The RISC-V advanced interrupt architecture (AIA) specification defines
advanced platform-level interrupt controller (APLIC) which has two modes
of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)
In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
as a local external interrupt.
Add a platform irqchip driver for the RISC-V APLIC direct-mode to
support RISC-V platforms having only wired interrupts.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
drivers/irqchip/Kconfig | 5 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
drivers/irqchip/irq-riscv-aplic-main.c | 211 +++++++++++++++
drivers/irqchip/irq-riscv-aplic-main.h | 44 +++
include/linux/irqchip/riscv-aplic.h | 145 ++++++++++
6 files changed, 732 insertions(+)
create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
create mode 100644 include/linux/irqchip/riscv-aplic.h
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 2fc0cb32341a..dbc8811d3764 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -546,6 +546,11 @@ config SIFIVE_PLIC
select IRQ_DOMAIN_HIERARCHY
select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
+config RISCV_APLIC
+ bool
+ depends on RISCV
+ select IRQ_DOMAIN_HIERARCHY
+
config RISCV_IMSIC
bool
depends on RISCV
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index abca445a3229..7f8289790ed8 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM) += irq-qcom-mpm.o
obj-$(CONFIG_CSKY_MPINTC) += irq-csky-mpintc.o
obj-$(CONFIG_CSKY_APB_INTC) += irq-csky-apb-intc.o
obj-$(CONFIG_RISCV_INTC) += irq-riscv-intc.o
+obj-$(CONFIG_RISCV_APLIC) += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
obj-$(CONFIG_RISCV_IMSIC) += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o
obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o
diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
new file mode 100644
index 000000000000..06bace9b7497
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-direct.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+#define APLIC_DISABLE_IDELIVERY 0
+#define APLIC_ENABLE_IDELIVERY 1
+#define APLIC_DISABLE_ITHRESHOLD 1
+#define APLIC_ENABLE_ITHRESHOLD 0
+
+struct aplic_direct {
+ struct aplic_priv priv;
+ struct irq_domain *irqdomain;
+ struct cpumask lmask;
+};
+
+struct aplic_idc {
+ unsigned int hart_index;
+ void __iomem *regs;
+ struct aplic_direct *direct;
+};
+
+static unsigned int aplic_direct_parent_irq;
+static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
+
+static void aplic_direct_irq_eoi(struct irq_data *d)
+{
+ /*
+ * The fasteoi_handler requires irq_eoi() callback hence
+ * provide a dummy handler.
+ */
+}
+
+#ifdef CONFIG_SMP
+static int aplic_direct_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
+ bool force)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+ struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
+ struct aplic_idc *idc;
+ unsigned int cpu, val;
+ struct cpumask amask;
+ void __iomem *target;
+
+ cpumask_and(&amask, &direct->lmask, mask_val);
+
+ if (force)
+ cpu = cpumask_first(&amask);
+ else
+ cpu = cpumask_any_and(&amask, cpu_online_mask);
+
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
+
+ idc = per_cpu_ptr(&aplic_idcs, cpu);
+ target = priv->regs + APLIC_TARGET_BASE + (d->hwirq - 1) * sizeof(u32);
+ val = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
+ val |= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
+ writel(val, target);
+
+ irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
+ return IRQ_SET_MASK_OK_DONE;
+}
+#endif
+
+static struct irq_chip aplic_direct_chip = {
+ .name = "APLIC-DIRECT",
+ .irq_mask = aplic_irq_mask,
+ .irq_unmask = aplic_irq_unmask,
+ .irq_set_type = aplic_irq_set_type,
+ .irq_eoi = aplic_direct_irq_eoi,
+#ifdef CONFIG_SMP
+ .irq_set_affinity = aplic_direct_set_affinity,
+#endif
+ .flags = IRQCHIP_SET_TYPE_MASKED |
+ IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int aplic_direct_irqdomain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
+ unsigned long *hwirq, unsigned int *type)
+{
+ struct aplic_priv *priv = d->host_data;
+
+ return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
+}
+
+static int aplic_direct_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct aplic_priv *priv = domain->host_data;
+ struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
+ struct irq_fwspec *fwspec = arg;
+ irq_hw_number_t hwirq;
+ unsigned int type;
+ int i, ret;
+
+ ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq_domain_set_info(domain, virq + i, hwirq + i, &aplic_direct_chip,
+ priv, handle_fasteoi_irq, NULL, NULL);
+ irq_set_affinity(virq + i, &direct->lmask);
+ }
+
+ return 0;
+}
+
+static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
+ .translate = aplic_direct_irqdomain_translate,
+ .alloc = aplic_direct_irqdomain_alloc,
+ .free = irq_domain_free_irqs_top,
+};
+
+/*
+ * To handle an APLIC direct interrupts, we just read the CLAIMI register
+ * which will return highest priority pending interrupt and clear the
+ * pending bit of the interrupt. This process is repeated until CLAIMI
+ * register return zero value.
+ */
+static void aplic_direct_handle_irq(struct irq_desc *desc)
+{
+ struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
+ struct irq_domain *irqdomain = idc->direct->irqdomain;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ irq_hw_number_t hw_irq;
+ int irq;
+
+ chained_irq_enter(chip, desc);
+
+ while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
+ hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
+ irq = irq_find_mapping(irqdomain, hw_irq);
+
+ if (unlikely(irq <= 0)) {
+ dev_warn_ratelimited(idc->direct->priv.dev,
+ "hw_irq %lu mapping not found\n", hw_irq);
+ } else {
+ generic_handle_irq(irq);
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
+{
+ u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
+ u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
+
+ /* Priority must be less than threshold for interrupt triggering */
+ writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
+
+ /* Delivery must be set to 1 for interrupt triggering */
+ writel(de, idc->regs + APLIC_IDC_IDELIVERY);
+}
+
+static int aplic_direct_dying_cpu(unsigned int cpu)
+{
+ if (aplic_direct_parent_irq)
+ disable_percpu_irq(aplic_direct_parent_irq);
+
+ return 0;
+}
+
+static int aplic_direct_starting_cpu(unsigned int cpu)
+{
+ if (aplic_direct_parent_irq) {
+ enable_percpu_irq(aplic_direct_parent_irq,
+ irq_get_trigger_type(aplic_direct_parent_irq));
+ }
+
+ return 0;
+}
+
+static int aplic_direct_parse_parent_hwirq(struct device *dev, u32 index,
+ u32 *parent_hwirq, unsigned long *parent_hartid)
+{
+ struct of_phandle_args parent;
+ int rc;
+
+ /*
+ * Currently, only OF fwnode is supported so extend this
+ * function for ACPI support.
