This patch simplifies the Range object hierarchy in preparation for an
address range class that also allows striping (e.g. selecting a few
bits as matching in addition to the range).
To extend the AddrRange class to an AddrRegion, the first step is to
simplify the hierarchy such that we can make it as lean as possible
before adding the new functionality. The only class using Range and
MetaRange is AddrRange, and the three classes are now collapsed into
one.
This patch removes the use of g_system_ptr for event scheduling. Each consumer
object now needs to specify upfront an EventManager object it would use for
scheduling events. This makes the ruby memory system more amenable for a
multi-threaded simulation.
This patch makes a minor addition to the SimpleMemory by enforcing a
maximum data rate. The bandwidth is configurable, and a reasonable
value (12.8GB/s) has been choosen as the default.
The changes do add some complexity to the SimpleMemory, but they
should definitely be justifiable as this enables a far more realistic
setup using even this simple memory controller.
The rate regulation is done for reads and writes combined to reflect
the bidirectional data busses used by most (if not all) relevant
memories. Moreover, the regulation is done per packet as opposed to
long term, as it is the short term data rate (data bus width times
frequency) that is the limiting factor.
A follow-up patch bumps the stats for the regressions.
This patch adds Link-Time Optimization when building the fast target
using gcc >= 4.6, and adds a scons flag to disable it (-no-lto). No
check is performed to guarantee that the linker supports LTO and use
of the linker plugin, so the user has to ensure that binutils GNU ld
>= 2.21 or the gold linker is available. Typically, if gcc >= 4.6 is
available, the latter should not be a problem. Currently the LTO
option is only useful for gcc >= 4.6, due to the limited support on
clang and earlier versions of gcc. The intention is to also add
support for clang once the LTO integration matures.
The same number of jobs is used for the parallel phase of LTO as the
jobs specified on the scons command line, using the -flto=n flag that
was introduced with gcc 4.6. The gold linker also supports concurrent
and incremental linking, but this is not used at this point.
The compilation and linking time is increased by almost 50% on
average, although ARM seems to be particularly demanding with an
increase of almost 100%. Also beware when using this as gcc uses a
tremendous amount of memory and temp space in the process. You have
been warned.
After some careful consideration, and plenty discussions, the flag is
only added to the fast target, and the warning that was issued in an
earlier version of this patch is now removed. Similarly, the flag used
to enable LTO, now the default is to use it, and the flag has been
modified to disable LTO. The rationale behind this decision is that
opt is used for development, whereas fast is only used for long runs,
e.g. regressions or more elaborate experiments where the additional
compile and link time is amortized by a much larger run time.
When it comes to the return on investment, the regression seems to be
roughly 15% faster with LTO. For a bit more detail, I ran twolf on
ARM.fast, with three repeated runs, and they all finish within 42
minutes (+- 25 seconds) without LTO and 31 minutes (+- 25 seconds)
with LTO, i.e. LTO gives an impressive >25% speed-up for this case.
Without LTO (ARM.fast twolf)
real 42m37.632s
user 42m34.448s
sys 0m0.390s
real 41m51.793s
user 41m50.384s
sys 0m0.131s
real 41m45.491s
user 41m39.791s
sys 0m0.139s
With LTO (ARM.fast twolf)
real 30m33.588s
user 30m5.701s
sys 0m0.141s
real 31m27.791s
user 31m24.674s
sys 0m0.111s
real 31m25.500s
user 31m16.731s
sys 0m0.106s
This patch adds a new target called 'perf' that facilitates profiling
using google perftools rather than gprof. The perftools CPU profiler
offers plenty useful information in addition to gprof, and the latter
is kept mostly to offer profiling also on non-Linux hosts.
This patch restructures the ccflags such that the common parts are
defined in a single location, also capturing all the target types in a
single place.
The patch also adds a corresponding ldflags in preparation for
google-perf profiling support and the addition of Link-Time
Optimization.
This patch shifts the version of gcc for which we enable c++0x from
4.6 to 4.4 The more long term plan is to see what the c++0x features
can bring and what level of support would be enabled simply by bumping
the required version of gcc from 4.3 to 4.4.
A few minor things had to be fixed in the code base, most notably the
choice of a hashmap implementation. In the Ruby Sequencer there were
also a few minor issues that gcc 4.4 was not too happy about.
When switching from an atomic CPU to any of the timing CPUs, a drain is
unnecessary since no events are scheduled in atomic mode. However, when
trying to switch CPUs starting with a timing CPU, there may be events
scheduled. This change ensures that all events are drained from the system
by calling m5.drain before switching CPUs.
The profileEvent pointer is tested against NULL in various places, but
it is not initialized unless running in full-system mode. In SE mode, this
can result in segmentation faults when profileEvent default intializes to
something other than NULL.
This patch addresses a few minor issues reported by the clang static
analyzer.
The analysis was run with:
scan-build -disable-checker deadcode \
-enable-checker experimental.core \
-disable-checker experimental.core.CastToStruct \
-enable-checker experimental.cpluscplus
This seperates the functionality to clear the state in a block into
blk.hh and the functionality to udpate the tag information into the
tags. This gets rid of the case where calling invalidateBlk on an
already-invalid block does something different than calling it on a
valid block, which was confusing.
The patch introduces two predicates for condition code registers -- one
tests if a register needs to be read, the other tests whether a register
needs to be written to. These predicates are evaluated twice -- during
construction of the microop and during its execution. Register reads
and writes are elided depending on how the predicates evaluate.
The D flag bit is part of the cc flag bit register currently. But since it
is not being used any where in the implementation, it creates an unnecessary
dependency. Hence, it is being moved to a separate register.
This patch is meant for allowing predicated reads and writes. Note that this
predication is different from the ISA provided predication. They way we
currently provide the ISA description for X86, we read/write registers that
do not need to be actually read/written. This is likely to be true for other
ISAs as well. This patch allows for read and write predicates to be associated
with operands. It allows for the register indices for source and destination
registers to be decided at the time when the microop is constructed. The
run time indicies come in to play only when the at least one of the
predicates has been provided. This patch will not affect any of the ISAs that
do not provide these predicates. Also the patch assumes that the order in
which operands appear in any function of the microop is same across all the
functions of the microops. A subsequent patch will enable predication for the
x86 ISA.
If I understand correctly, this was put in place so that a debugger can be
attached when the protocol aborts. While this sounds useful, it is a problem
when the simulation is not being actively monitored. I think it is better to
remove this.
Despite gzwrite taking an unsigned for length, it returns an int for
bytes written; gzwrite fails if (int)len < 0. Because of this, call
gzwrite with len no larger than INT_MAX: write in blocks of INT_MAX if
data to be written is larger than INT_MAX.
This patch prunes the range_ops header that is no longer used. The
bridge used it to do filtering of address ranges, but this is changed
since quite some time.
Ultimately this patch aims to simplify the handling of ranges before
specialising the AddrRange to an AddrRegion that also allows striping
bits to be selected.
This patch aims to simplify the use of the Range class before
introducing a more elaborate AddrRegion to replace the AddrRange. The
SackRange is the only use of the range class besides address ranges,
and the removal of this use makes for an easier modification of the
range class.
The functionlity that is removed with this patch is not used anywhere
throughout the code base.
This patch addresses a previously highlighted issue with the default
latencies used for PIO and PCI devices. The values are merely educated
guesses and might not represent the particular system you want to
model. However, the values in this patch are definitely far more
realistic than the previous ones.
In i8254xGBe, the writeConfig method is updated to use configDelay
instead of pioDelay.
A follow-up patch will update the regression stats.
Includes a small change in sim_object.cc that adds the name space to
the output stream parameter in serializeAll. Leaving out the name
space unfortunately confuses Doxygen.
Simulation objects normally register derived statistics, presumably
what regFormulas originally was meant for, in regStats(). This patch
removes regRegformulas since there is no need to have a separate
method call to register formulas.
Implement some code we used to panic on as it actually does happen with the
e1000 driver in Linux 3.3+. We used to assume that a TSO header would never
be part of a larger payload, however it appears as though it now can be.
Some bare metal build flows seem to build binaries that we aren't necessarily
expecting. Initialize everything to 0, so we don't make any assumptions about
what is or isn't in the binary.
