[PATCH V14 12/15] irqchip: Add Loongson Extended I/O interrupt controller support

Jianmin Lv
2022-07-03T08:46:33Z

From: Huacai Chen <chenhuacai@loongson.cn>

EIOINTC stands for "Extended I/O Interrupts" that described in Section
11.2 of "Loongson 3A5000 Processor Reference Manual". For more
information please refer Documentation/loongarch/irq-chip-model.rst.

Loongson-3A5000 has 4 cores per NUMA node, and each NUMA node has an
EIOINTC; while Loongson-3C5000 has 16 cores per NUMA node, and each NUMA
node has 4 EIOINTCs. In other words, 16 cores of one NUMA node in
Loongson-3C5000 are organized in 4 groups, each group connects to an
EIOINTC. We call the "group" here as an EIOINTC node, so each EIOINTC
node always includes 4 cores (both in Loongson-3A5000 and Loongson-
3C5000).

Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
arch/loongarch/include/asm/irq.h | 11 +-
drivers/irqchip/Kconfig | 10 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-loongson-eiointc.c | 413 +++++++++++++++++++++++++++++++++
include/linux/cpuhotplug.h | 1 +
5 files changed, 426 insertions(+), 10 deletions(-)
create mode 100644 drivers/irqchip/irq-loongson-eiointc.c

diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
index a07315a..a826ac4 100644
--- a/arch/loongarch/include/asm/irq.h
+++ b/arch/loongarch/include/asm/irq.h
@@ -87,15 +87,6 @@ struct acpi_vector_group {
extern int find_pch_pic(u32 gsi);
extern int eiointc_get_node(int id);

-static inline void eiointc_enable(void)
-{
- uint64_t misc;
-
- misc = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
- misc |= IOCSR_MISC_FUNC_EXT_IOI_EN;
- iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
-}
-
struct acpi_madt_lio_pic;
struct acpi_madt_eio_pic;
struct acpi_madt_ht_pic;
@@ -107,7 +98,7 @@ static inline void eiointc_enable(void)

int liointc_acpi_init(struct irq_domain *parent,
struct acpi_madt_lio_pic *acpi_liointc);
-struct irq_domain *eiointc_acpi_init(struct irq_domain *parent,
+int eiointc_acpi_init(struct irq_domain *parent,
struct acpi_madt_eio_pic *acpi_eiointc);

int htvec_acpi_init(struct irq_domain *parent,
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index c1d527f..e918579 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -555,6 +555,16 @@ config LOONGSON_LIOINTC
help
Support for the Loongson Local I/O Interrupt Controller.

