1 files changed, 519 insertions, 0 deletions
diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
new file mode 100644
index 000000000000..08fce845f668
--- /dev/null
+++ b/arch/loongarch/kvm/intc/pch_pic.c
@@ -0,0 +1,519 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#include <asm/kvm_eiointc.h>
+#include <asm/kvm_pch_pic.h>
+#include <asm/kvm_vcpu.h>
+#include <linux/count_zeros.h>
+
+/* update the isr according to irq level and route irq to eiointc */
+static void pch_pic_update_irq(struct loongarch_pch_pic *s, int irq, int level)
+{
+	u64 mask = BIT(irq);
+
+	/*
+	 * set isr and route irq to eiointc and
+	 * the route table is in htmsi_vector[]
+	 */
+	if (level) {
+		if (mask & s->irr & ~s->mask) {
+			s->isr |= mask;
+			irq = s->htmsi_vector[irq];
+			eiointc_set_irq(s->kvm->arch.eiointc, irq, level);
+		}
+	} else {
+		if (mask & s->isr & ~s->irr) {
+			s->isr &= ~mask;
+			irq = s->htmsi_vector[irq];
+			eiointc_set_irq(s->kvm->arch.eiointc, irq, level);
+		}
+	}
+}
+
+/* update batch irqs, the irq_mask is a bitmap of irqs */
+static void pch_pic_update_batch_irqs(struct loongarch_pch_pic *s, u64 irq_mask, int level)
+{
+	int irq, bits;
+
+	/* find each irq by irqs bitmap and update each irq */
+	bits = sizeof(irq_mask) * 8;
+	irq = find_first_bit((void *)&irq_mask, bits);
+	while (irq < bits) {
+		pch_pic_update_irq(s, irq, level);
+		bitmap_clear((void *)&irq_mask, irq, 1);
+		irq = find_first_bit((void *)&irq_mask, bits);
+	}
+}
+
+/* called when a irq is triggered in pch pic */
+void pch_pic_set_irq(struct loongarch_pch_pic *s, int irq, int level)
+{
+	u64 mask = BIT(irq);
+
+	spin_lock(&s->lock);
+	if (level)
+		s->irr |= mask; /* set irr */
+	else {
+		/*
+		 * In edge triggered mode, 0 does not mean to clear irq
+		 * The irr register variable is cleared when cpu writes to the
+		 * PCH_PIC_CLEAR_START address area
+		 */
+		if (s->edge & mask) {
+			spin_unlock(&s->lock);
+			return;
+		}
+		s->irr &= ~mask;
+	}
+	pch_pic_update_irq(s, irq, level);
+	spin_unlock(&s->lock);
+}
+
+/* msi irq handler */
+void pch_msi_set_irq(struct kvm *kvm, int irq, int level)
+{
+	eiointc_set_irq(kvm->arch.eiointc, irq, level);
+}
+
+/*
+ * pch pic register is 64-bit, but it is accessed by 32-bit,
+ * so we use high to get whether low or high 32 bits we want
+ * to read.
+ */
+static u32 pch_pic_read_reg(u64 *s, int high)
+{
+	u64 val = *s;
+
+	/* read the high 32 bits when high is 1 */
+	return high ? (u32)(val >> 32) : (u32)val;
+}
+
+/*
+ * pch pic register is 64-bit, but it is accessed by 32-bit,
+ * so we use high to get whether low or high 32 bits we want
+ * to write.