This patch is a first step to using Cycles as a parameter type. The
main affected modules are the CPUs and the Ruby caches. There are
definitely plenty more places that are affected, but this patch serves
as a starting point to making the transition.
An important part of this patch is to actually enable parameters to be
specified as Param.Cycles which involves some changes to params.py.
The =operator for the DataBlock class was incorrectly interpreting the class
member m_alloc. This variable stands for whether the assigned memory for the
data block needs to be freed or not by the class itself. It seems that the
=operator interpreted the variable as whether the memory is assigned to the
data block. This wrong interpretation was causing values not to propagate
to RubySystem::m_mem_vec_ptr. This caused major issues with restoring from
checkpoints when using a protocol which verified that the cache data was
consistent with the backing store (i.e. MOESI-hammer).
This patch addresses the comments and feedback on the preceding patch
that reworks the clocks and now more clearly shows where cycles
(relative cycle counts) are used to express time.
Instead of bumping the existing patch I chose to make this a separate
patch, merely to try and focus the discussion around a smaller set of
changes. The two patches will be pushed together though.
This changes done as part of this patch are mostly following directly
from the introduction of the wrapper class, and change enough code to
make things compile and run again. There are definitely more places
where int/uint/Tick is still used to represent cycles, and it will
take some time to chase them all down. Similarly, a lot of parameters
should be changed from Param.Tick and Param.Unsigned to
Param.Cycles.
In addition, the use of curTick is questionable as there should not be
an absolute cycle. Potential solutions can be built on top of this
patch. There is a similar situation in the o3 CPU where
lastRunningCycle is currently counting in Cycles, and is still an
absolute time. More discussion to be had in other words.
An additional change that would be appropriate in the future is to
perform a similar wrapping of Tick and probably also introduce a
Ticks class along with suitable operators for all these classes.
This patch introduces the notion of a clock update function that aims
to avoid costly divisions when turning the current tick into a
cycle. Each clocked object advances a private (hidden) cycle member
and a tick member and uses these to implement functions for getting
the tick of the next cycle, or the tick of a cycle some time in the
future.
In the different modules using the clocks, changes are made to avoid
counting in ticks only to later translate to cycles. There are a few
oddities in how the O3 and inorder CPU count idle cycles, as seen by a
few locations where a cycle is subtracted in the calculation. This is
done such that the regression does not change any stats, but should be
revisited in a future patch.
Another, much needed, change that is not done as part of this patch is
to introduce a new typedef uint64_t Cycle to be able to at least hint
at the unit of the variables counting Ticks vs Cycles. This will be
done as a follow-up patch.
As an additional follow up, the thread context still uses ticks for
the book keeping of last activate and last suspend and this should
probably also be changed into cycles as well.
This patch tightens up the semantics around port binding and checks
that the ports that are being bound are currently not connected, and
similarly connected before unbind is called.
The patch consequently also changes the order of the unbind and bind
for the switching of CPUs to ensure that the rules are adhered
to. Previously the ports would be "over-written" without any check.
There are no changes in behaviour due to this patch, and the only
place where the unbind functionality is used is in the CPU.
This patch updates how the checker CPU handles the ports such that the
regressions will once again run without causing a panic.
A minor amount of tidying up was also done as part of this patch.
This patch disables a warning for unused values which causes problems
when compiling the swig-generated sources using recent llvm-based
compilers like llvm-gcc and clang.
The memory size variable was a 32-bit int. This meant that the size of the
memory was limited to 4GB. This patch changes the type of the variable to
64-bit to support larger memory sizes. Thanks to Raghuraman Balasubramanian
for bringing this to notice.
This patch does a bunch of house-keeping updates on the DMA, including
indentation, and formatting, but most importantly breaks out the
response handling such that it can be shared between the atomic and
timing modes. It also removes a potential bug caused by the atomic
handling of responses only deleting the allocated request (pkt->req)
once the DMA action completes instead of doing so for every packet.
Before this patch, the handling of responses was near identical for
atomic and timing, but the code was simply duplicated. With this
patch, the handleResp method deals with the responses in both cases.
There are further updates to make after removing the NACKs, but that
will be part of a separate follow-up patch. This patch does not change
the behaviour of any regression.
This patch removes the NACK frrom the packet as there is no longer any
module in the system that issues them (the bridge was the only one and
the previous patch removes that).
The handling of NACKs was mostly avoided throughout the code base, by
using e.g. panic or assert false, but in a few locations the NACKs
were actually dealt with (although NACKs never occured in any of the
regressions). Most notably, the DMA port will now never receive a NACK
and the backoff time is thus never changed. As a consequence, the
entire backoff mechanism (similar to a PCI bus) is now removed and the
DMA port entirely relies on the bus performing the arbitration and
issuing a retry when appropriate. This is more in line with e.g. PCIe.
Surprisingly, this patch has no impact on any of the regressions. As
mentioned in the patch that removes the NACK from the bridge, a
follow-up patch should change the request and response buffer size for
at least one regression to also verify that the system behaves as
expected when the bridge fills up.
This patch removes the NACKing in the bridge, as the split
request/response busses now ensure that protocol deadlocks do not
occur, i.e. the message-dependency chain is broken by always allowing
responses to make progress without being stalled by requests. The
NACKs had limited support in the system with most components ignoring
their use (with a suitable call to panic), and as the NACKs are no
longer needed to avoid protocol deadlocks, the cleanest way is to
simply remove them.
The bridge is the starting point as this is the only place where the
NACKs are created. A follow-up patch will remove the code that deals
with NACKs in the endpoints, e.g. the X86 table walker and DMA
port. Ultimately the type of packet can be complete removed (until
someone sees a need for modelling more complex protocols, which can
now be done in parts of the system since the port and interface is
split).
As a consequence of the NACK removal, the bridge now has to send a
retry to a master if the request or response queue was full on the
first attempt. This change also makes the bridge ports very similar to
QueuedPorts, and a later patch will change the bridge to use these. A
first step in this direction is taken by aligning the name of the
member functions, as done by this patch.
A bit of tidying up has also been done as part of the simplifications.
Surprisingly, this patch has no impact on any of the
regressions. Hence, there was never any NACKs issued. In a follow-up
patch I would suggest changing the size of the bridge buffers set in
FSConfig.py to also test the situation where the bridge fills up.
This patch extends the queued port interfaces with methods for
scheduling the transmission of a timing request/response. The methods
are named similar to the corresponding sendTiming(Snoop)Req/Resp,
replacing the "send" with "sched". As the queues are currently
unbounded, the methods always succeed and hence do not return a value.
This functionality was previously provided in the subclasses by
calling PacketQueue::schedSendTiming with the appropriate
parameters. With this change, there is no need to introduce these
extra methods in the subclasses, and the use of the queued interface
is more uniform and explicit.
This patch removes the overloading of the parameter, which seems both
redundant, and possibly incorrect.
The PciConfigAll now also uses a Param.Latency rather than a
Param.Tick. For backwards compatibility it still sets the pio_latency
to 1 tick. All the comments have also been updated to not state that
it is in simticks when it is not necessarily the case.
This patch removes the overloading of the parameter, which seems both
redundant, and possibly incorrect.
The inorder CPU is particularly interesting as it uses a different
name for the parameter, and never make any use of it internally.
This patch allows packets to be enqueued in the same tick as they are
intended to be sent. This does not imply they actually are sent that
tick, although that is possible.
This change is useful for module that use the queued ports primarly to
avoid handling the flow control involved in sending and retrying
packets.
This patch tidies up the EventManager constructor and prunes a corner
case where the EventManager would initialise its eventq pointer to
NULL. This would cause segmentation faults on actual use and should
never happen.
This patch makes the Tick unsigned and removes the UTick typedef. The
ticks should never be negative, and there was only one major issue
with removing it, caused by the o3 CPU using a -1 as an initial value.
The patch has no impact on any regressions.
This patch moves the clock of the CPU, bus, and numerous devices to
the new class ClockedObject, that sits in between the SimObject and
MemObject in the class hierarchy. Although there are currently a fair
amount of MemObjects that do not make use of the clock, they
potentially should do so, e.g. the caches should at some point have
the same clock as the CPU, potentially with a 1:n ratio. This patch
does not introduce any new clock objects or object hierarchies
(clusters, clock domains etc), but is still a step in the direction of
having a more structured approach clock domains.
