commit e5f2e4c69643bc3cd385306a9e5d29e11578148c
author Daniil Tatianin <d-tatianin@yandex-team.ru> Thu Apr 11 22:51:35 2024 +0300
committer Kevin O'Connor <kevin@koconnor.net> Mon Apr 15 09:21:37 2024 -0400
tree e8253d6d8af8c9ad51a118d8cf1709150c593754
parent 731c88d503ef07a06a03dd17a6e9163941b329da

pciinit: don't misalign large BARs

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 <d-tatianin@yandex-team.ru>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

src/fw/pciinit.c

diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
index 6b13cd5..bb44dc2 100644
--- a/src/fw/pciinit.c
+++ b/src/fw/pciinit.c
@@ -970,9 +970,11 @@
             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) {