[M] Change in coreboot[main]: mainboard/qemu-riscv: Add PCI support

[Alper Nebi Yasak (Code Review)]

Attention is currently required from: Alper Nebi Yasak, Arthur Heymans, ron minnich.

Hello Arthur Heymans, Philipp Hug, build bot (Jenkins), ron minnich,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/80378?usp=email

to look at the new patch set (#2).

The following approvals got outdated and were removed:
Code-Review+2 by Arthur Heymans, Verified+1 by build bot (Jenkins)

Change subject: mainboard/qemu-riscv: Add PCI support
......................................................................

mainboard/qemu-riscv: Add PCI support

Add PCI support for the qemu-riscv mainboard like how it is done for
qemu-aarch64. The resulting build can be used with a QEMU command line
like:

qemu-system-riscv64 \
        -display gtk,show-tabs=on \
        -bios build/coreboot.rom \
    -drive if=pflash,file=build/coreboot.rom,format=raw \
        -M virt -m 1G \
        -device pcie-root-port \
        -serial stdio -device bochs-display \
        ...

One complication is that the PCIe high MMIO base depends on the amount
of available RAM for 64-bit RISC-V VMs [1], but not for 32-bit ones.

[1] https://gitlab.com/qemu-project/qemu/-/blob/v8.2.2/hw/riscv/virt.c#L1474-148...

Change-Id: Ie57b35620af82c681d1f0d78fa8e514e4df0d2ac
Signed-off-by: Alper Nebi Yasak 
---
A src/arch/riscv/include/arch/pci_ops.h
M src/mainboard/emulation/qemu-riscv/Kconfig
M src/mainboard/emulation/qemu-riscv/devicetree.cb
M src/mainboard/emulation/qemu-riscv/include/mainboard/addressmap.h
M src/mainboard/emulation/qemu-riscv/mainboard.c
5 files changed, 64 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/78/80378/2