// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */

#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/bitops.h>
#include "ls3a_ipi.h"
#include "ls7a_irq.h"
#include "ls3a_ext_irq.h"

void ls7a_ioapic_lock(struct ls7a_kvm_ioapic *s, unsigned long *flags)
{
	unsigned long tmp;
	spin_lock_irqsave(&s->lock, tmp);
	*flags = tmp;
}

void ls7a_ioapic_unlock(struct ls7a_kvm_ioapic *s, unsigned long *flags)
{
	unsigned long tmp;
	tmp = *flags;
	spin_unlock_irqrestore(&s->lock, tmp);
}

static void kvm_ls7a_ioapic_raise(struct kvm *kvm, unsigned long mask)
{
	unsigned long irqnum, val;
	struct ls7a_kvm_ioapic *s = ls7a_ioapic_irqchip(kvm);
	struct kvm_ls7a_ioapic_state *state;
	struct kvm_loongarch_interrupt irq;
	int i;

	state = &s->ls7a_ioapic;
	irq.cpu = -1;
	val = mask & state->intirr & (~state->int_mask);
	val &= ~state->intisr;
	for_each_set_bit(i, &val, 64) {
		state->intisr |= 0x1ULL << i;
		irqnum = state->htmsi_vector[i];
		kvm_debug("msi_irq_handler,%ld,up\n", irqnum);
		msi_irq_handler(kvm, irqnum, 1);
	}

	kvm->stat.ls7a_ioapic_update++;
}

static void kvm_ls7a_ioapic_lower(struct kvm *kvm, unsigned long mask)
{
	unsigned long irqnum, val;
	struct ls7a_kvm_ioapic *s = ls7a_ioapic_irqchip(kvm);
	struct kvm_ls7a_ioapic_state *state;
	struct kvm_loongarch_interrupt irq;
	int i;

	state = &s->ls7a_ioapic;
	irq.cpu = -1;
	val = mask & state->intisr;
	for_each_set_bit(i, &val, 64) {
		state->intisr &= ~(0x1ULL << i);
		irqnum = state->htmsi_vector[i];
		kvm_debug("msi_irq_handler,%ld,down\n", irqnum);
		msi_irq_handler(kvm, irqnum, 0);
	}

	kvm->stat.ls7a_ioapic_update++;
}

int kvm_ls7a_set_msi(struct kvm_kernel_irq_routing_entry *e,
		struct kvm *kvm, int irq_source_id, int level, bool line_status)
{
	if (!level)
		return -1;

	kvm_debug("msi data is 0x%x\n", e->msi.data);
	msi_irq_handler(kvm, e->msi.data, 1);
	return 0;
}

int kvm_ls7a_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
{
	struct kvm_kernel_irq_routing_entry route;

	if (msi->flags != 0)
		return -EINVAL;

	kvm->stat.ls7a_msi_irq++;
	route.msi.address_lo = msi->address_lo;
	route.msi.address_hi = msi->address_hi;
	route.msi.data = msi->data;

	kvm_debug("msi data is 0x%x\n", route.msi.data);
	return kvm_ls7a_set_msi(&route, kvm,
				KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);

}

int kvm_ls7a_ioapic_set_irq(struct kvm *kvm, int irq, int level)
{
	struct ls7a_kvm_ioapic *s;
	struct kvm_ls7a_ioapic_state *state;
	uint64_t mask = 1ULL << irq;
	s = ls7a_ioapic_irqchip(kvm);
	state = &s->ls7a_ioapic;
	BUG_ON(irq < 0 || irq >= LS7A_IOAPIC_NUM_PINS);

