cpu: Fix LLSC atomic CPU wakeup

Writes to locked memory addresses (LLSC) did not wake up the locking
CPU. This can lead to deadlocks on multi-core runs. In AtomicSimpleCPU,
recvAtomicSnoop was checking if the incoming packet was an invalidation
(isInvalidate) and only then handled a locked snoop. But, writes are
seen instead of invalidates when running without caches (fast-forward
configurations). As as simple fix, now handleLockedSnoop is also called
even if the incoming snoop packet are from writes.

tests/quick/fs/10.linux-boot/ref/alpha/linux/tsunami-simple-timing-dual/config.ini

@@ -104,7 +104,6 @@ clk_domain=system.cpu_clk_domain
 clusivity=mostly_incl
 demand_mshr_reserve=1
 eventq_index=0
-forward_snoops=true
 hit_latency=2
 is_read_only=false
 max_miss_count=0
@@ -146,7 +145,6 @@ clk_domain=system.cpu_clk_domain
 clusivity=mostly_incl
 demand_mshr_reserve=1
 eventq_index=0
-forward_snoops=true
 hit_latency=2
 is_read_only=true
 max_miss_count=0
@@ -234,7 +232,6 @@ clk_domain=system.cpu_clk_domain
 clusivity=mostly_incl
 demand_mshr_reserve=1
 eventq_index=0
-forward_snoops=true
 hit_latency=2
 is_read_only=false
 max_miss_count=0
@@ -276,7 +273,6 @@ clk_domain=system.cpu_clk_domain
 clusivity=mostly_incl
 demand_mshr_reserve=1
 eventq_index=0
-forward_snoops=true
 hit_latency=2
 is_read_only=true
 max_miss_count=0
@@ -410,7 +406,6 @@ clk_domain=system.clk_domain
 clusivity=mostly_incl
 demand_mshr_reserve=1
 eventq_index=0
-forward_snoops=false
 hit_latency=50
 is_read_only=false
 max_miss_count=0
@@ -447,7 +442,6 @@ clk_domain=system.cpu_clk_domain
 clusivity=mostly_incl
 demand_mshr_reserve=1
 eventq_index=0
-forward_snoops=true
 hit_latency=20
 is_read_only=false
 max_miss_count=0
@@ -482,6 +476,7 @@ clk_domain=system.clk_domain
 eventq_index=0
 forward_latency=4
 frontend_latency=3
+point_of_coherency=true
 response_latency=2
 snoop_filter=Null
 snoop_response_latency=4
@@ -615,6 +610,7 @@ clk_domain=system.cpu_clk_domain
 eventq_index=0
 forward_latency=0
 frontend_latency=1
+point_of_coherency=false
 response_latency=1
 snoop_filter=system.toL2Bus.snoop_filter
 snoop_response_latency=1

tests/quick/fs/10.linux-boot/ref/alpha/linux/tsunami-simple-timing-dual/simout

@@ -1,9 +1,9 @@
 gem5 Simulator System.  http://gem5.org
 gem5 is copyrighted software; use the --copyright option for details.
 
-gem5 compiled Jan 21 2016 13:49:21
-gem5 started Jan 21 2016 13:50:00
-gem5 executing on zizzer, pid 33973
+gem5 compiled Feb 29 2016 18:59:12
+gem5 started Feb 29 2016 18:59:20
+gem5 executing on redacted.arm.com, pid 18325
 command line: build/ALPHA/gem5.opt -d build/ALPHA/tests/opt/quick/fs/10.linux-boot/alpha/linux/tsunami-simple-timing-dual -re /z/atgutier/gem5/gem5-commit/tests/run.py build/ALPHA/tests/opt/quick/fs/10.linux-boot/alpha/linux/tsunami-simple-timing-dual
 
 Global frequency set at 1000000000000 ticks per second
@@ -11,4 +11,4 @@ info: kernel located at: /dist/m5/system/binaries/vmlinux
       0: system.tsunami.io.rtc: Real-time clock set to Thu Jan  1 00:00:00 2009
 info: Entering event queue @ 0.  Starting simulation...
 info: Launching CPU 1 @ 881785000
-Exiting @ tick 1982594146000 because m5_exit instruction encountered
+Exiting @ tick 1982592736000 because m5_exit instruction encountered