+ */
+ if (!is_of_node(dev->fwnode))
+ return -EINVAL;
+
+ rc = of_irq_parse_one(to_of_node(dev->fwnode), index, &parent);
+ if (rc)
+ return rc;
+
+ rc = riscv_of_parent_hartid(parent.np, parent_hartid);
+ if (rc)
+ return rc;
+
+ *parent_hwirq = parent.args[0];
+ return 0;
+}
+
+int aplic_direct_setup(struct device *dev, void __iomem *regs)
+{
+ int i, j, rc, cpu, current_cpu, setup_count = 0;
+ struct aplic_direct *direct;
+ struct irq_domain *domain;
+ struct aplic_priv *priv;
+ struct aplic_idc *idc;
+ unsigned long hartid;
+ u32 v, hwirq;
+
+ direct = devm_kzalloc(dev, sizeof(*direct), GFP_KERNEL);
+ if (!direct)
+ return -ENOMEM;
+ priv = &direct->priv;
+
+ rc = aplic_setup_priv(priv, dev, regs);
+ if (rc) {
+ dev_err(dev, "failed to create APLIC context\n");
+ return rc;
+ }
+
+ /* Setup per-CPU IDC and target CPU mask */
+ current_cpu = get_cpu();
+ for (i = 0; i < priv->nr_idcs; i++) {
+ rc = aplic_direct_parse_parent_hwirq(dev, i, &hwirq, &hartid);
+ if (rc) {
+ dev_warn(dev, "parent irq for IDC%d not found\n", i);
+ continue;
+ }
+
+ /*
+ * Skip interrupts other than external interrupts for
+ * current privilege level.
+ */
+ if (hwirq != RV_IRQ_EXT)
+ continue;
+
+ cpu = riscv_hartid_to_cpuid(hartid);
+ if (cpu < 0) {
+ dev_warn(dev, "invalid cpuid for IDC%d\n", i);
+ continue;
+ }
+
+ cpumask_set_cpu(cpu, &direct->lmask);
+
+ idc = per_cpu_ptr(&aplic_idcs, cpu);
+ idc->hart_index = i;
+ idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
+ idc->direct = direct;
+
+ aplic_idc_set_delivery(idc, true);
+
+ /*
+ * Boot cpu might not have APLIC hart_index = 0 so check
+ * and update target registers of all interrupts.
+ */
+ if (cpu == current_cpu && idc->hart_index) {
+ v = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
+ v |= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
+ for (j = 1; j <= priv->nr_irqs; j++)
+ writel(v, priv->regs + APLIC_TARGET_BASE + (j - 1) * sizeof(u32));
+ }
+
+ setup_count++;
+ }
+ put_cpu();
+
+ /* Find parent domain and register chained handler */
+ domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+ DOMAIN_BUS_ANY);
+ if (!aplic_direct_parent_irq && domain) {
+ aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+ if (aplic_direct_parent_irq) {
+ irq_set_chained_handler(aplic_direct_parent_irq,
+ aplic_direct_handle_irq);
+
+ /*
+ * Setup CPUHP notifier to enable parent
+ * interrupt on all CPUs
+ */
+ cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "irqchip/riscv/aplic:starting",
+ aplic_direct_starting_cpu,
+ aplic_direct_dying_cpu);
+ }
+ }
+
+ /* Fail if we were not able to setup IDC for any CPU */
+ if (!setup_count)
+ return -ENODEV;
+
+ /* Setup global config and interrupt delivery */
+ aplic_init_hw_global(priv, false);
+
+ /* Create irq domain instance for the APLIC */
+ direct->irqdomain = irq_domain_create_linear(dev->fwnode, priv->nr_irqs + 1,
+ &aplic_direct_irqdomain_ops, priv);
+ if (!direct->irqdomain) {
+ dev_err(dev, "failed to create direct irq domain\n");
+ return -ENOMEM;
+ }
+
+ /* Advertise the interrupt controller */
+ dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
+ priv->nr_irqs, priv->nr_idcs);
+
+ return 0;
+}
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
new file mode 100644
index 000000000000..160ff99d6979
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+
+#include "irq-riscv-aplic-main.h"
+
+void aplic_irq_unmask(struct irq_data *d)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+ writel(d->hwirq, priv->regs + APLIC_SETIENUM);
+}
+
+void aplic_irq_mask(struct irq_data *d)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+ writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
+}
+
+int aplic_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+ void __iomem *sourcecfg;
+ u32 val = 0;
+
+ switch (type) {
+ case IRQ_TYPE_NONE:
+ val = APLIC_SOURCECFG_SM_INACTIVE;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ val = APLIC_SOURCECFG_SM_LEVEL_LOW;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ val = APLIC_SOURCECFG_SM_EDGE_FALL;
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ val = APLIC_SOURCECFG_SM_EDGE_RISE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
+ sourcecfg += (d->hwirq - 1) * sizeof(u32);
+ writel(val, sourcecfg);
+
+ return 0;
+}
+
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+ unsigned long *hwirq, unsigned int *type)
+{
+ if (WARN_ON(fwspec->param_count < 2))
+ return -EINVAL;
+ if (WARN_ON(!fwspec->param[0]))
+ return -EINVAL;
+
+ /* For DT, gsi_base is always zero. */
+ *hwirq = fwspec->param[0] - gsi_base;
+ *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+
+ WARN_ON(*type == IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
+{
+ u32 val;
+#ifdef CONFIG_RISCV_M_MODE
+ u32 valh;
+
+ if (msi_mode) {
+ val = lower_32_bits(priv->msicfg.base_ppn);
+ valh = FIELD_PREP(APLIC_xMSICFGADDRH_BAPPN, upper_32_bits(priv->msicfg.base_ppn));
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXW, priv->msicfg.lhxw);
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXW, priv->msicfg.hhxw);
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXS, priv->msicfg.lhxs);
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXS, priv->msicfg.hhxs);
+ writel(val, priv->regs + APLIC_xMSICFGADDR);
+ writel(valh, priv->regs + APLIC_xMSICFGADDRH);
+ }
+#endif
+
+ /* Setup APLIC domaincfg register */
+ val = readl(priv->regs + APLIC_DOMAINCFG);
+ val |= APLIC_DOMAINCFG_IE;
+ if (msi_mode)
+ val |= APLIC_DOMAINCFG_DM;
+ writel(val, priv->regs + APLIC_DOMAINCFG);
+ if (readl(priv->regs + APLIC_DOMAINCFG) != val)
+ dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n", val);
+}
+
+static void aplic_init_hw_irqs(struct aplic_priv *priv)
+{
+ int i;
+
+ /* Disable all interrupts */
+ for (i = 0; i <= priv->nr_irqs; i += 32)
+ writel(-1U, priv->regs + APLIC_CLRIE_BASE + (i / 32) * sizeof(u32));
+
+ /* Set interrupt type and default priority for all interrupts */
+ for (i = 1; i <= priv->nr_irqs; i++) {
+ writel(0, priv->regs + APLIC_SOURCECFG_BASE + (i - 1) * sizeof(u32));
+ writel(APLIC_DEFAULT_PRIORITY,
+ priv->regs + APLIC_TARGET_BASE + (i - 1) * sizeof(u32));
+ }
+
+ /* Clear APLIC domaincfg */
+ writel(0, priv->regs + APLIC_DOMAINCFG);
+}
+
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs)
+{
+ struct of_phandle_args parent;
+ int rc;
+
+ /*
+ * Currently, only OF fwnode is supported so extend this
+ * function for ACPI support.
