diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mem/snoop_filter.cc | 41 | ||||
| -rw-r--r-- | src/mem/snoop_filter.hh | 21 |
2 files changed, 34 insertions, 28 deletions
diff --git a/src/mem/snoop_filter.cc b/src/mem/snoop_filter.cc index 3e1dae6c7..8168c3d91 100644 --- a/src/mem/snoop_filter.cc +++ b/src/mem/snoop_filter.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013-2017 ARM Limited + * Copyright (c) 2013-2017,2019 ARM Limited * All rights reserved * * The license below extends only to copyright in the software and shall @@ -49,11 +49,13 @@ #include "debug/SnoopFilter.hh" #include "sim/system.hh" +const int SnoopFilter::SNOOP_MASK_SIZE; + void SnoopFilter::eraseIfNullEntry(SnoopFilterCache::iterator& sf_it) { SnoopItem& sf_item = sf_it->second; - if (!(sf_item.requested | sf_item.holder)) { + if ((sf_item.requested | sf_item.holder).none()) { cachedLocations.erase(sf_it); DPRINTF(SnoopFilter, "%s: Removed SF entry.\n", __func__); @@ -96,8 +98,7 @@ SnoopFilter::lookupRequest(const Packet* cpkt, const SlavePort& slave_port) totRequests++; if (is_hit) { - // Single bit set -> value is a power of two - if (isPow2(interested)) + if (interested.count() == 1) hitSingleRequests++; else hitMultiRequests++; @@ -114,8 +115,9 @@ SnoopFilter::lookupRequest(const Packet* cpkt, const SlavePort& slave_port) if (cpkt->needsResponse()) { if (!cpkt->cacheResponding()) { // Max one request per address per port - panic_if(sf_item.requested & req_port, "double request :( " \ - "SF value %x.%x\n", sf_item.requested, sf_item.holder); + panic_if((sf_item.requested & req_port).any(), + "double request :( SF value %x.%x\n", + sf_item.requested, sf_item.holder); // Mark in-flight requests to distinguish later on sf_item.requested |= req_port; @@ -126,7 +128,8 @@ SnoopFilter::lookupRequest(const Packet* cpkt, const SlavePort& slave_port) // to the CPU, already -> the response will not be seen by this // filter -> we do not need to keep the in-flight request, but make // sure that we know that that cluster has a copy - panic_if(!(sf_item.holder & req_port), "Need to hold the value!"); + panic_if((sf_item.holder & req_port).none(), + "Need to hold the value!"); DPRINTF(SnoopFilter, "%s: not marking request. SF value %x.%x\n", __func__, sf_item.requested, sf_item.holder); @@ -134,7 +137,7 @@ SnoopFilter::lookupRequest(const Packet* cpkt, const SlavePort& slave_port) } else { // if (!cpkt->needsResponse()) assert(cpkt->isEviction()); // make sure that the sender actually had the line - panic_if(!(sf_item.holder & req_port), "requester %x is not a " \ + panic_if((sf_item.holder & req_port).none(), "requester %x is not a " \ "holder :( SF value %x.%x\n", req_port, sf_item.requested, sf_item.holder); // CleanEvicts and Writebacks -> the sender and all caches above @@ -206,8 +209,8 @@ SnoopFilter::lookupSnoop(const Packet* cpkt) SnoopMask interested = (sf_item.holder | sf_item.requested); totSnoops++; - // Single bit set -> value is a power of two - if (isPow2(interested)) + + if (interested.count() == 1) hitSingleSnoops++; else hitMultiSnoops++; @@ -222,7 +225,7 @@ SnoopFilter::lookupSnoop(const Packet* cpkt) assert(cpkt->isWriteback() || cpkt->req->isUncacheable() || (cpkt->isInvalidate() == cpkt->needsWritable()) || cpkt->req->isCacheMaintenance()); - if (cpkt->isInvalidate() && !sf_item.requested) { + if (cpkt->isInvalidate() && sf_item.requested.none()) { // Early clear of the holder, if no other request is currently going on // @todo: This should possibly be updated even though we do not filter // upward snoops @@ -266,11 +269,12 @@ SnoopFilter::updateSnoopResponse(const Packet* cpkt, __func__, sf_item.requested, sf_item.holder); // The source should have the line - panic_if(!(sf_item.holder & rsp_mask), "SF value %x.