dev-arm: Cleanup GICv3 initialization

This patch is removing the unnecessary initState() / reset() methods
from GICv3 classes, since we can initialize everything at
construction/init time

Change-Id: Ia70edcc4ca4f11878fac0024342e4f2cd81883a0
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20636
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: Initialize GICD_TYPER once at construction time

Change-Id: Ib4dfdf7005709c22b4ba95099b1192f6edd6ff06
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20635
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: Implement message-based SPIs

Change-Id: I35e79dfd572c3e0d9cadc8e0aab01befd6004ece
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20631
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: Add GICD_SGIR register

The Distributor Software Generated Interrupt Register is implemented
only if affinity routing is disabled. Since this configuration is
currently not supported in gem5, it has to be treated as RES0.

Change-Id: I9ffcb31b26fc17547f74a4f1d43ce72c59786fa8
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20630
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: Rewrite GICv3 update

The GICv3 update methods are method which are invoked anytime the model
needs to evaluate a change in its state, which most of the time means
managing the state of an interrupt (forwarding it to a PE, deasserting
it, etc).
The way it is currently done is a little bit obscure and doesn't
handle correctly IRQ prioritization.
Example:
An IRQ which is handled by the redistributor (PPI or LPI) was not
competing with any pending interrupts coming from the distributor (SPIs)
once raised by a peripheral.

Also the way the pending state of an interrupt was removed at the
cpu interface level wasn't happening in place where this was actually
happening (E.g. when activating it), but happened with a weird
fullUpdate semantic, where if there was a pending interrupt in a
cpu interface, all cpu interfaces had their pending interrupt (if any)
been disabled.

With this patch, state update always starts at the distributor, and
it goes down until the cpu interface where a Gicv3CPUInterface::update
method selects the winning interrupt coming from distributor/redistributor
to be forwarded to the PE.

Change-Id: I1c517cbc4bf107cc2d7ae7beb2692e3cf5187a40
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20614
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

dev-arm: Add GITS_PIDR2 register to the ITS memory map

The GITS Peripheral Identification Register #2 bits assignments are the
same as those for GICD_PIDR2.

Change-Id: I235008a383e08dd557d899cb3aa18202ef943f8b
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20254
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

dev-arm: Add Gicv3Distributor members for GICv3 GICD_PIDRx

There is no need of calculating the value every time the registers
are read.

Change-Id: I58b87abb585fb9928959992927f00d9c000a4c35
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20253
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

dev-arm: Add named variable for GICD_TYPER.IDBits

This could be used by other GICv3 components to query the maximum
number of implemented interrupt identifiers

Change-Id: I132e50de331aea22523260bcefba7e961b53eccd
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18599
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

dev-arm: Fix GICv3 overflow for INTID > 256

SPIs can get to a maximum number of 1023, so that an uint8_t is not capable
of representing all of them.

Change-Id: I7a2c43b41ac93eabdfcf8311681240416b954177
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17631
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: cleanup of gicv3 code

Change-Id: I9aba90022f6408838c4ab87c6b90bba438752e53
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/16222
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>

dev-arm: Add a GICv3 model

Change-Id: Ib0067fc743f84ff7be9f12d2fc33ddf63736bdd1
Reviewed-on: https://gem5-review.googlesource.com/c/13436
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>