+ */
+ if (!is_of_node(dev->fwnode))
+ return -EINVAL;
+
+ /* Save device pointer and register base */
+ priv->dev = dev;
+ priv->regs = regs;
+
+ /* Find out number of interrupt sources */
+ rc = of_property_read_u32(to_of_node(dev->fwnode), "riscv,num-sources",
+ &priv->nr_irqs);
+ if (rc) {
+ dev_err(dev, "failed to get number of interrupt sources\n");
+ return rc;
+ }
+
+ /*
+ * Find out number of IDCs based on parent interrupts
+ *
+ * If "msi-parent" property is present then we ignore the
+ * APLIC IDCs which forces the APLIC driver to use MSI mode.
+ */
+ if (!of_property_present(to_of_node(dev->fwnode), "msi-parent")) {
+ while (!of_irq_parse_one(to_of_node(dev->fwnode), priv->nr_idcs, &parent))
+ priv->nr_idcs++;
+ }
+
+ /* Setup initial state APLIC interrupts */
+ aplic_init_hw_irqs(priv);
+
+ return 0;
+}
+
+static int aplic_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ bool msi_mode = false;
+ void __iomem *regs;
+ int rc;
+
+ /* Map the MMIO registers */
+ regs = devm_platform_ioremap_resource(pdev, 0);
+ if (!regs) {
+ dev_err(dev, "failed map MMIO registers\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * If msi-parent property is present then setup APLIC MSI
+ * mode otherwise setup APLIC direct mode.
+ */
+ if (is_of_node(dev->fwnode))
+ msi_mode = of_property_present(to_of_node(dev->fwnode), "msi-parent");
+ if (msi_mode)
+ rc = -ENODEV;
+ else
+ rc = aplic_direct_setup(dev, regs);
+ if (rc)
+ dev_err(dev, "failed to setup APLIC in %s mode\n", msi_mode ? "MSI" : "direct");
+
+ return rc;
+}
+
+static const struct of_device_id aplic_match[] = {
+ { .compatible = "riscv,aplic" },
+ {}
+};
+
+static struct platform_driver aplic_driver = {
+ .driver = {
+ .name = "riscv-aplic",
+ .of_match_table = aplic_match,
+ },
+ .probe = aplic_probe,
+};
+builtin_platform_driver(aplic_driver);
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
new file mode 100644
index 000000000000..4cfbadf37ddc
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_APLIC_MAIN_H
+#define _IRQ_RISCV_APLIC_MAIN_H
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+#define APLIC_DEFAULT_PRIORITY 1
+
+struct aplic_msicfg {
+ phys_addr_t base_ppn;
+ u32 hhxs;
+ u32 hhxw;
+ u32 lhxs;
+ u32 lhxw;
+};
+
+struct aplic_priv {
+ struct device *dev;
+ u32 gsi_base;
+ u32 nr_irqs;
+ u32 nr_idcs;
+ void __iomem *regs;
+ struct aplic_msicfg msicfg;
+};
+
+void aplic_irq_unmask(struct irq_data *d);
+void aplic_irq_mask(struct irq_data *d);
+int aplic_irq_set_type(struct irq_data *d, unsigned int type);
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+ unsigned long *hwirq, unsigned int *type);
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs);
+int aplic_direct_setup(struct device *dev, void __iomem *regs);
+
+#endif
diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
new file mode 100644
index 000000000000..ec8f7df50583
--- /dev/null
+++ b/include/linux/irqchip/riscv-aplic.h
@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
+#define __LINUX_IRQCHIP_RISCV_APLIC_H
+
+#include <linux/bitops.h>
+
+#define APLIC_MAX_IDC BIT(14)
+#define APLIC_MAX_SOURCE 1024
+
+#define APLIC_DOMAINCFG 0x0000
+#define APLIC_DOMAINCFG_RDONLY 0x80000000
+#define APLIC_DOMAINCFG_IE BIT(8)
+#define APLIC_DOMAINCFG_DM BIT(2)
+#define APLIC_DOMAINCFG_BE BIT(0)
+
+#define APLIC_SOURCECFG_BASE 0x0004
+#define APLIC_SOURCECFG_D BIT(10)
+#define APLIC_SOURCECFG_CHILDIDX_MASK 0x000003ff
+#define APLIC_SOURCECFG_SM_MASK 0x00000007
+#define APLIC_SOURCECFG_SM_INACTIVE 0x0
+#define APLIC_SOURCECFG_SM_DETACH 0x1
+#define APLIC_SOURCECFG_SM_EDGE_RISE 0x4
+#define APLIC_SOURCECFG_SM_EDGE_FALL 0x5
+#define APLIC_SOURCECFG_SM_LEVEL_HIGH 0x6
+#define APLIC_SOURCECFG_SM_LEVEL_LOW 0x7
+
+#define APLIC_MMSICFGADDR 0x1bc0
+#define APLIC_MMSICFGADDRH 0x1bc4
+#define APLIC_SMSICFGADDR 0x1bc8
+#define APLIC_SMSICFGADDRH 0x1bcc
+
+#ifdef CONFIG_RISCV_M_MODE
+#define APLIC_xMSICFGADDR APLIC_MMSICFGADDR
+#define APLIC_xMSICFGADDRH APLIC_MMSICFGADDRH
+#else
+#define APLIC_xMSICFGADDR APLIC_SMSICFGADDR
+#define APLIC_xMSICFGADDRH APLIC_SMSICFGADDRH
+#endif
+
+#define APLIC_xMSICFGADDRH_L BIT(31)
+#define APLIC_xMSICFGADDRH_HHXS_MASK 0x1f
+#define APLIC_xMSICFGADDRH_HHXS_SHIFT 24
+#define APLIC_xMSICFGADDRH_HHXS (APLIC_xMSICFGADDRH_HHXS_MASK << \
+ APLIC_xMSICFGADDRH_HHXS_SHIFT)
+#define APLIC_xMSICFGADDRH_LHXS_MASK 0x7
+#define APLIC_xMSICFGADDRH_LHXS_SHIFT 20
+#define APLIC_xMSICFGADDRH_LHXS (APLIC_xMSICFGADDRH_LHXS_MASK << \
+ APLIC_xMSICFGADDRH_LHXS_SHIFT)
+#define APLIC_xMSICFGADDRH_HHXW_MASK 0x7
+#define APLIC_xMSICFGADDRH_HHXW_SHIFT 16
+#define APLIC_xMSICFGADDRH_HHXW (APLIC_xMSICFGADDRH_HHXW_MASK << \
+ APLIC_xMSICFGADDRH_HHXW_SHIFT)
+#define APLIC_xMSICFGADDRH_LHXW_MASK 0xf
+#define APLIC_xMSICFGADDRH_LHXW_SHIFT 12
+#define APLIC_xMSICFGADDRH_LHXW (APLIC_xMSICFGADDRH_LHXW_MASK << \
+ APLIC_xMSICFGADDRH_LHXW_SHIFT)
+#define APLIC_xMSICFGADDRH_BAPPN_MASK 0xfff
+#define APLIC_xMSICFGADDRH_BAPPN_SHIFT 0
+#define APLIC_xMSICFGADDRH_BAPPN (APLIC_xMSICFGADDRH_BAPPN_MASK << \
+ APLIC_xMSICFGADDRH_BAPPN_SHIFT)
+
+#define APLIC_xMSICFGADDR_PPN_SHIFT 12
+
+#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
+ (BIT(__lhxs) - 1)
+
+#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
