The Amazon's Annapurna Labs Fabric Interrupt Controller has 32 inputs
lines. A FIC (Fabric Interrupt Controller) may be cascaded into another FIC
or directly to the main CPU Interrupt Controller (e.g. GIC).
This driver introduces support for initialization based on device-tree
compatibility and run-time for dynamically added FICs (e.g. FICs embedded
to PCIe devices).
Signed-off-by: Talel Shenhar <talel@xxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/irqchip/Kconfig | 11 ++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-al-fic.c | 346 +++++++++++++++++++++++++++++++++++++++++
include/linux/irqchip/al-fic.h | 21 +++
5 files changed, 386 insertions(+)
create mode 100644 drivers/irqchip/irq-al-fic.c
create mode 100644 include/linux/irqchip/al-fic.h
diff --git a/MAINTAINERS b/MAINTAINERS
index f485597..c28a97f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1209,6 +1209,13 @@ S: Maintained
F: Documentation/devicetree/bindings/interrupt-controller/arm,vic.txt
F: drivers/irqchip/irq-vic.c
+AMAZON ANNAPURNA LABS FIC DRIVER
+M: Talel Shenhar <talel@xxxxxxxxxx>
+S: Maintained
+F: Documentation/devicetree/bindings/interrupt-controller/amazon,al-fic.txt
+F: drivers/irqchip/irq-al-fic.c
+F: include/linux/irqchip/al-fic.h
+
ARM SMMU DRIVERS
M: Will Deacon <will.deacon@xxxxxxx>
R: Robin Murphy <robin.murphy@xxxxxxx>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 51a5ef0..1e51f0f 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -89,6 +89,17 @@ config ALPINE_MSI
select PCI_MSI
select GENERIC_IRQ_CHIP
+config AL_FIC
+ bool "Amazon's Annapurna Labs Fabric Interrupt Controller"
+ depends on OF || COMPILE_TEST
+ select GENERIC_IRQ_CHIP
+ select IRQ_DOMAIN
+ select GENERIC_IRQ_MULTI_HANDLER
+ select IRQ_DOMAIN_HIERARCHY
+ select SPARSE_IRQ
+ help
+ Support Amazon's Annapurna Labs Fabric Interrupt Controller.
+
config ATMEL_AIC_IRQ
bool
select GENERIC_IRQ_CHIP
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 794c13d..a20eba5 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_IRQCHIP) += irqchip.o
+obj-$(CONFIG_AL_FIC) += irq-al-fic.o
obj-$(CONFIG_ALPINE_MSI) += irq-alpine-msi.o
obj-$(CONFIG_ATH79) += irq-ath79-cpu.o
obj-$(CONFIG_ATH79) += irq-ath79-misc.o
diff --git a/drivers/irqchip/irq-al-fic.c b/drivers/irqchip/irq-al-fic.c
new file mode 100644
index 0000000..d881d42
--- /dev/null
+++ b/drivers/irqchip/irq-al-fic.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/irqchip/al-fic.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+/* FIC Registers */
+#define AL_FIC_CAUSE 0x00
+#define AL_FIC_MASK 0x10
+#define AL_FIC_CONTROL 0x28
+
+#define CONTROL_TRIGGER_RISING BIT(3)
+#define CONTROL_MASK_MSI_X BIT(5)
+
+#define NR_FIC_IRQS 32
+
+MODULE_AUTHOR("Talel Shenhar");
+MODULE_DESCRIPTION("Amazon's Annapurna Labs Interrupt Controller Driver");
+MODULE_LICENSE("GPL v2");
+
+enum al_fic_state {
+ AL_FIC_CLEAN = 0,
+ AL_FIC_CONFIGURED_LEVEL,
+ AL_FIC_CONFIGURED_RAISING_EDGE,
+};
+
+struct al_fic {
+ void __iomem *base;
+ struct irq_domain *domain;
+ const char *name;
+ unsigned int parent_irq;
+ enum al_fic_state state;
+};
+
+static void al_fic_set_trigger(struct al_fic *fic,
+ struct irq_chip_generic *gc,
+ enum al_fic_state new_state)
+{
+ irq_flow_handler_t handler;
+ u32 control = readl(fic->base + AL_FIC_CONTROL);
+
+ if (new_state == AL_FIC_CONFIGURED_LEVEL) {
+ handler = handle_level_irq;
+ control &= ~CONTROL_TRIGGER_RISING;
+ } else {
+ handler = handle_edge_irq;
+ control |= CONTROL_TRIGGER_RISING;
+ }
+ gc->chip_types->handler = handler;
+ fic->state = new_state;
+ writel(control, fic->base + AL_FIC_CONTROL);
+}
+
+static int al_fic_irq_set_type(struct irq_data *data, unsigned int flow_type)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct al_fic *fic = gc->private;
+ enum al_fic_state new_state;
+ int ret = 0;
+
+ irq_gc_lock(gc);
+
+ if (!(flow_type & IRQ_TYPE_LEVEL_HIGH) &&
+ !(flow_type & IRQ_TYPE_EDGE_RISING)) {
+ pr_err("fic doesn't support flow type %d\n", flow_type);
+ ret = -EPERM;
+ goto err;
+ }
+
+ new_state = (flow_type & IRQ_TYPE_LEVEL_HIGH) ?