+config LOONGSON_EIOINTC
+ bool "Loongson Extend I/O Interrupt Controller"
+ depends on LOONGARCH
+ depends on MACH_LOONGSON64
+ default MACH_LOONGSON64
+ select IRQ_DOMAIN_HIERARCHY
+ select GENERIC_IRQ_CHIP
+ help
+ Support for the Loongson3 Extend I/O Interrupt Vector Controller.
+
config LOONGSON_HTPIC
bool "Loongson3 HyperTransport PIC Controller"
depends on MACH_LOONGSON64 && MIPS
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 242b8b3..0cfd4f0 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -104,6 +104,7 @@ obj-$(CONFIG_TI_SCI_INTR_IRQCHIP) += irq-ti-sci-intr.o
obj-$(CONFIG_TI_SCI_INTA_IRQCHIP) += irq-ti-sci-inta.o
obj-$(CONFIG_TI_PRUSS_INTC) += irq-pruss-intc.o
obj-$(CONFIG_LOONGSON_LIOINTC) += irq-loongson-liointc.o
+obj-$(CONFIG_LOONGSON_EIOINTC) += irq-loongson-eiointc.o
obj-$(CONFIG_LOONGSON_HTPIC) += irq-loongson-htpic.o
obj-$(CONFIG_LOONGSON_HTVEC) += irq-loongson-htvec.o
obj-$(CONFIG_LOONGSON_PCH_PIC) += irq-loongson-pch-pic.o
diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
new file mode 100644
index 0000000..9ddb9ac
--- /dev/null
+++ b/drivers/irqchip/irq-loongson-eiointc.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Loongson Extend I/O Interrupt Controller support
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#define pr_fmt(fmt) "eiointc: " 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>
+
+#define EIOINTC_REG_NODEMAP 0x14a0
+#define EIOINTC_REG_IPMAP 0x14c0
+#define EIOINTC_REG_ENABLE 0x1600
+#define EIOINTC_REG_BOUNCE 0x1680
+#define EIOINTC_REG_ISR 0x1800
+#define EIOINTC_REG_ROUTE 0x1c00
+
+#define VEC_REG_COUNT 4
+#define VEC_COUNT_PER_REG 64
+#define VEC_COUNT (VEC_REG_COUNT * VEC_COUNT_PER_REG)
+#define VEC_REG_IDX(irq_id) ((irq_id) / VEC_COUNT_PER_REG)
+#define VEC_REG_BIT(irq_id) ((irq_id) % VEC_COUNT_PER_REG)
+#define EIOINTC_ALL_ENABLE 0xffffffff
+
+#define MAX_EIO_NODES (NR_CPUS / CORES_PER_EIO_NODE)
+
+static int nr_pics;
+
+struct eiointc_priv {
+ u32 node;
+ nodemask_t node_map;
+ cpumask_t cpuspan_map;
+ struct fwnode_handle *domain_handle;
+ struct irq_domain *eiointc_domain;
+};
+
+static struct eiointc_priv *eiointc_priv[MAX_IO_PICS];
+
+static void eiointc_enable(void)
+{
+ uint64_t misc;
+
+ misc = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
+ misc |= IOCSR_MISC_FUNC_EXT_IOI_EN;
+ iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
+}
+
+static int cpu_to_eio_node(int cpu)
+{
+ return cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
+}
+
+static void eiointc_set_irq_route(int pos, unsigned int cpu, unsigned int mnode, nodemask_t *node_map)
+{
+ int i, node, cpu_node, route_node;
+ unsigned char coremap[MAX_EIO_NODES];
+ uint32_t pos_off, data, data_byte, data_mask;
+
+ pos_off = pos & ~3;
+ data_byte = pos & 3;
+ data_mask = ~BIT_MASK(data_byte) & 0xf;
+
+ memset(coremap, 0, sizeof(unsigned char) * MAX_EIO_NODES);
+
+ /* Calculate node and coremap of target irq */
+ cpu_node = cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
+ coremap[cpu_node] |= BIT(cpu_logical_map(cpu) % CORES_PER_EIO_NODE);
+
+ for_each_online_cpu(i) {
+ node = cpu_to_eio_node(i);
+ if (!node_isset(node, *node_map))
+ continue;
+
+ /* EIO node 0 is in charge of inter-node interrupt dispatch */
+ route_node = (node == mnode) ? cpu_node : node;
+ data = ((coremap[node] | (route_node << 4)) << (data_byte * 8));
+ csr_any_send(EIOINTC_REG_ROUTE + pos_off, data, data_mask, node * CORES_PER_EIO_NODE);
+ }
+}
+
+static DEFINE_RAW_SPINLOCK(affinity_lock);
+
+static int eiointc_set_irq_affinity(struct irq_data *d, const struct cpumask *affinity, bool force)
+{
+ unsigned int cpu;
+ unsigned long flags;
+ uint32_t vector, regaddr;
+ struct cpumask intersect_affinity;
+ struct eiointc_priv *priv = d->domain->host_data;
+
+ if (!IS_ENABLED(CONFIG_SMP))
