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Merge branch 'thread-irq-simpler' into devel

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This commit is contained in:
Linus Walleij 2016-12-07 15:24:12 +01:00
commit acf1fcf772
13 changed files with 176 additions and 105 deletions
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60
Documentation/gpio/driver.txt
View File

@ -175,8 +175,8 @@ The IRQ portions of the GPIO block are implemented using an irqchip, using
the header <linux/irq.h>. So basically such a driver is utilizing two sub-
systems simultaneously: gpio and irq.
RT_FULL: GPIO driver should not use spinlock_t or any sleepable APIs
(like PM runtime) as part of its irq_chip implementation on -RT.
RT_FULL: a realtime compliant GPIO driver should not use spinlock_t or any
sleepable APIs (like PM runtime) as part of its irq_chip implementation.
- spinlock_t should be replaced with raw_spinlock_t [1].
- If sleepable APIs have to be used, these can be done from the .irq_bus_lock()
and .irq_bus_unlock() callbacks, as these are the only slowpath callbacks
@ -185,33 +185,32 @@ RT_FULL: GPIO driver should not use spinlock_t or any sleepable APIs
GPIO irqchips usually fall in one of two categories:
* CHAINED GPIO irqchips: these are usually the type that is embedded on
an SoC. This means that there is a fast IRQ handler for the GPIOs that
an SoC. This means that there is a fast IRQ flow handler for the GPIOs that
gets called in a chain from the parent IRQ handler, most typically the
system interrupt controller. This means the GPIO irqchip is registered
using irq_set_chained_handler() or the corresponding
gpiochip_set_chained_irqchip() helper function, and the GPIO irqchip
handler will be called immediately from the parent irqchip, while
holding the IRQs disabled. The GPIO irqchip will then end up calling
something like this sequence in its interrupt handler:
system interrupt controller. This means that the GPIO irqchip handler will
be called immediately from the parent irqchip, while holding the IRQs
disabled. The GPIO irqchip will then end up calling something like this
sequence in its interrupt handler:
static irqreturn_t tc3589x_gpio_irq(int irq, void *data)
static irqreturn_t foo_gpio_irq(int irq, void *data)
chained_irq_enter(...);
generic_handle_irq(...);
chained_irq_exit(...);
Chained GPIO irqchips typically can NOT set the .can_sleep flag on
struct gpio_chip, as everything happens directly in the callbacks.
struct gpio_chip, as everything happens directly in the callbacks: no
slow bus traffic like I2C can be used.
RT_FULL: Note, chained IRQ handlers will not be forced threaded on -RT.
As result, spinlock_t or any sleepable APIs (like PM runtime) can't be used
in chained IRQ handler.
if required (and if it can't be converted to the nested threaded GPIO irqchip)
- chained IRQ handler can be converted to generic irq handler and this way
it will be threaded IRQ handler on -RT and hard IRQ handler on non-RT
If required (and if it can't be converted to the nested threaded GPIO irqchip)
a chained IRQ handler can be converted to generic irq handler and this way
it will be a threaded IRQ handler on -RT and a hard IRQ handler on non-RT
(for example, see [3]).
Know W/A: The generic_handle_irq() is expected to be called with IRQ disabled,
so IRQ core will complain if it will be called from IRQ handler which is
forced thread. The "fake?" raw lock can be used to W/A this problem:
so the IRQ core will complain if it is called from an IRQ handler which is
forced to a thread. The "fake?" raw lock can be used to W/A this problem:
raw_spinlock_t wa_lock;
static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank)
@ -243,7 +242,7 @@ GPIO irqchips usually fall in one of two categories:
by the driver. The hallmark of this driver is to call something like
this in its interrupt handler:
static irqreturn_t tc3589x_gpio_irq(int irq, void *data)
static irqreturn_t foo_gpio_irq(int irq, void *data)
...
handle_nested_irq(irq);
@ -256,23 +255,31 @@ associated irqdomain and resource allocation callbacks, the gpiolib has
some helpers that can be enabled by selecting the GPIOLIB_IRQCHIP Kconfig
symbol:
* gpiochip_irqchip_add(): adds an irqchip to a gpiochip. It will pass
* gpiochip_irqchip_add(): adds a chained irqchip to a gpiochip. It will pass
the struct gpio_chip* for the chip to all IRQ callbacks, so the callbacks
need to embed the gpio_chip in its state container and obtain a pointer
to the container using container_of().
(See Documentation/driver-model/design-patterns.txt)
If there is a need to exclude certain GPIOs from the IRQ domain, one can
set .irq_need_valid_mask of the gpiochip before gpiochip_add_data() is
called. This allocates .irq_valid_mask with as many bits set as there are
GPIOs in the chip. Drivers can exclude GPIOs by clearing bits from this
mask. The mask must be filled in before gpiochip_irqchip_add() is called.
* gpiochip_irqchip_add_nested(): adds a nested irqchip to a gpiochip.
Apart from that it works exactly like the chained irqchip.
* gpiochip_set_chained_irqchip(): sets up a chained irq handler for a
gpio_chip from a parent IRQ and passes the struct gpio_chip* as handler
data. (Notice handler data, since the irqchip data is likely used by the
parent irqchip!) This is for the chained type of chip. This is also used
to set up a nested irqchip if NULL is passed as handler.
parent irqchip!).
* gpiochip_set_nested_irqchip(): sets up a nested irq handler for a
gpio_chip from a parent IRQ. As the parent IRQ has usually been
explicitly requested by the driver, this does very little more than
mark all the child IRQs as having the other IRQ as parent.
If there is a need to exclude certain GPIOs from the IRQ domain, you can
set .irq_need_valid_mask of the gpiochip before gpiochip_add_data() is
called. This allocates an .irq_valid_mask with as many bits set as there
are GPIOs in the chip. Drivers can exclude GPIOs by clearing bits from this
mask. The mask must be filled in before gpiochip_irqchip_add() or
gpiochip_irqchip_add_nested() is called.
To use the helpers please keep the following in mind:
@ -323,6 +330,9 @@ When implementing an irqchip inside a GPIO driver, these two functions should
typically be called in the .startup() and .shutdown() callbacks from the
irqchip.
When using the gpiolib irqchip helpers, these callback are automatically
assigned.
Real-Time compliance for GPIO IRQ chips
---------------------------------------