The most contentious part of this patch is the serialisation of clocks
that some of the modules (but not all) did previously. This
serialisation should not be needed as the clock is set through the
parameters even when restoring from the checkpoint. In other words,
the state is "stored" in the Python code that creates the modules.
The nextCycle methods are also simplified and the clock phase
parameter of the CPU is removed (this could be part of a clock object
once they are introduced).
Alpha System was overriding loadState() function to setup some functional
event. The system tried to read/write to memory before the Ruby memory had
unserialized the state. With this patch, Alpha System overrides the
startup() function, and sets up functional events in this function. This
works because startup() is called after Ruby memory system has unserialized
the memory state.
This patch fixes some problems with the drain/switchout functionality
for the O3 cpu and for the ARM ISA and adds some useful debug print
statements.
This is an incremental fix as there are still a few bugs/mem leaks with the
switchout code. Particularly when switching from an O3CPU to a
TimingSimpleCPU. However, when switching from O3 to O3 cores with the ARM ISA
I haven't encountered any more assertion failures; now the kernel will
typically panic inside of simulation.
New tool chains seem to be looking for kernel versions newer than what
this this was previously set to. Also take this opportunity to change
the hostname we report in uname to sim.gem5.org.
This patch moves instantiateTopology into Ruby.py and removes the
mem/ruby/network/topologies directory. It also adds some extra inheritance to
the topologies to clean up some issues in the existing topologies.
Off-by-one loop termination meant that we were stuffing
the terminating '\0' into the std::string value, which
makes for difficult-to-debug string comparison failures.
This replaces a (potentially uninitialized) string
field with a virtual function so that we can have
a safe interface without requiring changes to the
eio code.
Enable different whitelists for different OS/arch combinations,
since some use the generic Linux definitions only, and others
use definitions inherited from earlier Unix flavors on those
architectures.
Also update x86 function pointers so ioctl is no longer
unimplemented on that platform.
This patch is a revised version of Vince Weaver's earlier patch.
when using the checker i ran into problems where an instruction reading the
cpu id register failed because the ids did not match, and hence, the result
of the instruction did not match. this patch ensures that the ids match so
this instruction does not fail. this problem only seemed to manifest itself
when multiple cores were in the system, either multi-core, or extra switched-
out cores present in the system.
removes the optimization that forwards an exclusive copy to a requester on a
read, only for the i-cache. this optimization isn't necessary because we
typically won't be writing to the i-cache.
According to the A15 TRM the value of this register is as follows (assuming 16 word = 64 byte lines)
[31:29] Format - b100 specifies v7
[28] RAZ - b0
[27:24] CWG log2(max writeback size #words) - 0x4 16 words
[23:20] ERG log2(max reservation size #words) - 0x4 16 words
[19:16] DminLine log2(smallest dcache line #words) - 0x4 16 words
[15:14] L1Ip L1 index/tagging policy - b11 specifies PIPT
[13:4] RAZ - b0000000000
[3:0] IminLine log2(smallest icache line #words) - 0x4 16 words
This patch changes the simple memory to have a single slave port
rather than a vector port. The simple memory makes no attempts at
modelling the contention between multiple ports, and any such
multiplexing and demultiplexing could be done in a bus (or crossbar)
outside the memory controller. This scenario also matches with the
ongoing work on a SimpleDRAM model, which will be a single-ported
single-channel controller that can be used in conjunction with a bus
(or crossbar) to create a multi-port multi-channel controller.
There are only very few regressions that make use of the vector port,
and these are all for functional accesses only. To facilitate these
cases, memtest and memtest-ruby have been updated to also have a
"functional" bus to perform the (de)multiplexing of the functional
memory accesses.
This patch removes printConfig() functions from all structures in Ruby.
Most of the information is already part of config.ini, and where ever it
is not, it would become in due course.
This enables configuration scripts to set up mappings
from process virtual addresses to specific physical
addresses in SE mode. This feature is needed to
support modeling of user-accessible memories or
devices in SE mode, avoiding the complexities of FS
mode and the need to write a device driver.
This patch models a cache as separate tag and data arrays. The patch exposes
the banked array as another resource that is checked by SLICC before a
transition is allowed to execute. This is similar to how TBE entries and slots
in output ports are modeled.
Updates to Ruby to support statistics counting of cache accesses. This feature
serves multiple purposes beyond simple stats collection. It provides the
foundation for ruby to model the cache tag and data arrays as physical
resources, as well as provide the necessary input data for McPAT power
modeling.
Instead of just passing a list of controllers to the makeTopology function
in src/mem/ruby/network/topologies/<Topo>.py we pass in a function pointer
which knows how to make the topology, possibly with some extra state set
in the configs/ruby/<protocol>.py file. Thus, we can move all of the files
from network/topologies to configs/topologies. A new class BaseTopology
is added which all topologies in configs/topologies must inheirit from and
follow its API.
--HG--
rename : src/mem/ruby/network/topologies/Crossbar.py => configs/topologies/Crossbar.py
rename : src/mem/ruby/network/topologies/Mesh.py => configs/topologies/Mesh.py
rename : src/mem/ruby/network/topologies/MeshDirCorners.py => configs/topologies/MeshDirCorners.py
rename : src/mem/ruby/network/topologies/Pt2Pt.py => configs/topologies/Pt2Pt.py
rename : src/mem/ruby/network/topologies/Torus.py => configs/topologies/Torus.py
This patch renames the queue() accessor to the less ambigious
eventQueue, and also removes the cast operator. The queue() member
function cause problems in derived classes that declare members with
the same name, e.g. a MemObject subclass that has a packet queue on
its own. The operator is not causing any harm at this point, but as it
is not used there is little point in keeping it.
This patch makes the queue implementation in the SimpleTimingPort
private to avoid confusion with the protected member queue in the
QueuedSlavePort. The SimpleTimingPort provides the queue_impl to the
QueuedSlavePort and it can be accessed via the reference in the base
class. The use of the member name queue is thus no longer overloaded.
This patch is a first step to align the port names used in the Python
world and the C++ world. Ultimately it serves to make the use of
config.json together with output from the simulation easier, including
post-processing of statistics.
Most notably, the CPU, cache, and bus is addressed in this patch, and
there might be other ports that should be updated accordingly. The
dash name separator has also been replaced with a "." which is what is
used to concatenate the names in python, and a separation is made
between the master and slave port in the bus.
This patch changes the default bus width to a more sensible 8 bytes
(64 bits), which is in line with most on-chip buses. Although there
are cases where a wider or narrower bus is useful, the 8 bytes is a
good compromise to serve as the default.
This patch changes essentially all statistics, and will be bundled
with the outstanding changes to the bus.
This patch splits the existing buses into multiple layers. The
non-coherent bus is split into a request and a response layer, and the
coherent bus adds an additional layer for the snoop responses. The
layer is modified to be templatised on the port type, such that the
different layers can have retryLists with either master or slave
ports. This patch also removes the dynamic cast from the retry, as
previously promised when moving the recvRetry from the port base class
to the master/slave port respectively.
Overall, the split bus more closely reflects any modern on-chip bus
and should be at step in the right direction. From this point, it
would be reasonable straight forward to add separate layers (and thus
contention points and arbitration) for each port and thus create a
true crossbar.
The regressions all produce the correct output, but have varying
degrees of changes to their statistics. A separate patch will be
pushed with the updates to the reference statistics.
This patch moves all flow control, arbitration and state information
into a bus layer. The layer is thus responsible for all the state
transitions, and for keeping hold of the retry list. Consequently the
layer is also responsible for the draining.
With this change, the non-coherent and coherent bus are given a single
layer to avoid changing any temporal behaviour, but the patch opens up
for adding more layers.
This patch adds a state enum and member variable in the bus, tracking
the bus state, thus eliminating the need for tickNextIdle and inRetry,
and fixing an issue that allowed the bus to be occupied by multiple
packets at once (hopefully it also makes it easier to understand the
code).
The bus, in its current form, uses tickNextIdle and inRetry to keep
track of the state of the bus. However, it only updates tickNextIdle
_after_ forwarding a packet using sendTiming, and the result is that
the bus is still seen as idle, and a module that receives the packet
and starts transmitting new packets in zero time will still see the
bus as idle (and this is done by a number of DMA devices). The issue
can also be seen in isOccupied where the bus calls reschedule on an
event instead of schedule.
