mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Strashko, Grygorii](/assets/img/avatar_default.png)
The below call chain generates "scheduling while atomic" backtrace and causes system crash when Keystone 2 IRQ chip driver is used with RT-kernel: gic_handle_irq() |-__handle_domain_irq() |-generic_handle_irq() |-keystone_irq_handler() |-regmap_read() |-regmap_lock_spinlock() |-rt_spin_lock() The reason is that Keystone driver dispatches IRQ using chained IRQ handler and accesses I/O memory through syscon->regmap(mmio) which is implemented as fast_io regmap and uses regular spinlocks for synchronization, but spinlocks transformed to rt_mutexes on RT. Hence, convert Keystone 2 IRQ driver to use generic irq handler instead of chained IRQ handler. This way it will be compatible with RT kernel where it will be forced thread IRQ handler while in non-RT kernel it still will be executed in HW IRQ context. Cc: Suman Anna <s-anna@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Tested-by: Suman Anna <s-anna@ti.com> Link: https://lkml.kernel.org/r/20161208233310.10329-1-grygorii.strashko@ti.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
240 lines
6 KiB
C
240 lines
6 KiB
C
/*
|
|
* Texas Instruments Keystone IRQ controller IP driver
|
|
*
|
|
* Copyright (C) 2014 Texas Instruments, Inc.
|
|
* Author: Sajesh Kumar Saran <sajesh@ti.com>
|
|
* Grygorii Strashko <grygorii.strashko@ti.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation version 2.
|
|
*
|
|
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
|
|
* kind, whether express or implied; without even the implied warranty
|
|
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#include <linux/irq.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irqdomain.h>
|
|
#include <linux/irqchip.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_platform.h>
|
|
#include <linux/mfd/syscon.h>
|
|
#include <linux/regmap.h>
|
|
|
|
/* The source ID bits start from 4 to 31 (total 28 bits)*/
|
|
#define BIT_OFS 4
|
|
#define KEYSTONE_N_IRQ (32 - BIT_OFS)
|
|
|
|
struct keystone_irq_device {
|
|
struct device *dev;
|
|
struct irq_chip chip;
|
|
u32 mask;
|
|
int irq;
|
|
struct irq_domain *irqd;
|
|
struct regmap *devctrl_regs;
|
|
u32 devctrl_offset;
|
|
raw_spinlock_t wa_lock;
|
|
};
|
|
|
|
static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq)
|
|
{
|
|
int ret;
|
|
u32 val = 0;
|
|
|
|
ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val);
|
|
if (ret < 0)
|
|
dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret);
|
|
return val;
|
|
}
|
|
|
|
static inline void
|
|
keystone_irq_writel(struct keystone_irq_device *kirq, u32 value)
|
|
{
|
|
int ret;
|
|
|
|
ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value);
|
|
if (ret < 0)
|
|
dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret);
|
|
}
|
|
|
|
static void keystone_irq_setmask(struct irq_data *d)
|
|
{
|
|
struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
|
|
|
|
kirq->mask |= BIT(d->hwirq);
|
|
dev_dbg(kirq->dev, "mask %lu [%x]\n", d->hwirq, kirq->mask);
|
|
}
|
|
|
|
static void keystone_irq_unmask(struct irq_data *d)
|
|
{
|
|
struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
|
|
|
|
kirq->mask &= ~BIT(d->hwirq);
|
|
dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask);
|
|
}
|
|
|
|
static void keystone_irq_ack(struct irq_data *d)
|
|
{
|
|
/* nothing to do here */
|
|
}
|
|
|
|
static irqreturn_t keystone_irq_handler(int irq, void *keystone_irq)
|
|
{
|
|
struct keystone_irq_device *kirq = keystone_irq;
|
|
unsigned long wa_lock_flags;
|
|
unsigned long pending;
|
|
int src, virq;
|
|
|
|
dev_dbg(kirq->dev, "start irq %d\n", irq);
|
|
|
|
pending = keystone_irq_readl(kirq);
|
|
keystone_irq_writel(kirq, pending);
|
|
|
|
dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);
|
|
|
|
pending = (pending >> BIT_OFS) & ~kirq->mask;
|
|
|
|
dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);
|
|
|
|
for (src = 0; src < KEYSTONE_N_IRQ; src++) {
|
|
if (BIT(src) & pending) {
|
|
virq = irq_find_mapping(kirq->irqd, src);
|
|
dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
|
|
src, virq);
|
|
if (!virq)
|
|
dev_warn(kirq->dev, "spurious irq detected hwirq %d, virq %d\n",
|
|
src, virq);
|
|
raw_spin_lock_irqsave(&kirq->wa_lock, wa_lock_flags);
|
|
generic_handle_irq(virq);
|
|
raw_spin_unlock_irqrestore(&kirq->wa_lock,
|
|
wa_lock_flags);
|
|
}
|
|
}
|
|
|
|
dev_dbg(kirq->dev, "end irq %d\n", irq);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
|
|
irq_hw_number_t hw)
|
|
{
|
|
struct keystone_irq_device *kirq = h->host_data;
|
|
|
|
irq_set_chip_data(virq, kirq);
|
|
irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
|
|
irq_set_probe(virq);
|
|
return 0;
|
|
}
|
|
|
|
static const struct irq_domain_ops keystone_irq_ops = {
|
|
.map = keystone_irq_map,
|
|
.xlate = irq_domain_xlate_onecell,
|
|
};
|
|
|
|
static int keystone_irq_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct device_node *np = dev->of_node;
|
|
struct keystone_irq_device *kirq;
|
|
int ret;
|
|
|
|
if (np == NULL)
|
|
return -EINVAL;
|
|
|
|
kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
|
|
if (!kirq)
|
|
return -ENOMEM;
|
|
|
|
kirq->devctrl_regs =
|
|
syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
|
|
if (IS_ERR(kirq->devctrl_regs))
|
|
return PTR_ERR(kirq->devctrl_regs);
|
|
|
|
ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
|
|
&kirq->devctrl_offset);
|
|
if (ret) {
|
|
dev_err(dev, "couldn't read the devctrl_offset offset!\n");
|
|
return ret;
|
|
}
|
|
|
|
kirq->irq = platform_get_irq(pdev, 0);
|
|
if (kirq->irq < 0) {
|
|
dev_err(dev, "no irq resource %d\n", kirq->irq);
|
|
return kirq->irq;
|
|
}
|
|
|
|
kirq->dev = dev;
|
|
kirq->mask = ~0x0;
|
|
kirq->chip.name = "keystone-irq";
|
|
kirq->chip.irq_ack = keystone_irq_ack;
|
|
kirq->chip.irq_mask = keystone_irq_setmask;
|
|
kirq->chip.irq_unmask = keystone_irq_unmask;
|
|
|
|
kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
|
|
&keystone_irq_ops, kirq);
|
|
if (!kirq->irqd) {
|
|
dev_err(dev, "IRQ domain registration failed\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
raw_spin_lock_init(&kirq->wa_lock);
|
|
|
|
platform_set_drvdata(pdev, kirq);
|
|
|
|
ret = request_irq(kirq->irq, keystone_irq_handler,
|
|
0, dev_name(dev), kirq);
|
|
if (ret) {
|
|
irq_domain_remove(kirq->irqd);
|
|
return ret;
|
|
}
|
|
|
|
/* clear all source bits */
|
|
keystone_irq_writel(kirq, ~0x0);
|
|
|
|
dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int keystone_irq_remove(struct platform_device *pdev)
|
|
{
|
|
struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
|
|
int hwirq;
|
|
|
|
free_irq(kirq->irq, kirq);
|
|
|
|
for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
|
|
irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
|
|
|
|
irq_domain_remove(kirq->irqd);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id keystone_irq_dt_ids[] = {
|
|
{ .compatible = "ti,keystone-irq", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
|
|
|
|
static struct platform_driver keystone_irq_device_driver = {
|
|
.probe = keystone_irq_probe,
|
|
.remove = keystone_irq_remove,
|
|
.driver = {
|
|
.name = "keystone_irq",
|
|
.of_match_table = of_match_ptr(keystone_irq_dt_ids),
|
|
}
|
|
};
|
|
|
|
module_platform_driver(keystone_irq_device_driver);
|
|
|
|
MODULE_AUTHOR("Texas Instruments");
|
|
MODULE_AUTHOR("Sajesh Kumar Saran");
|
|
MODULE_AUTHOR("Grygorii Strashko");
|
|
MODULE_DESCRIPTION("Keystone IRQ chip");
|
|
MODULE_LICENSE("GPL v2");
|