linux_dsm_epyc7002/include/linux/irqdesc.h
Marc Zyngier 76ba59f836 genirq: Add irq_domain-aware core IRQ handler
Calling irq_find_mapping from outside a irq_{enter,exit} section is
unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled:
If coming from the idle state, the rcu_read_lock call in irq_find_mapping
will generate an unpleasant warning:

<quote>
===============================
[ INFO: suspicious RCU usage. ]
3.16.0-rc1+ #135 Not tainted
-------------------------------
include/linux/rcupdate.h:871 rcu_read_lock() used illegally while idle!

other info that might help us debug this:

RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
1 lock held by swapper/0/0:
 #0:  (rcu_read_lock){......}, at: [<ffffffc00010206c>]
irq_find_mapping+0x4c/0x198
</quote>

As this issue is fairly widespread and involves at least three
different architectures, a possible solution is to add a new
handle_domain_irq entry point into the generic IRQ code that
the interrupt controller code can call.

This new function takes an irq_domain, and calls into irq_find_domain
inside the irq_{enter,exit} block. An additional "lookup" parameter is
used to allow non-domain architecture code to be replaced by this as well.

Interrupt controllers can then be updated to use the new mechanism.

This code is sitting behind a new CONFIG_HANDLE_DOMAIN_IRQ, as not all
architectures implement set_irq_regs (yes, mn10300, I'm looking at you...).

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1409047421-27649-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-09-03 12:57:27 +00:00

207 lines
5.9 KiB
C

#ifndef _LINUX_IRQDESC_H
#define _LINUX_IRQDESC_H
/*
* Core internal functions to deal with irq descriptors
*
* This include will move to kernel/irq once we cleaned up the tree.
* For now it's included from <linux/irq.h>
*/
struct irq_affinity_notify;
struct proc_dir_entry;
struct module;
struct irq_desc;
struct irq_domain;
struct pt_regs;
/**
* struct irq_desc - interrupt descriptor
* @irq_data: per irq and chip data passed down to chip functions
* @kstat_irqs: irq stats per cpu
* @handle_irq: highlevel irq-events handler
* @preflow_handler: handler called before the flow handler (currently used by sparc)
* @action: the irq action chain
* @status: status information
* @core_internal_state__do_not_mess_with_it: core internal status information
* @depth: disable-depth, for nested irq_disable() calls
* @wake_depth: enable depth, for multiple irq_set_irq_wake() callers
* @irq_count: stats field to detect stalled irqs
* @last_unhandled: aging timer for unhandled count
* @irqs_unhandled: stats field for spurious unhandled interrupts
* @threads_handled: stats field for deferred spurious detection of threaded handlers
* @threads_handled_last: comparator field for deferred spurious detection of theraded handlers
* @lock: locking for SMP
* @affinity_hint: hint to user space for preferred irq affinity
* @affinity_notify: context for notification of affinity changes
* @pending_mask: pending rebalanced interrupts
* @threads_oneshot: bitfield to handle shared oneshot threads
* @threads_active: number of irqaction threads currently running
* @wait_for_threads: wait queue for sync_irq to wait for threaded handlers
* @dir: /proc/irq/ procfs entry
* @name: flow handler name for /proc/interrupts output
*/
struct irq_desc {
struct irq_data irq_data;
unsigned int __percpu *kstat_irqs;
irq_flow_handler_t handle_irq;
#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
irq_preflow_handler_t preflow_handler;
#endif
struct irqaction *action; /* IRQ action list */
unsigned int status_use_accessors;
unsigned int core_internal_state__do_not_mess_with_it;
unsigned int depth; /* nested irq disables */
unsigned int wake_depth; /* nested wake enables */
unsigned int irq_count; /* For detecting broken IRQs */
unsigned long last_unhandled; /* Aging timer for unhandled count */
unsigned int irqs_unhandled;
atomic_t threads_handled;
int threads_handled_last;
raw_spinlock_t lock;
struct cpumask *percpu_enabled;
#ifdef CONFIG_SMP
const struct cpumask *affinity_hint;
struct irq_affinity_notify *affinity_notify;
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_var_t pending_mask;
#endif
#endif
unsigned long threads_oneshot;
atomic_t threads_active;
wait_queue_head_t wait_for_threads;
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *dir;
#endif
int parent_irq;
struct module *owner;
const char *name;
} ____cacheline_internodealigned_in_smp;
#ifndef CONFIG_SPARSE_IRQ
extern struct irq_desc irq_desc[NR_IRQS];
#endif
static inline struct irq_data *irq_desc_get_irq_data(struct irq_desc *desc)
{
return &desc->irq_data;
}
static inline struct irq_chip *irq_desc_get_chip(struct irq_desc *desc)
{
return desc->irq_data.chip;
}
static inline void *irq_desc_get_chip_data(struct irq_desc *desc)
{
return desc->irq_data.chip_data;
}
static inline void *irq_desc_get_handler_data(struct irq_desc *desc)
{
return desc->irq_data.handler_data;
}
static inline struct msi_desc *irq_desc_get_msi_desc(struct irq_desc *desc)
{
return desc->irq_data.msi_desc;
}
/*
* Architectures call this to let the generic IRQ layer
* handle an interrupt. If the descriptor is attached to an
* irqchip-style controller then we call the ->handle_irq() handler,
* and it calls __do_IRQ() if it's attached to an irqtype-style controller.
*/
static inline void generic_handle_irq_desc(unsigned int irq, struct irq_desc *desc)
{
desc->handle_irq(irq, desc);
}
int generic_handle_irq(unsigned int irq);
#ifdef CONFIG_HANDLE_DOMAIN_IRQ
/*
* Convert a HW interrupt number to a logical one using a IRQ domain,
* and handle the result interrupt number. Return -EINVAL if
* conversion failed. Providing a NULL domain indicates that the
* conversion has already been done.
*/
int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
bool lookup, struct pt_regs *regs);
static inline int handle_domain_irq(struct irq_domain *domain,
unsigned int hwirq, struct pt_regs *regs)
{
return __handle_domain_irq(domain, hwirq, true, regs);
}
#endif
/* Test to see if a driver has successfully requested an irq */
static inline int irq_has_action(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
return desc->action != NULL;
}
/* caller has locked the irq_desc and both params are valid */
static inline void __irq_set_handler_locked(unsigned int irq,
irq_flow_handler_t handler)
{
struct irq_desc *desc;
desc = irq_to_desc(irq);
desc->handle_irq = handler;
}
/* caller has locked the irq_desc and both params are valid */
static inline void
__irq_set_chip_handler_name_locked(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handler, const char *name)
{
struct irq_desc *desc;
desc = irq_to_desc(irq);
irq_desc_get_irq_data(desc)->chip = chip;
desc->handle_irq = handler;
desc->name = name;
}
static inline int irq_balancing_disabled(unsigned int irq)
{
struct irq_desc *desc;
desc = irq_to_desc(irq);
return desc->status_use_accessors & IRQ_NO_BALANCING_MASK;
}
static inline int irq_is_percpu(unsigned int irq)
{
struct irq_desc *desc;
desc = irq_to_desc(irq);
return desc->status_use_accessors & IRQ_PER_CPU;
}
static inline void
irq_set_lockdep_class(unsigned int irq, struct lock_class_key *class)
{
struct irq_desc *desc = irq_to_desc(irq);
if (desc)
lockdep_set_class(&desc->lock, class);
}
#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
static inline void
__irq_set_preflow_handler(unsigned int irq, irq_preflow_handler_t handler)
{
struct irq_desc *desc;
desc = irq_to_desc(irq);
desc->preflow_handler = handler;
}
#endif
#endif