	if (state->intedge & mask) {
		/* edge triggered */
		if (level) {
			if ((state->last_intirr & mask) == 0) {
				state->intirr |= mask;
				kvm_ls7a_ioapic_raise(kvm, mask);
			}
			state->last_intirr |= mask;
		} else
			state->last_intirr &= ~mask;
	} else {
		/* level triggered */
		if (!!level) {
			if ((state->intirr & mask) == 0) {
				state->intirr |= mask;
				kvm_ls7a_ioapic_raise(kvm, mask);
			}
		} else {
			if (state->intirr & mask) {
				state->intirr &= ~mask;
				kvm_ls7a_ioapic_lower(kvm, mask);
			}
		}
	}
	kvm->stat.ls7a_ioapic_set_irq++;
	return 0;
}

static int ls7a_ioapic_reg_write(struct ls7a_kvm_ioapic *s,
			  gpa_t addr, int len, const void *val)
{
	struct kvm *kvm;
	struct kvm_ls7a_ioapic_state *state;
	int64_t offset_tmp;
	uint64_t offset;
	uint64_t old, himask, lowmask;
	unsigned long data, flags;

	offset = addr & 0xfff;
	kvm = s->kvm;
	state = &(s->ls7a_ioapic);
	lowmask = 0xFFFFFFFFUL;
	himask = lowmask << 32;

	if (offset & (len - 1)) {
		printk("%s(%d):unaligned address access %llx size %d \n",
			__FUNCTION__, __LINE__, addr, len);
		return 0;
	}

	if (8 == len) {
		data = *(uint64_t *)val;
		switch (offset) {
		case LS7A_INT_MASK_OFFSET:
			old = state->int_mask;
			state->int_mask = data;
			if (old & ~data)
				kvm_ls7a_ioapic_raise(kvm, old & ~data);
			if (~old & data)
				kvm_ls7a_ioapic_lower(kvm, ~old & data);
			break;
		case LS7A_INT_STATUS_OFFSET:
			state->intisr = data;
			break;
		case LS7A_INT_EDGE_OFFSET:
			state->intedge = data;
			break;
		case LS7A_INT_CLEAR_OFFSET:
			/*
			 * For emulated device, only clear edge triggered irq
			 * on writing INTCLR reg no effect on level triggered
			 * irq
			 * However for pass-through device with level-triggered
			 * intx, here need clear interrupt
			 */
			old  = data;
			data = data & state->intedge;
			state->intirr &= ~data;
			kvm_ls7a_ioapic_lower(kvm, data);
			state->intisr &= ~data;

			data = old & ~state->intedge;
			ls7a_ioapic_unlock(kvm->arch.v_ioapic, &flags);
			for_each_set_bit(offset_tmp, &data, 64)
				kvm_notify_acked_irq(kvm, 0, offset_tmp);
			ls7a_ioapic_lock(kvm->arch.v_ioapic, &flags);
			break;
		case LS7A_INT_POL_OFFSET:
			state->int_polarity = data;
			break;
		case LS7A_HTMSI_EN_OFFSET:
			state->htmsi_en = data;
			break;
		case LS7A_AUTO_CTRL0_OFFSET:
		case LS7A_AUTO_CTRL1_OFFSET:
			break;
		default:
			WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
			break;
		}
	} else if (4 == len) {
		data = *(uint32_t *)val;
		switch (offset) {
		case LS7A_INT_MASK_OFFSET:
			old = state->int_mask & lowmask;
			state->int_mask = (state->int_mask & himask) | data;
			if (old & ~data)
				kvm_ls7a_ioapic_raise(kvm, old & ~data);
			if (~old & data)
				kvm_ls7a_ioapic_lower(kvm, ~old & data);
			break;
		case LS7A_INT_MASK_OFFSET + 4:
			data = data << 32;
			old = state->int_mask & himask;
			state->int_mask = (state->int_mask & lowmask) | data;
			if (old & ~data)
				kvm_ls7a_ioapic_raise(kvm, old & ~data);
			if (~old & data)
				kvm_ls7a_ioapic_lower(kvm, ~old & data);
			break;
		case LS7A_INT_STATUS_OFFSET:
			state->intisr = (state->intisr & himask) | data;
			break;
		case LS7A_INT_STATUS_OFFSET + 4:
			data = data << 32;
			state->intisr = (state->intisr & lowmask) | data;
			break;
		case LS7A_INT_EDGE_OFFSET:
			state->intedge = (state->intedge & himask) | data;
			break;
		case LS7A_INT_EDGE_OFFSET + 4:
			data = data << 32;
			state->intedge = (state->intedge & lowmask) | data;
			break;
		case LS7A_INT_CLEAR_OFFSET + 4:
			data = data << 32;
			fallthrough;
		case LS7A_INT_CLEAR_OFFSET:
			old  = data;
			data = data & state->intedge;
			state->intirr &= ~data;
			kvm_ls7a_ioapic_lower(kvm, data);
			state->intisr &= ~data;

