@@ -1146,7 +1146,6 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
min_align = calculate_mem_align(aligns, max_order);
min_align = max(min_align, win_align);
size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), min_align);
- add_align = max(min_align, add_align);
if (bus->self && size0 &&
!pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type,
@@ -1159,8 +1158,21 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
}
if (realloc_head && (add_size > 0 || children_add_size > 0)) {
+ add_align = max(min_align, add_align);
size1 = calculate_memsize(size, min_size, add_size, children_add_size,
resource_size(b_res), add_align);
+
+ if (bus->self && size1 &&
+ !pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type,
+ size1, add_align)) {
+ min_align = 1ULL << (max_order + __ffs(SZ_1M));
+ min_align = max(min_align, win_align);
+ size1 = calculate_memsize(size, min_size, add_size, children_add_size,
+ resource_size(b_res), win_align);
+ pci_info(bus->self,
+ "bridge window %pR to %pR requires relaxed alignment rules\n",
+ b_res, &bus->busn_res);
+ }
}
if (!size0 && !size1) {
The commit 566f1dd52816 ("PCI: Relax bridge window tail sizing rules") relaxed the bridge window requirements for non-optional size (size0) but pbus_size_mem() also handles optional sizes (IOV resources) using size1. This can manifest, e.g., as a failure to resize a BAR back to its original size after it was first shrunk when device has a VF BAR resource because the bridge window (size1) is enlarged beyond what is strictly required to fit the downstream resources. Allow using relaxed bridge window tail sizing rules also with the optional resources (size1) so that the remove/realloc cycle during BAR resize (smaller and back to the original size) does not fail unexpectedly due to sudden increase in bridge window size demand. Move also add_align calculation into more logical place next to size1 assignment as they are strongly related to each other. Fixes: 566f1dd52816 ("PCI: Relax bridge window tail sizing rules") Reported-by: Michał Winiarski <michal.winiarski@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> --- drivers/pci/setup-bus.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)