X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6d2010ae8f7a6078e10b361c6962983bab233e0f..94ff46dc2849db4d43eaaf144872decc522aafb4:/iokit/Kernel/IOCommandGate.cpp?ds=sidebyside diff --git a/iokit/Kernel/IOCommandGate.cpp b/iokit/Kernel/IOCommandGate.cpp index 29ecd859e..1ae9bcf08 100644 --- a/iokit/Kernel/IOCommandGate.cpp +++ b/iokit/Kernel/IOCommandGate.cpp @@ -2,7 +2,7 @@ * Copyright (c) 1998-2000, 2009-2010 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #include @@ -68,191 +68,266 @@ do { \ #endif /* IOKITSTATS */ -bool IOCommandGate::init(OSObject *inOwner, Action inAction) +bool +IOCommandGate::init(OSObject *inOwner, Action inAction) { - bool res = super::init(inOwner, (IOEventSource::Action) inAction); - if (res) { - IOStatisticsInitializeCounter(); - } + bool res = super::init(inOwner, (IOEventSource::Action) inAction); + if (res) { + IOStatisticsInitializeCounter(); + } - return res; + return res; } IOCommandGate * IOCommandGate::commandGate(OSObject *inOwner, Action inAction) { - IOCommandGate *me = new IOCommandGate; + IOCommandGate *me = new IOCommandGate; - if (me && !me->init(inOwner, inAction)) { - me->release(); - return 0; - } + if (me && !me->init(inOwner, inAction)) { + me->release(); + return NULL; + } - return me; + return me; } -/* virtual */ void IOCommandGate::disable() +/* virtual */ void +IOCommandGate::disable() { - if (workLoop && !workLoop->inGate()) - OSReportWithBacktrace("IOCommandGate::disable() called when not gated"); + if (workLoop && !workLoop->inGate()) { + OSReportWithBacktrace("IOCommandGate::disable() called when not gated"); + } - super::disable(); + super::disable(); } -/* virtual */ void IOCommandGate::enable() +/* virtual */ void +IOCommandGate::enable() { - if (workLoop) { - closeGate(); - super::enable(); - wakeupGate(&enabled, /* oneThread */ false); // Unblock sleeping threads - openGate(); - } + if (workLoop) { + closeGate(); + super::enable(); + wakeupGate(&enabled, /* oneThread */ false); // Unblock sleeping threads + openGate(); + } } -/* virtual */ void IOCommandGate::free() +/* virtual */ void +IOCommandGate::free() { - setWorkLoop(0); - super::free(); + if (workLoop) { + setWorkLoop(NULL); + } + super::free(); } -/* virtual */ void IOCommandGate::setWorkLoop(IOWorkLoop *inWorkLoop) +enum{ + kSleepersRemoved = 0x00000001, + kSleepersWaitEnabled = 0x00000002, + kSleepersActions = 0x00000100, + kSleepersActionsMask = 0xffffff00, +}; + +/* virtual */ void +IOCommandGate::setWorkLoop(IOWorkLoop *inWorkLoop) { - uintptr_t *sleepersP = (uintptr_t *) &reserved; - if (!inWorkLoop && workLoop) { // tearing down - closeGate(); - *sleepersP |= 1; - while (*sleepersP >> 1) { - thread_wakeup_with_result(&enabled, THREAD_INTERRUPTED); - sleepGate(sleepersP, THREAD_UNINT); + IOWorkLoop * wl; + uintptr_t * sleepersP = (uintptr_t *) &reserved; + bool defer; + + if (!inWorkLoop && (wl = workLoop)) { // tearing down + wl->closeGate(); + *sleepersP |= kSleepersRemoved; + while (*sleepersP & kSleepersWaitEnabled) { + thread_wakeup_with_result(&enabled, THREAD_INTERRUPTED); + sleepGate(sleepersP, THREAD_UNINT); + } + *sleepersP &= ~kSleepersWaitEnabled; + defer = (0 != (kSleepersActionsMask & *sleepersP)); + if (!defer) { + super::setWorkLoop(NULL); + *sleepersP &= ~kSleepersRemoved; + } + wl->openGate(); + return; } - *sleepersP = 0; - openGate(); - } - else - super::setWorkLoop(inWorkLoop); + super::setWorkLoop(inWorkLoop); } -IOReturn IOCommandGate::runCommand(void *arg0, void *arg1, - void *arg2, void *arg3) +IOReturn +IOCommandGate::runCommand(void *arg0, void *arg1, + void *arg2, void *arg3) { - return runAction((Action) action, arg0, arg1, arg2, arg3); + return runAction((Action) action, arg0, arg1, arg2, arg3); } -IOReturn IOCommandGate::attemptCommand(void *arg0, void *arg1, - void *arg2, void *arg3) +IOReturn +IOCommandGate::attemptCommand(void *arg0, void *arg1, + void *arg2, void *arg3) { - return attemptAction((Action) action, arg0, arg1, arg2, arg3); + return attemptAction((Action) action, arg0, arg1, arg2, arg3); } -IOReturn IOCommandGate::runAction(Action inAction, - void *arg0, void *arg1, - void *arg2, void *arg3) + +static IOReturn +IOCommandGateActionToBlock(OSObject *owner, + void *arg0, void *arg1, + void *arg2, void *arg3) { - if (!inAction) - return kIOReturnBadArgument; + return ((IOEventSource::ActionBlock) arg0)(); +} - // closeGate is recursive needn't worry if we already hold the lock. - closeGate(); +IOReturn +IOCommandGate::runActionBlock(ActionBlock _action) +{ + return runAction(&IOCommandGateActionToBlock, _action); +} - // If the command gate is disabled and we aren't on the workloop thread - // itself then sleep until we get enabled. - IOReturn res; - if (!workLoop->onThread()) { - while (!enabled) { - uintptr_t *sleepersP = (uintptr_t *) &reserved; +IOReturn +IOCommandGate::runAction(Action inAction, + void *arg0, void *arg1, + void *arg2, void *arg3) +{ + IOWorkLoop * wl; + uintptr_t * sleepersP; - *sleepersP += 2; - IOReturn res = sleepGate(&enabled, THREAD_ABORTSAFE); - *sleepersP -= 2; + if (!inAction) { + return kIOReturnBadArgument; + } + if (!(wl = workLoop)) { + return kIOReturnNotReady; + } - bool wakeupTearDown = (*sleepersP & 1); - if (res || wakeupTearDown) { - openGate(); + // closeGate is recursive needn't worry if we already hold the lock. + wl->closeGate(); + sleepersP = (uintptr_t *) &reserved; + + // If the command gate is disabled and we aren't on the workloop thread + // itself then sleep until we get enabled. + IOReturn res; + if (!wl->onThread()) { + while (!enabled) { + IOReturn sleepResult = kIOReturnSuccess; + if (workLoop) { + *sleepersP |= kSleepersWaitEnabled; + sleepResult = wl->sleepGate(&enabled, THREAD_INTERRUPTIBLE); + *sleepersP &= ~kSleepersWaitEnabled; + } + bool wakeupTearDown = (!workLoop || (0 != (*sleepersP & kSleepersRemoved))); + if ((kIOReturnSuccess != sleepResult) || wakeupTearDown) { + wl->openGate(); + + if (wakeupTearDown) { + wl->wakeupGate(sleepersP, false); // No further resources used + } + return kIOReturnAborted; + } + } + } - if (wakeupTearDown) - commandWakeup(sleepersP); // No further resources used + bool trace = (gIOKitTrace & kIOTraceCommandGates) ? true : false; - return kIOReturnAborted; - } + if (trace) { + IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION), + VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner)); } - } - bool trace = ( gIOKitTrace & kIOTraceCommandGates ) ? true : false; - - if (trace) - IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION), - (uintptr_t) inAction, (uintptr_t) owner); - - IOStatisticsActionCall(); - - // Must be gated and on the work loop or enabled - res = (*inAction)(owner, arg0, arg1, arg2, arg3); - - if (trace) + IOStatisticsActionCall(); + + // Must be gated and on the work loop or enabled + + *sleepersP += kSleepersActions; + res = (*inAction)(owner, arg0, arg1, arg2, arg3); + *sleepersP -= kSleepersActions; + + if (trace) { IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION), - (uintptr_t) inAction, (uintptr_t) owner); - - openGate(); - - return res; + VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner)); + } + + if (kSleepersRemoved == ((kSleepersActionsMask | kSleepersRemoved) & *sleepersP)) { + // no actions outstanding + *sleepersP &= ~kSleepersRemoved; + super::setWorkLoop(NULL); + } + + wl->openGate(); + + return res; } -IOReturn IOCommandGate::attemptAction(Action inAction, - void *arg0, void *arg1, - void *arg2, void *arg3) +IOReturn +IOCommandGate::attemptAction(Action inAction, + void *arg0, void *arg1, + void *arg2, void *arg3) { - IOReturn res; - - if (!inAction) - return kIOReturnBadArgument; - - // Try to close the gate if can't get return immediately. - if (!tryCloseGate()) - return kIOReturnCannotLock; - - // If the command gate is disabled then sleep until we get a wakeup - if (!workLoop->onThread() && !enabled) - res = kIOReturnNotPermitted; - else { - - bool trace = ( gIOKitTrace & kIOTraceCommandGates ) ? true : false; - - if (trace) - IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION), - (uintptr_t) inAction, (uintptr_t) owner); - - IOStatisticsActionCall(); - - res = (*inAction)(owner, arg0, arg1, arg2, arg3); - - if (trace) - IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION), - (uintptr_t) inAction, (uintptr_t) owner); - } - - openGate(); - - return res; + IOReturn res; + IOWorkLoop * wl; + + if (!inAction) { + return kIOReturnBadArgument; + } + if (!(wl = workLoop)) { + return kIOReturnNotReady; + } + + // Try to close the gate if can't get return immediately. + if (!wl->tryCloseGate()) { + return kIOReturnCannotLock; + } + + // If the command gate is disabled then sleep until we get a wakeup + if (!wl->onThread() && !enabled) { + res = kIOReturnNotPermitted; + } else { + bool trace = (gIOKitTrace & kIOTraceCommandGates) ? true : false; + + if (trace) { + IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION), + VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner)); + } + + IOStatisticsActionCall(); + + res = (*inAction)(owner, arg0, arg1, arg2, arg3); + + if (trace) { + IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION), + VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner)); + } + } + + wl->openGate(); + + return res; } -IOReturn IOCommandGate::commandSleep(void *event, UInt32 interruptible) +IOReturn +IOCommandGate::commandSleep(void *event, UInt32 interruptible) { - if (!workLoop->inGate()) - return kIOReturnNotPermitted; + if (!workLoop->inGate()) { + /* The equivalent of 'msleep' while not holding the mutex is invalid */ + panic("invalid commandSleep while not holding the gate"); + } - return sleepGate(event, interruptible); + return sleepGate(event, interruptible); } -IOReturn IOCommandGate::commandSleep(void *event, AbsoluteTime deadline, UInt32 interruptible) +IOReturn +IOCommandGate::commandSleep(void *event, AbsoluteTime deadline, UInt32 interruptible) { - if (!workLoop->inGate()) - return kIOReturnNotPermitted; + if (!workLoop->inGate()) { + /* The equivalent of 'msleep' while not holding the mutex is invalid */ + panic("invalid commandSleep while not holding the gate"); + } - return sleepGate(event, deadline, interruptible); + return sleepGate(event, deadline, interruptible); } -void IOCommandGate::commandWakeup(void *event, bool oneThread) +void +IOCommandGate::commandWakeup(void *event, bool oneThread) { - wakeupGate(event, oneThread); + wakeupGate(event, oneThread); }