			data = old & ~state->intedge;
			ls7a_ioapic_unlock(kvm->arch.v_ioapic, &flags);
			for_each_set_bit(offset_tmp, &data, 64)
				kvm_notify_acked_irq(kvm, 0, offset_tmp);
			ls7a_ioapic_lock(kvm->arch.v_ioapic, &flags);
			break;
		case LS7A_INT_POL_OFFSET:
			state->int_polarity = (state->int_polarity & himask) | data;
			break;
		case LS7A_INT_POL_OFFSET+4:
			data = data << 32;
			state->int_polarity = (state->int_polarity & lowmask) | data;
			break;
		case LS7A_HTMSI_EN_OFFSET:
			state->htmsi_en = (state->htmsi_en & himask) | data;
			break;
		case LS7A_HTMSI_EN_OFFSET+4:
			data = data << 32;
			state->htmsi_en = (state->htmsi_en & lowmask) | data;
			break;
		case LS7A_AUTO_CTRL0_OFFSET:
		case LS7A_AUTO_CTRL0_OFFSET+4:
		case LS7A_AUTO_CTRL1_OFFSET:
		case LS7A_AUTO_CTRL1_OFFSET+4:
			break;
		default:
			WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
			break;
		}
	} else if (1 == len) {
		data = *(unsigned char *)val;
		if (offset >= LS7A_HTMSI_VEC_OFFSET) {
			offset_tmp = offset - LS7A_HTMSI_VEC_OFFSET;
			if (offset_tmp >= 0 && offset_tmp < 64) {
				state->htmsi_vector[offset_tmp] =
					(uint8_t)(data & 0xff);
			}
		} else if (offset >=  LS7A_ROUTE_ENTRY_OFFSET) {
			offset_tmp = offset - LS7A_ROUTE_ENTRY_OFFSET;
			if (offset_tmp >= 0 && offset_tmp < 64) {
				state->route_entry[offset_tmp] =
					(uint8_t)(data & 0xff);
			}
		} else {
			WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
		}
	} else {
		WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
	}
	kvm->stat.ioapic_reg_write++;
	return 0;
}

static inline struct ls7a_kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
{
	return container_of(dev, struct ls7a_kvm_ioapic, dev_ls7a_ioapic);
}

static int kvm_ls7a_ioapic_write(struct kvm_vcpu *vcpu,
				 struct kvm_io_device *this,
				 gpa_t addr, int len, const void *val)
{
	struct ls7a_kvm_ioapic *s = to_ioapic(this);
	unsigned long flags;

	ls7a_ioapic_lock(s->kvm->arch.v_ioapic, &flags);
	ls7a_ioapic_reg_write(s, addr, len, val);
	ls7a_ioapic_unlock(s->kvm->arch.v_ioapic, &flags);

	return 0;
}

static int ls7a_ioapic_reg_read(struct ls7a_kvm_ioapic *s,
		       gpa_t addr, int len, void *val)
{
	uint64_t offset, offset_tmp;
	struct kvm *kvm;
	struct kvm_ls7a_ioapic_state *state;
	uint64_t result = 0, lowmask, himask;