+ AL_FIC_CONFIGURED_LEVEL : AL_FIC_CONFIGURED_RAISING_EDGE;
+
+ /* A given FIC instance can be either all level or all edge triggered.
+ * This is generally fixed depending on what pieces of HW it's wired up
+ * to.
+ *
+ * We configure it based on the sensitivity of the first source
+ * being setup, and reject any subsequent attempt at configuring it in a
+ * different way.
+ */
+ if (fic->state == AL_FIC_CLEAN) {
+ al_fic_set_trigger(fic, gc, new_state);
+ } else if (fic->state != new_state) {
+ pr_err("fic %s state already configured to %d\n",
+ fic->name, fic->state);
+ ret = -EPERM;
+ goto err;
+ }
+
+err:
+ irq_gc_unlock(gc);
+
+ return ret;
+}
+
+static void al_fic_irq_handler(struct irq_desc *desc)
+{
+ struct al_fic *fic = irq_desc_get_handler_data(desc);
+ struct irq_domain *domain = fic->domain;
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
+ struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
+ unsigned long pending;
+ unsigned int irq;
+ u32 hwirq;
+
+ chained_irq_enter(irqchip, desc);
+
+ pending = readl(fic->base + AL_FIC_CAUSE);
+ pending &= ~gc->mask_cache;
+
+ for_each_set_bit(hwirq, &pending, domain->revmap_size) {
+ irq = irq_find_mapping(domain, hwirq);
+ generic_handle_irq(irq);
+ }
+
+ chained_irq_exit(irqchip, desc);
+}
+
+static int al_fic_register(struct device_node *node,
+ struct al_fic *fic)
+{
+ struct irq_chip_generic *gc;
+ int ret;
+
+ fic->domain = irq_domain_add_linear(node,
+ NR_FIC_IRQS,
+ &irq_generic_chip_ops,
+ fic);
+ if (!fic->domain) {
+ pr_err("fail to add irq domain\n");
+ return -ENOMEM;
+ }
+
+ ret = irq_alloc_domain_generic_chips(fic->domain,
+ NR_FIC_IRQS,
+ 1, fic->name,
+ handle_level_irq,
+ 0, 0, IRQ_GC_INIT_MASK_CACHE);
+ if (ret) {
+ pr_err("fail to allocate generic chip (%d)\n", ret);
+ goto err_domain_remove;
+ }
+
+ gc = irq_get_domain_generic_chip(fic->domain, 0);
+ gc->reg_base = fic->base;
+ gc->chip_types->regs.mask = AL_FIC_MASK;
+ gc->chip_types->regs.ack = AL_FIC_CAUSE;
+ gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
+ gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;
+ gc->chip_types->chip.irq_ack = irq_gc_ack_clr_bit;
+ gc->chip_types->chip.irq_set_type = al_fic_irq_set_type;
+ gc->chip_types->chip.flags = IRQCHIP_SKIP_SET_WAKE;
+ gc->private = fic;
+
+ irq_set_chained_handler_and_data(fic->parent_irq,
+ al_fic_irq_handler,
+ fic);
+ return 0;
+
+err_domain_remove:
+ irq_domain_remove(fic->domain);
+
+ return ret;
+}
+
+/**
+ * al_fic_wire_get_domain() - returns the irq_domain assigned to this fic
+ * @fic: fic context configured to Legacy mode
+ *
+ * A fic configured to Legacy mode requires domain to map the hwirqs to virtual
+ * irqs. This API supplies the domain allocated to this fic.
+ *
+ * Returns the irq_domain or ERR_PTR on error.
+ */
+struct irq_domain *al_fic_wire_get_domain(struct al_fic *fic)
+{
+ if (!fic)
+ return ERR_PTR(-EINVAL);
+ if (!fic->domain)
+ return ERR_PTR(-EPERM);
+
+ return fic->domain;
+}
+EXPORT_SYMBOL_GPL(al_fic_wire_get_domain);
+
+static void al_fic_hw_init(struct al_fic *fic)
+{
+ u32 control = CONTROL_MASK_MSI_X;
+
+ /* mask out all interrupts */
+ writel(0xFFFFFFFF, fic->base + AL_FIC_MASK);
+
+ /* clear any pending interrupt */
+ writel(0, fic->base + AL_FIC_CAUSE);
+
+ writel(control, fic->base + AL_FIC_CONTROL);
+}
+
+/**
+ * al_fic_wire_init() - initialize and configure fic in wire mode
+ * @of_node: optional pointer to interrupt controller's device tree node.
