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2018-03-22mem-cache: Create MRU replacement policyDaniel R. Carvalho
Implementation of a Most Recently Used replacement policy. Change-Id: Id52cb247ca25d4523dcc53490d113695dac6a3f1 Reviewed-on: https://gem5-review.googlesource.com/8889 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-22mem-cache: Split array indexing and replacement policies.Daniel R. Carvalho
Replacement policies (LRU, Random) are currently considered as array indexing methods, but have completely different functionalities: - Array indexers determine the possible locations for block allocation. This information is used to generate replacement candidates when conflicts happen. - Replacement policies determine which of the replacement candidates should be evicted to make room for new allocations. For this reason, they were split into different classes. Advantages: - Easier and more straightforward to implement other replacement policies (RRIP, LFU, ARC, ...) - Allow easier future implementation of cache organization schemes As now we can't assure the use of sets, the previous way to create a true LRU is not viable. Now a timestamp_bits parameter controls how many bits are dedicated for the timestamp, and a true LRU can be achieved through an infinite number of bits (although a few bits suffice in practice). Change-Id: I23750db121f1474d17831137e6ff618beb2b3eda Reviewed-on: https://gem5-review.googlesource.com/8501 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-21mem-cache: Allow clean operations when block allocation failsNikos Nikoleris
Block allocation can fail when there is an in-service MSHR that operates on the victim block. This can happed due to: * an upgrade operation: a request that needs a writable copy of the block finds a shared (non-writable) copy of the block in the cache and has allocates an MSHR for the pending upgrade operation, or * a clean operation: a clean request finds a dirty copy of the block and allocates an MSHR for the pending clean operation. This changes relaxes an assertion to allow for the 2nd case (cache clean operations). Change-Id: Ib51482160b5f2b3702ed744b0eac2029d34bc9d4 Reviewed-by: Curtis Dunham <curtis.dunham@arm.com> Reviewed-on: https://gem5-review.googlesource.com/9021 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-12mem-ruby: Fix RubyPrefetcher support in MESI_Two_LevelRico Amslinger
Only a small quantity of prefetches were issued, as the positive feedback mechanism was not implemented. This commit adds a new action po_observeHit, which notifies the RubyPrefetcher of successful prefetches and resets the prefetch flag. When a cache line was replaced by a prefetch, the wrong queue could be stalled. This commit adds a new event PF_L1_Replacement, which stalls the correct queue. The behavior when receiving a prefetch or instruction fetch while in PF_IS_I (prefetch caused GETs, but got invalidated before the response was received) was undefined. This was changed to drop the prefetch request or change the state to non-prefetch, respectively. This behavior is analogous to IS_I (non-prefetch caused GETs, but got invalidated before the response was received) and the data case, respectively. In my local branch a major (20+%) performance increase can be observed in SPEC2006 gobmk and leslie3d when enabling the prefetcher. Some other benchmarks like bwaves, GemsFDTD, sphinx and wrf show smaller (~10%) performance increases. Unfortunately, the performance in most other SPEC benchmarks is still poor, most likely as the prefetcher does not detect strides fast/often enough. In order to push the change timely (most benchmarks have runtimes in the order of days on my machine even with the smallest parameters) after checkout, I have only run gobmk with the base repository + this commit. The results match those of my local branch. Change-Id: I9903a2fcd02060ea5e619b409f31f7d6fac47ae8 Reviewed-on: https://gem5-review.googlesource.com/8801 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Swapnil Haria <swapnilster@gmail.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-03-09mem-cache: Use CacheBlk parameter on address regenerationDaniel R. Carvalho
Skewed caches need to know the way to regenerate a block address. Change-Id: I62c61ac9509eff2f37bad36862751956db7a6e40 Reviewed-on: https://gem5-review.googlesource.com/8782 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-08mem-cache: Fix missing overridesJason Lowe-Power
clang doesn't like inconsistent overrides. Add override to all overidden functions in lru.hh Change-Id: I100ff4a7d90757439afee879ff9838c15f5c0b1d Signed-off-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-on: https://gem5-review.googlesource.com/8861 Reviewed-by: Gabe Black <gabeblack@google.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-07mem-cache: Make the block invalidate functions virtualNikos Nikoleris