%x does not have "\ - "the line\n", sf_item.requested, sf_item.holder); + panic_if((sf_item.holder & rsp_mask).none(), + "SF value %x.%x does not have the line\n", + sf_item.requested, sf_item.holder); // The destination should have had a request in - panic_if(!(sf_item.requested & req_mask), "SF value %x.%x missing "\ + panic_if((sf_item.requested & req_mask).none(), "SF value %x.%x missing "\ "the original request\n", sf_item.requested, sf_item.holder); // If the snoop response has no sharers the line is passed in @@ -287,7 +291,7 @@ SnoopFilter::updateSnoopResponse(const Packet* cpkt, // @todo Deal with invalidating responses sf_item.holder |= req_mask; sf_item.requested &= ~req_mask; - assert(sf_item.requested | sf_item.holder); + assert((sf_item.requested | sf_item.holder).any()); DPRINTF(SnoopFilter, "%s: new SF value %x.%x\n", __func__, sf_item.requested, sf_item.holder); } @@ -359,8 +363,9 @@ SnoopFilter::updateResponse(const Packet* cpkt, const SlavePort& slave_port) __func__, sf_item.requested, sf_item.holder); // Make sure we have seen the actual request, too - panic_if(!(sf_item.requested & slave_mask), "SF value %x.%x missing "\ - "request bit\n", sf_item.requested, sf_item.holder); + panic_if((sf_item.requested & slave_mask).none(), + "SF value %x.%x missing request bit\n", + sf_item.requested, sf_item.holder); sf_item.requested &= ~slave_mask; // Update the residency of the cache line. @@ -376,7 +381,7 @@ SnoopFilter::updateResponse(const Packet* cpkt, const SlavePort& slave_port) // Any other response implies that a cache above will have the // block. sf_item.holder |= slave_mask; - assert(sf_item.holder | sf_item.requested); + assert((sf_item.holder | sf_item.requested).any()); } DPRINTF(SnoopFilter, "%s: new SF value %x.%x\n", __func__, sf_item.requested, sf_item.holder); diff --git a/src/mem/snoop_filter.hh b/src/mem/snoop_filter.hh index 85cc75e9b..9c066155c 100644 --- a/src/mem/snoop_filter.hh +++ b/src/mem/snoop_filter.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013-2016 ARM Limited + * Copyright (c) 2013-2016,2019 ARM Limited * All rights reserved * * The license below extends only to copyright in the software and shall @@ -45,6 +45,7 @@ #ifndef __MEM_SNOOP_FILTER_HH__ #define __MEM_SNOOP_FILTER_HH__ +#include <bitset> #include <unordered_map> #include <utility> @@ -86,6 +87,10 @@ */ class SnoopFilter : public SimObject { public: + + // Change for systems with more than 256 ports tracked by this object + static const int SNOOP_MASK_SIZE = 256; + typedef std::vector<QueuedSlavePort*> SnoopList; SnoopFilter (const SnoopFilterParams *p) : @@ -114,9 +119,9 @@ class SnoopFilter : public SimObject { } // make sure we can deal with this many ports - fatal_if(id > 8 * sizeof(SnoopMask), + fatal_if(id > SNOOP_MASK_SIZE, "Snoop filter only supports %d snooping ports, got %d\n", - 8 * sizeof(SnoopMask), id); + SNOOP_MASK_SIZE, id); } /** @@ -198,13 +203,9 @@ class SnoopFilter : public SimObject { /** * The underlying type for the bitmask we use for tracking. This - * limits the number of snooping ports supported per crossbar. For - * the moment it is an uint64_t to offer maximum - * scalability. However, it is possible to use e.g. a uint16_t or - * uint32_to slim down the footprint of the hash map (and - * ultimately improve the simulation performance). + * limits the number of snooping ports supported per crossbar. */ - typedef uint64_t SnoopMask; + typedef std::bitset<SNOOP_MASK_SIZE> SnoopMask; /** * Per cache line item tracking a bitmask of SlavePorts who have an @@ -314,7 +315,7 @@ SnoopFilter::maskToPortList(SnoopMask port_mask) const { SnoopList res; for (const auto& p : slavePorts) - if (port_mask & portToMask(*p)) + if ((port_mask & portToMask(*p)).any()) res.push_back(p); return res; } |