12
drivers/gpio/gpio-adnp.c
View File

@ -468,17 +468,19 @@ static int adnp_irq_setup(struct adnp *adnp)
return err;
}
err = gpiochip_irqchip_add(chip,
&adnp_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
err = gpiochip_irqchip_add_nested(chip,
&adnp_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
if (err) {
dev_err(chip->parent,
"could not connect irqchip to gpiochip\n");
return err;
}
gpiochip_set_nested_irqchip(chip, &adnp_irq_chip, adnp->client->irq);
return 0;
}

6
drivers/gpio/gpio-crystalcove.c
View File

@ -351,8 +351,8 @@ static int crystalcove_gpio_probe(struct platform_device *pdev)
return retval;
}
gpiochip_irqchip_add(&cg->chip, &crystalcove_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
gpiochip_irqchip_add_nested(&cg->chip, &crystalcove_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
retval = request_threaded_irq(irq, NULL, crystalcove_gpio_irq_handler,
IRQF_ONESHOT, KBUILD_MODNAME, cg);
@ -362,6 +362,8 @@ static int crystalcove_gpio_probe(struct platform_device *pdev)
return retval;
}
gpiochip_set_nested_irqchip(&cg->chip, &crystalcove_irqchip, irq);
return 0;
}

1
drivers/gpio/gpio-dln2.c
View File

@ -467,7 +467,6 @@ static int dln2_gpio_probe(struct platform_device *pdev)
dln2->gpio.base = -1;
dln2->gpio.ngpio = pins;
dln2->gpio.can_sleep = true;
dln2->gpio.irq_not_threaded = true;
dln2->gpio.set = dln2_gpio_set;
dln2->gpio.get = dln2_gpio_get;
dln2->gpio.request = dln2_gpio_request;