This change makes the cache block invalidation function in the BaseTags and CacheBlk class virtual to enable derived classes. Change-Id: I2e64b01c6ca637f16d10474fc8b08eeec3f23453 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8287 Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
2018-03-07mem-cache: Make invalidate a common function between tag classesNikos Nikoleris
invalidate was defined as a separate function in the base associative and fully-associative tags classes although both functions should implement identical functionality. This patch moves the invalidate function in the base tags class. Change-Id: I206ee969b00ab9e05873c6d87531474fcd712907 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8286 Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-07mem-cache: Allow prefetchers to override setCache.Xiaoyu Ma
This lets them hook setCache, perhaps to set up additional state based on the set cache. Change-Id: Ic3b34fa43d052c71e8ef733a57fe47c70899cd27 Reviewed-on: https://gem5-review.googlesource.com/8701 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-06scons: Switch from the print statement to the print function.Gabe Black
Starting with version 3, scons imposes using the print function instead of the print statement in code it processes. To get things building again, this change moves all python code within gem5 to use the function version. Another change by another author separately made this same change to the site_tools and site_init.py files. Change-Id: I2de7dc3b1be756baad6f60574c47c8b7e80ea3b0 Reviewed-on: https://gem5-review.googlesource.com/8761 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-06mem-cache: Fix bug generated by 8282Daniel R. Carvalho
Merge 1ae7fced4d32898531a6875a339ef00e43e20e66 generated a bug in tagsInUse calculation. Change-Id: I079e327a0a26a7968f2ed8e433dd6e790c80998b Reviewed-on: https://gem5-review.googlesource.com/8781 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-06mem-cache: Populate whenReady for blocks filled from writebacksNikos Nikoleris
Writebacks write data to either an existing block or a newly allocated block. In either case we need to populate the whenReady field of the block which will determine when the new value can be used. Change-Id: I5788fad0b8086a1be96714639bf6a9470b334926 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Curtis Dunham <curtis.dunham@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8285 Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-06mem-cache: Use findBlock() in accessBlock()Daniel R. Carvalho
Use placement policy specific block search within generic access. Change-Id: I6070035e6e00595bcf073d4011f78a55ba7e7a8a Reviewed-on: https://gem5-review.googlesource.com/8721 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-05mem-cache: Remove redundant block initialization on allocationNikos Nikoleris
Change-Id: I7496e12e6a517529316c480d5f6e2ade601f0e2d Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8282 Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-02mem-cache: Remove mumBlock redundant initialiation from FALRUNikos Nikoleris
Change-Id: Id3afec0a62446d6d0f44ccb655032343037637e0 Reviewed-by: Curtis Dunham <curtis.dunham@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8281 Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-02mem-cache: Populate the secure bit when the temp block is filledNikos Nikoleris
The secure bit should be set when we fill a block with data from a secure location, as indicated by the packet that triggers the fill. This patch fixes a bug in which the cache wouldn't populate the secure bit when filling the temp block. Change-Id: I95c706146449804ff42b205b25dd79750f3e882a Reviewed-by: Curtis Dunham <curtis.dunham@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8284 Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
2018-03-02mem-cache: Remove unnecessary block initialization on writebackNikos Nikoleris
Change-Id: Ia9b825bcbb8d326705f74c15a93a88703153ba5a Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8283 Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
2018-03-01mem-cache: Remove extra block init in BaseSetAssocDaniel R. Carvalho
Removed extra initialization of cache block just after they have been created and organized the comments. Change-Id: I75c1beaf0489e3e530fd8cbff2739dc7593e3e6f Reviewed-on: https://gem5-review.googlesource.com/8661 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-01mem-cache: Vectorize C arrays in BaseSetAssoc.Daniel R. Carvalho
Transform BaseSetAssoc's arrays into C++ vectors to avoid unnecessary resource management. Change-Id: I656f42f29e5f9589eba491b410ca1df5a64f2f34 Reviewed-on: https://gem5-review.googlesource.com/8621 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-02-24mem-cache: Fix CacheSet memory leakDaniel R. Carvalho