This patch addresses the problem by marking the bus as _not_ idle
already by the time we conclude that the bus is not occupied and we
will deal with the packet.
As a result of not allowing multiple packets to occupy the bus, some
regressions have slight changes in their statistics. A separate patch
updates these accordingly.
Further ahead, a follow-on patch will introduce a separate state
variable for request/responses/snoop responses, and thus implement a
split request/response bus with separate flow control for the
different message types (even further ahead it will introduce a
multi-layer bus).
This patch makes getAddrRanges const throughout the code base. There
is no reason why it should not be, and making it const prevents adding
any unintentional side-effects.
This patch adds getAddrRanges to the master port, and thus avoids
going through getSlavePort to be able to ask the slave. Similar to the
previous patch that added isSnooping to the SlavePort, this patch aims
to introduce an additional level of hierarchy in the ports (base port
being protocol-agnostic) and getSlave/MasterPort will return port
pointers to these base classes.
The function is named getAddrRanges also on the master port, but does
nothing besides asking the connected slave port. The slave port, as
before, has to provide an implementation and actually produce a list
of address ranges. The initial design used the name getSlaveAddrRanges
for the new function, but the more verbose name was later changed.
This patch adds isSnooping to the slave port, and thus avoids going
through getMasterPort to be able to ask the master. Over the course of
the next few patches, all getMasterPort/getSlavePort in Port and
MemObject are to be protocol agnostic, and the snooping is part of the
protocol layer.
The function is already present on the master port, where it is
implemented by the module itself, e.g. a cache. On the slave side, it
is merely asking the connected master port. The same name is used by
both functions despite their difference in behaviour. The initial
design used isMasterSnooping on the slave port side, but the more
verbose function name was later changed.
This patch is the last part of moving all protocol-related
functionality out of the Port base class. All the send/recv functions
are already moved, and the retry (which still governs all the timing
transport functions) is the only part that remained in the base class.
The only point where this currently causes a bit of inconvenience is
in the bus where the retry list is global and holds Port pointers (not
Master/SlavePort). This is about to change with the split into a
request/response bus and will soon be removed anyway.
The patch has no impact on any regressions.
This patch is the result of static analysis identifying a number of
memory leaks. The leaks are all benign as they are a result of not
deallocating memory in the desctructor. The fix still has value as it
removes false positives in the static analysis.
This patch fixes two warnings, one related to a narrowing conversion
(int to MachInst), and one due to the cast operator for arguments and
a mismatch in const-ness (const void* and void*).
The LRU policy always evicted the least recently touched way, even if it
contained valid data and another way was invalid, as can happen if a block has
been invalidated by coherance. This can result in caches never warming up even
though they are replacing blocks. This modifies the LRU policy to move blocks
to LRU position on invalidation.
Currently when multiple CPUs perform a load-linked/store-conditional sequence,
the loads all create a list of reservations which is then scanned when the
stores occur. A reservation matching the context and address of the store is
sought, BUT all reservations matching the address are also erased at this point.
The upshot is that a store-conditional will remove all reservations even if the
store itself does not succeed. A livelock was observed using 7-8 CPUs where a
thread would erase the reservations of other threads, not succeed, loop and put
its own reservation in again only to have it blown by another thread that
unsuccessfully now tries to store-conditional -- no forward progress was made,
hanging the system.
The correct way to do this is to only blow a reservation when a store
(conditional or not) actually /occurs/ to its address. One thread always wins
(the one that does the store-conditional first).
Add new flag (named pushedRAS) in the PredictorHistory structure.
This flag tracks whether the RAS has been pushed or not during a prediction.
Then, in the squash function it is used to pop the RAS if necessary.
npc in PCState for ARM was being calculated before the current flags were
updated with the next flags. This causes an issue as the npc is incremented by
two or four depending on the current flags (thumb or not) and was leading to
branches that were predicted correctly being identified as mispredicted.
This patch fixes a failing compilation caused by MaxMiscDestRegs being
zero. According to gcc 4.6, the result is a comparison that is always
false due to limited range of data type.
This patch is a temporary fix until Andreas' four-phase patches
get reviewed and committed. Removing FastAlloc seems to have exposed
an issue which previously was reasonable rare in which packets are freed
before the sending cache is done with them. This change puts incoming packets
no a pendingDelete queue which are deleted at the start of the next call and
thus breaks the dependency between when the caller returns true and when the
packet is actually used by the sending cache.
Running valgrind on a multi-core linux boot and the memtester results in no
valgrind warnings.
Due to recent changes to X86 TLB, gem5 stopped compiling on
gcc version 4.4.3. This patch provides the fix for that problem. The patch
is tested on gcc 4.4.3. The change is not required for more recent
versions of gcc (like on 4.6.3).
initCPU() will be called to initialize switched out CPUs for the simple and
inorder CPU models. this patch prevents those CPUs from being initialized
because they should get their state from the active CPU when it is switched
out.
This change allows designating a system as MP capable or not as some
bootloaders/kernels care that it's set right. You can have a single
processor MP capable system, but you can't have a multi-processor
UP only system. This change also fixes the initialization of the MIDR
register.
While FastAlloc provides a small performance increase (~1.5%) over regular malloc it isn't thread safe.
After removing FastAlloc and using tcmalloc I've seen a performance increase of 12% over libc malloc
when running twolf for ARM.
The CPUID instruction was implemented so that it would only write its results
if the instruction was successful. This works fine on the simple CPU where
unwritten registers retain their old values, but on a CPU like O3 with
renaming this is broken. The instruction needs to write the old values back
into the registers explicitly if they aren't being changed.
There are some bits of some fields of the ExtMachInst which are not actually
used for anything but are included in the hash of an ExtMachInst for
simplicity and efficiency. This change makes sure the decoder's internal
working ExtMachInst is completely initialized, even these unused bits, so that
there isn't any nondeterministic behavior, no valgrind messages about
uninitialized variables, and no potential false misses/redundant entries in
the decode cache.
This patch introduces a class hierarchy of buses, a non-coherent one,
and a coherent one, splitting the existing bus functionality. By doing
so it also enables further specialisation of the two types of buses.
A non-coherent bus connects a number of non-snooping masters and
slaves, and routes the request and response packets based on the
address. The request packets issued by the master connected to a
non-coherent bus could still snoop in caches attached to a coherent
bus, as is the case with the I/O bus and memory bus in most system
configurations. No snoops will, however, reach any master on the
non-coherent bus itself. The non-coherent bus can be used as a
template for modelling PCI, PCIe, and non-coherent AMBA and OCP buses,
and is typically used for the I/O buses.
A coherent bus connects a number of (potentially) snooping masters and
slaves, and routes the request and response packets based on the
address, and also forwards all requests to the snoopers and deals with
the snoop responses. The coherent bus can be used as a template for
modelling QPI, HyperTransport, ACE and coherent OCP buses, and is
typically used for the L1-to-L2 buses and as the main system
interconnect.
The configuration scripts are updated to use a NoncoherentBus for all
peripheral and I/O buses.
A bit of minor tidying up has also been done.
--HG--
rename : src/mem/bus.cc => src/mem/coherent_bus.cc
rename : src/mem/bus.hh => src/mem/coherent_bus.hh
rename : src/mem/bus.cc => src/mem/noncoherent_bus.cc
rename : src/mem/bus.hh => src/mem/noncoherent_bus.hh
This patch makes two very minor changes to please gcc 4.7. The
CopyData function no longer exists and this has been replaced. For
some reason previous versions of gcc did not complain on the const
char casting not having an implementation, but this is now addressed.
This patch merely remove the Packet* from the isOccupied member
function. Historically this was used to check if the packet was an
express snoop, but this is now done outside this function (where
relevant).
The main aim of this patch is to arrive at a suitable port interface
for vector ports, including both the packet and the port id. This
patch changes the bus transport functions
(recvFunctional/Atomic/Timing) to require a PortId parameter
indicating the source port. Previously this information was passed by
setting the source field of the packet, and this is only required in
the case of a timing request.
With this patch, the use of the source and destination field is also
more restrictive, as they are only needed for timing accesses. The
modifications to these fields for atomic snoops is now removed
entirely, also making minor modifications to the cache.