	state = &(s->ls7a_ioapic);
	kvm = s->kvm;
	offset = addr & 0xfff;
	lowmask = 0xFFFFFFFFUL;
	himask = lowmask << 32;
	if (offset & (len - 1)) {
		printk("%s(%d):unaligned address access %llx size %d \n",
			__FUNCTION__, __LINE__, addr, len);
		return 0;
	}

	if (8 == len) {
		switch (offset) {
		case LS7A_INT_MASK_OFFSET:
			result = state->int_mask;
			break;
		case LS7A_INT_STATUS_OFFSET:
			result = state->intisr & (~state->int_mask);
			break;
		case LS7A_INT_EDGE_OFFSET:
			result = state->intedge;
			break;
		case LS7A_INT_POL_OFFSET:
			result = state->int_polarity;
			break;
		case LS7A_HTMSI_EN_OFFSET:
			result = state->htmsi_en;
			break;
		case LS7A_AUTO_CTRL0_OFFSET:
		case LS7A_AUTO_CTRL1_OFFSET:
			break;
		case LS7A_INT_ID_OFFSET:
			result = LS7A_INT_ID_VER;
			result = (result << 32) + LS7A_INT_ID_VAL;
			break;
		default:
			WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
			break;
		}
		if (val != NULL)
			*(uint64_t *)val = result;
	} else if (4 == len) {
		switch (offset) {
		case LS7A_INT_MASK_OFFSET:
			result = state->int_mask & lowmask;
			break;
		case LS7A_INT_MASK_OFFSET + 4:
			result = state->int_mask & himask;
			result = result >> 32;
			break;
		case LS7A_INT_STATUS_OFFSET:
			result = state->intisr & (~state->int_mask) & lowmask;
			break;
		case LS7A_INT_STATUS_OFFSET + 4:
			result = state->intisr & (~state->int_mask) & himask;
			result = result >> 32;
			break;
		case LS7A_INT_EDGE_OFFSET:
			result = state->intedge & lowmask;
			break;
		case LS7A_INT_EDGE_OFFSET + 4:
			result = state->intedge & himask;
			result = result >> 32;
			break;
		case LS7A_INT_POL_OFFSET:
			result = state->int_polarity & lowmask;
			break;
		case LS7A_INT_POL_OFFSET + 4:
			result = state->int_polarity & himask;
			result = result >> 32;
			break;
		case LS7A_HTMSI_EN_OFFSET:
			result = state->htmsi_en & lowmask;
			break;
		case LS7A_HTMSI_EN_OFFSET + 4:
			result = state->htmsi_en & himask;
			result = result >> 32;
			break;
		case LS7A_AUTO_CTRL0_OFFSET:
		case LS7A_AUTO_CTRL0_OFFSET + 4:
		case LS7A_AUTO_CTRL1_OFFSET:
		case LS7A_AUTO_CTRL1_OFFSET + 4:
			break;
		case LS7A_INT_ID_OFFSET:
			result = LS7A_INT_ID_VAL;
			break;
		case LS7A_INT_ID_OFFSET + 4:
			result = LS7A_INT_ID_VER;
			break;
		default:
			WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
			break;
		}
		if (val != NULL)
			*(uint32_t *)val = result;
	} else if (1 == len) {
		if (offset >= LS7A_HTMSI_VEC_OFFSET) {
			offset_tmp = offset - LS7A_HTMSI_VEC_OFFSET;
			if (offset_tmp >= 0 && offset_tmp < 64) {
				result = state->htmsi_vector[offset_tmp];
			}
		} else if (offset >=  LS7A_ROUTE_ENTRY_OFFSET) {
			offset_tmp = offset - LS7A_ROUTE_ENTRY_OFFSET;
			if (offset_tmp >= 0 && offset_tmp < 64) {
				result = state->route_entry[offset_tmp];
			}
		} else {
			WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
		}
		if (val != NULL)
			*(unsigned char *)val = result;
	} else {
		WARN_ONCE(1, "Abnormal address access:addr 0x%llx,len %d\n", addr, len);
	}
	kvm->stat.ioapic_reg_read++;
	return result;
}