17
drivers/gpio/gpio-max732x.c
View File

@ -520,20 +520,19 @@ static int max732x_irq_setup(struct max732x_chip *chip,
client->irq);
return ret;
}
ret = gpiochip_irqchip_add(&chip->gpio_chip,
&max732x_irq_chip,
irq_base,
handle_simple_irq,
IRQ_TYPE_NONE);
ret = gpiochip_irqchip_add_nested(&chip->gpio_chip,
&max732x_irq_chip,
irq_base,
handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(&client->dev,
"could not connect irqchip to gpiochip\n");
return ret;
}
gpiochip_set_chained_irqchip(&chip->gpio_chip,
&max732x_irq_chip,
client->irq,
NULL);
gpiochip_set_nested_irqchip(&chip->gpio_chip,
&max732x_irq_chip,
client->irq);
}
return 0;

17
drivers/gpio/gpio-mcp23s08.c
View File

@ -473,21 +473,20 @@ static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
return err;
}
err = gpiochip_irqchip_add(chip,
&mcp23s08_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
err = gpiochip_irqchip_add_nested(chip,
&mcp23s08_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
if (err) {
dev_err(chip->parent,
"could not connect irqchip to gpiochip: %d\n", err);
return err;
}
gpiochip_set_chained_irqchip(chip,
&mcp23s08_irq_chip,
mcp->irq,
NULL);
gpiochip_set_nested_irqchip(chip,
&mcp23s08_irq_chip,
mcp->irq);
return 0;
}

16
drivers/gpio/gpio-pca953x.c
View File

@ -636,20 +636,20 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
return ret;
}
ret = gpiochip_irqchip_add(&chip->gpio_chip,
&pca953x_irq_chip,
irq_base,
handle_simple_irq,
IRQ_TYPE_NONE);
ret = gpiochip_irqchip_add_nested(&chip->gpio_chip,
&pca953x_irq_chip,
irq_base,
handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(&client->dev,
"could not connect irqchip to gpiochip\n");
return ret;
}
gpiochip_set_chained_irqchip(&chip->gpio_chip,
&pca953x_irq_chip,
client->irq, NULL);
gpiochip_set_nested_irqchip(&chip->gpio_chip,
&pca953x_irq_chip,
client->irq);
}
return 0;

11
drivers/gpio/gpio-pcf857x.c
View File

@ -378,9 +378,10 @@ static int pcf857x_probe(struct i2c_client *client,
/* Enable irqchip if we have an interrupt */
if (client->irq) {
status = gpiochip_irqchip_add(&gpio->chip, &pcf857x_irq_chip,
0, handle_level_irq,
IRQ_TYPE_NONE);
status = gpiochip_irqchip_add_nested(&gpio->chip,
&pcf857x_irq_chip,
0, handle_level_irq,
IRQ_TYPE_NONE);
if (status) {
dev_err(&client->dev, "cannot add irqchip\n");
goto fail;
@ -393,8 +394,8 @@ static int pcf857x_probe(struct i2c_client *client,
if (status)
goto fail;
gpiochip_set_chained_irqchip(&gpio->chip, &pcf857x_irq_chip,
client->irq, NULL);
gpiochip_set_nested_irqchip(&gpio->chip, &pcf857x_irq_chip,
client->irq);
gpio->irq_parent = client->irq;
}

17
drivers/gpio/gpio-stmpe.c
View File

@ -484,21 +484,20 @@ static int stmpe_gpio_probe(struct platform_device *pdev)
if (stmpe_gpio->norequest_mask & BIT(i))
clear_bit(i, stmpe_gpio->chip.irq_valid_mask);
}
ret = gpiochip_irqchip_add(&stmpe_gpio->chip,
&stmpe_gpio_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
ret = gpiochip_irqchip_add_nested(&stmpe_gpio->chip,
&stmpe_gpio_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(&pdev->dev,
"could not connect irqchip to gpiochip\n");
goto out_disable;
}
gpiochip_set_chained_irqchip(&stmpe_gpio->chip,
&stmpe_gpio_irq_chip,
irq,
NULL);
gpiochip_set_nested_irqchip(&stmpe_gpio->chip,
&stmpe_gpio_irq_chip,
irq);
}
platform_set_drvdata(pdev, stmpe_gpio);

