This patch implements the functionality for forwarding invalidations and
replacements from the L1 cache of the Ruby memory system to the O3 CPU. The
implementation adds a list of ports to RubyPort. Whenever a replacement or an
invalidation is performed, the L1 cache forwards this to all the ports, which
is the LSQ in case of the O3 CPU.
This command will be sent from the memory system (Ruby) to the LSQ of
an O3 CPU so that the LSQ, if it needs to, invalidates the address in
the request packet.
This patch removes the idiosyncratic nature of the default bus port
and makes it yet another port in the list of interfaces. Rather than
having a specific pointer to the default port we merely track the
identifier of this port. This change makes future port diversification
easier and overall cleans up the bus code.
In preparation for the introduction of Master and Slave ports, this
patch removes the default port parameter in the Python port and thus
forces the argument list of the Port to contain only the
description. The drawback at this point is that the config port and
dma port of PCI and DMA devices have to be connected explicitly. This
is key for future diversification as the pio and config port are
slaves, but the dma port is a master.
This patch makes the bus bridge uni-directional and specialises the
bus ports to be a master port and a slave port. This greatly
simplifies the assumptions on both sides as either port only has to
deal with requests or responses. The following patches introduce the
notion of master and slave ports, and would not be possible without
this split of responsibilities.
In making the bridge unidirectional, the address range mechanism of
the bridge is also changed. For the cases where communication is
taking place both ways, an additional bridge is needed. This causes
issues with the existing mechanism, as the busses cannot determine
when to stop iterating the address updates from the two bridges. To
avoid this issue, and also greatly simplify the specification, the
bridge now has a fixed set of address ranges, specified at creation
time.
The functional ports are no longer used and this patch cleans up the
legacy that is still present in buses, memories, CPUs etc. Note that
this does not refer to the class FunctionalPort (already removed), but
rather ports with the name (and use) functional.
This patch simplifies the address-range determination mechanism and
also unifies the naming across ports and devices. It further splits
the queries for determining if a port is snooping and what address
ranges it responds to (aiming towards a separation of
cache-maintenance ports and pure memory-mapped ports). Default
behaviours are such that most ports do not have to define isSnooping,
and master ports need not implement getAddrRanges.
This patch removes the default port and instead relies on the peer
being set to NULL initially. The binding check (i.e. is a port
connected or not) will eventually be moved to the init function of the
modules.
This patch removes the inheritance of EventManager from the ports and
moves all responsibility for event queues to the owner. Eventually the
event manager should be the interface block, which could either be the
structural owner or a subblock like a LSQ in the O3 CPU for example.
This patch performs minimal changes to move the instruction and data
ports from specialised subclasses to the base CPU (to the largest
degree possible). Ultimately it servers to make the CPU(s) have a
well-defined interface to the memory sub-system.
Port proxies are used to replace non-structural ports, and thus enable
all ports in the system to correspond to a structural entity. This has
the advantage of accessing memory through the normal memory subsystem
and thus allowing any constellation of distributed memories, address
maps, etc. Most accesses are done through the "system port" that is
used for loading binaries, debugging etc. For the entities that belong
to the CPU, e.g. threads and thread contexts, they wrap the CPU data
port in a port proxy.
The following replacements are made:
FunctionalPort > PortProxy
TranslatingPort > SETranslatingPortProxy
VirtualPort > FSTranslatingPortProxy
--HG--
rename : src/mem/vport.cc => src/mem/fs_translating_port_proxy.cc
rename : src/mem/vport.hh => src/mem/fs_translating_port_proxy.hh
rename : src/mem/translating_port.cc => src/mem/se_translating_port_proxy.cc
rename : src/mem/translating_port.hh => src/mem/se_translating_port_proxy.hh
This patch changes the access permission for the WB_E_W state from
Busy to Read_Write to avoid having issues in follow-on patches with
functional accesses going through Ruby. This change was made after
consultation with all involved parties and is more of a work-around
than a fix.
The system port is used as a globally reachable access point to the
memory subsystem. The benefit of using an actual port is that the
usual infrastructure is used to resolve any access and thus makes the
overall system able to handle distributed memories in any
configuration, and also makes the accesses agnostic to the address
map. This patch only introduces the port and does not actually use it
for anything.
This patch changes the functionalAccess member function in the cache
model such that it is aware of what port the access came from, i.e. if
it came from the CPU side or from the memory side. By adding this
information, it is possible to respect the 'forwardSnoops' flag for
snooping requests coming from the memory side and not forward
them. This fixes an outstanding issue with the IO bus getting accesses
that have no valid destination port and also cleans up future changes
to the bus model.
A recent changeset (aae12ce9f34c) removed support for
PAL-mode breakpoints in Alpha, since it was awkward
and likely unused. This patch lets a user know if they
potentially run into this limitation.
The definition for the class CacheMsg was removed long back. Some declaration
had still survived, which was recently removed. Since the PerfectCacheMemory
class relied on this particular declaration, its absence let to compilation
breaking down. Hence this patch.
Currently there is an assumption that restoration from a checkpoint will
happen by first restoring to an atomic CPU and then switching to a timing
CPU. This patch adds support for directly restoring to a timing CPU. It
adds a new option '--restore-with-cpu' which is used to specify the type
of CPU to which the checkpoint should be restored to. It defaults to
'atomic' which was the case before.
This patch resurrects ruby's cache warmup capability. It essentially
makes use of all the infrastructure that was added to the controllers,
memories and the cache recorder.
This patch adds function to the Sparse Memory so that the blocks can be
recorded in a cache trace. The blocks are added to the cache recorder
which can later write them into a file.
This patch adds functions to the memory vector class that can be used for
collating memory pages to raw trace and for populating pages from a raw
trace.
The SparseMemEntry structure includes just one void* pointer. It seems
unnecessary that we have a structure for this. The patch removes the
structure and makes use of a typedef on void* instead.