+ (BIT(__lhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
+ ((__lhxs))
+#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
+ (APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
+ APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
+
+#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
+ (BIT(__hhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
+ ((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
+#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
+ (APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
+ APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
+
+#define APLIC_IRQBITS_PER_REG 32
+
+#define APLIC_SETIP_BASE 0x1c00
+#define APLIC_SETIPNUM 0x1cdc
+
+#define APLIC_CLRIP_BASE 0x1d00
+#define APLIC_CLRIPNUM 0x1ddc
+
+#define APLIC_SETIE_BASE 0x1e00
+#define APLIC_SETIENUM 0x1edc
+
+#define APLIC_CLRIE_BASE 0x1f00
+#define APLIC_CLRIENUM 0x1fdc
+
+#define APLIC_SETIPNUM_LE 0x2000
+#define APLIC_SETIPNUM_BE 0x2004
+
+#define APLIC_GENMSI 0x3000
+
+#define APLIC_TARGET_BASE 0x3004
+#define APLIC_TARGET_HART_IDX_SHIFT 18
+#define APLIC_TARGET_HART_IDX_MASK 0x3fff
+#define APLIC_TARGET_HART_IDX (APLIC_TARGET_HART_IDX_MASK << \
+ APLIC_TARGET_HART_IDX_SHIFT)
+#define APLIC_TARGET_GUEST_IDX_SHIFT 12
+#define APLIC_TARGET_GUEST_IDX_MASK 0x3f
+#define APLIC_TARGET_GUEST_IDX (APLIC_TARGET_GUEST_IDX_MASK << \
+ APLIC_TARGET_GUEST_IDX_SHIFT)
+#define APLIC_TARGET_IPRIO_SHIFT 0
+#define APLIC_TARGET_IPRIO_MASK 0xff
+#define APLIC_TARGET_IPRIO (APLIC_TARGET_IPRIO_MASK << \
+ APLIC_TARGET_IPRIO_SHIFT)
+#define APLIC_TARGET_EIID_SHIFT 0
+#define APLIC_TARGET_EIID_MASK 0x7ff
+#define APLIC_TARGET_EIID (APLIC_TARGET_EIID_MASK << \
+ APLIC_TARGET_EIID_SHIFT)
+
+#define APLIC_IDC_BASE 0x4000
+#define APLIC_IDC_SIZE 32
+
+#define APLIC_IDC_IDELIVERY 0x00
+
+#define APLIC_IDC_IFORCE 0x04
+
+#define APLIC_IDC_ITHRESHOLD 0x08
+
+#define APLIC_IDC_TOPI 0x18
+#define APLIC_IDC_TOPI_ID_SHIFT 16
+#define APLIC_IDC_TOPI_ID_MASK 0x3ff
+#define APLIC_IDC_TOPI_ID (APLIC_IDC_TOPI_ID_MASK << \
+ APLIC_IDC_TOPI_ID_SHIFT)
+#define APLIC_IDC_TOPI_PRIO_SHIFT 0
+#define APLIC_IDC_TOPI_PRIO_MASK 0xff
+#define APLIC_IDC_TOPI_PRIO (APLIC_IDC_TOPI_PRIO_MASK << \
+ APLIC_IDC_TOPI_PRIO_SHIFT)
+
+#define APLIC_IDC_CLAIMI 0x1c
+
+#endif
--
2.34.1
> diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> +static const struct of_device_id aplic_match[] = {
> + { .compatible = "riscv,aplic" },
> + {}
> +};
> +
> +static struct platform_driver aplic_driver = {
> + .driver = {
> + .name = "riscv-aplic",
> + .of_match_table = aplic_match,
> + },
> + .probe = aplic_probe,
> +};
> +builtin_platform_driver(aplic_driver);
Dear Anup Patel and all concerned,
I am writing to inquire about the historical rationale behind defining the APLIC driver's
initialization priority using builtin_platform_driver in the current implementation.
In our environment, we are encountering an issue where this priority level causes ACPI-based PCIe
enumeration to be executed in the system_unbound_wq work queue. This parallel execution model
results in PCIe devices being enumerated in an arbitrary order rather than strictly following the
sequence defined in the ACPI DSDT table.
The random enumeration order is adversely affecting customer experience, particularly in scenarios
where device ordering is critical for proper system operation or application compatibility.
We are considering modifying the APLIC driver's initialization priority to ensure PCIe enumeration
occurs sequentially according to the DSDT specification. However, before proceeding with such
changes, we wanted to consult with you regarding:
1. Were there specific technical considerations that led to the current priority selection?
2. Are there any potential side effects or broader impacts that we might have overlooked?
3. Would you support such a priority adjustment, or do you have alternative suggestions to
address the enumeration order issue?
We greatly appreciate your insights and expertise on this matter, as it will help us make an
informed decision while maintaining system stability and compatibility.
Thank you for your time and consideration.
Best regards,
Liqiang
Hi Liqiang,
On Thu, Nov 20, 2025 at 10:43:11PM +0800, niliqiang wrote:
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > +static const struct of_device_id aplic_match[] = {
> > + { .compatible = "riscv,aplic" },
> > + {}
> > +};
> > +
> > +static struct platform_driver aplic_driver = {
> > + .driver = {
> > + .name = "riscv-aplic",
> > + .of_match_table = aplic_match,
> > + },
> > + .probe = aplic_probe,
> > +};
> > +builtin_platform_driver(aplic_driver);
>
> Dear Anup Patel and all concerned,
>
> I am writing to inquire about the historical rationale behind defining the APLIC driver's
> initialization priority using builtin_platform_driver in the current implementation.
>
> In our environment, we are encountering an issue where this priority level causes ACPI-based PCIe
> enumeration to be executed in the system_unbound_wq work queue. This parallel execution model
> results in PCIe devices being enumerated in an arbitrary order rather than strictly following the
> sequence defined in the ACPI DSDT table.