CacheSet blocks were being allocated but never freed. Used vector to avoid using pure C array. Change-Id: I6f32fa5a305ff4e1d7602535026c1396764102ed Reviewed-on: https://gem5-review.googlesource.com/8603 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-02-19mem: fix page_table bug for .fast buildBrandon Potter
Since b8b13206c8, the '.fast' build has failed to compile with an error caused by a variable and an assert. As a reminder, assert macros are optimized out of the build for '.fast'. If an assert check requires a variable that is unused anywhere else in the code, the compiler complains that the variable is unused and the scons build fails. The solution is to add a M5_VAR_USED specifier to tell the compiler to ignore the variable. Change-Id: I38f6bbed1e4c0506c5bbc1206c21f1f7e3d8dfe6 Reviewed-on: https://gem5-review.googlesource.com/8462 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com> Maintainer: Jason Lowe-Power <jason@lowepower.com> Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2018-02-19mem: Refactor port proxies to support secure accessesAndreas Sandberg
The current physical port proxy doesn't know how to tag memory accesses as secure. Refactor the class slightly to create a set of methods (readBlobPhys, writeBlobPhys, memsetBlobPhys) that always access physical memory and take a set of Request::Flags as an argument. The new port proxy, SecurePortProxy, uses this interface to issue secure physical accesses. Change-Id: I8232a4b35025be04ec8f91a00f0580266bacb338 Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8364 Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-02-16mem: Add PortProxy read/write helper with explicit endiannessAndreas Sandberg
Change-Id: Ia9a11ca68b2892dafd02f2c37324b99b35c77d34 Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8146 Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2018-02-14mem, sim-se: Fixed seg-fault in EmulationPageTable::remapRico Amslinger
When moving a memory region the target region should be unmapped. The assertion does reflect this, but the following line accesses the invalid pointer regardless. This commit replaces the pointer access with an emplace. Change-Id: I85f9be4e6c223eab447c75043e593ed3f90017e1 Reviewed-on: https://gem5-review.googlesource.com/8261 Reviewed-by: Gabe Black <gabeblack@google.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-02-09Fix DDR4_2400_8x8 DRAMCTRL configurationWendy Elsasser
Change-Id: I7af361e146909acc158590354ab22732d4b2f3d5 Signed-off-by: Wendy Elsasser <wendy.elsasser@arm.com> Reviewed-by: Curtis Dunham <curtis.dunham@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8101 Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-02-08mem-cache: Make cache warmup percentage a parameter.Daniel R. Carvalho
The warmupPercentage is the percentage of different tags (based on the cache size) that need to be touched in order to warm up the cache. If Warmup failed (i.e., not enough tags were touched), warmup_cycle = 0. The warmup is not being taken into account to calculate the stats (i.e., stats acquisition starts before cache is warmed up). Maybe in the future this functionality should be added. Change-Id: I2b93a99c19fddb99a4c60e6d4293fa355744d05e Reviewed-on: https://gem5-review.googlesource.com/8061 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-02-07mem-cache: Only pendingModified MSHRs can satisfy CMO snoopsNikos Nikoleris
We set the satisfied flag when a cache clean request encounters: 1) a block with the dirty bit set, or 2) a pending modified MSHR which means that the cache will get copy of the block that will be soon modified. This changeset fixes a previous bug that set the satisfied flag on snooping MSHR hits even the pendingModified flags was not set. Change-Id: I4968c4820997be5cc1238148eea12a1ba39837d4 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Sudhanshu Jha <sudhanshu.jha@arm.com> Reviewed-on: https://gem5-review.googlesource.com/7822 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-02-07mem-cache: Cleaned blocks should be marked as not writableNikos Nikoleris
A writeclean packet writes a dirty block to the memory below and therefore sets the dirty flag for the block when the memory below is a cache. If the block was also marked as writable it can satisfy future write requests without further requests/snoops. This can lead to multiple copies of the same block marked as dirty which is not allowed. This changeset clears the writable flag from the cleaned block to prevent the cache from satisfying future write requests without sending a downstream request. Change-Id: I14d3c62fd33f81b1a8ba62374c8565ccab00a6fe Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/7821 Maintainer: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2018-02-06mem-cache: Remove extra numSets zero check.Daniel R. Carvalho