static int kvm_ls7a_ioapic_read(struct kvm_vcpu *vcpu,
				struct kvm_io_device *this,
				gpa_t addr, int len, void *val)
{
	struct ls7a_kvm_ioapic *s = to_ioapic(this);
	unsigned long flags;
	uint64_t result = 0;

	ls7a_ioapic_lock(s->kvm->arch.v_ioapic, &flags);
	result = ls7a_ioapic_reg_read(s, addr, len, val);
	ls7a_ioapic_unlock(s->kvm->arch.v_ioapic, &flags);
	return 0;
}

static const struct kvm_io_device_ops kvm_ls7a_ioapic_ops = {
	.read     = kvm_ls7a_ioapic_read,
	.write    = kvm_ls7a_ioapic_write,
};

static int kvm_ls7a_ioapic_alias_read(struct kvm_vcpu *vcpu,
		struct kvm_io_device *this, gpa_t addr, int len, void *val)
{
	struct ls7a_kvm_ioapic *s;
	unsigned long flags;

	s = container_of(this, struct ls7a_kvm_ioapic, ls7a_ioapic_alias);
	ls7a_ioapic_lock(s->kvm->arch.v_ioapic, &flags);
	ls7a_ioapic_reg_read(s, addr, len, val);
	ls7a_ioapic_unlock(s->kvm->arch.v_ioapic, &flags);
	return 0;
}

static int kvm_ls7a_ioapic_alias_write(struct kvm_vcpu *vcpu,
		struct kvm_io_device *this, gpa_t addr, int len, const void *val)
{
	struct ls7a_kvm_ioapic *s;
	unsigned long flags;

	s = container_of(this, struct ls7a_kvm_ioapic, ls7a_ioapic_alias);
	ls7a_ioapic_lock(s->kvm->arch.v_ioapic, &flags);
	ls7a_ioapic_reg_write(s, addr, len, val);
	ls7a_ioapic_unlock(s->kvm->arch.v_ioapic, &flags);

	return 0;
}

static const struct kvm_io_device_ops kvm_ls7a_ioapic_ops_alias = {
	.read     = kvm_ls7a_ioapic_alias_read,
	.write    = kvm_ls7a_ioapic_alias_write,
};

int kvm_create_ls7a_ioapic(struct kvm *kvm)
{
	struct ls7a_kvm_ioapic *s;
	int ret;
	unsigned long ls7a_ioapic_reg_base;

	s = kzalloc(sizeof(struct ls7a_kvm_ioapic), GFP_KERNEL);
	if (!s)
		return -ENOMEM;
	spin_lock_init(&s->lock);
	s->kvm = kvm;

	ls7a_ioapic_reg_base = LS7A_IOAPIC_GUEST_REG_BASE;

	/*
	 * Initialize MMIO device
	 */
	kvm_iodevice_init(&s->dev_ls7a_ioapic, &kvm_ls7a_ioapic_ops);
	mutex_lock(&kvm->slots_lock);
	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ls7a_ioapic_reg_base,
						   0x1000, &s->dev_ls7a_ioapic);
	if (ret < 0) {
		kvm_err("Failed register ioapic, err:%d\n", ret);
		goto fail_unlock;
	}

	ls7a_ioapic_reg_base = LS7A_IOAPIC_GUEST_REG_BASE_ALIAS;
	kvm_iodevice_init(&s->ls7a_ioapic_alias, &kvm_ls7a_ioapic_ops_alias);
	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ls7a_ioapic_reg_base,
						0x1000, &s->ls7a_ioapic_alias);
	if (ret < 0) {
		kvm_err("Failed register alias ioapic, err:%d\n", ret);
		kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
				&s->dev_ls7a_ioapic);
		goto fail_unlock;
	}
	mutex_unlock(&kvm->slots_lock);

