 reg_u32[EXTIOI_IRQS_U32_NUMS];
+		u8 reg_u8[EXTIOI_IRQS_U8_NUMS];
+	} isr;
+	union coreisr {
+		u64 reg_u64[EXTIOI_ROUTE_MAX_VCPUS][EXTIOI_IRQS_U64_NUMS];
+		u32 reg_u32[EXTIOI_ROUTE_MAX_VCPUS][EXTIOI_IRQS_U32_NUMS];
+		u8 reg_u8[EXTIOI_ROUTE_MAX_VCPUS][EXTIOI_IRQS_U8_NUMS];
+	} coreisr;
+	union enable {
+		u64 reg_u64[EXTIOI_IRQS_U64_NUMS];
+		u32 reg_u32[EXTIOI_IRQS_U32_NUMS];
+		u8 reg_u8[EXTIOI_IRQS_U8_NUMS];
+	} enable;
+
+	/* use one byte to config ipmap for 32 irqs at once */
+	union ipmap {
+		u64 reg_u64;
+		u32 reg_u32[EXTIOI_IRQS_U32_NUMS / 4];
+		u8 reg_u8[EXTIOI_IRQS_U8_NUMS / 4];
+	} ipmap;
+	/* use one byte to config coremap for one irq */
+	union coremap {
+		u64 reg_u64[EXTIOI_IRQS / 8];
+		u32 reg_u32[EXTIOI_IRQS / 4];
+		u8 reg_u8[EXTIOI_IRQS];
+	} coremap;
+
+	DECLARE_BITMAP(sw_coreisr[EXTIOI_ROUTE_MAX_VCPUS][LS3A_INTC_IP], EXTIOI_IRQS);
+	uint8_t  sw_coremap[EXTIOI_IRQS];
+};
+
+void extioi_set_irq(struct loongarch_extioi *s, int irq, int level);
+int kvm_loongarch_register_extioi_device(void);
+#endif /* LOONGARCH_EXTIOI_H */

arch/loongarch/include/asm/kvm_host.h

@@ -20,6 +20,7 @@
 #include <asm/kvm_mmu.h>
 #include <asm/loongarch.h>
 #include <asm/kvm_ipi.h>
+#include <asm/kvm_extioi.h>
 
 /* Loongarch KVM register ids */
 #define KVM_GET_IOC_CSR_IDX(id)		((id & KVM_CSR_IDX_MASK) >> LOONGARCH_REG_SHIFT)
@@ -113,6 +114,7 @@ struct kvm_arch {
 	s64 time_offset;
 	struct kvm_context __percpu *vmcs;
 	struct loongarch_ipi *ipi;
+	struct loongarch_extioi *extioi;
 };
 
 #define CSR_MAX_NUMS		0x800

arch/loongarch/kvm/Makefile

@@ -19,5 +19,6 @@ kvm-y += tlb.o
 kvm-y += vcpu.o
 kvm-y += vm.o
 kvm-y += intc/ipi.o
+kvm-y += intc/extioi.o
 
 CFLAGS_exit.o	+= $(call cc-option,-Wno-override-init,)