numSets is unsigned, so it cannot be lower than 0. Besides, isPowerOf2(0) is false by definition (and implemmentation*), so there is no need for the double check. * As presented in base/intmath.hh Change-Id: I3f6296694a937434feddc7ed21f11c2a6fdfc5a9 Reviewed-on: https://gem5-review.googlesource.com/7901 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2018-02-06mem: Standardize mem folder header guardsDaniel R. Carvalho
Standardize all header guards in the mem directory according to the most frequent patterns. In general they have the form: mem: __FOLDER_TREE_FILE_NAME_HH__ ruby: __FOLDER_TREE_FILENAME_HH__ Change-Id: I983853e292deb302becf151bf0e970057dc24774 Reviewed-on: https://gem5-review.googlesource.com/7881 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-01-23tarch, mem: Abstract the data stored in the SE page tables.Gabe Black
Rather than store the actual TLB entry that corresponds to a mapping, we can just store some abstracted information (address, a few flags) and then let the caller turn that into the appropriate entry. There could potentially be some small amount of overhead from creating entries vs. storing them and just installing them, but it's likely pretty minimal since that only happens on a TLB miss (ideally rare), and, if it is problematic, there could be some preallocated TLB entries which are just minimally filled in as necessary. This has the nice effect of finally making the page tables ISA agnostic. Change-Id: I11e630f60682f0a0029b0683eb8ff0135fbd4317 Reviewed-on: https://gem5-review.googlesource.com/7350 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-23x86, mem: Rewrite the multilevel page table class.Gabe Black
The new version extracts all the x86 specific aspects of the class, and builds the interface around a variable collection of template arguments which are classes that represent the different levels of the page table. The multilevel page table class is now much more ISA independent. Change-Id: Id42e168a78d0e70f80ab2438480cb6e00a3aa636 Reviewed-on: https://gem5-review.googlesource.com/7347 Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-20x86, mem: Don't try to force physical addresses on the system.Gabe Black
Use the system object to allocate physical memory instead of manually placing certain structures and then forcing the system to start other allocations after them in physical memory. Change-Id: Ie18c81645c3b648c64a6d7a649a0e50f7028f344 Reviewed-on: https://gem5-review.googlesource.com/7346 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
2018-01-20x86, mem: Get rid of PageTableOps::getBasePtr.Gabe Black
Pass this constant into the page table constructor. Change-Id: Icbf730f18d9dfcfebd10a196f7f799514728b0fb Reviewed-on: https://gem5-review.googlesource.com/7345 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
2018-01-20x86, mem: Pass the multi level page table layout in as a parameter.Gabe Black
Don't get it from a global constant declared in an ISA header file. Change-Id: Ie19440abdd76500a5e12e6791e6f755ad9e95af3 Reviewed-on: https://gem5-review.googlesource.com/7344 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2018-01-20arch, mem: Make the page table lookup function return a pointer.Gabe Black
This avoids having a copy in the lookup function itself, and the declaration of a lot of temporary TLB entry pointers in callers. The gpu TLB seems to have had the most dependence on the original signature of the lookup function, partially because it was relying on a somewhat unsafe copy to a TLB entry using a base class pointer type. Change-Id: I8b1cf494468163deee000002d243541657faf57f Reviewed-on: https://gem5-review.googlesource.com/7343 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-19arch, mem, sim: Consolidate and rename the SE mode page table classes.Gabe Black
Now that Nothing inherits from PageTableBase directly, it can be merged into FuncPageTable. This change also takes the opportunity to rename the combined class to EmulationPageTable which lets you know that it's specifically for SE mode. Also remove the page table entry cache since it doesn't seem to actually improve performance. The TLBs likely absorb the majority of the locality, essentially acting like a cache like they would in real hardware. Change-Id: If1bcb91aed08686603bf7bee37298c0eee826e13 Reviewed-on: https://gem5-review.googlesource.com/7342 Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-17mem: Change the multilevel page table to inherit from FuncPageTable.Gabe Black