>
> The random enumeration order is adversely affecting customer experience, particularly in scenarios
> where device ordering is critical for proper system operation or application compatibility.
>
> We are considering modifying the APLIC driver's initialization priority to ensure PCIe enumeration
> occurs sequentially according to the DSDT specification. However, before proceeding with such
> changes, we wanted to consult with you regarding:
>
> 1. Were there specific technical considerations that led to the current priority selection?
> 2. Are there any potential side effects or broader impacts that we might have overlooked?
> 3. Would you support such a priority adjustment, or do you have alternative suggestions to
> address the enumeration order issue?
>
> We greatly appreciate your insights and expertise on this matter, as it will help us make an
> informed decision while maintaining system stability and compatibility.
>
> Thank you for your time and consideration.
>
IRQ subsystem maintainers rejected the idea of relying on initcalls to
enforce probe order because initcalls do not guarantee ordering. The
Linux driver model instead ensures probe order through device
dependencies. Since PCI INTx depends on the APLIC being probed first,
the PCI host bridge probe cannot occur until after the APLIC probe
completes. This requirement and behavior are the same for both DT and
ACPI. In DT, the driver model uses fw_devlink to establish probe
ordering, while in ACPI this is handled through either an explicit _DEP
or, on RISC-V, the GSI mapping.
Typically, this dependency appears in the DSDT only for the PCI host
bridge. Individual PCIe devices are enumerated through the standard PCI
scan once the host bridge has been probed. Therefore, I’m not sure what
you meant by a probe sequence defined in the DSDT for PCIe devices.
Regards,
Sunil
The following commit has been merged into the irq/core branch of tip:
Commit-ID: 2333df5ae51ead2188d07c99e841e159a664741e
Gitweb: https://git.kernel.org/tip/2333df5ae51ead2188d07c99e841e159a664741e
Author: Anup Patel <apatel@ventanamicro.com>
AuthorDate: Thu, 07 Mar 2024 19:33:04 +05:30
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 25 Mar 2024 17:38:29 +01:00
irqchip: Add RISC-V advanced PLIC driver for direct-mode
The RISC-V advanced interrupt architecture (AIA) specification defines
advanced platform-level interrupt controller (APLIC) which has two modes
of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)
In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
as a local external interrupt.
Add a platform irqchip driver for the RISC-V APLIC direct-mode to
support RISC-V platforms having only wired interrupts.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240307140307.646078-7-apatel@ventanamicro.com
---
drivers/irqchip/Kconfig | 5 +-
drivers/irqchip/Makefile | 1 +-
drivers/irqchip/irq-riscv-aplic-direct.c | 326 ++++++++++++++++++++++-
drivers/irqchip/irq-riscv-aplic-main.c | 211 ++++++++++++++-
drivers/irqchip/irq-riscv-aplic-main.h | 44 +++-
include/linux/irqchip/riscv-aplic.h | 145 ++++++++++-
6 files changed, 732 insertions(+)
create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
create mode 100644 include/linux/irqchip/riscv-aplic.h
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 8f6ce41..f672847 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -540,6 +540,11 @@ config RISCV_INTC
depends on RISCV
select IRQ_DOMAIN_HIERARCHY
+config RISCV_APLIC
+ bool
+ depends on RISCV
+ select IRQ_DOMAIN_HIERARCHY
+
config RISCV_IMSIC
bool
depends on RISCV
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c139098..5adbe7a 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM) += irq-qcom-mpm.o
obj-$(CONFIG_CSKY_MPINTC) += irq-csky-mpintc.o
obj-$(CONFIG_CSKY_APB_INTC) += irq-csky-apb-intc.o
obj-$(CONFIG_RISCV_INTC) += irq-riscv-intc.o
+obj-$(CONFIG_RISCV_APLIC) += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
obj-$(CONFIG_RISCV_IMSIC) += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o
obj-$(CONFIG_STARFIVE_JH8100_INTC) += irq-starfive-jh8100-intc.o
diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
new file mode 100644
index 0000000..06bace9
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-direct.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+#define APLIC_DISABLE_IDELIVERY 0
+#define APLIC_ENABLE_IDELIVERY 1
+#define APLIC_DISABLE_ITHRESHOLD 1
+#define APLIC_ENABLE_ITHRESHOLD 0
+
+struct aplic_direct {
+ struct aplic_priv priv;
+ struct irq_domain *irqdomain;
+ struct cpumask lmask;
+};
+
+struct aplic_idc {
+ unsigned int hart_index;
+ void __iomem *regs;
+ struct aplic_direct *direct;
+};
+
+static unsigned int aplic_direct_parent_irq;
+static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
+
+static void aplic_direct_irq_eoi(struct irq_data *d)
+{
+ /*
+ * The fasteoi_handler requires irq_eoi() callback hence
+ * provide a dummy handler.
+ */
+}
+
+#ifdef CONFIG_SMP
+static int aplic_direct_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
+ bool force)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+ struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
+ struct aplic_idc *idc;
+ unsigned int cpu, val;
+ struct cpumask amask;
+ void __iomem *target;
+
+ cpumask_and(&amask, &direct->lmask, mask_val);
+
+ if (force)
+ cpu = cpumask_first(&amask);
+ else
+ cpu = cpumask_any_and(&amask, cpu_online_mask);
+
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
+
+ idc = per_cpu_ptr(&aplic_idcs, cpu);
+ target = priv->regs + APLIC_TARGET_BASE + (d->hwirq - 1) * sizeof(u32);
+ val = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
+ val |= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
+ writel(val, target);
+
+ irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
+ return IRQ_SET_MASK_OK_DONE;
+}
+#endif
+
+static struct irq_chip aplic_direct_chip = {
+ .name = "APLIC-DIRECT",
+ .irq_mask = aplic_irq_mask,
+ .irq_unmask = aplic_irq_unmask,
+ .irq_set_type = aplic_irq_set_type,
+ .irq_eoi = aplic_direct_irq_eoi,
+#ifdef CONFIG_SMP
+ .irq_set_affinity = aplic_direct_set_affinity,
+#endif
+ .flags = IRQCHIP_SET_TYPE_MASKED |
+ IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int aplic_direct_irqdomain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
+ unsigned long *hwirq, unsigned int *type)
+{
+ struct aplic_priv *priv = d->host_data;
+
+ return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
+}
+
+static int aplic_direct_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct aplic_priv *priv = domain->host_data;
+ struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
+ struct irq_fwspec *fwspec = arg;
+ irq_hw_number_t hwirq;
+ unsigned int type;
+ int i, ret;
+
+ ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq_domain_set_info(domain, virq + i, hwirq + i, &aplic_direct_chip,
+ priv, handle_fasteoi_irq, NULL, NULL);
+ irq_set_affinity(virq + i, &direct->lmask);
+ }
+
+ return 0;
+}
+
+static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
+ .translate = aplic_direct_irqdomain_translate,
+ .alloc = aplic_direct_irqdomain_alloc,
+ .free = irq_domain_free_irqs_top,
+};
+
+/*
+ * To handle an APLIC direct interrupts, we just read the CLAIMI register
+ * which will return highest priority pending interrupt and clear the
+ * pending bit of the interrupt. This process is repeated until CLAIMI
+ * register return zero value.
