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authorAndreas Hansson <andreas.hansson@arm.com>2012-01-17 12:55:09 -0600
committerAndreas Hansson <andreas.hansson@arm.com>2012-01-17 12:55:09 -0600
commit2208ea049f60618e432c69c065926bcbc810581a (patch)
treedcc2c0afed74ec56969df9fa20b92655f767c158 /src/dev/arm
parente731cf4c1df8db0c7bcb689aba0146199a93b64e (diff)
downloadgem5-2208ea049f60618e432c69c065926bcbc810581a.tar.xz
MEM: Make the bus bridge unidirectional and fixed address range
This patch makes the bus bridge uni-directional and specialises the bus ports to be a master port and a slave port. This greatly simplifies the assumptions on both sides as either port only has to deal with requests or responses. The following patches introduce the notion of master and slave ports, and would not be possible without this split of responsibilities. In making the bridge unidirectional, the address range mechanism of the bridge is also changed. For the cases where communication is taking place both ways, an additional bridge is needed. This causes issues with the existing mechanism, as the busses cannot determine when to stop iterating the address updates from the two bridges. To avoid this issue, and also greatly simplify the specification, the bridge now has a fixed set of address ranges, specified at creation time.
Diffstat (limited to 'src/dev/arm')
-rw-r--r--src/dev/arm/RealView.py31
1 files changed, 24 insertions, 7 deletions
diff --git a/src/dev/arm/RealView.py b/src/dev/arm/RealView.py
index 96f3c8a61..cd7744362 100644
--- a/src/dev/arm/RealView.py
+++ b/src/dev/arm/RealView.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2009 ARM Limited
+# Copyright (c) 2009-2011 ARM Limited
# All rights reserved.
#
# The license below extends only to copyright in the software and shall
@@ -177,12 +177,18 @@ class RealViewPBX(RealView):
rtc_fake = AmbaFake(pio_addr=0x10017000, amba_id=0x41031)
- # Attach I/O devices that are on chip
- def attachOnChipIO(self, bus):
+ # Attach I/O devices that are on chip and also set the appropriate
+ # ranges for the bridge
+ def attachOnChipIO(self, bus, bridge):
self.gic.pio = bus.port
self.l2x0_fake.pio = bus.port
self.a9scu.pio = bus.port
self.local_cpu_timer.pio = bus.port
+ # Bridge ranges based on excluding what is part of on-chip I/O
+ # (gic, l2x0, a9scu, local_cpu_timer)
+ bridge.ranges = [AddrRange(self.realview_io.pio_addr,
+ self.a9scu.pio_addr - 1),
+ AddrRange(self.flash_fake.pio_addr, Addr.max)]
# Attach I/O devices to specified bus object. Can't do this
# earlier, since the bus object itself is typically defined at the
@@ -248,10 +254,16 @@ class RealViewEB(RealView):
- # Attach I/O devices that are on chip
- def attachOnChipIO(self, bus):
+ # Attach I/O devices that are on chip and also set the appropriate
+ # ranges for the bridge
+ def attachOnChipIO(self, bus, bridge):
self.gic.pio = bus.port
self.l2x0_fake.pio = bus.port
+ # Bridge ranges based on excluding what is part of on-chip I/O
+ # (gic, l2x0)
+ bridge.ranges = [AddrRange(self.realview_io.pio_addr,
+ self.gic.cpu_addr - 1),
+ AddrRange(self.flash_fake.pio_addr, Addr.max)]
# Attach I/O devices to specified bus object. Can't do this
# earlier, since the bus object itself is typically defined at the
@@ -329,10 +341,15 @@ class VExpress_ELT(RealView):
usb_fake = IsaFake(pio_addr=0xFB000000, pio_size=0x1ffff)
- # Attach I/O devices that are on chip
- def attachOnChipIO(self, bus):
+ # Attach I/O devices that are on chip and also set the appropriate
+ # ranges for the bridge
+ def attachOnChipIO(self, bus, bridge):
self.gic.pio = bus.port
self.a9scu.pio = bus.port
+ # Bridge ranges based on excluding what is part of on-chip I/O
+ # (gic, a9scu)
+ bridge.ranges = [AddrRange(self.pci_cfg_base, self.a9scu.pio_addr - 1),
+ AddrRange(self.local_cpu_timer.pio_addr, Addr.max)]
# Attach I/O devices to specified bus object. Can't do this
# earlier, since the bus object itself is typically defined at the