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* Copyright (c) 2014 Apple Computer, Inc. All rights reserved.
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* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
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* Please obtain a copy of the License at
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#ifndef __IOKIT_IOINTERRUPTACCOUNTING_PRIVATE_H
#define __IOKIT_IOINTERRUPTACCOUNTING_PRIVATE_H
/*
* Header containing interrupt accounting related prototypes/defines that should be kept private to
* xnu itself (no userspace, no kexts, no nothing!).
*/
#include <stdint.h>
#include <IOKit/IOInterruptAccounting.h>
#include <kern/queue.h>
class OSObject;
class IOSimpleReporter;
/*
* A brief overview. Interrupt accounting (as implemented in IOKit) pertains to infrastructure for
* gathering information (currently, statistics only) on interrupts, and allowing them to be reported
* (either to userspace through IOReporting, or through lldb; lldb macros have yet to be implemented).
*
* Currently, interrupt accounting consists of of a relationship between an IOService (a nub, which
* will contain interrupt specifiers), an IOInterruptEventSource (if we add other interrupt target
* abstractions, support could be added for them as well), and objects necessary to support them. An
* interrupt is "named" by a tuple of {provider, interrupt index}; no nub should ever have more than
* one interrupt registered for a given index, so this tuple should be unique.
*
* The "additional objects" mentioned above consist of an IOReporter object (lazily allocated and
* tied to the nub; once allocated it will live until the nub is freed), and a statistics object
* (effectively part of the IOIES in terms of lifecycle). The statistics object is used by the
* interrupt codepath itself, and by the nub when it needs to update the reporter; the reporter is
* used to report values to userspace.
*
* As a consequence of the above relationship, we do not track statistics for directly registered
* interrupt handlers. We have no guarantees what the handler or the target may be; if you don't
* follow the generic IOKit interrupt model, you will not be tracked by interrupt accounting. For
* now, this means you must use an IOIES to be eligible for interrupt accounting. We also do not
* track IOIES' that do not have providers (this is indicative that it is only being used to drive
* workloop activity, and is not actually handling interrupts).
*/
/*
* This is meant to let us set up the set of interrupt statistics we are actually interested in, by
* setting a boot-arg. If we want to track a statistic, the bit corresponding to the index for that
* statistic should be set in the bitmask.
*
* There is a bit of a mismatch here, in that our IOReporting channel namespace allows for 256 statistics,
* but this bitmask actually limits it to 32.
*/
extern uint32_t gInterruptAccountingStatisticBitmask;
/*
* Check the bitmask by statistic index; useful for setting the initial value and conditionalizing code.
*/
#define IA_GET_ENABLE_BIT(statisticIndex) \
(((uint32_t) 1) << ((uint32_t) statisticIndex))
#define IA_GET_STATISTIC_ENABLED(statisticIndex) \
(IA_GET_ENABLE_BIT(statisticIndex) & gInterruptAccountingStatisticBitmask)
/*
* Check if any valid statistics are enabled.
*/
#define IA_ANY_STATISTICS_ENABLED \
((IA_GET_ENABLE_BIT(kInterruptAccountingInvalidStatisticIndex) - 1) & gInterruptAccountingStatisticBitmask)
/*
* Actual string names for the statistics we gather.
*/
#define kInterruptAccountingChannelNameFirstLevelCount (" First Level Interrupt Handler Count")
#define kInterruptAccountingChannelNameSecondLevelCount (" Second Level Interrupt Handler Count")
#define kInterruptAccountingChannelNameFirstLevelTime (" First Level Interrupt Handler Time (MATUs)")
#define kInterruptAccountingChannelNameSecondLevelCPUTime (" Second Level Interrupt Handler CPU Time (MATUs)")
#define kInterruptAccountingChannelNameSecondLevelSystemTime ("Second Level Interrupt Handler System Time (MATUs)")
#define kInterruptAccountingChannelNameNoThreadWakeups (" Interrupts that did not try to wake a thread")
#define kInterruptAccountingChannelNameTotalThreadWakeups (" Sleeping threads woken up by this interrupt")
#define kInterruptAccountingChannelNamePackageWakeups (" Package wakeups caused by this interrupt")
#define kInterruptAccountingChannelNameCPUWakeups (" CPU wakeups caused by this interrupt")
#define kInterruptAccountingChannelNameIdleExits (" Idle exits caused by this interrupt")
static const char * const kInterruptAccountingStatisticNameArray[IA_NUM_INTERRUPT_ACCOUNTING_STATISTICS] = {
[kInterruptAccountingFirstLevelCountIndex] = kInterruptAccountingChannelNameFirstLevelCount,
[kInterruptAccountingSecondLevelCountIndex] = kInterruptAccountingChannelNameSecondLevelCount,
[kInterruptAccountingFirstLevelTimeIndex] = kInterruptAccountingChannelNameFirstLevelTime,
[kInterruptAccountingSecondLevelCPUTimeIndex] = kInterruptAccountingChannelNameSecondLevelCPUTime,
[kInterruptAccountingSecondLevelSystemTimeIndex] = kInterruptAccountingChannelNameSecondLevelSystemTime,
[kInterruptAccountingNoThreadWakeupsIndex] = kInterruptAccountingChannelNameNoThreadWakeups,
[kInterruptAccountingTotalThreadWakeupsIndex] = kInterruptAccountingChannelNameTotalThreadWakeups,
[kInterruptAccountingPackageWakeupsIndex] = kInterruptAccountingChannelNamePackageWakeups,
[kInterruptAccountingCPUWakeupsIndex] = kInterruptAccountingChannelNameCPUWakeups,
[kInterruptAccountingIdleExitsIndex] = kInterruptAccountingChannelNameIdleExits,
};
/*
* For updating the statistics in the data structure. We cannot guarantee all of our platforms will be
* able to do a 64-bit store in a single transaction. So, for new platforms, call out to the hardware
* atomic add routine; it will either be unsupported, or do the right thing. For architectures or
* platforms that do support it; just do regular assignment.