+ */
+static void aplic_direct_handle_irq(struct irq_desc *desc)
+{
+ struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
+ struct irq_domain *irqdomain = idc->direct->irqdomain;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ irq_hw_number_t hw_irq;
+ int irq;
+
+ chained_irq_enter(chip, desc);
+
+ while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
+ hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
+ irq = irq_find_mapping(irqdomain, hw_irq);
+
+ if (unlikely(irq <= 0)) {
+ dev_warn_ratelimited(idc->direct->priv.dev,
+ "hw_irq %lu mapping not found\n", hw_irq);
+ } else {
+ generic_handle_irq(irq);
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
+{
+ u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
+ u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
+
+ /* Priority must be less than threshold for interrupt triggering */
+ writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
+
+ /* Delivery must be set to 1 for interrupt triggering */
+ writel(de, idc->regs + APLIC_IDC_IDELIVERY);
+}
+
+static int aplic_direct_dying_cpu(unsigned int cpu)
+{
+ if (aplic_direct_parent_irq)
+ disable_percpu_irq(aplic_direct_parent_irq);
+
+ return 0;
+}
+
+static int aplic_direct_starting_cpu(unsigned int cpu)
+{
+ if (aplic_direct_parent_irq) {
+ enable_percpu_irq(aplic_direct_parent_irq,
+ irq_get_trigger_type(aplic_direct_parent_irq));
+ }
+
+ return 0;
+}
+
+static int aplic_direct_parse_parent_hwirq(struct device *dev, u32 index,
+ u32 *parent_hwirq, unsigned long *parent_hartid)
+{
+ struct of_phandle_args parent;
+ int rc;
+
+ /*
+ * Currently, only OF fwnode is supported so extend this
+ * function for ACPI support.
+ */
+ if (!is_of_node(dev->fwnode))
+ return -EINVAL;
+
+ rc = of_irq_parse_one(to_of_node(dev->fwnode), index, &parent);
+ if (rc)
+ return rc;
+
+ rc = riscv_of_parent_hartid(parent.np, parent_hartid);
+ if (rc)
+ return rc;
+
+ *parent_hwirq = parent.args[0];
+ return 0;
+}
+
+int aplic_direct_setup(struct device *dev, void __iomem *regs)
+{
+ int i, j, rc, cpu, current_cpu, setup_count = 0;
+ struct aplic_direct *direct;
+ struct irq_domain *domain;
+ struct aplic_priv *priv;
+ struct aplic_idc *idc;
+ unsigned long hartid;
+ u32 v, hwirq;
+
+ direct = devm_kzalloc(dev, sizeof(*direct), GFP_KERNEL);
+ if (!direct)
+ return -ENOMEM;
+ priv = &direct->priv;
+
+ rc = aplic_setup_priv(priv, dev, regs);
+ if (rc) {
+ dev_err(dev, "failed to create APLIC context\n");
+ return rc;
+ }
+
+ /* Setup per-CPU IDC and target CPU mask */
+ current_cpu = get_cpu();
+ for (i = 0; i < priv->nr_idcs; i++) {
+ rc = aplic_direct_parse_parent_hwirq(dev, i, &hwirq, &hartid);
+ if (rc) {
+ dev_warn(dev, "parent irq for IDC%d not found\n", i);
+ continue;
+ }
+
+ /*
+ * Skip interrupts other than external interrupts for
+ * current privilege level.
+ */
+ if (hwirq != RV_IRQ_EXT)
+ continue;
+
+ cpu = riscv_hartid_to_cpuid(hartid);
+ if (cpu < 0) {
+ dev_warn(dev, "invalid cpuid for IDC%d\n", i);
+ continue;
+ }
+
+ cpumask_set_cpu(cpu, &direct->lmask);
+
+ idc = per_cpu_ptr(&aplic_idcs, cpu);
+ idc->hart_index = i;
+ idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
+ idc->direct = direct;
+
+ aplic_idc_set_delivery(idc, true);
+
+ /*
+ * Boot cpu might not have APLIC hart_index = 0 so check
+ * and update target registers of all interrupts.
+ */
+ if (cpu == current_cpu && idc->hart_index) {
+ v = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
+ v |= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
+ for (j = 1; j <= priv->nr_irqs; j++)
+ writel(v, priv->regs + APLIC_TARGET_BASE + (j - 1) * sizeof(u32));
+ }
+
+ setup_count++;
+ }
+ put_cpu();
+
+ /* Find parent domain and register chained handler */
+ domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+ DOMAIN_BUS_ANY);
+ if (!aplic_direct_parent_irq && domain) {
+ aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+ if (aplic_direct_parent_irq) {
+ irq_set_chained_handler(aplic_direct_parent_irq,
+ aplic_direct_handle_irq);
+
+ /*
+ * Setup CPUHP notifier to enable parent
+ * interrupt on all CPUs
+ */
+ cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "irqchip/riscv/aplic:starting",
+ aplic_direct_starting_cpu,
+ aplic_direct_dying_cpu);
+ }
+ }
+
+ /* Fail if we were not able to setup IDC for any CPU */
+ if (!setup_count)
+ return -ENODEV;
+
+ /* Setup global config and interrupt delivery */
+ aplic_init_hw_global(priv, false);
+
+ /* Create irq domain instance for the APLIC */
+ direct->irqdomain = irq_domain_create_linear(dev->fwnode, priv->nr_irqs + 1,
+ &aplic_direct_irqdomain_ops, priv);
+ if (!direct->irqdomain) {
+ dev_err(dev, "failed to create direct irq domain\n");
+ return -ENOMEM;
+ }
+
+ /* Advertise the interrupt controller */
+ dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
+ priv->nr_irqs, priv->nr_idcs);
+
+ return 0;
+}
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
new file mode 100644
index 0000000..160ff99
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+
+#include "irq-riscv-aplic-main.h"
+
+void aplic_irq_unmask(struct irq_data *d)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+ writel(d->hwirq, priv->regs + APLIC_SETIENUM);
+}
+
