2019-06-03 13:44:50 +08:00
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// SPDX-License-Identifier: GPL-2.0-only
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irqchip: Add per-cpu interrupt partitioning library
We've unfortunately started seeing a situation where percpu interrupts
are partitioned in the system: one arbitrary set of CPUs has an
interrupt connected to a type of device, while another disjoint
set of CPUs has the same interrupt connected to another type of device.
This makes it impossible to have a device driver requesting this interrupt
using the current percpu-interrupt abstraction, as the same interrupt number
is now potentially claimed by at least two drivers, and we forbid interrupt
sharing on per-cpu interrupt.
A solution to this is to turn things upside down. Let's assume that our
system describes all the possible partitions for a given interrupt, and
give each of them a unique identifier. It is then possible to create
a namespace where the affinity identifier itself is a form of interrupt
number. At this point, it becomes easy to implement a set of partitions
as a cascaded irqchip, each affinity identifier being the HW irq.
This allows us to keep a number of nice properties:
- Each partition results in a separate percpu-interrupt (with a restrictied
affinity), which keeps drivers happy.
- Because the underlying interrupt is still per-cpu, the overhead of
the indirection can be kept pretty minimal.
- The core code can ignore most of that crap.
For that purpose, we implement a small library that deals with some of
the boilerplate code, relying on platform-specific drivers to provide
a description of the affinity sets and a set of callbacks.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/1460365075-7316-4-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-11 16:57:53 +08:00
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/*
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* Copyright (C) 2016 ARM Limited, All Rights Reserved.
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*/
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#include <linux/bitops.h>
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#include <linux/interrupt.h>
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#include <linux/irqchip.h>
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#include <linux/irqchip/chained_irq.h>
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#include <linux/irqchip/irq-partition-percpu.h>
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#include <linux/irqdomain.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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struct partition_desc {
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int nr_parts;
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struct partition_affinity *parts;
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struct irq_domain *domain;
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struct irq_desc *chained_desc;
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unsigned long *bitmap;
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struct irq_domain_ops ops;
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};
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static bool partition_check_cpu(struct partition_desc *part,
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unsigned int cpu, unsigned int hwirq)
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{
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return cpumask_test_cpu(cpu, &part->parts[hwirq].mask);
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}
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static void partition_irq_mask(struct irq_data *d)
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{
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struct partition_desc *part = irq_data_get_irq_chip_data(d);
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struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
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struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
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if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
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chip->irq_mask)
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chip->irq_mask(data);
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}
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static void partition_irq_unmask(struct irq_data *d)
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{
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struct partition_desc *part = irq_data_get_irq_chip_data(d);
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struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
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struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
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if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
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chip->irq_unmask)
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chip->irq_unmask(data);
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}
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static int partition_irq_set_irqchip_state(struct irq_data *d,
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enum irqchip_irq_state which,
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bool val)
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{
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struct partition_desc *part = irq_data_get_irq_chip_data(d);
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struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
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struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
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if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
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chip->irq_set_irqchip_state)
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return chip->irq_set_irqchip_state(data, which, val);
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return -EINVAL;
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}
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static int partition_irq_get_irqchip_state(struct irq_data *d,
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enum irqchip_irq_state which,
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bool *val)
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{
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struct partition_desc *part = irq_data_get_irq_chip_data(d);
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struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
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struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
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if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
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chip->irq_get_irqchip_state)
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return chip->irq_get_irqchip_state(data, which, val);
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return -EINVAL;
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}
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static int partition_irq_set_type(struct irq_data *d, unsigned int type)
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{
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struct partition_desc *part = irq_data_get_irq_chip_data(d);
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struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
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struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
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if (chip->irq_set_type)
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return chip->irq_set_type(data, type);
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return -EINVAL;
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}
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static void partition_irq_print_chip(struct irq_data *d, struct seq_file *p)
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{
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struct partition_desc *part = irq_data_get_irq_chip_data(d);
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struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
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struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
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seq_printf(p, " %5s-%lu", chip->name, data->hwirq);
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}
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static struct irq_chip partition_irq_chip = {
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.irq_mask = partition_irq_mask,
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.irq_unmask = partition_irq_unmask,
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.irq_set_type = partition_irq_set_type,
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.irq_get_irqchip_state = partition_irq_get_irqchip_state,
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.irq_set_irqchip_state = partition_irq_set_irqchip_state,
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.irq_print_chip = partition_irq_print_chip,
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};
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static void partition_handle_irq(struct irq_desc *desc)
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{
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struct partition_desc *part = irq_desc_get_handler_data(desc);
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struct irq_chip *chip = irq_desc_get_chip(desc);
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int cpu = smp_processor_id();
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int hwirq;
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chained_irq_enter(chip, desc);
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for_each_set_bit(hwirq, part->bitmap, part->nr_parts) {
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if (partition_check_cpu(part, cpu, hwirq))
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break;
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}
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2021-05-05 00:42:18 +08:00
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if (unlikely(hwirq == part->nr_parts))
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irqchip: Add per-cpu interrupt partitioning library
We've unfortunately started seeing a situation where percpu interrupts
are partitioned in the system: one arbitrary set of CPUs has an
interrupt connected to a type of device, while another disjoint
set of CPUs has the same interrupt connected to another type of device.
