[SeaBIOS] Re: [RESEND PATCH] fw/pciinit: don't misalign large BARs

[Daniil Tatianin]

Hey there!

Do we need more reviewed-bys before this can be merged?

Thanks!

On 4/11/24 10:51 PM, Daniil Tatianin wrote:
> Previously we would unconditionally lower the alignment for large BARs
> in case their alignment was greater than "pci_mem64_top >> 11", this
> would make it impossible to use these devices by the kernel:
>      [   13.821108] pci 0000:9c:00.0: can't claim BAR 1 [mem 0x66000000000-0x67fffffffff 64bit pref]: no compatible bridge window
>      [   13.823492] pci 0000:9d:00.0: can't claim BAR 1 [mem 0x64000000000-0x65fffffffff 64bit pref]: no compatible bridge window
>      [   13.824218] pci 0000:9e:00.0: can't claim BAR 1 [mem 0x62000000000-0x63fffffffff 64bit pref]: no compatible bridge window
>      [   13.828322] pci 0000:8a:00.0: can't claim BAR 1 [mem 0x6e000000000-0x6ffffffffff 64bit pref]: no compatible bridge window
>      [   13.830691] pci 0000:8b:00.0: can't claim BAR 1 [mem 0x6c000000000-0x6dfffffffff 64bit pref]: no compatible bridge window
>      [   13.832218] pci 0000:8c:00.0: can't claim BAR 1 [mem 0x6a000000000-0x6bfffffffff 64bit pref]: no compatible bridge window
>
> Fix it by only overwriting the alignment in case it's actually greater
> than the desired by the BAR window.
>
> Fixes: 96a8d130a8c ("be less conservative with the 64bit pci io window")
> Signed-off-by: Daniil Tatianin 
> Reviewed-by: Gerd Hoffmann
>
> src/fw/pciinit.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
> index 6b13cd5b..bb44dc29 100644
> --- a/src/fw/pciinit.c
> +++ b/src/fw/pciinit.c
> @@ -970,9 +970,11 @@ static int pci_bios_check_devices(struct pci_bus *busses)
>               int resource_optional = 0;
>               if (hotplug_support == HOTPLUG_PCIE)
>                   resource_optional = pcie_cap && (type == PCI_REGION_TYPE_IO);
>        u64 top_align = pci_mem64_top >> 11;
>         if (hotplug_support && pci_pad_mem64 && is64
>            && (type == PCI_REGION_TYPE_PREFMEM))
>            align = pci_mem64_top >> 11;
>            && (type == PCI_REGION_TYPE_PREFMEM) && (top_align > align))
>            align = top_align;
>         if (align > sum && hotplug_support && !resource_optional)
>             sum = align; /* reserve min size for hot-plug */
>         if (size > sum) {