[Bug 297536] sys/arm64/marvell: pci_advk driver regression on 16-CURRENT - failed to allocate bus number (ENXIO)

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=297536

            Bug ID: 297536
           Summary: sys/arm64/marvell: pci_advk driver regression on
                    16-CURRENT - failed to allocate bus number (ENXIO)
           Product: Base System
           Version: 16.0-CURRENT
          Hardware: arm64
                OS: Any
            Status: New
          Severity: Affects Some People
          Priority: ---
         Component: arm
          Assignee: [email protected]
          Reporter: [email protected]

Host Architecture: arm64 (aarch64)
SoC / Platform: Marvell Armada 3700 (Cortex-A53)
Regression: Yes (Functional on older branches/stable, broken on modern
stable/current)

[Overview]
An architectural regression exists within the Marvell Aardvark PCIe host bridge
controller driver (sys/arm64/marvell/pci_advk.c). While the parent controller
handles early hardware initialization, it fails during the Newbus child
attachment phase. The OFW PCI coordinator is unable to provision logical bus
resources to pci0, causing a complete failure to map the PCIe bus lanes. Any
downstream devices connected to the mPCIe/M.2 slot (such as Wi-Fi or NVMe
cards) are rendered completely invisible to the kernel.

[Dmesg / Boot Log Output]
pcib0: <Marvell Armada 3700 PCIe Bus Controller> mem 0xd0070000-0xd008ffff irq
5 on simplebus0
pcib0: link up
pci0: <OFW PCI bus> on pcib0
pci0: failed to allocate bus number
device_attach: pci0 attach returned 6

[Technical Analysis]
1. The hardware link layer successfully initializes and registers state changes
("pcib0: link up").
2. The failure occurs immediately afterward during `pci0_attach` inside the
Open Firmware PCI mapping layer.
3. The kernel returns error code 6 (ENXIO - Device not configured / No such
device or address). 
4. This points to a failure inside the driver's resource allocation mechanics
(advk_pcie_alloc_resource). The child `pci0` bus requests logical
identification number ranges via `SYS_RES_BUS`, but the host controller fails
to satisfy the resource allocation constraints imposed by modern FreeBSD
framework tracking rules. 

[Steps to Reproduce]
1. Install recent FreeBSD stable/14 or CURRENT on an Armada 3700 platform with
an active physical device populated in the mPCIe/M.2 slot.
2. Observe the early boot logs. The host bridge controller drops the child
attachment process immediately upon scanning the active lane.

[Expected Behavior]
The host bridge allocator should correctly catch the SYS_RES_BUS allocation
request, map the logical bus range via rman, return 0 (Success) to the Newbus
attachment loop, and enumerate the child devices on the bus.
[Note on Versions]

This hardware configuration attached and functioned perfectly under FreeBSD
14-based baselines. The allocation failure only began occurring after upstream
framework changes were pulled into the 16-CURRENT branch.

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