*
* We use this routine instead of a lock because at the moment, there is no way (in the interrupt context)
* to reconcile a lock (even a spinlock) with the IOReporting synchonization (as we have no guarantee that
* IOReporting will not block on a mutex, which would result in a panic if it held a spinlock). This
* means that reported values may have a disparity if we update the reporter values while an interrupt is
* being handled.
*
* Atomic modification should not be strictly required, as a given interrupt should not be dispatched to
* two processors at once (and the interrupt should serve to force out stores), and the second level
* handler should be synchonized by the work loop it runs on.
*/
#if __x86_64__ || __arm64__
#define IA_ADD_VALUE(target, value) \
(*(target) += (value))
#else /* !(__x86_64__ || __arm64__) */
#define IA_ADD_VALUE(target, value) \
(OSAddAtomic64((value), (target)))
#endif /* !(__x86_64__ || __arm64__) */
/*
* TODO: Should this be an OSObject? Or properly pull in its methods as member functions?
*/
struct IOInterruptAccountingData {
OSObject * owner; /* The owner of the statistics; currently always an IOIES or a subclass of it */
queue_chain_t chain;
/*
* We have no guarantee that the owner will not temporarily mutate its index value (i.e, in setWorkLoop
* for IOIES). To ensure we can properly recalculate our own identity (and our channel IDs for the
* reporter), stash the index we set up the reporter with here.
*
* Note that we should never remap the interrupt (point it to a different specifier). The mutation of
* the index value is usually to negate it; I am uncertain of the reason for this at the moment. The
* practical impact being that we should never need to update the stashed index value; it should stay
* valid for the lifetime of the owner.
*/
int interruptIndex;
bool enablePrimaryTimestamp;
volatile uint64_t primaryTimestamp __attribute__((aligned(8)));
/*
* As long as we are based on the simple reporter, all our channels will be 64 bits. Align the data
* to allow for safe atomic updates (we don't want to cross a cache line on any platform, but for some
* it would cause a panic).
*/
volatile uint64_t interruptStatistics[IA_NUM_INTERRUPT_ACCOUNTING_STATISTICS] __attribute__((aligned(8)));
};
/*
* Initializes global values/structures related to interrupt accounting.
*/
void interruptAccountingInit(void);
/*
* Routines for adding and removing objects from the global queue of IOInterruptAccountingData objects;
* the queue exists as a debugging aid (no entities other than these routines should care about the
* queue at runtime).
*/
void interruptAccountingDataAddToList(IOInterruptAccountingData * data);
void interruptAccountingDataRemoveFromList(IOInterruptAccountingData * data);
/*
* Updates reporter with the statistics contained within data. Invoked when IOReporting has been asked
* for updated statistics; requiring explicit synchronization of data between the statistic fields and
* the reporter helps keep interrupt accounting overhead down.
*/
void interruptAccountingDataUpdateChannels(IOInterruptAccountingData * data, IOSimpleReporter * reporter);
/*
* Initializes the statistics in data using the statistics currently held by reporter. Typically invoked
* when data is first associated with reporter. The nub that an interrupt is associated with will be
* longer lived than the interrupt; as a result, our owner may not be the first to register for a
* particular interrupt index with that nub, so we need to inherit the existing statistics (as we describe
* statistics in terms of {nub id, index}, not in terms of our owner).
*/
void interruptAccountingDataInheritChannels(IOInterruptAccountingData * data, IOSimpleReporter * reporter);
#endif /* __IOKIT_IOINTERRUPTACCOUNTING_PRIVATE_H */