+void aplic_irq_mask(struct irq_data *d)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+ writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
+}
+
+int aplic_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+ void __iomem *sourcecfg;
+ u32 val = 0;
+
+ switch (type) {
+ case IRQ_TYPE_NONE:
+ val = APLIC_SOURCECFG_SM_INACTIVE;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ val = APLIC_SOURCECFG_SM_LEVEL_LOW;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ val = APLIC_SOURCECFG_SM_EDGE_FALL;
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ val = APLIC_SOURCECFG_SM_EDGE_RISE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
+ sourcecfg += (d->hwirq - 1) * sizeof(u32);
+ writel(val, sourcecfg);
+
+ return 0;
+}
+
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+ unsigned long *hwirq, unsigned int *type)
+{
+ if (WARN_ON(fwspec->param_count < 2))
+ return -EINVAL;
+ if (WARN_ON(!fwspec->param[0]))
+ return -EINVAL;
+
+ /* For DT, gsi_base is always zero. */
+ *hwirq = fwspec->param[0] - gsi_base;
+ *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+
+ WARN_ON(*type == IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
+{
+ u32 val;
+#ifdef CONFIG_RISCV_M_MODE
+ u32 valh;
+
+ if (msi_mode) {
+ val = lower_32_bits(priv->msicfg.base_ppn);
+ valh = FIELD_PREP(APLIC_xMSICFGADDRH_BAPPN, upper_32_bits(priv->msicfg.base_ppn));
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXW, priv->msicfg.lhxw);
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXW, priv->msicfg.hhxw);
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXS, priv->msicfg.lhxs);
+ valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXS, priv->msicfg.hhxs);
+ writel(val, priv->regs + APLIC_xMSICFGADDR);
+ writel(valh, priv->regs + APLIC_xMSICFGADDRH);
+ }
+#endif
+
+ /* Setup APLIC domaincfg register */
+ val = readl(priv->regs + APLIC_DOMAINCFG);
+ val |= APLIC_DOMAINCFG_IE;
+ if (msi_mode)
+ val |= APLIC_DOMAINCFG_DM;
+ writel(val, priv->regs + APLIC_DOMAINCFG);
+ if (readl(priv->regs + APLIC_DOMAINCFG) != val)
+ dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n", val);
+}
+
+static void aplic_init_hw_irqs(struct aplic_priv *priv)
+{
+ int i;
+
+ /* Disable all interrupts */
+ for (i = 0; i <= priv->nr_irqs; i += 32)
+ writel(-1U, priv->regs + APLIC_CLRIE_BASE + (i / 32) * sizeof(u32));
+
+ /* Set interrupt type and default priority for all interrupts */
+ for (i = 1; i <= priv->nr_irqs; i++) {
+ writel(0, priv->regs + APLIC_SOURCECFG_BASE + (i - 1) * sizeof(u32));
+ writel(APLIC_DEFAULT_PRIORITY,
+ priv->regs + APLIC_TARGET_BASE + (i - 1) * sizeof(u32));
+ }
+
+ /* Clear APLIC domaincfg */
+ writel(0, priv->regs + APLIC_DOMAINCFG);
+}
+
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs)
+{
+ struct of_phandle_args parent;
+ int rc;
+
+ /*
+ * Currently, only OF fwnode is supported so extend this
+ * function for ACPI support.
+ */
+ if (!is_of_node(dev->fwnode))
+ return -EINVAL;
+
+ /* Save device pointer and register base */
+ priv->dev = dev;
+ priv->regs = regs;
+
+ /* Find out number of interrupt sources */
+ rc = of_property_read_u32(to_of_node(dev->fwnode), "riscv,num-sources",
+ &priv->nr_irqs);
+ if (rc) {
+ dev_err(dev, "failed to get number of interrupt sources\n");
+ return rc;
+ }
+
+ /*
+ * Find out number of IDCs based on parent interrupts
+ *
+ * If "msi-parent" property is present then we ignore the
+ * APLIC IDCs which forces the APLIC driver to use MSI mode.
+ */
+ if (!of_property_present(to_of_node(dev->fwnode), "msi-parent")) {
+ while (!of_irq_parse_one(to_of_node(dev->fwnode), priv->nr_idcs, &parent))
+ priv->nr_idcs++;
+ }
+
+ /* Setup initial state APLIC interrupts */
+ aplic_init_hw_irqs(priv);
+
+ return 0;
+}
+
+static int aplic_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ bool msi_mode = false;
+ void __iomem *regs;
+ int rc;
+
+ /* Map the MMIO registers */
+ regs = devm_platform_ioremap_resource(pdev, 0);
+ if (!regs) {
+ dev_err(dev, "failed map MMIO registers\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * If msi-parent property is present then setup APLIC MSI
+ * mode otherwise setup APLIC direct mode.
+ */
+ if (is_of_node(dev->fwnode))
+ msi_mode = of_property_present(to_of_node(dev->fwnode), "msi-parent");
+ if (msi_mode)
+ rc = -ENODEV;
+ else
+ rc = aplic_direct_setup(dev, regs);
+ if (rc)
+ dev_err(dev, "failed to setup APLIC in %s mode\n", msi_mode ? "MSI" : "direct");
+
+ return rc;
+}
+
+static const struct of_device_id aplic_match[] = {
+ { .compatible = "riscv,aplic" },
+ {}
+};
+
+static struct platform_driver aplic_driver = {
+ .driver = {
+ .name = "riscv-aplic",
+ .of_match_table = aplic_match,
+ },
+ .probe = aplic_probe,
+};
+builtin_platform_driver(aplic_driver);
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
new file mode 100644
index 0000000..4cfbadf
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_APLIC_MAIN_H
+#define _IRQ_RISCV_APLIC_MAIN_H
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+#define APLIC_DEFAULT_PRIORITY 1
+
+struct aplic_msicfg {
+ phys_addr_t base_ppn;
+ u32 hhxs;
+ u32 hhxw;
+ u32 lhxs;
+ u32 lhxw;
+};
+
+struct aplic_priv {
+ struct device *dev;
+ u32 gsi_base;
+ u32 nr_irqs;
+ u32 nr_idcs;
+ void __iomem *regs;