This makes it impossible to have a device driver requesting this interrupt
using the current percpu-interrupt abstraction, as the same interrupt number
is now potentially claimed by at least two drivers, and we forbid interrupt
sharing on per-cpu interrupt.
A solution to this is to turn things upside down. Let's assume that our
system describes all the possible partitions for a given interrupt, and
give each of them a unique identifier. It is then possible to create
a namespace where the affinity identifier itself is a form of interrupt
number. At this point, it becomes easy to implement a set of partitions
as a cascaded irqchip, each affinity identifier being the HW irq.
This allows us to keep a number of nice properties:
- Each partition results in a separate percpu-interrupt (with a restrictied
affinity), which keeps drivers happy.
- Because the underlying interrupt is still per-cpu, the overhead of
the indirection can be kept pretty minimal.
- The core code can ignore most of that crap.
For that purpose, we implement a small library that deals with some of
the boilerplate code, relying on platform-specific drivers to provide
a description of the affinity sets and a set of callbacks.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/1460365075-7316-4-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-11 16:57:53 +08:00
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handle_bad_irq(desc);
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2021-05-05 00:42:18 +08:00
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else
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generic_handle_domain_irq(part->domain, hwirq);
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irqchip: Add per-cpu interrupt partitioning library
We've unfortunately started seeing a situation where percpu interrupts
are partitioned in the system: one arbitrary set of CPUs has an
interrupt connected to a type of device, while another disjoint
set of CPUs has the same interrupt connected to another type of device.
This makes it impossible to have a device driver requesting this interrupt
using the current percpu-interrupt abstraction, as the same interrupt number
is now potentially claimed by at least two drivers, and we forbid interrupt
sharing on per-cpu interrupt.
A solution to this is to turn things upside down. Let's assume that our
system describes all the possible partitions for a given interrupt, and
give each of them a unique identifier. It is then possible to create
a namespace where the affinity identifier itself is a form of interrupt
number. At this point, it becomes easy to implement a set of partitions
as a cascaded irqchip, each affinity identifier being the HW irq.
This allows us to keep a number of nice properties:
- Each partition results in a separate percpu-interrupt (with a restrictied
affinity), which keeps drivers happy.
- Because the underlying interrupt is still per-cpu, the overhead of
the indirection can be kept pretty minimal.
- The core code can ignore most of that crap.