	kvm->arch.v_ioapic = s;

	return 0;

fail_unlock:
	mutex_unlock(&kvm->slots_lock);
	kfree(s);

	return -EFAULT;
}


int kvm_get_ls7a_ioapic(struct kvm *kvm, struct ls7a_ioapic_state *state)
{
	struct ls7a_kvm_ioapic *ls7a_ioapic = ls7a_ioapic_irqchip(kvm);
	struct kvm_ls7a_ioapic_state *ioapic_state =
					    &(ls7a_ioapic->ls7a_ioapic);
	unsigned long flags;

	ls7a_ioapic_lock(ls7a_ioapic, &flags);
	memcpy(state, ioapic_state, sizeof(struct kvm_ls7a_ioapic_state));
	ls7a_ioapic_unlock(ls7a_ioapic, &flags);
	kvm->stat.get_ls7a_ioapic++;
	return 0;
}

int kvm_set_ls7a_ioapic(struct kvm *kvm, struct ls7a_ioapic_state *state)
{
	struct ls7a_kvm_ioapic *ls7a_ioapic = ls7a_ioapic_irqchip(kvm);
	struct kvm_ls7a_ioapic_state *ioapic_state =
					    &(ls7a_ioapic->ls7a_ioapic);
	unsigned long flags;

	if (!ls7a_ioapic)
		return -EINVAL;

	ls7a_ioapic_lock(ls7a_ioapic, &flags);
	memcpy(ioapic_state, state, sizeof(struct kvm_ls7a_ioapic_state));
	ls7a_ioapic_unlock(ls7a_ioapic, &flags);
	kvm->stat.set_ls7a_ioapic++;
	return 0;
}

void kvm_destroy_ls7a_ioapic(struct kvm *kvm)
{
	struct ls7a_kvm_ioapic *vpic = kvm->arch.v_ioapic;
	if (!vpic)
		return;
	mutex_lock(&kvm->slots_lock);
	kvm_io_bus_unregister_dev(vpic->kvm, KVM_MMIO_BUS,
					&vpic->ls7a_ioapic_alias);
	kvm_io_bus_unregister_dev(vpic->kvm, KVM_MMIO_BUS,
					&vpic->dev_ls7a_ioapic);
	mutex_unlock(&kvm->slots_lock);
	kfree(vpic);
}

void kvm_dump_ls7a_ioapic_state(struct seq_file *m,
		struct ls7a_kvm_ioapic *ioapic)
{
	struct kvm_ls7a_ioapic_state *ioapic_state;
	unsigned long flags;
	int i = 0;

	if (!ioapic)
		return;

	seq_puts(m, "\nIOAPIC state:\n");
	ioapic_state = &(ioapic->ls7a_ioapic);

	ls7a_ioapic_lock(ioapic, &flags);
	seq_puts(m, "irq masked: ");
	for (i = 0; i < 64; i++) {
		if (!test_bit(i, (void *)&ioapic_state->int_mask))
			seq_printf(m, "%d ", i);
	}
	seq_printf(m, "\nhtmsi_en:0x%016llx\n"
			"intedge:0x%016llx",
			ioapic_state->htmsi_en,
			ioapic_state->intedge);

	seq_puts(m, "\nroute_entry: ");
	for (i = 0; i < 64; i++)
		seq_printf(m, "%d ", ioapic_state->route_entry[i]);

	seq_puts(m, "\nhtmsi_vector: ");
	for (i = 0; i < 64; i++)
		seq_printf(m, "%d ", ioapic_state->htmsi_vector[i]);

	seq_printf(m, "\nintirr:%016llx\n"
			"intisr:%016llx\n",
			ioapic_state->intirr,
			ioapic_state->intisr);
	ls7a_ioapic_unlock(ioapic, &flags);
}