+ */
+static u32 pch_pic_write_reg(u64 *s, int high, u32 v)
+{
+	u64 val = *s, data = v;
+
+	if (high) {
+		/*
+		 * Clear val high 32 bits
+		 * Write the high 32 bits when the high is 1
+		 */
+		*s = (val << 32 >> 32) | (data << 32);
+		val >>= 32;
+	} else
+		/*
+		 * Clear val low 32 bits
+		 * Write the low 32 bits when the high is 0
+		 */
+		*s = (val >> 32 << 32) | v;
+
+	return (u32)val;
+}
+
+static int loongarch_pch_pic_read(struct loongarch_pch_pic *s, gpa_t addr, int len, void *val)
+{
+	int offset, index, ret = 0;
+	u32 data = 0;
+	u64 int_id = 0;
+
+	offset = addr - s->pch_pic_base;
+
+	spin_lock(&s->lock);
+	switch (offset) {
+	case PCH_PIC_INT_ID_START ... PCH_PIC_INT_ID_END:
+		/* int id version */
+		int_id |= (u64)PCH_PIC_INT_ID_VER << 32;
+		/* irq number */
+		int_id |= (u64)31 << (32 + 16);
+		/* int id value */
+		int_id |= PCH_PIC_INT_ID_VAL;
+		*(u64 *)val = int_id;
+		break;
+	case PCH_PIC_MASK_START ... PCH_PIC_MASK_END:
+		offset -= PCH_PIC_MASK_START;
+		index = offset >> 2;
+		/* read mask reg */
+		data = pch_pic_read_reg(&s->mask, index);
+		*(u32 *)val = data;
+		break;
+	case PCH_PIC_HTMSI_EN_START ... PCH_PIC_HTMSI_EN_END:
+		offset -= PCH_PIC_HTMSI_EN_START;
+		index = offset >> 2;
+		/* read htmsi enable reg */
+		data = pch_pic_read_reg(&s->htmsi_en, index);
+		*(u32 *)val = data;
+		break;
+	case PCH_PIC_EDGE_START ... PCH_PIC_EDGE_END:
+		offset -= PCH_PIC_EDGE_START;
+		index = offset >> 2;
+		/* read edge enable reg */
+		data = pch_pic_read_reg(&s->edge, index);
+		*(u32 *)val = data;
+		break;
+	case PCH_PIC_AUTO_CTRL0_START ... PCH_PIC_AUTO_CTRL0_END:
+	case PCH_PIC_AUTO_CTRL1_START ... PCH_PIC_AUTO_CTRL1_END:
+		/* we only use default mode: fixed interrupt distribution mode */
+		*(u32 *)val = 0;
+		break;
+	case PCH_PIC_ROUTE_ENTRY_START ... PCH_PIC_ROUTE_ENTRY_END:
+		/* only route to int0: eiointc */
+		*(u8 *)val = 1;
+		break;
+	case PCH_PIC_HTMSI_VEC_START ... PCH_PIC_HTMSI_VEC_END:
+		offset -= PCH_PIC_HTMSI_VEC_START;
+		/* read htmsi vector */
+		data = s->htmsi_vector[offset];
+		*(u8 *)val = data;
+		break;
+	case PCH_PIC_POLARITY_START ... PCH_PIC_POLARITY_END:
+		/* we only use defalut value 0: high level triggered */
+		*(u32 *)val = 0;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	spin_unlock(&s->lock);
+
+	return ret;
+}
+
+static int kvm_pch_pic_read(struct kvm_vcpu *vcpu,
+			struct kvm_io_device *dev,
+			gpa_t addr, int len, void *val)
+{
+	int ret;
+	struct loongarch_pch_pic *s = vcpu->kvm->arch.pch_pic;
+
+	if (!s) {
+		kvm_err("%s: pch pic irqchip not valid!\n", __func__);
+		return -EINVAL;
+	}
+
+	/* statistics of pch pic reading */
+	vcpu->kvm->stat.pch_pic_read_exits++;
+	ret = loongarch_pch_pic_read(s, addr, len, val);
+
+	return ret;
+}
+
+static int loongarch_pch_pic_write(struct loongarch_pch_pic *s, gpa_t addr,
+					int len, const void *val)
+{
+	int ret;
+	u32 old, data, offset, index;
+	u64 irq;
+
+	ret = 0;
+	data = *(u32 *)val;
+	offset = addr - s->pch_pic_base;
+
+	spin_lock(&s->lock);
+	switch (offset) {
+	case PCH_PIC_MASK_START ... PCH_PIC_MASK_END:
+		offset -= PCH_PIC_MASK_START;
+		/* get whether high or low 32 bits we want to write */
+		index = offset >> 2;
+		old = pch_pic_write_reg(&s->mask, index, data);
+		/* enable irq when mask value change to 0 */
+		irq = (old & ~data) << (32 * index);
+		pch_pic_update_batch_irqs(s, irq, 1);
+		/* disable irq when mask value change to 1 */
+		irq = (~old & data) << (32 * index);
+		pch_pic_update_batch_irqs(s, irq, 0);
+		break;
+	case PCH_PIC_HTMSI_EN_START ... PCH_PIC_HTMSI_EN_END:
+		offset -= PCH_PIC_HTMSI_EN_START;
+		index = offset >> 2;
+		pch_pic_write_reg(&s->htmsi_en, index, data);
+		break;
