irqchip: Add Loongson HyperTransport Vector support

This controller appears on Loongson-3 chips for receiving interrupt
vectors from PCH's PIC and PCH's PCIe MSI interrupts.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200528152757.1028711-2-jiaxun.yang@flygoat.com
This commit is contained in:
Jiaxun Yang 2020-05-28 23:27:49 +08:00 committed by Marc Zyngier
parent 0e375f5101
commit 818e915fba
3 changed files with 223 additions and 0 deletions

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@ -532,4 +532,12 @@ config LOONGSON_HTPIC
help
Support for the Loongson-3 HyperTransport PIC Controller.
config LOONGSON_HTVEC
bool "Loongson3 HyperTransport Interrupt Vector Controller"
depends on MACH_LOONGSON64 || COMPILE_TEST
default MACH_LOONGSON64
select IRQ_DOMAIN_HIERARCHY
help
Support for the Loongson3 HyperTransport Interrupt Vector Controller.
endmenu

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@ -107,3 +107,4 @@ obj-$(CONFIG_TI_SCI_INTR_IRQCHIP) += irq-ti-sci-intr.o
obj-$(CONFIG_TI_SCI_INTA_IRQCHIP) += irq-ti-sci-inta.o
obj-$(CONFIG_LOONGSON_LIOINTC) += irq-loongson-liointc.o
obj-$(CONFIG_LOONGSON_HTPIC) += irq-loongson-htpic.o
obj-$(CONFIG_LOONGSON_HTVEC) += irq-loongson-htvec.o

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@ -0,0 +1,214 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
* Loongson HyperTransport Interrupt Vector support
*/
#define pr_fmt(fmt) "htvec: " fmt
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
/* Registers */
#define HTVEC_EN_OFF 0x20
#define HTVEC_MAX_PARENT_IRQ 4
#define VEC_COUNT_PER_REG 32
#define VEC_REG_COUNT 4
#define VEC_COUNT (VEC_COUNT_PER_REG * VEC_REG_COUNT)
#define VEC_REG_IDX(irq_id) ((irq_id) / VEC_COUNT_PER_REG)
#define VEC_REG_BIT(irq_id) ((irq_id) % VEC_COUNT_PER_REG)
struct htvec {
void __iomem *base;
struct irq_domain *htvec_domain;
raw_spinlock_t htvec_lock;
};
static void htvec_irq_dispatch(struct irq_desc *desc)
{
int i;
u32 pending;
bool handled = false;
struct irq_chip *chip = irq_desc_get_chip(desc);
struct htvec *priv = irq_desc_get_handler_data(desc);
chained_irq_enter(chip, desc);
for (i = 0; i < VEC_REG_COUNT; i++) {
pending = readl(priv->base + 4 * i);
while (pending) {
int bit = __ffs(pending);
generic_handle_irq(irq_linear_revmap(priv->htvec_domain, bit +
VEC_COUNT_PER_REG * i));
pending &= ~BIT(bit);
handled = true;
}
}
if (!handled)
spurious_interrupt();
chained_irq_exit(chip, desc);
}
static void htvec_ack_irq(struct irq_data *d)
{
struct htvec *priv = irq_data_get_irq_chip_data(d);
writel(BIT(VEC_REG_BIT(d->hwirq)),
priv->base + VEC_REG_IDX(d->hwirq) * 4);
}
static void htvec_mask_irq(struct irq_data *d)
{
u32 reg;
void __iomem *addr;
struct htvec *priv = irq_data_get_irq_chip_data(d);
raw_spin_lock(&priv->htvec_lock);
addr = priv->base + HTVEC_EN_OFF;
addr += VEC_REG_IDX(d->hwirq) * 4;
reg = readl(addr);
reg &= ~BIT(VEC_REG_BIT(d->hwirq));
writel(reg, addr);
raw_spin_unlock(&priv->htvec_lock);
}
static void htvec_unmask_irq(struct irq_data *d)
{
u32 reg;
void __iomem *addr;
struct htvec *priv = irq_data_get_irq_chip_data(d);
raw_spin_lock(&priv->htvec_lock);
addr = priv->base + HTVEC_EN_OFF;
addr += VEC_REG_IDX(d->hwirq) * 4;
reg = readl(addr);
reg |= BIT(VEC_REG_BIT(d->hwirq));
writel(reg, addr);
raw_spin_unlock(&priv->htvec_lock);
}
static struct irq_chip htvec_irq_chip = {
.name = "LOONGSON_HTVEC",
.irq_mask = htvec_mask_irq,
.irq_unmask = htvec_unmask_irq,
.irq_ack = htvec_ack_irq,
};
static int htvec_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
unsigned long hwirq;
unsigned int type, i;
struct htvec *priv = domain->host_data;
irq_domain_translate_onecell(domain, arg, &hwirq, &type);
for (i = 0; i < nr_irqs; i++) {
irq_domain_set_info(domain, virq + i, hwirq + i, &htvec_irq_chip,
priv, handle_edge_irq, NULL, NULL);
}
return 0;
}
static void htvec_domain_free(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs)
{
int i;
for (i = 0; i < nr_irqs; i++) {
struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
irq_set_handler(virq + i, NULL);
irq_domain_reset_irq_data(d);
}
}
static const struct irq_domain_ops htvec_domain_ops = {
.translate = irq_domain_translate_onecell,
.alloc = htvec_domain_alloc,
.free = htvec_domain_free,
};
static void htvec_reset(struct htvec *priv)
{
u32 idx;
/* Clear IRQ cause registers, mask all interrupts */
for (idx = 0; idx < VEC_REG_COUNT; idx++) {
writel_relaxed(0x0, priv->base + HTVEC_EN_OFF + 4 * idx);
writel_relaxed(0xFFFFFFFF, priv->base);
}
}
static int htvec_of_init(struct device_node *node,
struct device_node *parent)
{
struct htvec *priv;
int err, parent_irq[4], num_parents = 0, i;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
raw_spin_lock_init(&priv->htvec_lock);
priv->base = of_iomap(node, 0);
if (!priv->base) {
err = -ENOMEM;
goto free_priv;
}
/* Interrupt may come from any of the 4 interrupt line */
for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) {
parent_irq[i] = irq_of_parse_and_map(node, i);
if (parent_irq[i] <= 0)
break;
num_parents++;
}
if (!num_parents) {
pr_err("Failed to get parent irqs\n");
err = -ENODEV;
goto iounmap_base;
}
priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node),
VEC_COUNT,
&htvec_domain_ops,
priv);
if (!priv->htvec_domain) {
pr_err("Failed to create IRQ domain\n");
err = -ENOMEM;
goto iounmap_base;
}
htvec_reset(priv);
for (i = 0; i < num_parents; i++)
irq_set_chained_handler_and_data(parent_irq[i],
htvec_irq_dispatch, priv);
return 0;
iounmap_base:
iounmap(priv->base);
free_priv:
kfree(priv);
return err;
}
IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init);