17
drivers/gpio/gpio-tc3589x.c
View File

@ -337,21 +337,20 @@ static int tc3589x_gpio_probe(struct platform_device *pdev)
return ret;
}
ret = gpiochip_irqchip_add(&tc3589x_gpio->chip,
&tc3589x_gpio_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
ret = gpiochip_irqchip_add_nested(&tc3589x_gpio->chip,
&tc3589x_gpio_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(&pdev->dev,
"could not connect irqchip to gpiochip\n");
return ret;
}
gpiochip_set_chained_irqchip(&tc3589x_gpio->chip,
&tc3589x_gpio_irq_chip,
irq,
NULL);
gpiochip_set_nested_irqchip(&tc3589x_gpio->chip,
&tc3589x_gpio_irq_chip,
irq);
platform_set_drvdata(pdev, tc3589x_gpio);

6
drivers/gpio/gpio-wcove.c
View File

@ -426,8 +426,8 @@ static int wcove_gpio_probe(struct platform_device *pdev)
return ret;
}
ret = gpiochip_irqchip_add(&wg->chip, &wcove_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
if (ret) {
dev_err(dev, "Failed to add irqchip: %d\n", ret);
return ret;
@ -446,6 +446,8 @@ static int wcove_gpio_probe(struct platform_device *pdev)
return ret;
}
gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
return 0;
}

69
drivers/gpio/gpiolib.c
View File

@ -1440,7 +1440,7 @@ static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
}
/**
* gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
* gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip chain to
* @irqchip: the irqchip to chain to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
@ -1449,10 +1449,10 @@ static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
* coming out of the gpiochip. If the interrupt is nested rather than
* cascaded, pass NULL in this handler argument
*/
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
int parent_irq,
irq_flow_handler_t parent_handler)
static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
int parent_irq,
irq_flow_handler_t parent_handler)
{
unsigned int offset;
@ -1476,7 +1476,7 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
irq_set_chained_handler_and_data(parent_irq, parent_handler,
gpiochip);
gpiochip->irq_parent = parent_irq;
gpiochip->irq_chained_parent = parent_irq;
}
/* Set the parent IRQ for all affected IRQs */
@ -1487,8 +1487,47 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
parent_irq);
}
}
/**
* gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip chain to
* @irqchip: the irqchip to chain to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* chained irqchip
* @parent_handler: the parent interrupt handler for the accumulated IRQ
* coming out of the gpiochip. If the interrupt is nested rather than
* cascaded, pass NULL in this handler argument
*/
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
int parent_irq,
irq_flow_handler_t parent_handler)
{
gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
parent_handler);
}
EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
/**
* gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip nested handler to
* @irqchip: the irqchip to nest to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* nested irqchip
*/
void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
int parent_irq)
{
if (!gpiochip->irq_nested) {
chip_err(gpiochip, "tried to nest a chained gpiochip\n");
return;
}
gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
NULL);
}
EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
/**
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
* @d: the irqdomain used by this irqchip
@ -1511,8 +1550,8 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
*/
irq_set_lockdep_class(irq, chip->lock_key);
irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
/* Chips that can sleep need nested thread handlers */
if (chip->can_sleep && !chip->irq_not_threaded)
/* Chips that use nested thread handlers have them marked */
if (chip->irq_nested)
irq_set_nested_thread(irq, 1);
irq_set_noprobe(irq);
@ -1530,7 +1569,7 @@ static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
struct gpio_chip *chip = d->host_data;
if (chip->can_sleep)
if (chip->irq_nested)
irq_set_nested_thread(irq, 0);
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
@ -1585,9 +1624,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
acpi_gpiochip_free_interrupts(gpiochip);
if (gpiochip->irq_parent) {
irq_set_chained_handler(gpiochip->irq_parent, NULL);
irq_set_handler_data(gpiochip->irq_parent, NULL);
if (gpiochip->irq_chained_parent) {
irq_set_chained_handler(gpiochip->irq_chained_parent, NULL);
irq_set_handler_data(gpiochip->irq_chained_parent, NULL);
}
/* Remove all IRQ mappings and delete the domain */
@ -1611,7 +1650,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
}
/**
* gpiochip_irqchip_add() - adds an irqchip to a gpiochip
* _gpiochip_irqchip_add() - adds an irqchip to a gpiochip
* @gpiochip: the gpiochip to add the irqchip to
* @irqchip: the irqchip to add to the gpiochip
* @first_irq: if not dynamically assigned, the base (first) IRQ to
@ -1619,6 +1658,8 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
* @handler: the irq handler to use (often a predefined irq core function)
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
* to have the core avoid setting up any default type in the hardware.
* @nested: whether this is a nested irqchip calling handle_nested_irq()
* in its IRQ handler
* @lock_key: lockdep class
*
* This function closely associates a certain irqchip with a certain
@ -1640,6 +1681,7 @@ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type,
bool nested,
struct lock_class_key *lock_key)
{
struct device_node *of_node;
@ -1654,6 +1696,7 @@ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
pr_err("missing gpiochip .dev parent pointer\n");
return -EINVAL;
}
gpiochip->irq_nested = nested;
of_node = gpiochip->parent->of_node;
#ifdef CONFIG_OF_GPIO
/*