This patch removes the Packet::NodeID typedef and unifies it with the
Port::PortId. The src and dest fields in the packet are used to hold a
port id (e.g. in the bus), and thus the two should actually be the
same.
The typedef PortID is now global (in base/types.hh) and aligned with
the ThreadID in terms of capitalisation and naming of the
InvalidPortID constant.
Before this patch, two flags were used for valid destination and
source, rather than relying on a named value (InvalidPortID), and
this is now redundant, as the src and dest field themselves are
sufficient to tell whether the current value is a valid port
identifier or not. Consequently, the VALID_SRC and VALID_DST are
removed.
As part of the cleaning up, a number of int parameters and local
variables are updated to use PortID.
Note that Ruby still has its own NodeID typedef. Furthermore, the
MemObject getMaster/SlavePort still has an int idx parameter with a
default value of -1 which should eventually change to PortID idx =
InvalidPortID.
This patch updates the comments for the src and dest fields to reflect
their actual use. Due to a number of patches (e.g. removing the
Broadcast flag), the old comments are no longer indicative of the
current usage.
This patch splits the PacketBuffer class into a RequestState and a
DeferredRequest and DeferredResponse. Only the requests need a
SenderState, and the deferred requests and responses only need an
associated point in time for the request and the response queue.
Besides the cleaning up, the goal is to simplify the transition to a
new port handshake, and with these changes, the two packet queues are
starting to look very similar to the generic packet queue, but
currently they do a few unique things relating to the NACK and
counting of requests/responses that the packet queue cannot be
conveniently used. This will be addressed in a later patch.
The GDT can be accessed by user level software running in compatibility mode
by moving segment selectors into segment registers. The GDT needs to be set up
at an address accessible in this mode.
A small change was added a while ago to keep addresses from overflowing 32
bits when larger addresses shouldn't be accessible to software. That change
truncated when not in long mode, but really it should have truncated when not
in 64 bit mode. The difference is whether compatibility mode is included, a
mode that's supposed to act like a legacy 32 bit mode.
This will allow it to be specialized by the ISAs. The existing caching scheme
is provided by the BasicDecodeCache in the GenericISA namespace and is built
from the generalized components.
--HG--
rename : src/cpu/decode_cache.cc => src/arch/generic/decode_cache.cc
These classes are always used together, and merging them will give the ISAs
more flexibility in how they cache things and manage the process.
--HG--
rename : src/arch/x86/predecoder_tables.cc => src/arch/x86/decoder_tables.cc
This patch removes unused commands and attributes from the packet to
avoid any confusion. It is part of an effort to clear up how and where
different commands and attributes are used.
This patch changes the organisation of the JSON output slightly to
make it easier to traverse and use the files. Most importantly, the
hierarchical dictionaries now use keys that correspond to the
attribute names also in the case of VectorParams (used to be
e.f. "cpu0 cpu1"). It also adds the name and the path to each
SimObject directory entry. Before this patch, to get cpu0, you would
have to query dict['system']['cpu0 cpu1'][0] and this could be a dict
with 'cpu0' : { cpu parameters }. Now you use dict['system']['cpu'][0]
and get { cpu parameters } (where one is "name" : "cpu0").
Additionally this patch includes more verbose information about the
ports, specifying their role, and using a JSON array rather than a
concatenated string for the peer.
This patch moves the DMA device to its own set of files, splitting it
from the IO device. There are no behavioural changes associated with
this patch.
The patch also grabs the opportunity to do some very minor tidying up,
including some white space removal and pruning some redundant
parameters.
Besides the immediate benefits of the separation-of-concerns, this
patch also makes upcoming changes more streamlined as it split the
devices that are only slaves and the DMA device that also acts as a
master.
--HG--
rename : src/dev/io_device.cc => src/dev/dma_device.cc
rename : src/dev/io_device.hh => src/dev/dma_device.hh
This patch makes the (device) DmaPort non-snooping and removes the
recvSnoop constructor parameter and instead introduces a
SnoopingDmaPort subclass for the ARM table walker.
Functionality is unchanged, as are the stats, and the patch merely
clarifies that the normal DMA ports are not snooping (although they
may issue requests that are snooped by others, as done with PCI, PCIe,
AMBA4 ACE etc).
Currently this port is declared in the ARM table walker as it is not
used anywhere else. If other ports were to have similar behaviour it
could be moved in a future patch.
This patch turns the existing warning into a fatal, as there should
never be any cases where a (non-vector) port is assigned to and then
later connected to something else. If this behaviour is allowed, as it
used to be, there are cases where the wrong number of C++ ports are
created when instantiating objects with VectorPorts (obviously that
could be fixed, but the better approach is to simply not allow it).
The scheduling of the deadlock check event was being done incorrectly as the
clock was not being multiplied, so as to convert the time into ticks. This
patch removes that bug.
This patch moves the ECF and EZF bits to individual registers (ecfBit and
ezfBit) and the CF and OF bits to cfofFlag registers. This is being done
so as to lower the read after write dependencies on the the condition code
register. Ultimately we will have the following registers [ZAPS], [OF],
[CF], [ECF], [EZF] and [DF]. Note that this is only one part of the
solution for lowering the dependencies. The other part will check whether
or not the condition code register needs to be actually read. This would
be done through a separate patch.
If the length argument to mmap is larger than the arbitrary but reasonable
limit of 4GB, there's a good chance that the value is nonsense and not
intentional. Rather than attempting to satisfy the mmap anyway, this change
makes gem5 warn to make it more apparent what's going wrong.
Revised system visualization to reflect structure and memory hierarchy.
Improved visualization: less congested and cluttered; more colorful.
Nodes reflect components; directed edges reflect dirctional relation, from
a master port to a slave port. Requires pydot.
Fixed broken code which visualizes the system configuration by generating a
tree from each component's children, starting from root.
Requires DOT (hence pydot).
Symbol tables masked with the loadAddrMask create redundant entries
that could conflict with kernel function events that rely on the
original addresses. This patch guards the creation of those masked
symbol tables by default, with an option to enable them when needed
(for early-stage kernel debugging, etc.)
Track the point in the initialization where statistics have been registered.
After this point registering new masterIds can no longer work as some
SimObjects may have sized stats vectors based on the previous value. If someone
tries to register a masterId after this point the simulator executes fatal().
An older revision of the data sheet specified that txdctl.gran was 1 the granularity was
based on cache block and gran being 0 is based on descriptor count. The newer version of
the data sheet reverses this errata
This patch adds a communication monitor MemObject that can be inserted
between a master and slave port to provide a range of statistics about
the communication passing through it. The communication monitor is
non-invasive and does not change any properties or timing of the
packets, with the exception of adding a sender state to be able to
track latency. The statistics are only collected in timing mode (not
atomic) to avoid slowing down any fast forwarding.
An example of the statistics captured by the monitor are: read/write
burst lengths, bandwidth, request-response latency, outstanding
transactions, inter transaction time, transaction count, and address
distribution. The monitor can be used in combination with periodic
resetting and dumping of stats (through schedStatEvent) to study the
behaviour over time.
In future patches, a selection of convenience scripts will be added to
aid in visualising the statistics collected by the monitor.
This patch adds a guarding if-statement to avoid forwarding
uncacheable requests (or rather their corresponding request packets)
to bus snoopers. These packets should never have any effect on the
caches, and thus there is no need to forward them to the snoopers.
This patch fixes a bug that caused snoop requests to be placed in a
packet queue. Instead, the packet is now sent immediately using
sendTimingSnoopReq, thus bypassing the packet queue and any normal
responses waiting to be sent.
This patch moves send/recvTiming and send/recvTimingSnoop from the
Port base class to the MasterPort and SlavePort, and also splits them
into separate member functions for requests and responses:
send/recvTimingReq, send/recvTimingResp, and send/recvTimingSnoopReq,
send/recvTimingSnoopResp. A master port sends requests and receives
responses, and also receives snoop requests and sends snoop
responses. A slave port has the reciprocal behaviour as it receives
requests and sends responses, and sends snoop requests and receives
snoop responses.
