cache.cc (11288:57c340f947c7) cache.cc (11332:40bcb0e97de9)
1/*
2 * Copyright (c) 2010-2015 ARM Limited
3 * All rights reserved.
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software

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2147 // propagate the BLOCK_CACHED flag in Writeback packets and prevent
2148 // any CleanEvicts from travelling down the memory hierarchy.
2149 pkt->setBlockCached();
2150 DPRINTF(Cache, "Squashing %s from lower cache on writequeue hit"
2151 " %#x\n", pkt->cmdString(), pkt->getAddr());
2152 return;
2153 }
2154
1/*
2 * Copyright (c) 2010-2015 ARM Limited
3 * All rights reserved.
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software

--- 2138 unchanged lines hidden (view full) ---

2147 // propagate the BLOCK_CACHED flag in Writeback packets and prevent
2148 // any CleanEvicts from travelling down the memory hierarchy.
2149 pkt->setBlockCached();
2150 DPRINTF(Cache, "Squashing %s from lower cache on writequeue hit"
2151 " %#x\n", pkt->cmdString(), pkt->getAddr());
2152 return;
2153 }
2154
2155 if (wb_pkt->cmd == MemCmd::WritebackDirty) {
2156 // we have dirty data, and so will proceed to respond
2155 // conceptually writebacks are no different to other blocks in
2156 // this cache, so the behaviour is modelled after handleSnoop,
2157 // the difference being that instead of querying the block
2158 // state to determine if it is dirty and writable, we use the
2159 // command and fields of the writeback packet
2160 bool respond = wb_pkt->cmd == MemCmd::WritebackDirty &&
2161 pkt->needsResponse() && pkt->cmd != MemCmd::InvalidateReq;
2162 bool have_writable = !wb_pkt->hasSharers();
2163 bool invalidate = pkt->isInvalidate();
2164
2165 if (!pkt->req->isUncacheable() && pkt->isRead() && !invalidate) {
2166 assert(!pkt->needsWritable());
2167 pkt->setHasSharers();
2168 wb_pkt->setHasSharers();
2169 }
2170
2171 if (respond) {
2157 pkt->setCacheResponding();
2172 pkt->setCacheResponding();
2158 if (!pkt->needsWritable()) {
2159 // the packet should end up in the Shared state (non
2160 // writable) on the completion of the fill
2161 pkt->setHasSharers();
2162 // similarly, the writeback is no longer passing
2163 // writeable (the receiving cache should consider the
2164 // block Owned rather than Modified)
2165 wb_pkt->setHasSharers();
2166 } else {
2167 // we need to invalidate our copy. we do that
2168 // below.
2169 assert(pkt->isInvalidate());
2173
2174 if (have_writable) {
2175 pkt->setResponderHadWritable();
2170 }
2176 }
2177
2171 doTimingSupplyResponse(pkt, wb_pkt->getConstPtr<uint8_t>(),
2172 false, false);
2178 doTimingSupplyResponse(pkt, wb_pkt->getConstPtr<uint8_t>(),
2179 false, false);
2173 } else {
2174 // on hitting a clean writeback we play it safe and do not
2175 // provide a response, the block may be dirty somewhere
2176 // else
2177 assert(wb_pkt->isCleanEviction());
2178 // The cache technically holds the block until the
2179 // corresponding message reaches the crossbar
2180 // below. Therefore when a snoop encounters a CleanEvict
2181 // or WritebackClean message we must call
2182 // setHasSharers (just like when it encounters a
2183 // Writeback) to avoid the snoop filter prematurely
2184 // clearing the holder bit in the crossbar below
2185 if (!pkt->needsWritable()) {
2186 pkt->setHasSharers();
2187 // the writeback is no longer passing writeable (the
2188 // receiving cache should consider the block Owned
2189 // rather than Modified)
2190 wb_pkt->setHasSharers();
2191 } else {
2192 assert(pkt->isInvalidate());
2193 }
2194 }
2195
2180 }
2181
2196 if (pkt->isInvalidate()) {
2182 if (invalidate) {
2197 // Invalidation trumps our writeback... discard here
2198 // Note: markInService will remove entry from writeback buffer.
2199 markInService(wb_entry, false);
2200 delete wb_pkt;
2201 }
2202 }
2203
2204 // If this was a shared writeback, there may still be

--- 493 unchanged lines hidden --- 		2183 // Invalidation trumps our writeback... discard here
2184 // Note: markInService will remove entry from writeback buffer.
2185 markInService(wb_entry, false);
2186 delete wb_pkt;
2187 }
2188 }
2189
2190 // If this was a shared writeback, there may still be

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