For that purpose, we implement a small library that deals with some of
the boilerplate code, relying on platform-specific drivers to provide
a description of the affinity sets and a set of callbacks.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/1460365075-7316-4-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-11 16:57:53 +08:00
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chained_irq_exit(chip, desc);
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}
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static int partition_domain_alloc(struct irq_domain *domain, unsigned int virq,
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unsigned int nr_irqs, void *arg)
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{
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int ret;
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irq_hw_number_t hwirq;
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unsigned int type;
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struct irq_fwspec *fwspec = arg;
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struct partition_desc *part;
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BUG_ON(nr_irqs != 1);
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ret = domain->ops->translate(domain, fwspec, &hwirq, &type);
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if (ret)
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return ret;
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part = domain->host_data;
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set_bit(hwirq, part->bitmap);
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irq_set_chained_handler_and_data(irq_desc_get_irq(part->chained_desc),
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partition_handle_irq, part);
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irq_set_percpu_devid_partition(virq, &part->parts[hwirq].mask);
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irq_domain_set_info(domain, virq, hwirq, &partition_irq_chip, part,
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handle_percpu_devid_irq, NULL, NULL);
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irq_set_status_flags(virq, IRQ_NOAUTOEN);
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return 0;
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}
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static void partition_domain_free(struct irq_domain *domain, unsigned int virq,
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unsigned int nr_irqs)
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{
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struct irq_data *d;
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BUG_ON(nr_irqs != 1);
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d = irq_domain_get_irq_data(domain, virq);
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irq_set_handler(virq, NULL);
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irq_domain_reset_irq_data(d);
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}
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int partition_translate_id(struct partition_desc *desc, void *partition_id)
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{
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struct partition_affinity *part = NULL;
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int i;
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for (i = 0; i < desc->nr_parts; i++) {
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if (desc->parts[i].partition_id == partition_id) {
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part = &desc->parts[i];
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break;
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}
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}
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if (WARN_ON(!part)) {
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pr_err("Failed to find partition\n");
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return -EINVAL;
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}
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return i;
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}
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struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
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struct partition_affinity *parts,
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int nr_parts,
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int chained_irq,
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const struct irq_domain_ops *ops)
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{
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struct partition_desc *desc;
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struct irq_domain *d;
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BUG_ON(!ops->select || !ops->translate);
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desc = kzalloc(sizeof(*desc), GFP_KERNEL);
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if (!desc)
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return NULL;
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desc->ops = *ops;
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desc->ops.free = partition_domain_free;
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desc->ops.alloc = partition_domain_alloc;
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d = irq_domain_create_linear(fwnode, nr_parts, &desc->ops, desc);
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if (!d)
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goto out;
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desc->domain = d;
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treewide: kzalloc() -> kcalloc()
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:
kzalloc(a * b, gfp)
with:
kcalloc(a * b, gfp)
as well as handling cases of:
kzalloc(a * b * c, gfp)
with:
kzalloc(array3_size(a, b, c), gfp)
as it's slightly less ugly than:
kzalloc_array(array_size(a, b), c, gfp)
This does, however, attempt to ignore constant size factors like:
kzalloc(4 * 1024, gfp)
though any constants defined via macros get caught up in the conversion.
Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.
The Coccinelle script used for this was:
// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@
(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)
// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@
(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
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kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)
// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@
(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)
// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@
- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)
// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@
(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)
// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@
(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)
// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@
(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)
// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@
(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)
// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@
(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-13 05:03:40 +08:00
|
|
|
desc->bitmap = kcalloc(BITS_TO_LONGS(nr_parts), sizeof(long),
|
irqchip: Add per-cpu interrupt partitioning library
We've unfortunately started seeing a situation where percpu interrupts
are partitioned in the system: one arbitrary set of CPUs has an
interrupt connected to a type of device, while another disjoint
set of CPUs has the same interrupt connected to another type of device.
This makes it impossible to have a device driver requesting this interrupt
using the current percpu-interrupt abstraction, as the same interrupt number
is now potentially claimed by at least two drivers, and we forbid interrupt
sharing on per-cpu interrupt.
A solution to this is to turn things upside down. Let's assume that our
system describes all the possible partitions for a given interrupt, and
give each of them a unique identifier. It is then possible to create
a namespace where the affinity identifier itself is a form of interrupt
number. At this point, it becomes easy to implement a set of partitions
as a cascaded irqchip, each affinity identifier being the HW irq.
This allows us to keep a number of nice properties:
- Each partition results in a separate percpu-interrupt (with a restrictied
affinity), which keeps drivers happy.
- Because the underlying interrupt is still per-cpu, the overhead of
the indirection can be kept pretty minimal.
- The core code can ignore most of that crap.
For that purpose, we implement a small library that deals with some of
the boilerplate code, relying on platform-specific drivers to provide
a description of the affinity sets and a set of callbacks.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/1460365075-7316-4-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-11 16:57:53 +08:00
|
|
|
GFP_KERNEL);
|
|
|
|
if (WARN_ON(!desc->bitmap))
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
desc->chained_desc = irq_to_desc(chained_irq);
|
|
|
|
desc->nr_parts = nr_parts;
|
|
|
|
desc->parts = parts;
|
|
|
|
|
|
|
|
return desc;
|
|
|
|
out:
|
|
|
|
if (d)
|
|
|
|
irq_domain_remove(d);
|
|
|
|
kfree(desc);
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct irq_domain *partition_get_domain(struct partition_desc *dsc)
|
|
|
|
{
|
|
|
|
if (dsc)
|
|
|
|
return dsc->domain;
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|