sim: Add the notion of clock domains to all ClockedObjects

This patch adds the notion of source- and derived-clock domains to the
ClockedObjects. As such, all clock information is moved to the clock
domain, and the ClockedObjects are grouped into domains.

The clock domains are either source domains, with a specific clock
period, or derived domains that have a parent domain and a divider
(potentially chained). For piece of logic that runs at a derived clock
(a ratio of the clock its parent is running at) the necessary derived
clock domain is created from its corresponding parent clock
domain. For now, the derived clock domain only supports a divider,
thus ensuring a lower speed compared to its parent. Multiplier
functionality implies a PLL logic that has not been modelled yet
(create a separate clock instead).

The clock domains should be used as a mechanism to provide a
controllable clock source that affects clock for every clocked object
lying beneath it. The clock of the domain can (in a future patch) be
controlled by a handler responsible for dynamic frequency scaling of
the respective clock domains.

All the config scripts have been retro-fitted with clock domains. For
the System a default SrcClockDomain is created. For CPUs that run at a
different speed than the system, there is a seperate clock domain
created. This domain incorporates the CPU and the associated
caches. As before, Ruby runs under its own clock domain.

The clock period of all domains are pre-computed, such that no virtual
functions or multiplications are needed when calling
clockPeriod. Instead, the clock period is pre-computed when any
changes occur. For this to be possible, each clock domain tracks its
children.

7 files changed, 67 insertions, 14 deletions

diff --git a/configs/ruby/MESI_CMP_directory.py b/configs/ruby/MESI_CMP_directory.py
index c265bd4cb..4128f87ad 100644
--- a/configs/ruby/MESI_CMP_directory.py
+++ b/configs/ruby/MESI_CMP_directory.py
@@ -144,13 +144,22 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
                             system.memories.unproxy(system)))
     mem_module_size = phys_mem_size / options.num_dirs
 
+    # Run each of the ruby memory controllers at a ratio of the frequency of
+    # the ruby system
+    # clk_divider value is a fix to pass regression.
+    ruby_system.memctrl_clk_domain = DerivedClockDomain(
+                                          clk_domain=ruby_system.clk_domain,
+                                          clk_divider=3)
+
     for i in xrange(options.num_dirs):
         #
         # Create the Ruby objects associated with the directory controller
         #
 
-        mem_cntrl = RubyMemoryControl(version = i,
-                                      ruby_system = ruby_system)
+        mem_cntrl = RubyMemoryControl(
+                              clk_domain = ruby_system.memctrl_clk_domain,
+                              version = i,
+                              ruby_system = ruby_system)
 
         dir_size = MemorySize('0B')
         dir_size.value = mem_module_size
diff --git a/configs/ruby/MI_example.py b/configs/ruby/MI_example.py
index 0514a7240..6bbd35ea7 100644
--- a/configs/ruby/MI_example.py
+++ b/configs/ruby/MI_example.py
@@ -109,13 +109,22 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
                             system.memories.unproxy(system)))
     mem_module_size = phys_mem_size / options.num_dirs
 
+    # Run each of the ruby memory controllers at a ratio of the frequency of
+    # the ruby system.
+    # clk_divider value is a fix to pass regression.
+    ruby_system.memctrl_clk_domain = DerivedClockDomain(
+                                          clk_domain=ruby_system.clk_domain,
+                                          clk_divider=3)
+
     for i in xrange(options.num_dirs):
         #
         # Create the Ruby objects associated with the directory controller
         #
 
-        mem_cntrl = RubyMemoryControl(version = i,
-                                      ruby_system = ruby_system)
+        mem_cntrl = RubyMemoryControl(
+                              clk_domain = ruby_system.memctrl_clk_domain,
+                              version = i,
+                              ruby_system = ruby_system)
 
         dir_size = MemorySize('0B')
         dir_size.value = mem_module_size
diff --git a/configs/ruby/MOESI_CMP_directory.py b/configs/ruby/MOESI_CMP_directory.py
index f53758d71..81d04914c 100644
--- a/configs/ruby/MOESI_CMP_directory.py
+++ b/configs/ruby/MOESI_CMP_directory.py
@@ -139,13 +139,22 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
                             system.memories.unproxy(system)))
     mem_module_size = phys_mem_size / options.num_dirs
 
+    # Run each of the ruby memory controllers at a ratio of the frequency of
+    # the ruby system.
+    # clk_divider value is a fix to pass regression.
+    ruby_system.memctrl_clk_domain = DerivedClockDomain(
+                                          clk_domain=ruby_system.clk_domain,
+                                          clk_divider=3)
+
     for i in xrange(options.num_dirs):
         #
         # Create the Ruby objects associated with the directory controller
         #
 