32
include/linux/gpio/driver.h
View File

@ -82,8 +82,6 @@ enum single_ended_mode {
* implies that if the chip supports IRQs, these IRQs need to be threaded
* as the chip access may sleep when e.g. reading out the IRQ status
* registers.
* @irq_not_threaded: flag must be set if @can_sleep is set but the
* IRQs don't need to be threaded
* @read_reg: reader function for generic GPIO
* @write_reg: writer function for generic GPIO
* @pin2mask: some generic GPIO controllers work with the big-endian bits
@ -109,8 +107,10 @@ enum single_ended_mode {
* for GPIO IRQs, provided by GPIO driver
* @irq_default_type: default IRQ triggering type applied during GPIO driver
* initialization, provided by GPIO driver
* @irq_parent: GPIO IRQ chip parent/bank linux irq number,
* provided by GPIO driver
* @irq_chained_parent: GPIO IRQ chip parent/bank linux irq number,
* provided by GPIO driver for chained interrupt (not for nested
* interrupts).
* @irq_nested: True if set the interrupt handling is nested.
* @irq_need_valid_mask: If set core allocates @irq_valid_mask with all
* bits set to one
* @irq_valid_mask: If not %NULL holds bitmask of GPIOs which are valid to
@ -166,7 +166,6 @@ struct gpio_chip {
u16 ngpio;
const char *const *names;
bool can_sleep;
bool irq_not_threaded;
#if IS_ENABLED(CONFIG_GPIO_GENERIC)
unsigned long (*read_reg)(void __iomem *reg);
@ -192,7 +191,8 @@ struct gpio_chip {
unsigned int irq_base;
irq_flow_handler_t irq_handler;
unsigned int irq_default_type;
int irq_parent;
int irq_chained_parent;
bool irq_nested;
bool irq_need_valid_mask;
unsigned long *irq_valid_mask;
struct lock_class_key *lock_key;
@ -270,24 +270,40 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
int parent_irq,
irq_flow_handler_t parent_handler);
void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
int parent_irq);
int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type,
bool nested,
struct lock_class_key *lock_key);
/* FIXME: I assume threaded IRQchips do not have the lockdep problem */
static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type)
{
return _gpiochip_irqchip_add(gpiochip, irqchip, first_irq,
handler, type, true, NULL);
}
#ifdef CONFIG_LOCKDEP
#define gpiochip_irqchip_add(...) \
( \
({ \
static struct lock_class_key _key; \
_gpiochip_irqchip_add(__VA_ARGS__, &_key); \
_gpiochip_irqchip_add(__VA_ARGS__, false, &_key); \
}) \
)
#else
#define gpiochip_irqchip_add(...) \
_gpiochip_irqchip_add(__VA_ARGS__, NULL)
_gpiochip_irqchip_add(__VA_ARGS__, false, NULL)
#endif
#endif /* CONFIG_GPIOLIB_IRQCHIP */