KVM looks up translations using the image of the page table in the guest's memory, but we don't have to. By maintaining that image in addition to rather than instead of maintaining an abstract copy makes our lookups faster, and ironically avoids duplicate implementation. Change-Id: I9ff4cae6f7cf4027c3738b75f74eae50dde2fda1 Reviewed-on: https://gem5-review.googlesource.com/7341 Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-15mem: Track TLB entries in the lookup cache as pointers.Gabe Black
Using the architectural page table on x86 and the functional page table on ARM, both with the twolf benchmark in SE mode, there was no performance penalty for doing so, and again possibly a performance improvement. By using a pointer instead of an inline instance, it's possible for the actual type of the TLB entry to be hidden somewhat, taking a step towards abstracting away another aspect of the ISAs. Since the TLB entries are no longer overwritten and now need to be allocated and freed, this change introduces return types from the updateCache and eraseCacheEntry functions. These functions will return the pointer to any entry which has been displaced from the cache which the caller can either free or ignore, depending on whether the entry has a purpose outside of the cache. Because the functional page table stores its entries over a longer time period, it will generally not delete the pointer returned from those functions. The "architechtural" page table, ie the one which is backed by memory, doesn't have any other use for the TlbEntrys and will delete them. That leads to more news and deletes than there used to be. To address that, and also to speed up the architectural page table in general, it would be a good idea to augment the functional page table with an image of the table in memory, instead of replacing it with one. The functional page table would provide quick lookups and also avoid having to translate page table entries to TLB entries, making performance essentially equivalent to the functional case. The backing page tables, which are primarily for consumption by the physical hardware when in KVM, can be updated when mappings change but otherwise left alone. If we end up doing that, we could just let the ISA specific process classes enable whatever additional TLB machinery they need, likely a backing copy in memory, without any knowledge or involvement from the ISA agnostic class. We would be able to get rid of the useArchPT setting and the bits of code in the configs which set it. Change-Id: I2e21945cd852bb1b3d0740fe6a4c5acbfd9548c5 Reviewed-on: https://gem5-review.googlesource.com/6983 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
2018-01-11mem-ruby: Fix wakeup timeouts for the MOESI_CMP_token protocolNikos Nikoleris
This changeset fixes a bug that was affecting the MOESI_CMP_token protocol where setting the next timeout required an absolute tick in the future. Change-Id: Ibfdb59354e13c7e552cb3389e71bda010f333249 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/7163 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-01-11mem-ruby: Remove function that maps responses to a DMA engineNikos Nikoleris
The function map_Address_to_DMA was used to route responses to the first (and assumed to be the only) DMA engine in the system. This function is now unused as protocols handle responses and route them to the right DMA engine. Change-Id: I2fba913cf2f12321d1a1e38e7ee85bdf26b8a47a Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/7162 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-01-11mem-ruby: Add support for multiple DMA engines in MESI_Two_LevelNikos Nikoleris
Previously the MESI_Two_Level protocol supported systems with a single DMA engine and responses from the directory to DMA requests were routed back to the only DMA engine. This changeset adds support for multiple DMA engines in the system by routing the response to the DMA engine that originally sent the request. Change-Id: I10ceda682ea29746636862ec8ef2a9c4220ca045 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/7161 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-01-11arch,mem: Remove the default value for page size.Gabe Black
This breaks one more architecture dependence outside of the ISAs. Change-Id: I071f9ed73aef78e1cd1752247c183e30854b2d28 Reviewed-on: https://gem5-review.googlesource.com/6982 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
2018-01-11arch,mem: Move page table construction into the arch classes.Gabe Black
This gets rid of an awkward NoArchPageTable class, and also gives the arch a place to inject ISA specific parameters (specifically page size) without having to have TheISA:: in the generic version of these types. Change-Id: I1412f303460d5c43dafdb9b3cd07af81c908a441 Reviewed-on: https://gem5-review.googlesource.com/6981 Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-10style: change C/C++ source permissions to noexecBKP