-        mem_cntrl = RubyMemoryControl(version = i,
-                                      ruby_system = ruby_system)
+        mem_cntrl = RubyMemoryControl(
+                              clk_domain = ruby_system.memctrl_clk_domain,
+                              version = i,
+                              ruby_system = ruby_system)
 
         dir_size = MemorySize('0B')
         dir_size.value = mem_module_size
diff --git a/configs/ruby/MOESI_CMP_token.py b/configs/ruby/MOESI_CMP_token.py
index f3ad05a92..9c2598a1d 100644
--- a/configs/ruby/MOESI_CMP_token.py
+++ b/configs/ruby/MOESI_CMP_token.py
@@ -160,13 +160,22 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
                             system.memories.unproxy(system)))
     mem_module_size = phys_mem_size / options.num_dirs
 
+    # Run each of the ruby memory controllers at a ratio of the frequency of
+    # the ruby system
+    # clk_divider value is a fix to pass regression.
+    ruby_system.memctrl_clk_domain = DerivedClockDomain(
+                                          clk_domain=ruby_system.clk_domain,
+                                          clk_divider=3)
+
     for i in xrange(options.num_dirs):
         #
         # Create the Ruby objects associated with the directory controller
         #
 
-        mem_cntrl = RubyMemoryControl(version = i,
-                                      ruby_system = ruby_system)
+        mem_cntrl = RubyMemoryControl(
+                              clk_domain = ruby_system.memctrl_clk_domain,
+                              version = i,
+                              ruby_system = ruby_system)
 
         dir_size = MemorySize('0B')
         dir_size.value = mem_module_size
diff --git a/configs/ruby/MOESI_hammer.py b/configs/ruby/MOESI_hammer.py
index 30fb0f0b7..11ea579ea 100644
--- a/configs/ruby/MOESI_hammer.py
+++ b/configs/ruby/MOESI_hammer.py
@@ -158,13 +158,22 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
         else:
             pf_start_bit = block_size_bits
 
+    # Run each of the ruby memory controllers at a ratio of the frequency of
+    # the ruby system
+    # clk_divider value is a fix to pass regression.
+    ruby_system.memctrl_clk_domain = DerivedClockDomain(
+                                          clk_domain=ruby_system.clk_domain,
+                                          clk_divider=3)
+
     for i in xrange(options.num_dirs):
         #
         # Create the Ruby objects associated with the directory controller
         #
 
-        mem_cntrl = RubyMemoryControl(version = i,
-                                      ruby_system = ruby_system)
+        mem_cntrl = RubyMemoryControl(
+                              clk_domain = ruby_system.memctrl_clk_domain,
+                              version = i,
+                              ruby_system = ruby_system)
 
         dir_size = MemorySize('0B')
         dir_size.value = mem_module_size
diff --git a/configs/ruby/Network_test.py b/configs/ruby/Network_test.py
index c1a1f9509..c4df4dddb 100644
--- a/configs/ruby/Network_test.py
+++ b/configs/ruby/Network_test.py
@@ -107,13 +107,22 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
                             system.memories.unproxy(system)))
     mem_module_size = phys_mem_size / options.num_dirs
 
+    # Run each of the ruby memory controllers at a ratio of the frequency of
+    # the ruby system.
+    # clk_divider value is a fix to pass regression.
+    ruby_system.memctrl_clk_domain = DerivedClockDomain(
+                                          clk_domain=ruby_system.clk_domain,
+                                          clk_divider=3)
+
     for i in xrange(options.num_dirs):
         #
         # Create the Ruby objects associated with the directory controller
         #
 
-        mem_cntrl = RubyMemoryControl(version = i,
-                                      ruby_system = ruby_system)
+        mem_cntrl = RubyMemoryControl(
+                              clk_domain = ruby_system.memctrl_clk_domain,
+                              version = i,
+                              ruby_system = ruby_system)
 
         dir_size = MemorySize('0B')
         dir_size.value = mem_module_size
diff --git a/configs/ruby/Ruby.py b/configs/ruby/Ruby.py
index 5c5e84197..a35ef4f09 100644
--- a/configs/ruby/Ruby.py
+++ b/configs/ruby/Ruby.py
@@ -95,8 +95,7 @@ def create_topology(controllers, options):
 
 def create_system(options, system, piobus = None, dma_ports = []):
 
-    system.ruby = RubySystem(clock = options.ruby_clock,
-                             stats_filename = options.ruby_stats,
+    system.ruby = RubySystem(stats_filename = options.ruby_stats,
                              no_mem_vec = options.use_map)
     ruby = system.ruby