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kernel_optimize_test/drivers/irqchip/qcom-pdc.c
Marc Zyngier 4bbd910de1 irqchip/qcom-pdc: Fix broken locking 
[ Upstream commit a6aca2f460e203781dc41391913cc5b54f4bc0ce ]

pdc_enable_intr() serves as a primitive to qcom_pdc_gic_{en,dis}able,
and has a raw spinlock for mutual exclusion, which is uses with
interruptible primitives.

This means that this critical section can itself be interrupted.
Should the interrupt also be a PDC interrupt, and the endpoint driver
perform an irq_disable() on that interrupt, we end-up in a deadlock.

Fix this by using the irqsave/irqrestore variants of the locking
primitives.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Maulik Shah <quic_mkshah@quicinc.com>
Link: https://lore.kernel.org/r/20220224101226.88373-5-maz@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:31 +02:00

464 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2017-2019, The Linux Foundation. All rights reserved.
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/soc/qcom/irq.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/types.h>
#define PDC_MAX_IRQS 168
#define PDC_MAX_GPIO_IRQS 256
#define CLEAR_INTR(reg, intr) (reg & ~(1 << intr))
#define ENABLE_INTR(reg, intr) (reg | (1 << intr))
#define IRQ_ENABLE_BANK 0x10
#define IRQ_i_CFG 0x110
#define PDC_NO_PARENT_IRQ ~0UL
struct pdc_pin_region {
u32 pin_base;
u32 parent_base;
u32 cnt;
};
static DEFINE_RAW_SPINLOCK(pdc_lock);
static void __iomem *pdc_base;
static struct pdc_pin_region *pdc_region;
static int pdc_region_cnt;
static void pdc_reg_write(int reg, u32 i, u32 val)
{
writel_relaxed(val, pdc_base + reg + i * sizeof(u32));
}
static u32 pdc_reg_read(int reg, u32 i)
{
return readl_relaxed(pdc_base + reg + i * sizeof(u32));
}
static int qcom_pdc_gic_get_irqchip_state(struct irq_data *d,
enum irqchip_irq_state which,
bool *state)
{
if (d->hwirq == GPIO_NO_WAKE_IRQ)
return 0;
return irq_chip_get_parent_state(d, which, state);
}
static int qcom_pdc_gic_set_irqchip_state(struct irq_data *d,
enum irqchip_irq_state which,
bool value)
{
if (d->hwirq == GPIO_NO_WAKE_IRQ)
return 0;
return irq_chip_set_parent_state(d, which, value);
}
static void pdc_enable_intr(struct irq_data *d, bool on)
{
int pin_out = d->hwirq;
unsigned long flags;
u32 index, mask;
u32 enable;
index = pin_out / 32;
mask = pin_out % 32;
raw_spin_lock_irqsave(&pdc_lock, flags);
enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
raw_spin_unlock_irqrestore(&pdc_lock, flags);
}
static void qcom_pdc_gic_disable(struct irq_data *d)
{
if (d->hwirq == GPIO_NO_WAKE_IRQ)
return;
pdc_enable_intr(d, false);
irq_chip_disable_parent(d);
}
static void qcom_pdc_gic_enable(struct irq_data *d)
{
if (d->hwirq == GPIO_NO_WAKE_IRQ)
return;
pdc_enable_intr(d, true);
irq_chip_enable_parent(d);
}
static void qcom_pdc_gic_mask(struct irq_data *d)
{
if (d->hwirq == GPIO_NO_WAKE_IRQ)
return;
irq_chip_mask_parent(d);
}
static void qcom_pdc_gic_unmask(struct irq_data *d)
{
if (d->hwirq == GPIO_NO_WAKE_IRQ)
return;
irq_chip_unmask_parent(d);
}
/*
* GIC does not handle falling edge or active low. To allow falling edge and
* active low interrupts to be handled at GIC, PDC has an inverter that inverts
* falling edge into a rising edge and active low into an active high.
* For the inverter to work, the polarity bit in the IRQ_CONFIG register has to
* set as per the table below.