For all MemObjects that have only master ports or slave ports (but not
both), e.g. a CPU, or a PIO device, this patch merely adds more
clarity to what kind of access is taking place. For example, a CPU
port used to call sendTiming, and will now call
sendTimingReq. Similarly, a response previously came back through
recvTiming, which is now recvTimingResp. For the modules that have
both master and slave ports, e.g. the bus, the behaviour was
previously relying on branches based on pkt->isRequest(), and this is
now replaced with a direct call to the apprioriate member function
depending on the type of access. Please note that send/recvRetry is
still shared by all the timing accessors and remains in the Port base
class for now (to maintain the current bus functionality and avoid
changing the statistics of all regressions).
The packet queue is split into a MasterPort and SlavePort version to
facilitate the use of the new timing accessors. All uses of the
PacketQueue are updated accordingly.
With this patch, the type of packet (request or response) is now well
defined for each type of access, and asserts on pkt->isRequest() and
pkt->isResponse() are now moved to the appropriate send member
functions. It is also worth noting that sendTimingSnoopReq no longer
returns a boolean, as the semantics do not alow snoop requests to be
rejected or stalled. All these assumptions are now excplicitly part of
the port interface itself.
This patch makes some rather trivial simplifications to the bus in
that it changes the use of BusMasterPort and BusSlavePort pointers to
simply use MasterPort and SlavePort (iterators are also updated
accordingly).
This change is a step towards a future patch that introduces a
separation of the interface and the structural port itself.
This patch introduces the PortId type, moves the definition of
INVALID_PORT_ID to the Port class, and also gives every port an id to
reflect the fact that each element in a vector port has an
identifier/index.
Previously the bus and Ruby testers (and potentially other users of
the vector ports) added the id field in their port subclasses, and now
this functionality is always present as it is moved to the base class.
This patch changes the guards for the definition of hash functions to
also exclude the int64_t and uint64_t hash functions in the case we
are using the c++0x STL <unordered_map> (and <hash>) or the TR1
version of the same header. Previously the guard only covered the hash
function for strings, but it seems there is also no need to define a
hash for the 64-bit integer types, and this has caused problems with
builds on 32-bit Ubuntu.
It's possible for two page table walks to overlap which will go in the same
place in the TLB's trie. They would land on top of each other, so this change
adds some code which detects if an address already matches an entry and if so
throws away the new one.
Put the { on the same line as the if and put a space between the if and the
open paren. Also, use the # format modifier which puts a 0x in front of hex
values automatically. If the ExtMachInst type isn't integral and actually
prints something more complicated, the # falls away harmlessly and we aren't
left with a phantom 0x followed by a bunch of unrelated text.
The parameter is _machInst, which is very similar to the member machInst. If
machInst is used to pass the parameter to a lower level constructor, what
really happens is that machInst is set to whatever it already happened to be,
effectively leaving it uninitialized.
This change also adjusts the TlbEntry class so that it stores the number of
address bits wide a page is rather than its size in bytes. In other words,
instead of storing 4K for a 4K page, it stores 12. 12 is easy to turn into 4K,
but it's a little harder going the other way.
This change adds a trie data structure which stores an arbitrary pointer type
based on an address and a number of relevant bits. Then lookups can be done
against the trie where the tree is traversed and the first legitimate match
found is returned.
This patch simplifies future patches by changing the pointer type used
in a number of the Ruby testers to use MasterPort instead of using a
derived CpuPort class. There is no reason for using the more
specialised pointers, and there is no longer a need to do any casting.
With the latest changes to the tester, organising ports as readers and
writes, things got a bit more complicated, and the "type" now had to
be removed to be able to fall back to using MasterPort rather than
CpuPort.
This patch simplifies the packet by removing the broadcast flag and
instead more firmly relying on (and enforcing) the semantics of
transactions in the classic memory system, i.e. request packets are
routed from a master to a slave based on the address, and when they
are created they have neither a valid source, nor destination. On
their way to the slave, the request packet is updated with a source
field for all modules that multiplex packets from multiple master
(e.g. a bus). When a request packet is turned into a response packet
(at the final slave), it moves the potentially populated source field
to the destination field, and the response packet is routed through
any multiplexing components back to the master based on the
destination field.
Modules that connect multiplexing components, such as caches and
bridges store any existing source and destination field in the sender
state as a stack (just as before).
The packet constructor is simplified in that there is no longer a need
to pass the Packet::Broadcast as the destination (this was always the
case for the classic memory system). In the case of Ruby, rather than
using the parameter to the constructor we now rely on setDest, as
there is already another three-argument constructor in the packet
class.
In many places where the packet information was printed as part of
DPRINTFs, request packets would be printed with a numeric "dest" that
would always be -1 (Broadcast) and that field is now removed from the
printing.
This patch introduces port access methods that separates snoop
request/responses from normal memory request/responses. The
differentiation is made for functional, atomic and timing accesses and
builds on the introduction of master and slave ports.
Before the introduction of this patch, the packets belonging to the
different phases of the protocol (request -> [forwarded snoop request
-> snoop response]* -> response) all use the same port access
functions, even though the snoop packets flow in the opposite
direction to the normal packet. That is, a coherent master sends
normal request and receives responses, but receives snoop requests and
sends snoop responses (vice versa for the slave). These two distinct
phases now use different access functions, as described below.
Starting with the functional access, a master sends a request to a
slave through sendFunctional, and the request packet is turned into a
response before the call returns. In a system without cache coherence,
this is all that is needed from the functional interface. For the
cache-coherent scenario, a slave also sends snoop requests to coherent
masters through sendFunctionalSnoop, with responses returned within
the same packet pointer. This is currently used by the bus and caches,
and the LSQ of the O3 CPU. The send/recvFunctional and
send/recvFunctionalSnoop are moved from the Port super class to the
appropriate subclass.
Atomic accesses follow the same flow as functional accesses, with
request being sent from master to slave through sendAtomic. In the
case of cache-coherent ports, a slave can send snoop requests to a
master through sendAtomicSnoop. Just as for the functional access
methods, the atomic send and receive member functions are moved to the
appropriate subclasses.
The timing access methods are different from the functional and atomic
in that requests and responses are separated in time and
send/recvTiming are used for both directions. Hence, a master uses
sendTiming to send a request to a slave, and a slave uses sendTiming
to send a response back to a master, at a later point in time. Snoop
requests and responses travel in the opposite direction, similar to
what happens in functional and atomic accesses. With the introduction
of this patch, it is possible to determine the direction of packets in
the bus, and no longer necessary to look for both a master and a slave
port with the requested port id.
In contrast to the normal recvFunctional, recvAtomic and recvTiming
that are pure virtual functions, the recvFunctionalSnoop,
recvAtomicSnoop and recvTimingSnoop have a default implementation that
calls panic. This is to allow non-coherent master and slave ports to
not implement these functions.
This patch adds a very basic pretty-printing of the test status
(passed or failed) to highlight failing tests even more: green for
passed, and red for failed. The printing only uses ANSI it the target
output is a tty and supports ANSI colours. Hence, any regression
scripts that are outputting to files or sending e-mails etc should
still be fine.
This patch addresses a number of minor issues that cause problems when
compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it
avoids using the deprecated ext/hash_map and instead uses
unordered_map (and similarly so for the hash_set). To make use of the
new STL containers, g++ and clang has to be invoked with "-std=c++0x",
and this is now added for all gcc versions >= 4.6, and for clang >=
3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1
unordered_map to avoid the deprecation warning.
The addition of c++0x in turn causes a few problems, as the
compiler is more stringent and adds a number of new warnings. Below,
the most important issues are enumerated:
1) the use of namespaces is more strict, e.g. for isnan, and all
headers opening the entire namespace std are now fixed.
2) another other issue caused by the more stringent compiler is the
narrowing of the embedded python, which used to be a char array,
and is now unsigned char since there were values larger than 128.
3) a particularly odd issue that arose with the new c++0x behaviour is
found in range.hh, where the operator< causes gcc to complain about
the template type parsing (the "<" is interpreted as the beginning
of a template argument), and the problem seems to be related to the
begin/end members introduced for the range-type iteration, which is
a new feature in c++11.
As a minor update, this patch also fixes the build flags for the clang
debug target that used to be shared with gcc and incorrectly use
"-ggdb".
Partial backout of cset 8b223e308b08.