+	case PCH_PIC_EDGE_START ... PCH_PIC_EDGE_END:
+		offset -= PCH_PIC_EDGE_START;
+		index = offset >> 2;
+		/* 1: edge triggered, 0: level triggered */
+		pch_pic_write_reg(&s->edge, index, data);
+		break;
+	case PCH_PIC_CLEAR_START ... PCH_PIC_CLEAR_END:
+		offset -= PCH_PIC_CLEAR_START;
+		index = offset >> 2;
+		/* write 1 to clear edge irq */
+		old = pch_pic_read_reg(&s->irr, index);
+		/*
+		 * get the irq bitmap which is edge triggered and
+		 * already set and to be cleared
+		 */
+		irq = old & pch_pic_read_reg(&s->edge, index) & data;
+		/* write irr to the new state where irqs have been cleared */
+		pch_pic_write_reg(&s->irr, index, old & ~irq);
+		/* update cleared irqs */
+		pch_pic_update_batch_irqs(s, irq, 0);
+		break;
+	case PCH_PIC_AUTO_CTRL0_START ... PCH_PIC_AUTO_CTRL0_END:
+		offset -= PCH_PIC_AUTO_CTRL0_START;
+		index = offset >> 2;
+		/* we only use default mode: fixed interrupt distribution mode */
+		pch_pic_write_reg(&s->auto_ctrl0, index, 0);
+		break;
+	case PCH_PIC_AUTO_CTRL1_START ... PCH_PIC_AUTO_CTRL1_END:
+		offset -= PCH_PIC_AUTO_CTRL1_START;
+		index = offset >> 2;
+		/* we only use default mode: fixed interrupt distribution mode */
+		pch_pic_write_reg(&s->auto_ctrl1, index, 0);
+		break;
+	case PCH_PIC_ROUTE_ENTRY_START ... PCH_PIC_ROUTE_ENTRY_END:
+		offset -= PCH_PIC_ROUTE_ENTRY_START;
+		/* only route to int0: eiointc */
+		s->route_entry[offset] = 1;
+		break;
+	case PCH_PIC_HTMSI_VEC_START ... PCH_PIC_HTMSI_VEC_END:
+		/* route table to eiointc */
+		offset -= PCH_PIC_HTMSI_VEC_START;
+		s->htmsi_vector[offset] = (u8)data;
+		break;
+	case PCH_PIC_POLARITY_START ... PCH_PIC_POLARITY_END:
+		offset -= PCH_PIC_POLARITY_START;
+		index = offset >> 2;
+		/* we only use defalut value 0: high level triggered */
+		pch_pic_write_reg(&s->polarity, index, 0);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	spin_unlock(&s->lock);
+
+	return ret;
+}
+
+static int kvm_pch_pic_write(struct kvm_vcpu *vcpu,
+			struct kvm_io_device *dev,
+			gpa_t addr, int len, const void *val)
+{
+	int ret;
+	struct loongarch_pch_pic *s = vcpu->kvm->arch.pch_pic;
+
+	if (!s) {
+		kvm_err("%s: pch pic irqchip not valid!\n", __func__);
+		return -EINVAL;
+	}
+
+	/* statistics of pch pic writing */
+	vcpu->kvm->stat.pch_pic_write_exits++;
+	ret = loongarch_pch_pic_write(s, addr, len, val);
+
+	return ret;
+}
+
+static const struct kvm_io_device_ops kvm_pch_pic_ops = {
+	.read	= kvm_pch_pic_read,
+	.write	= kvm_pch_pic_write,
+};
+
+static int kvm_pch_pic_init(struct kvm_device *dev, u64 addr)
+{
+	int ret;
+	struct kvm *kvm = dev->kvm;
+	struct kvm_io_device *device;
+	struct loongarch_pch_pic *s = dev->kvm->arch.pch_pic;
+
+	s->pch_pic_base = addr;
+	device = &s->device;
+	/* init device by pch pic writing and reading ops */
+	kvm_iodevice_init(device, &kvm_pch_pic_ops);
+	mutex_lock(&kvm->slots_lock);
+	/* register pch pic device */
+	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, addr, PCH_PIC_SIZE, device);
+	mutex_unlock(&kvm->slots_lock);
+
+	return (ret < 0) ? -EFAULT : 0;
+}
+
+/* used by user space to get or set pch pic registers */
+static int kvm_pch_pic_regs_access(struct kvm_device *dev,
+				struct kvm_device_attr *attr,
+				bool is_write)
+{
+	int addr, offset, len = 8, ret = 0;
+	void __user *data;
+	void *p = NULL;
+	struct loongarch_pch_pic *s;
+
+	s = dev->kvm->arch.pch_pic;
+	addr = attr->attr;
+	data = (void __user *)attr->addr;
+
+	/* get pointer to pch pic register by addr */
+	switch (addr) {
+	case PCH_PIC_MASK_START:
+		p = &s->mask;
+		break;
+	case PCH_PIC_HTMSI_EN_START:
+		p = &s->htmsi_en;
+		break;
+	case PCH_PIC_EDGE_START:
+		p = &s->edge;
+		break;
+	case PCH_PIC_AUTO_CTRL0_START:
+		p = &s->auto_ctrl0;
+		break;
+	case PCH_PIC_AUTO_CTRL1_START:
+		p = &s->auto_ctrl1;
+		break;
+	case PCH_PIC_ROUTE_ENTRY_START ... PCH_PIC_ROUTE_ENTRY_END:
+		offset = addr - PCH_PIC_ROUTE_ENTRY_START;
+		p = &s->route_entry[offset];
+		len = 1;
+		break;
+	case PCH_PIC_HTMSI_VEC_START ... PCH_PIC_HTMSI_VEC_END:
+		offset = addr - PCH_PIC_HTMSI_VEC_START;
+		p = &s->htmsi_vector[offset];
+		len = 1;
+		break;
+	case PCH_PIC_INT_IRR_START:
+		p = &s->irr;
+		break;
+	case PCH_PIC_INT_ISR_START:
+		p = &s->isr;
+		break;
+	case PCH_PIC_POLARITY_START:
+		p = &s->polarity;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	spin_lock(&s->lock);
+	/* write or read value according to is_write */
+	if (is_write) {
+		if (copy_from_user(p, data, len))
+			ret = -EFAULT;
+	} else {
+		if (copy_to_user(data, p, len))
+			ret = -EFAULT;
+	}
+	spin_unlock(&s->lock);
+
+	return ret;
+}
+
+static int kvm_pch_pic_get_attr(struct kvm_device *dev,
+				struct kvm_device_attr *attr)
+{
+	switch (attr->group) {
+	case KVM_DEV_LOONGARCH_PCH_PIC_GRP_REGS:
+		return kvm_pch_pic_regs_access(dev, attr, false);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int kvm_pch_pic_set_attr(struct kvm_device *dev,
+				struct kvm_device_attr *attr)
+{
+	u64 addr;
+	void __user *uaddr = (void __user *)(long)attr->addr;
+
+	switch (attr->group) {
+	case KVM_DEV_LOONGARCH_PCH_PIC_GRP_CTRL:
+		switch (attr->attr) {
+		case KVM_DEV_LOONGARCH_PCH_PIC_CTRL_INIT:
+			if (copy_from_user(&addr, uaddr, sizeof(addr)))
+				return -EFAULT;
+
+			if (!dev->kvm->arch.pch_pic) {
+				kvm_err("%s: please create pch_pic irqchip first!\n", __func__);
+				return -ENODEV;
+			}
+
+			return kvm_pch_pic_init(dev, addr);
+		default:
+			kvm_err("%s: unknown group (%d) attr (%lld)\n", __func__, attr->group,
+					attr->attr);
+			return -EINVAL;
+		}
+	case KVM_DEV_LOONGARCH_PCH_PIC_GRP_REGS:
+		return kvm_pch_pic_regs_access(dev, attr, true);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int kvm_setup_default_irq_routing(struct kvm *kvm)
+{
+	int i, ret;
+	u32 nr = KVM_IRQCHIP_NUM_PINS;
+	struct kvm_irq_routing_entry *entries;
+
+	entries = kcalloc(nr, sizeof(*entries), GFP_KERNEL);
+	if (!entries)
+		return -ENOMEM;
+
+	for (i = 0; i < nr; i++) {
+		entries[i].gsi = i;
+		entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
+		entries[i].u.irqchip.irqchip = 0;
+		entries[i].u.irqchip.pin = i;
+	}
+	ret = kvm_set_irq_routing(kvm, entries, nr, 0);
+	kfree(entries);
+
+	return ret;
+}
+
+static int kvm_pch_pic_create(struct kvm_device *dev, u32 type)
+{
+	int ret;
+	struct kvm *kvm = dev->kvm;
+	struct loongarch_pch_pic *s;
+
+	/* pch pic should not has been created */
+	if (kvm->arch.pch_pic)
+		return -EINVAL;
+
+	ret = kvm_setup_default_irq_routing(kvm);
+	if (ret)
+		return -ENOMEM;
+
+	s = kzalloc(sizeof(struct loongarch_pch_pic), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	spin_lock_init(&s->lock);
+	s->kvm = kvm;
+	kvm->arch.pch_pic = s;
+
+	return 0;
+}
+
+static void kvm_pch_pic_destroy(struct kvm_device *dev)
+{
+	struct kvm *kvm;
+	struct loongarch_pch_pic *s;
+
+	if (!dev || !dev->kvm || !dev->kvm->arch.pch_pic)
+		return;
+
+	kvm = dev->kvm;
+	s = kvm->arch.pch_pic;
+	/* unregister pch pic device and free it's memory */
+	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
+	kfree(s);
+}
+
+static struct kvm_device_ops kvm_pch_pic_dev_ops = {
+	.name = "kvm-loongarch-pch-pic",
+	.create = kvm_pch_pic_create,
+	.destroy = kvm_pch_pic_destroy,
+	.set_attr = kvm_pch_pic_set_attr,
+	.get_attr = kvm_pch_pic_get_attr,
+};
+
+int kvm_loongarch_register_pch_pic_device(void)
+{
+	return kvm_register_device_ops(&kvm_pch_pic_dev_ops, KVM_DEV_TYPE_LOONGARCH_PCHPIC);
+}