* Level sensitive active low LOW
* Rising edge sensitive NOT USED
* Falling edge sensitive LOW
* Dual Edge sensitive NOT USED
* Level sensitive active High HIGH
* Falling Edge sensitive NOT USED
* Rising edge sensitive HIGH
* Dual Edge sensitive HIGH
*/
enum pdc_irq_config_bits {
PDC_LEVEL_LOW = 0b000,
PDC_EDGE_FALLING = 0b010,
PDC_LEVEL_HIGH = 0b100,
PDC_EDGE_RISING = 0b110,
PDC_EDGE_DUAL = 0b111,
};
/**
* qcom_pdc_gic_set_type: Configure PDC for the interrupt
*
* @d: the interrupt data
* @type: the interrupt type
*
* If @type is edge triggered, forward that as Rising edge as PDC
* takes care of converting falling edge to rising edge signal
* If @type is level, then forward that as level high as PDC
* takes care of converting falling edge to rising edge signal
*/
static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type)
{
int pin_out = d->hwirq;
enum pdc_irq_config_bits pdc_type;
enum pdc_irq_config_bits old_pdc_type;
int ret;
if (pin_out == GPIO_NO_WAKE_IRQ)
return 0;
switch (type) {
case IRQ_TYPE_EDGE_RISING:
pdc_type = PDC_EDGE_RISING;
break;
case IRQ_TYPE_EDGE_FALLING:
pdc_type = PDC_EDGE_FALLING;
type = IRQ_TYPE_EDGE_RISING;
break;
case IRQ_TYPE_EDGE_BOTH:
pdc_type = PDC_EDGE_DUAL;
type = IRQ_TYPE_EDGE_RISING;
break;
case IRQ_TYPE_LEVEL_HIGH:
pdc_type = PDC_LEVEL_HIGH;
break;
case IRQ_TYPE_LEVEL_LOW:
pdc_type = PDC_LEVEL_LOW;
type = IRQ_TYPE_LEVEL_HIGH;
break;
default:
WARN_ON(1);
return -EINVAL;
}
old_pdc_type = pdc_reg_read(IRQ_i_CFG, pin_out);
pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
ret = irq_chip_set_type_parent(d, type);
if (ret)
return ret;
/*
* When we change types the PDC can give a phantom interrupt.
* Clear it. Specifically the phantom shows up when reconfiguring
* polarity of interrupt without changing the state of the signal
* but let's be consistent and clear it always.
*
* Doing this works because we have IRQCHIP_SET_TYPE_MASKED so the
* interrupt will be cleared before the rest of the system sees it.
*/
if (old_pdc_type != pdc_type)
irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, false);
return 0;
}
static struct irq_chip qcom_pdc_gic_chip = {
.name = "PDC",
.irq_eoi = irq_chip_eoi_parent,
.irq_mask = qcom_pdc_gic_mask,
.irq_unmask = qcom_pdc_gic_unmask,
.irq_disable = qcom_pdc_gic_disable,
.irq_enable = qcom_pdc_gic_enable,
.irq_get_irqchip_state = qcom_pdc_gic_get_irqchip_state,
.irq_set_irqchip_state = qcom_pdc_gic_set_irqchip_state,
.irq_retrigger = irq_chip_retrigger_hierarchy,
.irq_set_type = qcom_pdc_gic_set_type,
.flags = IRQCHIP_MASK_ON_SUSPEND |
IRQCHIP_SET_TYPE_MASKED |
IRQCHIP_SKIP_SET_WAKE |
IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND,
.irq_set_vcpu_affinity = irq_chip_set_vcpu_affinity_parent,
.irq_set_affinity = irq_chip_set_affinity_parent,
};
static irq_hw_number_t get_parent_hwirq(int pin)
{
int i;
struct pdc_pin_region *region;
for (i = 0; i < pdc_region_cnt; i++) {
region = &pdc_region[i];
if (pin >= region->pin_base &&
pin < region->pin_base + region->cnt)
return (region->parent_base + pin - region->pin_base);
}
return PDC_NO_PARENT_IRQ;
}
static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
unsigned long *hwirq, unsigned int *type)
{
if (is_of_node(fwspec->fwnode)) {
if (fwspec->param_count != 2)
return -EINVAL;
*hwirq = fwspec->param[0];
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
return 0;
}
return -EINVAL;
}
static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *data)
{
struct irq_fwspec *fwspec = data;
struct irq_fwspec parent_fwspec;
irq_hw_number_t hwirq, parent_hwirq;
unsigned int type;
int ret;
ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
if (ret)
return ret;
ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
&qcom_pdc_gic_chip, NULL);
if (ret)
return ret;
parent_hwirq = get_parent_hwirq(hwirq);
if (parent_hwirq == PDC_NO_PARENT_IRQ)
return 0;
if (type & IRQ_TYPE_EDGE_BOTH)
type = IRQ_TYPE_EDGE_RISING;