Although it's great that there's currently no need
for Werror=false in the current tree, some of us
have uncommitted code that still needs this option.
This patch fixes a bug in Ruby that caused non-deterministic
simulation when changing the underlying hash map implementation. The
reason is order-dependent behaviour in combination with iteration over
the hash map contents. The two locations where a sorted container is
assumed are now changed to make use of a std::map instead of the
unordered hash map.
With this change, the stats changes slightly and the follow-on
changeset will update the relevant statistics.
Fixes checkpointing with respect to lost events after swapping event queues.
Also adds DPRINTFs to better understand what's going on when Ruby serializes
and unserializes.
This patch removes the assumption on having on single instance of
PhysicalMemory, and enables a distributed memory where the individual
memories in the system are each responsible for a single contiguous
address range.
All memories inherit from an AbstractMemory that encompasses the basic
behaviuor of a random access memory, and provides untimed access
methods. What was previously called PhysicalMemory is now
SimpleMemory, and a subclass of AbstractMemory. All future types of
memory controllers should inherit from AbstractMemory.
To enable e.g. the atomic CPU and RubyPort to access the now
distributed memory, the system has a wrapper class, called
PhysicalMemory that is aware of all the memories in the system and
their associated address ranges. This class thus acts as an
infinitely-fast bus and performs address decoding for these "shortcut"
accesses. Each memory can specify that it should not be part of the
global address map (used e.g. by the functional memories by some
testers). Moreover, each memory can be configured to be reported to
the OS configuration table, useful for populating ATAG structures, and
any potential ACPI tables.
Checkpointing support currently assumes that all memories have the
same size and organisation when creating and resuming from the
checkpoint. A future patch will enable a more flexible
re-organisation.
--HG--
rename : src/mem/PhysicalMemory.py => src/mem/AbstractMemory.py
rename : src/mem/PhysicalMemory.py => src/mem/SimpleMemory.py
rename : src/mem/physical.cc => src/mem/abstract_mem.cc
rename : src/mem/physical.hh => src/mem/abstract_mem.hh
rename : src/mem/physical.cc => src/mem/simple_mem.cc
rename : src/mem/physical.hh => src/mem/simple_mem.hh
With recent changes to the memory system, a port cannot be assigned a peer
port twice. While making use of the Ruby memory system in FS mode, DMA
ports were assigned peer twice, once for the classic memory system
and once for the Ruby memory system. This patch removes this double
assignment of peer ports.
This patch changes the behaviour of the All proxy parameter to not
only consider the direct children, but also do a pre-order depth-first
traversal of the object tree and append all results from the
children.
This is used in a later patch to find all the memories in the system,
independent of where they are located in the hierarchy.
This patch removes the physmem_port from the Atomic CPU and instead
uses the system pointer to access the physmem when using the fastmem
option. The system already keeps track of the physmem and the valid
memory address ranges, and with this patch we merely make use of that
existing functionality. As a result of this change, the overloaded
getMasterPort in the Atomic CPU can be removed, thus unifying the CPUs.
Virtual (pre-segmentation) addresses are truncated based on address size, and
any non-64 bit linear address is truncated to 32 bits. This means that real
mode addresses aren't truncated down to 16 bits after their segment bases are
added in.
This patch removes the DRAM memory class in preparation for updates to
the memory system, with the first one introducing an abstract memory
class, and removing the assumption of a single physical memory.
This patch removes the physMemPort from the RubySequencer and instead
uses the system pointer to access the physmem. The system already
keeps track of the physmem and the valid memory address ranges, and
with this patch we merely make use of that existing functionality. The
memory is modified so that it is possible to call the access functions
(atomic and functional) without going through the port, and the memory
is allowed to be unconnected, i.e. have no ports (since Ruby does not
attach it like the conventional memory system).
This patch introduces the notion of a master and slave port in the C++
code, thus bringing the previous classification from the Python
classes into the corresponding simulation objects and memory objects.
The patch enables us to classify behaviours into the two bins and add
assumptions and enfore compliance, also simplifying the two
interfaces. As a starting point, isSnooping is confined to a master
port, and getAddrRanges to slave ports. More of these specilisations
are to come in later patches.
The getPort function is not getMasterPort and getSlavePort, and
returns a port reference rather than a pointer as NULL would never be
a valid return value. The default implementation of these two
functions is placed in MemObject, and calls fatal.
The one drawback with this specific patch is that it requires some
code duplication, e.g. QueuedPort becomes QueuedMasterPort and
QueuedSlavePort, and BusPort becomes BusMasterPort and BusSlavePort
(avoiding multiple inheritance). With the later introduction of the
port interfaces, moving the functionality outside the port itself, a
lot of the duplicated code will disappear again.
This patch unifies where initMemProxies is called, in the init()
method of each BaseCPU subclass, before TheISA::initCPU is
called. Moreover, it also ensures that initMemProxies is called in
both full-system and syscall-emulation mode, thus unifying also across
the modes. An additional check is added in the ThreadState to ensure
that initMemProxies is only called once.
This patch changes the name of a bitfield from W to W_FIELD to avoid
clashes with W being used as a class (typename) in the templatized
range_map. It also changes L to L_FIELD to avoid future problems. The
problem manifestes itself when the CPU includes a header that in turn
includes range_map.hh. The relevant parts of the decoder are updated.
This patch unifies the recvFunctional, recvAtomic and recvTiming to
all be based on a similar structure: 1) extract information about the
incoming packet, 2) send it out to the appropriate snoopers, 3)
determine where it is going, and 4) forward it to the right
destination. The naming of variables across the different access
functions is now consistent as well.
Additionally, the patch introduces the member functions releaseBus and
retryWaiting to better distinguish between the two cases when we
should tell a sender to retry. The first case is when the bus goes
from busy to idle, and the second case is when it receives a retry
from a destination that did not immediatelly accept a packet.
As a very minor change, the MMU debug flag is no longer used in the bus.
This patch decouples the queueing and the port interactions to
simplify the introduction of the master and slave ports. By separating
the queueing functionality from the port itself, it becomes much
easier to distinguish between master and slave ports, and still retain
the queueing ability for both (without code duplication).
As part of the split into a PacketQueue and a port, there is now also
a hierarchy of two port classes, QueuedPort and SimpleTimingPort. The
QueuedPort is useful for ports that want to leave the packet
transmission of outgoing packets to the queue and is used by both
master and slave ports. The SimpleTimingPort inherits from the
QueuedPort and adds the implemention of recvTiming and recvFunctional
through recvAtomic.
The PioPort and MessagePort are cleaned up as part of the changes.
--HG--
rename : src/mem/tport.cc => src/mem/packet_queue.cc
rename : src/mem/tport.hh => src/mem/packet_queue.hh
This patch removes the overriding of "-Werror" in a handful of
cases. The code compiles with gcc 4.6.3 and clang 3.0 without any
warnings, and thus without any errors. There are no functional changes
introduced by this patch. In the future, rather than ypassing
"-Werror", address the warnings.
This patch cleans up a number of minor issues aiming to get closer to
compliance with the C++0x standard as interpreted by gcc and clang
(compile with std=c++0x and -pedantic-errors). In particular, the
patch cleans up enums where the last item was succeded by a comma,
namespaces closed by a curcly brace followed by a semi-colon, and the
use of the GNU-extension typeof (replaced by templated functions). It
does not address variable-length arrays, zero-size arrays, anonymous
structs, range expressions in switch statements, and the use of long
long. The generated CPU code also has a large number of issues that
remain to be fixed, mainly related to overflows in implicit constant
conversion (due to shifts).
This patch makes the code compile with clang 2.9 and 3.0 again by
making two very minor changes. Firt, it maintains a strict typing in
the forward declaration of the BaseCPUParams. Second, it adds a
FullSystemInt flag of the type unsigned int next to the boolean
FullSystem flag. The FullSystemInt variable can be used in
decode-statements (expands to switch statements) in the instruction
decoder.
Making the CheckerCPU a runtime time option requires the code to be compatible
with ISAs other than ARM. This patch adds the appropriate function
stubs to allow compilation.
Enables the CheckerCPU to be selected at runtime with the --checker option
from the configs/example/fs.py and configs/example/se.py configuration
files. Also merges with the SE/FS changes.