+ struct aplic_msicfg msicfg;
+};
+
+void aplic_irq_unmask(struct irq_data *d);
+void aplic_irq_mask(struct irq_data *d);
+int aplic_irq_set_type(struct irq_data *d, unsigned int type);
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+ unsigned long *hwirq, unsigned int *type);
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs);
+int aplic_direct_setup(struct device *dev, void __iomem *regs);
+
+#endif
diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
new file mode 100644
index 0000000..ec8f7df
--- /dev/null
+++ b/include/linux/irqchip/riscv-aplic.h
@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
+#define __LINUX_IRQCHIP_RISCV_APLIC_H
+
+#include <linux/bitops.h>
+
+#define APLIC_MAX_IDC BIT(14)
+#define APLIC_MAX_SOURCE 1024
+
+#define APLIC_DOMAINCFG 0x0000
+#define APLIC_DOMAINCFG_RDONLY 0x80000000
+#define APLIC_DOMAINCFG_IE BIT(8)
+#define APLIC_DOMAINCFG_DM BIT(2)
+#define APLIC_DOMAINCFG_BE BIT(0)
+
+#define APLIC_SOURCECFG_BASE 0x0004
+#define APLIC_SOURCECFG_D BIT(10)
+#define APLIC_SOURCECFG_CHILDIDX_MASK 0x000003ff
+#define APLIC_SOURCECFG_SM_MASK 0x00000007
+#define APLIC_SOURCECFG_SM_INACTIVE 0x0
+#define APLIC_SOURCECFG_SM_DETACH 0x1
+#define APLIC_SOURCECFG_SM_EDGE_RISE 0x4
+#define APLIC_SOURCECFG_SM_EDGE_FALL 0x5
+#define APLIC_SOURCECFG_SM_LEVEL_HIGH 0x6
+#define APLIC_SOURCECFG_SM_LEVEL_LOW 0x7
+
+#define APLIC_MMSICFGADDR 0x1bc0
+#define APLIC_MMSICFGADDRH 0x1bc4
+#define APLIC_SMSICFGADDR 0x1bc8
+#define APLIC_SMSICFGADDRH 0x1bcc
+
+#ifdef CONFIG_RISCV_M_MODE
+#define APLIC_xMSICFGADDR APLIC_MMSICFGADDR
+#define APLIC_xMSICFGADDRH APLIC_MMSICFGADDRH
+#else
+#define APLIC_xMSICFGADDR APLIC_SMSICFGADDR
+#define APLIC_xMSICFGADDRH APLIC_SMSICFGADDRH
+#endif
+
+#define APLIC_xMSICFGADDRH_L BIT(31)
+#define APLIC_xMSICFGADDRH_HHXS_MASK 0x1f
+#define APLIC_xMSICFGADDRH_HHXS_SHIFT 24
+#define APLIC_xMSICFGADDRH_HHXS (APLIC_xMSICFGADDRH_HHXS_MASK << \
+ APLIC_xMSICFGADDRH_HHXS_SHIFT)
+#define APLIC_xMSICFGADDRH_LHXS_MASK 0x7
+#define APLIC_xMSICFGADDRH_LHXS_SHIFT 20
+#define APLIC_xMSICFGADDRH_LHXS (APLIC_xMSICFGADDRH_LHXS_MASK << \
+ APLIC_xMSICFGADDRH_LHXS_SHIFT)
+#define APLIC_xMSICFGADDRH_HHXW_MASK 0x7
+#define APLIC_xMSICFGADDRH_HHXW_SHIFT 16
+#define APLIC_xMSICFGADDRH_HHXW (APLIC_xMSICFGADDRH_HHXW_MASK << \
+ APLIC_xMSICFGADDRH_HHXW_SHIFT)
+#define APLIC_xMSICFGADDRH_LHXW_MASK 0xf
+#define APLIC_xMSICFGADDRH_LHXW_SHIFT 12
+#define APLIC_xMSICFGADDRH_LHXW (APLIC_xMSICFGADDRH_LHXW_MASK << \
+ APLIC_xMSICFGADDRH_LHXW_SHIFT)
+#define APLIC_xMSICFGADDRH_BAPPN_MASK 0xfff
+#define APLIC_xMSICFGADDRH_BAPPN_SHIFT 0
+#define APLIC_xMSICFGADDRH_BAPPN (APLIC_xMSICFGADDRH_BAPPN_MASK << \
+ APLIC_xMSICFGADDRH_BAPPN_SHIFT)
+
+#define APLIC_xMSICFGADDR_PPN_SHIFT 12
+
+#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
+ (BIT(__lhxs) - 1)
+
+#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
+ (BIT(__lhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
+ ((__lhxs))
+#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
+ (APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
+ APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
+
+#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
+ (BIT(__hhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
+ ((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
+#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
+ (APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
+ APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
+
+#define APLIC_IRQBITS_PER_REG 32
+
+#define APLIC_SETIP_BASE 0x1c00
+#define APLIC_SETIPNUM 0x1cdc
+
+#define APLIC_CLRIP_BASE 0x1d00
+#define APLIC_CLRIPNUM 0x1ddc
+
+#define APLIC_SETIE_BASE 0x1e00
+#define APLIC_SETIENUM 0x1edc
+
+#define APLIC_CLRIE_BASE 0x1f00
+#define APLIC_CLRIENUM 0x1fdc
+
+#define APLIC_SETIPNUM_LE 0x2000
+#define APLIC_SETIPNUM_BE 0x2004
+
+#define APLIC_GENMSI 0x3000
+
+#define APLIC_TARGET_BASE 0x3004
+#define APLIC_TARGET_HART_IDX_SHIFT 18
+#define APLIC_TARGET_HART_IDX_MASK 0x3fff
+#define APLIC_TARGET_HART_IDX (APLIC_TARGET_HART_IDX_MASK << \
+ APLIC_TARGET_HART_IDX_SHIFT)
+#define APLIC_TARGET_GUEST_IDX_SHIFT 12
+#define APLIC_TARGET_GUEST_IDX_MASK 0x3f
+#define APLIC_TARGET_GUEST_IDX (APLIC_TARGET_GUEST_IDX_MASK << \
+ APLIC_TARGET_GUEST_IDX_SHIFT)
+#define APLIC_TARGET_IPRIO_SHIFT 0
+#define APLIC_TARGET_IPRIO_MASK 0xff
+#define APLIC_TARGET_IPRIO (APLIC_TARGET_IPRIO_MASK << \
+ APLIC_TARGET_IPRIO_SHIFT)
+#define APLIC_TARGET_EIID_SHIFT 0
+#define APLIC_TARGET_EIID_MASK 0x7ff
+#define APLIC_TARGET_EIID (APLIC_TARGET_EIID_MASK << \
+ APLIC_TARGET_EIID_SHIFT)
+
+#define APLIC_IDC_BASE 0x4000
+#define APLIC_IDC_SIZE 32
+
+#define APLIC_IDC_IDELIVERY 0x00
+
+#define APLIC_IDC_IFORCE 0x04
+
+#define APLIC_IDC_ITHRESHOLD 0x08
+
+#define APLIC_IDC_TOPI 0x18
+#define APLIC_IDC_TOPI_ID_SHIFT 16
+#define APLIC_IDC_TOPI_ID_MASK 0x3ff
+#define APLIC_IDC_TOPI_ID (APLIC_IDC_TOPI_ID_MASK << \
+ APLIC_IDC_TOPI_ID_SHIFT)
+#define APLIC_IDC_TOPI_PRIO_SHIFT 0
+#define APLIC_IDC_TOPI_PRIO_MASK 0xff
+#define APLIC_IDC_TOPI_PRIO (APLIC_IDC_TOPI_PRIO_MASK << \
+ APLIC_IDC_TOPI_PRIO_SHIFT)
+
+#define APLIC_IDC_CLAIMI 0x1c
+
+#endif
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