Several files in the repository were tracked with execute permissions even though the files are just normal C/C++ files (and the one .isa). Change-Id: I976b096acab4a1fc74c5699ef1f9b222c1e635c2 Reviewed-on: https://gem5-review.googlesource.com/7241 Reviewed-by: Gabe Black <gabeblack@google.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2018-01-09mem-cache: Prune unnecessary writebacks in exclusive cachesNikos Nikoleris
Exclusive caches use the tempBlock to fill for responses from a downstream cache. The reason for this is that they only pass the block to the cache above without keeping a copy. When all requests are serviced the block is immediately invalidated unless it is dirty, in which case it has to be written back to the memory below. To avoid unnecessary writebacks, this changeset forces mostly exclusive caches to issuse requests that can only fetch clean data when possible. Reported-by: Quereshi Muhammad Avais <avais@kaist.ac.kr> Change-Id: I01b377563f5aa3e12d22f425a04db7c023071849 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/5061 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2017-12-22arch,cpu: "virtualize" the TLB interface.Gabe Black
CPUs have historically instantiated the architecture specific version of the TLBs to avoid a virtual function call, making them a little bit more dependent on what the current ISA is. Some simple performance measurement, the x86 twolf regression on the atomic CPU, shows that there isn't actually any performance benefit, and if anything the simulator goes slightly faster (although still within margin of error) when the TLB functions are virtual. This change switches everything outside of the architectures themselves to use the generic BaseTLB type, and then inside the ISA for them to cast that to their architecture specific type to call into architecture specific interfaces. The ARM TLB needed the most adjustment since it was using non-standard translation function signatures. Specifically, they all took an extra "type" parameter which defaulted to normal, and translateTiming returned a Fault. translateTiming actually doesn't need to return a Fault because everywhere that consumed it just stored it into a structure which it then deleted(?), and the fault is stored in the Translation object when the translation is done. A little more work is needed to fully obviate the arch/tlb.hh header, so the TheISA::TLB type is still visible outside of the ISAs. Specifically, the TlbEntry type is used in the generic PageTable which lives in src/mem. Change-Id: I51b68ee74411f9af778317eff222f9349d2ed575 Reviewed-on: https://gem5-review.googlesource.com/6921 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2017-12-15mem-ruby: Support atomic_noncaching acceses in rubySwapnil Haria
Ruby has no support for atomic_noncaching accesses, which prevents using it with kvm-cpu. This patch fixes this by directly forwarding atomic requests from the ruby port/sequencer to the corresponding directory based on the destination address of the packet. Change-Id: I0b4928bfda44fd9e5e48583c51d1ea422800da2d Reviewed-on: https://gem5-review.googlesource.com/5601 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Bradford Beckmann <brad.beckmann@amd.com> Maintainer: Jason Lowe-Power <jason@lowepower.com> Maintainer: Bradford Beckmann <brad.beckmann@amd.com>
2017-12-14misc: Updates for gcc7.2 for x86Jason Lowe-Power
GCC 7.2 is much stricter than previous GCC versions. The following changes are needed: * There is now a warning if there is an implicit fallthrough between two case statments. C++17 adds the [[fallthrough]]; declaration. However, to support non C++17 standards (i.e., C++11), we use M5_FALLTHROUGH. M5_FALLTHROUGH checks for [[fallthrough]] compliant C++17 compiler and if that doesn't exist, it defaults to nothing (no older compilers generate warnings). * The above resulted in a couple of bugs that were found. This is noted in the review request on gerrit. * throw() for dynamic exception specification is deprecated * There were a couple of new uninitialized variable warnings * Can no longer perform bitwise operations on a bool. * Must now include <functional> for std::function * Compiler bug for void* lambda. Changed to auto as work around. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82878 Change-Id: I5d4c782a4e133fa4cdb119e35d9aff68c6e2958e Signed-off-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-on: https://gem5-review.googlesource.com/5802 Reviewed-by: Gabe Black <gabeblack@google.com>
2017-12-13arm,sparc,x86,base,cpu,sim: Replace the Twin(32|64)_t types with.Gabe Black
Replace them with std::array<>s. Change-Id: I76624c87a1cd9b21c386a96147a18de92b8a8a34 Reviewed-on: https://gem5-review.googlesource.com/6602 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>