The change to port proxies recently moved code out of the constructor into
initState(). This is needed for code that loads data into memory, however
for code that setups symbol tables, kernel based events, etc this is the wrong
thing to do as that code is only called when a checkpoint isn't being restored
from.
1. --implicit-cache behavior is default.
2. makeEnv in src/SConscript is conditionally called.
3. decider set to MD5-timestamp
4. NO_HTML build option changed to SLICC_HTML (defaults to False)
This patch adds a creation-time check to the CPU to ensure that the
interrupt controller is created for the cases where it is needed,
i.e. if the CPU is not being switched in later and not a checker CPU.
The patch also adds the "createInterruptController" call to a number
of the regression scripts.
This patch renames the sendTiming member function in the RubyPort to
avoid inadvertently hiding Port::sendTiming (discovered through some
rather painful debugging). The RubyPort does, in fact, rely on the
functionality of the queued port and the implementation merely
schedules a send the next cycle. The new name for the member function
is sendNextCycle to better reflect this behaviour.
In the unlikely event that we ever shift to using C++11 the member
functions in Port should have a "final" identifier to prevent any
overriding in derived classes.
This change implements a PL031 real time clock.
--HG--
rename : src/dev/arm/timer_sp804.cc => src/dev/arm/rtc_pl031.cc
rename : src/dev/arm/timer_sp804.hh => src/dev/arm/rtc_pl031.hh
New kernels attempt to read CP14 what debug architecture is available.
These changes add the debug registers and return that none is currently
available.
The block is never inserted because it's the one extra block in the cache, but
it can be invalidated twice in a row. In that case the block doesn't have a
new master id (beacuse it was never inserted), however it is valid and
the accounting goes wrong at that point.
With the recent series of patches, the symbol table loading moved from
"construct" time to "init" time, but the kernel function event
callback registration was left behind. This patch moves it to the
proper location.
Add extra declarations to allow the compiler to pick up the right function.
Please note that these declarations have been added as part of the
clang-related changes.
This patch adds a function to X86 tlb that returns the
walker port. This port is required for correctly connecting
the walker ports for the cpu just switched in
This is a trivial patch that merely makes all the member functions of
the port proxies const. There is no good reason why they should not
be, and this change only serves to make it explicit that they are not
modified through their use.
This patch fixes a compilation error that occurs with gcc >= 4.6.1,
caused by swig not including cstddef and not using the std:: namespace
prefix for ptrdiff_t. There is an old patch,
http://reviews.m5sim.org/r/913/ that no longer applies cleanly and
this might be re-iterating the same issue.
We work around the problem by always enforcing the inclusion of
cstddef in all swig interface declarations, and also by explicitly
using std::ptrdiff_t.
If an instruction is executed speculatively and hits a situation where it
wants to panic, it should return a fault instead. If the instruction was
misspeculated, the fault can be thrown away. If the instruction wasn't
misspeculated, the fault will be invoked and the panic will still happen.
This patch splits the two cache ports into a master (memory-side) and
slave (cpu-side) subclass of port with slightly different
functionality. For example, it is only the CPU-side port that blocks
incoming requests, and only the memory-side port that schedules send
events outside of what the transmit list dictates.
This patch simplifies the two classes by relying further on
SimpleTimingPort and also generalises the latter to better accommodate
the changes (introducing trySendTiming and scheduleSend). The
memory-side cache port overrides sendDeferredPacket to be able to not
only send responses from the transmit list, but also send requests
based on the MSHRs.
A follow on patch further simplifies the SimpleTimingPort and the
cache ports.
This patch simplifies the mport in preparation for a split into a
master and slave role for the message ports. In particular,
sendMessageAtomic was only used in a single location and similarly so
sendMessageTiming. The affected interrupt device is updated
accordingly.
This patch simplfies the master ports used by RubyDirectedTester and
RubyTester by avoiding the use of SimpleTimingPort. Neither tester
made any use of the functionality offered by SimpleTimingPort besides
a trivial implementation of recvFunctional (only snoops) and
recvRangeChange (not relevant since there is only one master).
The patch does not change or add any functionality, it merely makes
the introduction of a master/slave port easier (in a future patch).
This patch moves the readBlob/writeBlob/memsetBlob from the Port class
to the PortProxy class, thus making a clear separation of the basic
port functionality (recv/send functional/atomic/timing), and the
higher-level functional accessors available on the port proxies.
There are only a few places in the code base where the blob functions
were used on ports, and they are all for peeking into the memory
system without making a normal memory access (in the memtest, and the
malta and tsunami pchip). The memtest also exemplifies how easy it is
to create a non-translating proxy if desired. The malta and tsunami
pchip used a slave port to perform a functional read, and this is now
changed to rely on the physProxy of the system (to which they already
have a pointer).
This patch is adding a clearer design intent to all objects that would
not be complete without a port proxy by making the proxies members
rathen than dynamically allocated. In essence, if NULL would not be a
valid value for the proxy, then we avoid using a pointer to make this
clear.
The same approach is used for the methods using these proxies, such as
loadSections, that now use references rather than pointers to better
reflect the fact that NULL would not be an acceptable value (in fact
the code would break and that is how this patch started out).
Overall the concept of "using a reference to express unconditional
composition where a NULL pointer is never valid" could be done on a
much broader scale throughout the code base, but for now it is only
done in the locations affected by the proxies.
This patch moves all port creation from the getPort method to be
consistently done in the MemObject's constructor. This is possible
thanks to the Swig interface passing the length of the vector ports.
Previously there was a mix of: 1) creating the ports as members (at
object construction time) and using getPort for the name resolution,
or 2) dynamically creating the ports in the getPort call. This is now
uniform. Furthermore, objects that would not be complete without a
port have these ports as members rather than having pointers to
dynamically allocated ports.
This patch also enables an elaboration-time enumeration of all the
ports in the system which can be used to determine the masterId.
This patch continues the unification of how the different CPU models
create and share their instruction and data ports. Most importantly,
it forces every CPU to have an instruction and a data port, and gives
these ports explicit getters in the BaseCPU (getDataPort and
getInstPort). The patch helps in simplifying the code, make
assumptions more explicit, andfurther ease future patches related to
the CPU ports.
The biggest changes are in the in-order model (that was not modified
in the previous unification patch), which now moves the ports from the
CacheUnit to the CPU. It also distinguishes the instruction fetch and
load-store unit from the rest of the resources, and avoids the use of
indices and casting in favour of keeping track of these two units
explicitly (since they are always there anyways). The atomic, timing
and O3 model simply return references to their already existing ports.
This patch adds a check in the findPort method to ensure that an
invalid port id is never returned. Previously this could happen if no
default port was set, and no address matched the request, in which
case -1 was returned causing a SEGFAULT when using the id to index in
the port array. To clean things up further a symbolic name is added
for the invalid port id.
Without this patch, undefined params cause a cryptic KeyError
in multidict inside get_config_as_dict(). This patch lets
undefined params through get_config_as_dict() so they can
once again generate meaningful error messages later on in
the configuration process.
This patch cleans up a number of remaining uses of bus.port which
is now split into bus.master and bus.slave. The only non-trivial change
is the memtest where the level building now has to be aware of the role
of the ports used in the previous level.
1. Updates the Branch Predictor correctly to the state
just after a mispredicted branch, if a squash occurs.
2. If a BTB does not find an entry, the branch is predicted not taken.
The global history is modified to correctly reflect this prediction.
3. Local history is now updated at the fetch stage instead of
execute stage.
4. In the Update stage of the branch predictor the local predictors are
now correctly updated according to the state of local history during
fetch stage.
This patch also improves performance by as much as 17% on some benchmarks
The copy-engine ports were previously created implicitly and bound
based on the dma port peer rather than relying on the normal Python
binding (connectPorts) being called explicitly. This patch makes the
copy engine port similar to all other ports in that they are visibly
in the Python class and bound using the normal explicit calls through
Python.
This patch adds basic information about the ports in the parameter
classes to be passed from the Python world to the corresponding C++
object. Currently, the only information passed is the number of
connected peers, which for a Port is either 0 or 1, and for a
VectorPort reflects the size of the VectorPort. The default port of
the bus had to be renamed to avoid using the name "default" as a field
in the parameter class. It is possible to extend the Swig'ed
information further and add e.g. a pair with a description and size.
