In order to add stall and wait facility for protocols, a keyword
wake_up_dependents was introduced. This patch removes the keyword,
instead this functionality is now implemented as function call.
In order to add stall and wait facility for protocols, a keyword
wake_up_all_dependents was introduced. This patch removes the keyword,
instead this functionality is now implemented as function call.
This patch integrates permissions with cache and memory states, and then
automates the setting of permissions within the generated code. No longer
does one need to manually set the permissions within the setState funciton.
This patch will faciliate easier functional access support by always correctly
setting permissions for both cache and memory states.
--HG--
rename : src/mem/slicc/ast/EnumDeclAST.py => src/mem/slicc/ast/StateDeclAST.py
rename : src/mem/slicc/ast/TypeFieldEnumAST.py => src/mem/slicc/ast/TypeFieldStateAST.py
By stalling and waiting the mandatory queue instead of recycling it, one can
ensure that no incoming messages are starved when the mandatory queue puts
signficant of pressure on the L1 cache controller (i.e. the ruby memtester).
--HG--
rename : src/mem/slicc/ast/WakeUpDependentsStatementAST.py => src/mem/slicc/ast/WakeUpAllDependentsStatementAST.py
The purpose of this patch is to change the way CacheMemory interfaces with
coherence protocols. Currently, whenever a cache controller (defined in the
protocol under consideration) needs to carry out any operation on a cache
block, it looks up the tag hash map and figures out whether or not the block
exists in the cache. In case it does exist, the operation is carried out
(which requires another lookup). As observed through profiling of different
protocols, multiple such lookups take place for a given cache block. It was
noted that the tag lookup takes anything from 10% to 20% of the simulation
time. In order to reduce this time, this patch is being posted.
I have to acknowledge that the many of the thoughts that went in to this
patch belong to Brad.
Changes to CacheMemory, TBETable and AbstractCacheEntry classes:
1. The lookup function belonging to CacheMemory class now returns a pointer
to a cache block entry, instead of a reference. The pointer is NULL in case
the block being looked up is not present in the cache. Similar change has
been carried out in the lookup function of the TBETable class.
2. Function for setting and getting access permission of a cache block have
been moved from CacheMemory class to AbstractCacheEntry class.
3. The allocate function in CacheMemory class now returns pointer to the
allocated cache entry.
Changes to SLICC:
1. Each action now has implicit variables - cache_entry and tbe. cache_entry,
if != NULL, must point to the cache entry for the address on which the action
is being carried out. Similarly, tbe should also point to the transaction
buffer entry of the address on which the action is being carried out.
2. If a cache entry or a transaction buffer entry is passed on as an
argument to a function, it is presumed that a pointer is being passed on.
3. The cache entry and the tbe pointers received __implicitly__ by the
actions, are passed __explicitly__ to the trigger function.
4. While performing an action, set/unset_cache_entry, set/unset_tbe are to
be used for setting / unsetting cache entry and tbe pointers respectively.
5. is_valid() and is_invalid() has been made available for testing whether
a given pointer 'is not NULL' and 'is NULL' respectively.
6. Local variables are now available, but they are assumed to be pointers
always.
7. It is now possible for an object of the derieved class to make calls to
a function defined in the interface.
8. An OOD token has been introduced in SLICC. It is same as the NULL token
used in C/C++. If you are wondering, OOD stands for Out Of Domain.
9. static_cast can now taken an optional parameter that asks for casting the
given variable to a pointer of the given type.
10. Functions can be annotated with 'return_by_pointer=yes' to return a
pointer.
11. StateMachine has two new variables, EntryType and TBEType. EntryType is
set to the type which inherits from 'AbstractCacheEntry'. There can only be
one such type in the machine. TBEType is set to the type for which 'TBE' is
used as the name.
All the protocols have been modified to conform with the new interface.
This patch allows messages to be stalled in their input buffers and wait
until a corresponding address changes state. In order to make this work,
all in_ports must be ranked in order of dependence and those in_ports that
may unblock an address, must wake up the stalled messages. Alot of this
complexity is handled in slicc and the specification files simply
annotate the in_ports.
--HG--
rename : src/mem/slicc/ast/CheckAllocateStatementAST.py => src/mem/slicc/ast/StallAndWaitStatementAST.py
rename : src/mem/slicc/ast/CheckAllocateStatementAST.py => src/mem/slicc/ast/WakeUpDependentsStatementAST.py
In addition to obvious changes, this required a slight change to the slicc
grammar to allow types with :: in them. Otherwise slicc barfs on std::string
which we need for the headers that slicc generates.
This patch includes the necessary changes to connect ruby objects using
the python configuration system. Mainly it consists of removing
unnecessary ruby object pointers and connecting the necessary object
pointers using the generated param objects. This patch includes the
slicc changes necessary to connect generated ruby objects together using
the python configuraiton system.
This patch changes the way that Ruby handles atomic RMW instructions. This implementation, unlike the prior one, is protocol independent. It works by locking an address from the sequencer immediately after the read portion of an RMW completes. When that address is locked, the coherence controller will only satisfy requests coming from one port (e.g., the mandatory queue) and will ignore all others. After the write portion completed, the line is unlocked. This should also work with multi-line atomics, as long as the blocks are always acquired in the same order.
Right now .cc and .hh files are handled separately, but then
they're just munged together at the end by scons, so it
doesn't buy us anything. Might as well munge from the start
since we'll eventually be adding generated Python files
to the list too.
This is simply a translation of the C++ slicc into python with very minimal
reorganization of the code. The output can be verified as nearly identical
by doing a "diff -wBur".
Slicc can easily be run manually by using util/slicc
