gem5  v22.0.0.2
syscall_desc.cc
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29 
30 #include "sim/syscall_desc.hh"
31 
32 #include "base/types.hh"
33 #include "sim/eventq.hh"
35 
36 namespace gem5
37 {
38 
39 class ThreadContext;
40 
41 void
43 {
44  DPRINTF_SYSCALL(Base, "Calling %s...\n", dumper(name(), tc));
45 
46  SyscallReturn retval = executor(this, tc);
47 
48  if (retval.needsRetry()) {
49  // Suspend this ThreadContext while the syscall is pending.
50  tc->suspend();
51 
52  DPRINTF_SYSCALL(Base, "%s needs retry.\n", name());
53  setupRetry(tc);
54  return;
55  }
56 
57  handleReturn(tc, retval);
58 }
59 
60 void
62 {
63  DPRINTF_SYSCALL(Base, "Retrying %s...\n", dumper(name(), tc));
64 
65  SyscallReturn retval = executor(this, tc);
66 
67  if (retval.needsRetry()) {
68  DPRINTF_SYSCALL(Base, "%s still needs retry.\n", name());
69  setupRetry(tc);
70  return;
71  }
72 
73  // We're done retrying, so reactivate this ThreadContext.
74  tc->activate();
75 
76  handleReturn(tc, retval);
77 }
78 
79 void
81 {
82  // Create an event which will retry the system call later.
83  auto retry = [this, tc]() { retrySyscall(tc); };
84  auto *event = new EventFunctionWrapper(retry, name(), true);
85 
86  // Schedule it in about 100 CPU cycles. That will give other contexts
87  // a chance to execute a bit of code before trying again.
88  auto *cpu = tc->getCpuPtr();
90  curTick() + cpu->cyclesToTicks(Cycles(100)));
91 }
92 
93 void
95 {
96  if (ret.suppressed()) {
97  DPRINTF_SYSCALL(Base, "No return value.\n", name());
98  } else {
99  returnInto(tc, ret);
100  DPRINTF_SYSCALL(Base, "Returned %d.\n", ret.encodedValue());
101  }
102 }
103 
104 } // namespace gem5
gem5::SyscallDesc::retrySyscall
void retrySyscall(ThreadContext *tc)
Definition: syscall_desc.cc:61
gem5::curTick
Tick curTick()
The universal simulation clock.
Definition: cur_tick.hh:46
syscall_debug_macros.hh
gem5::SyscallReturn
This class represents the return value from an emulated system call, including any errno setting.
Definition: syscall_return.hh:55
gem5::SyscallDesc::returnInto
virtual void returnInto(ThreadContext *tc, const SyscallReturn &ret)=0
For use within the system call executor if new threads are created and need something returned into t...
gem5::MipsISA::event
Bitfield< 10, 5 > event
Definition: pra_constants.hh:300
gem5::SyscallDesc::executor
Executor executor
Mechanism for ISAs to connect to the emul function definitions.
Definition: syscall_desc.hh:109
gem5::ThreadContext::activate
virtual void activate()=0
Set the status to Active.
gem5::SyscallDesc::doSyscall
void doSyscall(ThreadContext *tc)
Interface for invoking the system call funcion pointer.
Definition: syscall_desc.cc:42
gem5::Cycles
Cycles is a wrapper class for representing cycle counts, i.e.
Definition: types.hh:78
gem5::auxv::Base
@ Base
Definition: aux_vector.hh:74
gem5::ThreadContext
ThreadContext is the external interface to all thread state for anything outside of the CPU.
Definition: thread_context.hh:94
DPRINTF_SYSCALL
#define DPRINTF_SYSCALL(FLAGEXT, FMT,...)
This macro is intended to help with readability.
Definition: syscall_debug_macros.hh:57
gem5::SyscallDesc::setupRetry
void setupRetry(ThreadContext *tc)
Definition: syscall_desc.cc:80
gem5::SyscallReturn::encodedValue
int64_t encodedValue() const
The encoded value (as described above)
Definition: syscall_return.hh:122
gem5::SyscallDesc::dumper
Dumper dumper
Definition: syscall_desc.hh:110
gem5::SyscallDesc::handleReturn
void handleReturn(ThreadContext *tc, const SyscallReturn &ret)
Definition: syscall_desc.cc:94
gem5::EventFunctionWrapper
Definition: eventq.hh:1115
gem5::ThreadContext::suspend
virtual void suspend()=0
Set the status to Suspended.
gem5::curEventQueue
EventQueue * curEventQueue()
Definition: eventq.hh:88
types.hh
gem5::EventQueue::schedule
void schedule(Event *event, Tick when, bool global=false)
Schedule the given event on this queue.
Definition: eventq.hh:764
gem5::ThreadContext::getCpuPtr
virtual BaseCPU * getCpuPtr()=0
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: gpu_translation_state.hh:37
gem5::SyscallDesc::name
std::string name() const
Definition: syscall_desc.hh:80
gem5::SyscallReturn::suppressed
bool suppressed() const
Should returning this value be suppressed?
Definition: syscall_return.hh:100
syscall_desc.hh
gem5::SyscallReturn::needsRetry
bool needsRetry() const
Does the syscall need to be retried?
Definition: syscall_return.hh:97
eventq.hh

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