+ * @base: mmio to fic register
+ * @name: name of the fic
+ * @parent_irq: interrupt of parent
+ *
+ * This API will configure the fic hardware to to work in wire mode.
+ * In wire mode, fic hardware is generating a wire ("wired") interrupt.
+ * Interrupt can be generated based on positive edge or level - configuration is
+ * to be determined based on connected hardware to this fic.
+ *
+ * Returns fic context that allows the user to obtain the irq_domain by using
+ * al_fic_wire_get_domain().
+ */
+struct al_fic *al_fic_wire_init(struct device_node *node,
+ void __iomem *base,
+ const char *name,
+ unsigned int parent_irq)
+{
+ struct al_fic *fic;
+ int ret;
+
+ if (!base)
+ return ERR_PTR(-EINVAL);
+
+ fic = kzalloc(sizeof(*fic), GFP_KERNEL);
+ if (!fic)
+ return ERR_PTR(-ENOMEM);
+
+ fic->base = base;
+ fic->parent_irq = parent_irq;
+ fic->name = (name ?: "al-fic-wire");
+
+ al_fic_hw_init(fic);
+
+ ret = al_fic_register(node, fic);
+ if (ret) {
+ pr_err("fail to register irqchip\n");
+ goto err_free;
+ }
+
+ pr_debug("%s initialized successfully in Legacy mode (parent-irq=%u)\n",
+ fic->name, parent_irq);
+
+ return fic;
+
+err_free:
+ kfree(fic);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(al_fic_wire_init);
+
+/**
+ * al_fic_cleanup() - free all resources allocated by fic
+ * @fic: pointer to fic context
+ *
+ * This API will release the domain (in case of wire mode) and will free the
+ * context allocated for this fic.
+ * Caller should call this API only after all interrupts were released.
+ *
+ * Returns 0 on success or negative error code.
+ */
+int al_fic_cleanup(struct al_fic *fic)
+{
+ if (!fic)
+ return -EINVAL;
+
+ if (fic->domain) {
+ struct irq_chip_generic *gc;
+
+ gc = irq_get_domain_generic_chip(fic->domain, 0);
+ if (IS_ERR(gc)) {
+ pr_err("%s was not able to grab gc for fic (%lu)\n",
+ __func__, PTR_ERR(gc));
+ return PTR_ERR(gc);
+ }
+
+ irq_destroy_generic_chip(gc, 0, 0, 0);
+ irq_domain_remove(fic->domain);
+ }
+
+ kfree(fic);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(al_fic_cleanup);
+
+static int __init al_fic_init_dt(struct device_node *node,
+ struct device_node *parent)
+{
+ int ret;
+ void __iomem *base;
+ unsigned int parent_irq;
+ struct al_fic *fic;
+
+ if (!parent) {
+ pr_err("%s: unsupported - device require a parent\n",
+ node->name);
+ return -EINVAL;
+ }
+
+ base = of_iomap(node, 0);
+ if (!base) {
+ pr_err("%s: fail to map memory\n", node->name);
+ return -ENOMEM;
+ }
+
+ parent_irq = irq_of_parse_and_map(node, 0);
+ if (!parent_irq) {
+ pr_err("%s: fail to map irq\n", node->name);
+ ret = -EINVAL;
+ goto err_unmap;
+ }
+
+ fic = al_fic_wire_init(node,
+ base,
+ node->name,
+ parent_irq);
+ if (IS_ERR(fic)) {
+ pr_err("%s: fail to initialize irqchip (%lu)\n",
+ node->name,
+ PTR_ERR(fic));
+ ret = PTR_ERR(fic);
+ goto err_irq_dispose;
+ }
+
+ return 0;
+
+err_irq_dispose:
+ irq_dispose_mapping(parent_irq);
+err_unmap:
+ iounmap(base);
+
+ return ret;
+}
+
+IRQCHIP_DECLARE(al_fic, "amazon,al-fic", al_fic_init_dt);
diff --git a/include/linux/irqchip/al-fic.h b/include/linux/irqchip/al-fic.h
new file mode 100644
index 0000000..0833749
--- /dev/null
+++ b/include/linux/irqchip/al-fic.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ */
+
+#ifndef _AL_FIC_H_
+#define _AL_FIC_H_
+
+#include <linux/irqdomain.h>
+
+struct al_fic;
+
+struct irq_domain *al_fic_wire_get_domain(struct al_fic *fic);
+
+struct al_fic *al_fic_wire_init(struct device_node *node,
+ void __iomem *base,
+ const char *name,
+ unsigned int parent_irq);
+int al_fic_cleanup(struct al_fic *fic);
+
+#endif
--
2.7.4
