dev, arm: Warn on PL011 DMA disable

The PL011 spec specifies a DMACR register at offset 0x48, which isn't
implemented in the model. Currently any attempt to access the register
results in a panic.

This change swaps the panic for a warning only when software writes into
DMACR to disable DMA, keeping the panic otherwise.

Change-Id: I04586b52df8d5d174536276fd7ae19e77ff4681a
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15279
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: Use little endian packet accessors.

We know data is little endian, so we can use those accessors
explicitly.

Change-Id: Iee337109fcda134e1ac5a700e5141fd7060f9c45
Reviewed-on: https://gem5-review.googlesource.com/c/13457
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

Pl011: Added registers UART_RSR/UART_ECR

UART_RSR shows errors with the transmission and UART_ECR can clear
those (according to PL011 Technical Reference Manual Revision r1p4). As
these transmission errors never occur, they are implemented as RAZ/WI.

Both registers exist at the same offset 0x004. RSR is read-only, ECR is
write-only.

Signed-off-by: Maurice Becker <madnaurice@googlemail.com>
Change-Id: Ia9d13c90c65feccf3ecec36a782170755b1e1c02
Reviewed-on: https://gem5-review.googlesource.com/12686
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: Fix the address range for some I/O devices

Previously, many devices were incorrecty configured to respond to an
address range of size 0xfff. This changes fixes this and sets it to
0x1000.

Change-Id: I4b027a27adf60ceae4859e287d7f34443b398752
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11116
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Refactor UART->Terminal interface

The UART models currently assume that they are always wired to a
terminal. While true at the moment, this isn't necessarily a valid
assumption. This change introduces the SerialDevice class that defines
the interface for serial devices. Currently, Terminal is the only
class that implements this interface.

Change-Id: I74fefafbbaf5ac1ec0d4ec0b5a0f4b246fdad305
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4289
Reviewed-by: Gabe Black <gabeblack@google.com>

arm: Replace EventWrapper use with EventFunctionWrapper

Change-Id: I08de5f72513645d1fe92bde99fa205dde897e951
Signed-off-by: Sean Wilson <spwilson2@wisc.edu>
Reviewed-on: https://gem5-review.googlesource.com/3747
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

style: [patch 1/22] use /r/3648/ to reorganize includes

arm, dev: pl011 console interactivity

Improve PL011 console interactivity

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>

arm,dev: PL011 UART_FR read status enhancement

Given we do not simulate a FIFO currently there are only two states
we can be in upon read: empty or full. Properly signal the latter.

Add and sort constants for states in the header file.

Committed by Jason Lowe-Power <power.jg@gmail.com>

sim: Refactor the serialization base class

Objects that are can be serialized are supposed to inherit from the
Serializable class. This class is meant to provide a unified API for
such objects. However, so far it has mainly been used by SimObjects
due to some fundamental design limitations. This changeset redesigns
to the serialization interface to make it more generic and hide the
underlying checkpoint storage. Specifically:

* Add a set of APIs to serialize into a subsection of the current
object. Previously, objects that needed this functionality would
use ad-hoc solutions using nameOut() and section name
generation. In the new world, an object that implements the
interface has the methods serializeSection() and
unserializeSection() that serialize into a named /subsection/ of
the current object. Calling serialize() serializes an object into
the current section.

* Move the name() method from Serializable to SimObject as it is no
longer needed for serialization. The fully qualified section name
is generated by the main serialization code on the fly as objects
serialize sub-objects.

* Add a scoped ScopedCheckpointSection helper class. Some objects
need to serialize data structures, that are not deriving from
Serializable, into subsections. Previously, this was done using
nameOut() and manual section name generation. To simplify this,
this changeset introduces a ScopedCheckpointSection() helper
class. When this class is instantiated, it adds a new /subsection/
and subsequent serialization calls during the lifetime of this
helper class happen inside this section (or a subsection in case
of nested sections).

* The serialize() call is now const which prevents accidental state
manipulation during serialization. Objects that rely on modifying
state can use the serializeOld() call instead. The default
implementation simply calls serialize(). Note: The old-style calls
need to be explicitly called using the
serializeOld()/serializeSectionOld() style APIs. These are used by
default when serializing SimObjects.

* Both the input and output checkpoints now use their own named
types. This hides underlying checkpoint implementation from
objects that need checkpointing and makes it easier to change the
underlying checkpoint storage code.

dev, arm: Clean up PL011 and rewrite interrupt handling

The ARM PL011 UART model didn't clear and raise interrupts
correctly. This changeset rewrites the whole interrupt handling and
makes it both simpler and fixes several cases where the correct
interrupts weren't raised or cleared. Additionally, it cleans up many
other aspects of the code.

mem: Remove redundant Packet::allocate calls

This patch cleans up the packet memory allocation confusion. The data
is always allocated at the requesting side, when a packet is created
(or copied), and there is never a need for any device to allocate any
space if it is merely responding to a paket. This behaviour is in line
with how SystemC and TLM works as well, thus increasing
interoperability, and matching established conventions.

The redundant calls to Packet::allocate are removed, and the checks in
the function are tightened up to make sure data is only ever allocated
once. There are still some oddities in the packet copy constructor
where we copy the data pointer if it is static (without ownership),
and allocate new space if the data is dynamic (with ownership). The
latter is being worked on further in a follow-on patch.

dev: Allow additional UART interrupts to be set

This patch allows setting a few additional interrupts for status
changes that should never occur.

dev: make BasicPioDevice take size in constructor

Instead of relying on derived classes explicitly assigning
to the BasicPioDevice pioSize field, require them to pass
a size value in to the constructor.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>

dev/arm: get rid of AmbaDev namespace

It was confusing having an AmbaDev namespace along with an
AmbaDevice class. The namespace stuff is now moved in to
a new base AmbaDevice class, which is a mixin for classes
AmbaPioDevice (the former AmbaDevice) and AmbaDmaDevice
to provide the readId function as an inherited member function.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>

arm: Create a GIC base class and make the PL390 derive from it

This patch moves the GIC interface to a separate base class and makes
all interrupt devices use that base class instead of a pointer to the
PL390 implementation. This allows us to have multiple GIC
implementations. Future implementations will allow in-kernel GIC
implementations when using hardware virtualization.

ARM: pl011 raw interrupt fix

Raw interrupt was not being set when interrupt was disabled.
This patch sets the raw interrupt regardless of the mask.

fix some build problems from prior changesets

Replace curTick global variable with accessor functions.
This step makes it easy to replace the accessor functions
(which still access a global variable) with ones that access
per-thread curTick values.

ARM: Add checkpointing support

ARM: Change how the AMBA device ID checking is done to make it more generic

ARM: Add I/O devices for booting linux