+ return -EPERM;
+
+ raw_spin_lock_irqsave(&affinity_lock, flags);
+
+ cpumask_and(&intersect_affinity, affinity, cpu_online_mask);
+ cpumask_and(&intersect_affinity, &intersect_affinity, &priv->cpuspan_map);
+
+ if (cpumask_empty(&intersect_affinity)) {
+ raw_spin_unlock_irqrestore(&affinity_lock, flags);
+ return -EINVAL;
+ }
+ cpu = cpumask_first(&intersect_affinity);
+
+ if (!d->parent_data)
+ vector = d->hwirq;
+ else
+ vector = d->parent_data->hwirq;
+
+ regaddr = EIOINTC_REG_ENABLE + ((vector >> 5) << 2);
+
+ /* Mask target vector */
+ csr_any_send(regaddr, EIOINTC_ALL_ENABLE & (~BIT(vector & 0x1F)), 0x0, 0);
+ /* Set route for target vector */
+ eiointc_set_irq_route(vector, cpu, priv->node, &priv->node_map);
+ /* Unmask target vector */
+ csr_any_send(regaddr, EIOINTC_ALL_ENABLE, 0x0, 0);
+
+ irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
+ raw_spin_unlock_irqrestore(&affinity_lock, flags);
+
+ return IRQ_SET_MASK_OK;
+}
+
+static int eiointc_index(int node)
+{
+ int i;
+
+ for (i = 0; i < nr_pics; i++) {
+ if (node_isset(node, eiointc_priv[i]->node_map))
+ return i;
+ }
+
+ return -1;
+}
+
+static int eiointc_router_init(unsigned int cpu)
+{
+ int i, bit;
+ uint32_t data;
+ uint32_t node = cpu_to_eio_node(cpu);
+ uint32_t index = eiointc_index(node);
+
+ if (index < 0) {
+ pr_err("Error: invalid nodemap!\n");
+ return -1;
+ }
+
+ if ((cpu_logical_map(cpu) % CORES_PER_EIO_NODE) == 0) {
+ eiointc_enable();
+
+ for (i = 0; i < VEC_COUNT / 32; i++) {
+ data = (((1 << (i * 2 + 1)) << 16) | (1 << (i * 2)));
+ iocsr_write32(data, EIOINTC_REG_NODEMAP + i * 4);
+ }
+
+ for (i = 0; i < VEC_COUNT / 32 / 4; i++) {
+ bit = BIT(1 + index); /* Route to IP[1 + index] */
+ data = bit | (bit << 8) | (bit << 16) | (bit << 24);
+ iocsr_write32(data, EIOINTC_REG_IPMAP + i * 4);
+ }
+
+ for (i = 0; i < VEC_COUNT / 4; i++) {
+ /* Route to Node-0 Core-0 */
+ if (index == 0)
+ bit = BIT(cpu_logical_map(0));
+ else
+ bit = (eiointc_priv[index]->node << 4) | 1;
+
+ data = bit | (bit << 8) | (bit << 16) | (bit << 24);
+ iocsr_write32(data, EIOINTC_REG_ROUTE + i * 4);
+ }
+
+ for (i = 0; i < VEC_COUNT / 32; i++) {
+ data = 0xffffffff;
+ iocsr_write32(data, EIOINTC_REG_ENABLE + i * 4);
+ iocsr_write32(data, EIOINTC_REG_BOUNCE + i * 4);
+ }
+ }
+
+ return 0;
+}
+
+static void eiointc_irq_dispatch(struct irq_desc *desc)
+{
+ int i;
+ u64 pending;
+ bool handled = false;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct eiointc_priv *priv = irq_desc_get_handler_data(desc);
+
+ chained_irq_enter(chip, desc);
+
+ for (i = 0; i < VEC_REG_COUNT; i++) {
+ pending = iocsr_read64(EIOINTC_REG_ISR + (i << 3));
+ iocsr_write64(pending, EIOINTC_REG_ISR + (i << 3));
+ while (pending) {
+ int bit = __ffs(pending);
+ int irq = bit + VEC_COUNT_PER_REG * i;
+
+ generic_handle_domain_irq(priv->eiointc_domain, irq);
+ pending &= ~BIT(bit);
+ handled = true;
+ }
+ }
+
+ if (!handled)
+ spurious_interrupt();
+
+ chained_irq_exit(chip, desc);
+}
+
+static void eiointc_ack_irq(struct irq_data *d)
+{
+ if (d->parent_data)
+ irq_chip_ack_parent(d);
+}
+
+static void eiointc_mask_irq(struct irq_data *d)
+{
+ if (d->parent_data)
+ irq_chip_mask_parent(d);
+}
+
+static void eiointc_unmask_irq(struct irq_data *d)
+{
+ if (d->parent_data)
+ irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip eiointc_irq_chip = {
+ .name = "EIOINTC",
+ .irq_ack = eiointc_ack_irq,
+ .irq_mask = eiointc_mask_irq,
+ .irq_unmask = eiointc_unmask_irq,
+ .irq_set_affinity = eiointc_set_irq_affinity,
+};
+
+static int eiointc_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ int ret;
+ unsigned int i, type;
+ unsigned long hwirq = 0;
+ struct eiointc *priv = domain->host_data;
+
+ ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq_domain_set_info(domain, virq + i, hwirq + i, &eiointc_irq_chip,