arch/loongarch/kvm/intc/extioi.c

@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#include <asm/kvm_extioi.h>
+#include <asm/kvm_vcpu.h>
+#include <linux/count_zeros.h>
+
+static int kvm_loongarch_extioi_write(struct kvm_vcpu *vcpu,
+				struct kvm_io_device *dev,
+				gpa_t addr, int len, const void *val)
+{
+	return 0;
+}
+
+static int kvm_loongarch_extioi_read(struct kvm_vcpu *vcpu,
+				struct kvm_io_device *dev,
+				gpa_t addr, int len, void *val)
+{
+	return 0;
+}
+
+static const struct kvm_io_device_ops kvm_loongarch_extioi_ops = {
+	.read	= kvm_loongarch_extioi_read,
+	.write	= kvm_loongarch_extioi_write,
+};
+
+static int kvm_loongarch_extioi_get_attr(struct kvm_device *dev,
+				struct kvm_device_attr *attr)
+{
+	return 0;
+}
+
+static int kvm_loongarch_extioi_set_attr(struct kvm_device *dev,
+				struct kvm_device_attr *attr)
+{
+	return 0;
+}
+
+static void kvm_loongarch_extioi_destroy(struct kvm_device *dev)
+{
+	struct kvm *kvm;
+	struct loongarch_extioi *extioi;
+	struct kvm_io_device *device;
+
+	if (!dev)
+		return;
+
+	kvm = dev->kvm;
+	if (!kvm)
+		return;
+
+	extioi = kvm->arch.extioi;
+	if (!extioi)
+		return;
+
+	device = &extioi->device;
+	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, device);
+	kfree(extioi);
+}
+
+static int kvm_loongarch_extioi_create(struct kvm_device *dev, u32 type)
+{
+	int ret;
+	struct loongarch_extioi *s;
+	struct kvm_io_device *device;
+	struct kvm *kvm = dev->kvm;
+
+	/* extioi has been created */
+	if (kvm->arch.extioi)
+		return -EINVAL;
+
+	s = kzalloc(sizeof(struct loongarch_extioi), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+	spin_lock_init(&s->lock);
+	s->kvm = kvm;
+
+	/*
+	 * Initialize IOCSR device
+	 */
+	device = &s->device;
+	kvm_iodevice_init(device, &kvm_loongarch_extioi_ops);
+	mutex_lock(&kvm->slots_lock);
+	ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS, EXTIOI_BASE, EXTIOI_SIZE, device);
+	mutex_unlock(&kvm->slots_lock);
+	if (ret < 0) {
+		kfree(s);
+		return -EFAULT;
+	}
+
+	kvm->arch.extioi = s;
+
+	kvm_info("create extioi device successfully\n");
+	return 0;
+}
+
+static struct kvm_device_ops kvm_loongarch_extioi_dev_ops = {
+	.name = "kvm-loongarch-extioi",
+	.create = kvm_loongarch_extioi_create,
+	.destroy = kvm_loongarch_extioi_destroy,
+	.set_attr = kvm_loongarch_extioi_set_attr,
+	.get_attr = kvm_loongarch_extioi_get_attr,
+};
+
+int kvm_loongarch_register_extioi_device(void)
+{
+	return kvm_register_device_ops(&kvm_loongarch_extioi_dev_ops,
+					KVM_DEV_TYPE_LA_EXTIOI);
+}

arch/loongarch/kvm/main.c

@@ -9,6 +9,7 @@
 #include <asm/cacheflush.h>
 #include <asm/cpufeature.h>
 #include <asm/kvm_csr.h>
+#include <asm/kvm_extioi.h>
 #include "trace.h"
 
 unsigned long vpid_mask;
@@ -372,7 +373,10 @@ static int kvm_loongarch_env_init(void)
 	if (ret)
 		return ret;
 
-	return 0;
+	/* Register loongarch extioi interrupt controller interface. */
+	ret = kvm_loongarch_register_extioi_device();
+
+	return ret;
 }
 
 static void kvm_loongarch_env_exit(void)

include/uapi/linux/kvm.h

@@ -1477,6 +1477,8 @@ enum kvm_device_type {
 #define KVM_DEV_TYPE_RISCV_AIA		KVM_DEV_TYPE_RISCV_AIA
 	KVM_DEV_TYPE_LA_IPI,
 #define KVM_DEV_TYPE_LA_IPI		KVM_DEV_TYPE_LA_IPI
+	KVM_DEV_TYPE_LA_EXTIOI,
+#define KVM_DEV_TYPE_LA_EXTIOI		KVM_DEV_TYPE_LA_EXTIOI
 
 	KVM_DEV_TYPE_MAX,