if (type & IRQ_TYPE_LEVEL_MASK)
type = IRQ_TYPE_LEVEL_HIGH;
parent_fwspec.fwnode = domain->parent->fwnode;
parent_fwspec.param_count = 3;
parent_fwspec.param[0] = 0;
parent_fwspec.param[1] = parent_hwirq;
parent_fwspec.param[2] = type;
return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
&parent_fwspec);
}
static const struct irq_domain_ops qcom_pdc_ops = {
.translate = qcom_pdc_translate,
.alloc = qcom_pdc_alloc,
.free = irq_domain_free_irqs_common,
};
static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *data)
{
struct irq_fwspec *fwspec = data;
struct irq_fwspec parent_fwspec;
irq_hw_number_t hwirq, parent_hwirq;
unsigned int type;
int ret;
ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
if (ret)
return ret;
ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
&qcom_pdc_gic_chip, NULL);
if (ret)
return ret;
if (hwirq == GPIO_NO_WAKE_IRQ)
return 0;
parent_hwirq = get_parent_hwirq(hwirq);
if (parent_hwirq == PDC_NO_PARENT_IRQ)
return 0;
if (type & IRQ_TYPE_EDGE_BOTH)
type = IRQ_TYPE_EDGE_RISING;
if (type & IRQ_TYPE_LEVEL_MASK)
type = IRQ_TYPE_LEVEL_HIGH;
parent_fwspec.fwnode = domain->parent->fwnode;
parent_fwspec.param_count = 3;
parent_fwspec.param[0] = 0;
parent_fwspec.param[1] = parent_hwirq;
parent_fwspec.param[2] = type;
return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
&parent_fwspec);
}
static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
struct irq_fwspec *fwspec,
enum irq_domain_bus_token bus_token)
{
return bus_token == DOMAIN_BUS_WAKEUP;
}
static const struct irq_domain_ops qcom_pdc_gpio_ops = {
.select = qcom_pdc_gpio_domain_select,
.alloc = qcom_pdc_gpio_alloc,
.free = irq_domain_free_irqs_common,
};
static int pdc_setup_pin_mapping(struct device_node *np)
{
int ret, n, i;
u32 irq_index, reg_index, val;
n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
if (n <= 0 || n % 3)
return -EINVAL;
pdc_region_cnt = n / 3;
pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
if (!pdc_region) {
pdc_region_cnt = 0;
return -ENOMEM;
}
for (n = 0; n < pdc_region_cnt; n++) {
ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
n * 3 + 0,
&pdc_region[n].pin_base);
if (ret)
return ret;
ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
n * 3 + 1,
&pdc_region[n].parent_base);
if (ret)
return ret;
ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
n * 3 + 2,
&pdc_region[n].cnt);
if (ret)
return ret;
for (i = 0; i < pdc_region[n].cnt; i++) {
reg_index = (i + pdc_region[n].pin_base) >> 5;
irq_index = (i + pdc_region[n].pin_base) & 0x1f;
val = pdc_reg_read(IRQ_ENABLE_BANK, reg_index);
val &= ~BIT(irq_index);
pdc_reg_write(IRQ_ENABLE_BANK, reg_index, val);
}
}
return 0;
}
static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
{
struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
int ret;
pdc_base = of_iomap(node, 0);
if (!pdc_base) {
pr_err("%pOF: unable to map PDC registers\n", node);
return -ENXIO;
}
parent_domain = irq_find_host(parent);
if (!parent_domain) {
pr_err("%pOF: unable to find PDC's parent domain\n", node);
ret = -ENXIO;
goto fail;
}
ret = pdc_setup_pin_mapping(node);
if (ret) {
pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
goto fail;
}
pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
of_fwnode_handle(node),
&qcom_pdc_ops, NULL);
if (!pdc_domain) {
pr_err("%pOF: GIC domain add failed\n", node);
ret = -ENOMEM;
goto fail;
}
pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
PDC_MAX_GPIO_IRQS,
of_fwnode_handle(node),
&qcom_pdc_gpio_ops, NULL);
if (!pdc_gpio_domain) {
pr_err("%pOF: PDC domain add failed for GPIO domain\n", node);
ret = -ENOMEM;
goto remove;
}
irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
return 0;
remove:
irq_domain_remove(pdc_domain);
fail:
kfree(pdc_region);
iounmap(pdc_base);
return ret;
}
IRQCHIP_DECLARE(qcom_pdc, "qcom,pdc", qcom_pdc_init);
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