+ priv, handle_edge_irq, NULL, NULL);
+ }
+
+ return 0;
+}
+
+static void eiointc_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 eiointc_domain_ops = {
+ .translate = irq_domain_translate_onecell,
+ .alloc = eiointc_domain_alloc,
+ .free = eiointc_domain_free,
+};
+
+static void acpi_set_vec_parent(int node, struct irq_domain *parent, struct acpi_vector_group *vec_group)
+{
+ int i;
+
+ if (cpu_has_flatmode)
+ node = cpu_to_node(node * CORES_PER_EIO_NODE);
+
+ for (i = 0; i < MAX_IO_PICS; i++) {
+ if (node == vec_group[i].node) {
+ vec_group[i].parent = parent;
+ return;
+ }
+ }
+}
+
+struct irq_domain *acpi_get_vec_parent(int node, struct acpi_vector_group *vec_group)
+{
+ int i;
+
+ for (i = 0; i < MAX_IO_PICS; i++) {
+ if (node == vec_group[i].node)
+ return vec_group[i].parent;
+ }
+ return NULL;
+}
+
+static int __init
+pch_pic_parse_madt(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_bio_pic *pchpic_entry = (struct acpi_madt_bio_pic *)header;
+ unsigned int node = (pchpic_entry->address >> 44) & 0xf;
+ struct irq_domain *parent = acpi_get_vec_parent(node, pch_group);
+
+ if (parent)
+ return pch_pic_acpi_init(parent, pchpic_entry);
+
+ return -EINVAL;
+}
+
+static int __init
+pch_msi_parse_madt(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
+ struct irq_domain *parent = acpi_get_vec_parent(eiointc_priv[nr_pics - 1]->node, msi_group);
+
+ if (parent)
+ return pch_msi_acpi_init(parent, pchmsi_entry);
+
+ return -EINVAL;
+}
+
+static int __init acpi_cascade_irqdomain_init(void)
+{
+ acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC,
+ pch_pic_parse_madt, 0);
+ acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC,
+ pch_msi_parse_madt, 1);
+ return 0;
+}
+
+int __init eiointc_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_eio_pic *acpi_eiointc)
+{
+ int i, parent_irq;
+ unsigned long node_map;
+ struct eiointc_priv *priv;
+
+ if (!acpi_eiointc)
+ return -EINVAL;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_eiointc);
+ if (!priv->domain_handle) {
+ pr_err("Unable to allocate domain handle\n");
+ goto out_free_priv;
+ }
+
+ priv->node = acpi_eiointc->node;
+ node_map = acpi_eiointc->node_map ? : -1ULL;
+
+ for_each_possible_cpu(i) {
+ if (node_map & (1ULL << cpu_to_eio_node(i))) {
+ node_set(cpu_to_eio_node(i), priv->node_map);
+ cpumask_or(&priv->cpuspan_map, &priv->cpuspan_map, cpumask_of(i));
+ }
+ }
+
+ /* Setup IRQ domain */
+ priv->eiointc_domain = irq_domain_create_linear(priv->domain_handle, VEC_COUNT,
+ &eiointc_domain_ops, priv);
+ if (!priv->eiointc_domain) {
+ pr_err("loongson-eiointc: cannot add IRQ domain\n");
+ goto out_free_handle;
+ }
+
+ eiointc_priv[nr_pics++] = priv;
+
+ eiointc_router_init(0);
+
+ parent_irq = irq_create_mapping(parent, acpi_eiointc->cascade);
+ irq_set_chained_handler_and_data(parent_irq, eiointc_irq_dispatch, priv);
+
+ cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_LOONGARCH_STARTING,
+ "irqchip/loongarch/intc:starting",
+ eiointc_router_init, NULL);
+
+ acpi_set_vec_parent(acpi_eiointc->node, priv->eiointc_domain, pch_group);
+ acpi_set_vec_parent(acpi_eiointc->node, priv->eiointc_domain, msi_group);
+ acpi_cascade_irqdomain_init();
+
+ return 0;
+
+out_free_handle:
+ irq_domain_free_fwnode(priv->domain_handle);
+ priv->domain_handle = NULL;
+out_free_priv:
+ kfree(priv);
+
+ return -ENOMEM;
+}
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 19f0dbf..de662f3 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -151,6 +151,7 @@ enum cpuhp_state {
CPUHP_AP_IRQ_BCM2836_STARTING,
CPUHP_AP_IRQ_MIPS_GIC_STARTING,
CPUHP_AP_IRQ_RISCV_STARTING,
+ CPUHP_AP_IRQ_LOONGARCH_STARTING,
CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
CPUHP_AP_ARM_MVEBU_COHERENCY,
CPUHP_AP_MICROCODE_LOADER,
--
1.8.3.1