mem: Deduce if cache should forward snoops

Information
Submitter:	Andreas Hansson
Repository:	gem5
Branch:	default
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Description

Changeset 11310:02553e77fa45
---------------------------
mem: Deduce if cache should forward snoops

This patch changes how the cache determines if snoops should be
forwarded from the memory side to the CPU side. Instead of having a
parameter, the cache now looks at the port connected on the CPU side,
and if it is a snooping port, then snoops are forwarded. Less error
prone, and less parameters to worry about.

The patch also tidies up the CPU classes to ensure that their I-side
port is not snooping by removing overrides to the snoop request
handler, such that snoop requests will panic via the default
MasterPort implement

Testing Done

I don't see the "treats any snoops as an error" aspect mentioned in the last line of the description... is that because you're no longer overriding some default implementation that causes an error? I don't see that either, but I didn't look very hard...

Andreas Hansson Jan. 21, 2016, 9:08 a.m. (Jan. 21, 2016, 9:08 a.m.)
```
Indeed, we use the default instead.
```

Steve Reinhardt Jan. 21, 2016, 10:01 a.m. (Jan. 21, 2016, 10:01 a.m.)

Ah, I see, it's the default MasterPort implementation. I suggest changing the last paragraph of the description to something like:

The patch also tidies up the CPU classes to ensure that their I-side
port is not snooping by removing overrides to the snoop request
handler, such that snoop requests will panic via the default
MasterPort implementation.

src/mem/cache/base.cc (Diff revision 1)

short comment about this being overridden in init() would be nice

Description:

~		Changeset 11285:d896fba0ee10
	~	Changeset 11310:02553e77fa45

		mem: Deduce if cache should forward snoops

		This patch changes how the cache determines if snoops should be
		forwarded from the memory side to the CPU side. Instead of having a
		parameter, the cache now looks at the port connected on the CPU side,
		and if it is a snooping port, then snoops are forwarded. Less error
		prone, and less parameters to worry about.

		The patch also tidies up the CPU classes to ensure that their I-side
~		port is not snooping, and treats any snoops as an error.
	~	port is not snooping by removing overrides to the snoop request
	+	handler, such that snoop requests will panic via the default
	+	MasterPort implement

Diff:

Revision 2 (+10 -18)

Show changes

	configs/common/Caches.py
	configs/common/O3_ARM_v7a.py
	src/cpu/minor/cpu.hh
	src/cpu/minor/lsq.hh
	src/cpu/o3/cpu.hh
	src/cpu/simple/atomic.hh
	src/cpu/simple/timing.hh
	src/mem/cache/Cache.py
	2 more

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Description:

Changeset 11285:d896fba0ee10

Changeset 11310:02553e77fa45

Diff:

Status: Closed (submitted)