[U-Boot] inappropriate PCI configuration on arm64 qemu?

[AKASHI Takahiro]

When I tried to add a SD card to qemu's virt machine (2.10.0) as,
	------
        -device sdhci-pci \
        -device sd-card,drive=my_sd \
        -drive if=none,id=my_sd,format=raw,file=/path/my/sd.img
	------
u-boot doesn't configure a SDHCI controller properly and an attached
device is never detected.

Digging into the code, I found
* reading BAR5 in dm_pciauto_setup_device() shows BAR5 is a 32-bit address,
* pciauto_region_allocate() allocates a 64-bit address (0x80.ABCD.0000)
  to BAR5 as res->bus_lower is 0x80.0000.0000
* Upper 32-bit value is not written back to BAR5 because of !found_mem64
  (BAR5 is the last one and no succeeding BAR anyway.)

On the other hand,
* Qemu defines two PCI memory regions for MMIO:
        (from qemu's hw/arm/virt.c)
	------
	[VIRT_PCIE_MMIO] =          { 0x10000000, 0x2eff0000 },
	[VIRT_PCIE_PIO] =           { 0x3eff0000, 0x00010000 },
	[VIRT_PCIE_ECAM] =          { 0x3f000000, 0x01000000 },
	[VIRT_MEM] =                { 0x40000000, RAMLIMIT_BYTES },
	/* Second PCIe window, 512GB wide at the 512GB boundary */
	[VIRT_PCIE_MMIO_HIGH] =   { 0x8000000000ULL, 0x8000000000ULL },
	------
* A PCI card is configured in decode_regions() so that
  'hose' has only one entry per each type of memory regions.
  This behavior was introduced by Simon's patch:
	------
	commit 9526d83ac5a
	Author: Simon Glass <sjg at chromium.org>
	Date:   Thu Nov 19 20:26:58 2015 -0700

	    dm: pci: Support decoding ranges with duplicate entries
	------
* As a result, MMIO region (0x1000.0000-0x2eff.0000) is overwritten
  and MMIO_HIGH is the only one available at runtime.

I believe that this behavior is the root cause of my issue, and
by reverting the patch mentioned above, everything works fine.

While I understand a concern mentioned in the commit message,
there should be a better way to manage the case.

Any ideas?

Thanks,
-Takahiro AKASHI