PCI: Check invalid align earlier in pbus_size_mem()

Check for invalid align before any bridge window sizing actions in
pbus_size_mem() to avoid need to roll back any sizing calculations.

Placing the check earlier will make it easier to add more optional size
related calculations at where the SR-IOV logic currently is in
pbus_size_mem().

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251219174036.16738-13-ilpo.jarvinen@linux.intel.com

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index a5b6c555a45bfb5534da21277507d665e2c2bbd0..3d1d3cefcdbad0819d010fa2bc2bb997cd9e9125 100644 (file)
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -19,6 +19,7 @@
 #include <linux/bug.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/errno.h>
@@ -1311,31 +1312,29 @@ static void pbus_size_mem(struct pci_bus *bus, struct resource *b_res,
                                continue;
 
                        r_size = resource_size(r);
-
-                       /* Put SRIOV requested res to the optional list */
-                       if (realloc_head && pci_resource_is_optional(dev, i)) {
-                               add_align = max(pci_resource_alignment(dev, r), add_align);
-                               add_to_list(realloc_head, dev, r, 0, 0 /* Don't care */);
-                               children_add_size += r_size;
-                               continue;
-                       }
-
+                       align = pci_resource_alignment(dev, r);
                        /*
                         * aligns[0] is for 1MB (since bridge memory
                         * windows are always at least 1MB aligned), so
                         * keep "order" from being negative for smaller
                         * resources.
                         */
-                       align = pci_resource_alignment(dev, r);
-                       order = __ffs(align) - __ffs(SZ_1M);
-                       if (order < 0)
-                               order = 0;
+                       order = max_t(int, __ffs(align) - __ffs(SZ_1M), 0);
                        if (order >= ARRAY_SIZE(aligns)) {
                                pci_warn(dev, "%s %pR: disabling; bad alignment %#llx\n",
                                         r_name, r, (unsigned long long) align);
                                r->flags = 0;
                                continue;
                        }
+
+                       /* Put SRIOV requested res to the optional list */
+                       if (realloc_head && pci_resource_is_optional(dev, i)) {
+                               add_align = max(align, add_align);
+                               add_to_list(realloc_head, dev, r, 0, 0 /* Don't care */);
+                               children_add_size += r_size;
+                               continue;
+                       }
+
                        size += max(r_size, align);
 
                        aligns[order] += align;