PCI: Use pbus_select_window() in space available checker

pbus_upstream_space_available() figures out the upstream bridge window
resources on its own. Migrate it to use pbus_select_window().

Note: pbus_select_window() -> pbus_select_window_for_type() calls
find_bus_resource_of_type() for root bus, which does not do parent check
similar to what pbus_upstream_space_available() did earlier, but the
difference does not matter because pbus_upstream_space_available() itself
stops when it encounters the root bus.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-19-ilpo.jarvinen@linux.intel.com

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 5ec446c2b7797419f6dd22d2e0237c3fa9f4ade2..865bacae9cac242f600ba6eeeb93f12b73904a45 100644 (file)
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1221,19 +1221,20 @@ static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
 /**
  * pbus_upstream_space_available - Check no upstream resource limits allocation
  * @bus:       The bus
- * @mask:      Mask the resource flag, then compare it with type
- * @type:      The type of resource from bridge
+ * @res:       The resource to help select the correct bridge window
  * @size:      The size required from the bridge window
  * @align:     Required alignment for the resource
  *
- * Checks that @size can fit inside the upstream bridge resources that are
- * already assigned.
+ * Check that @size can fit inside the upstream bridge resources that are
+ * already assigned. Select the upstream bridge window based on the type of
+ * @res.
  *
  * Return: %true if enough space is available on all assigned upstream
  * resources.
  */
-static bool pbus_upstream_space_available(struct pci_bus *bus, unsigned long mask,
-                                         unsigned long type, resource_size_t size,
+static bool pbus_upstream_space_available(struct pci_bus *bus,
+                                         struct resource *res,
+                                         resource_size_t size,
                                          resource_size_t align)
 {
        struct resource_constraint constraint = {
@@ -1241,39 +1242,39 @@ static bool pbus_upstream_space_available(struct pci_bus *bus, unsigned long mas
                .align = align,
        };
        struct pci_bus *downstream = bus;
-       struct resource *res;
 
        while ((bus = bus->parent)) {
                if (pci_is_root_bus(bus))
                        break;
 
-               pci_bus_for_each_resource(bus, res) {
-                       if (!res || !res->parent || (res->flags & mask) != type)
-                               continue;
-
-                       if (resource_size(res) >= size) {
-                               struct resource gap = {};
+               res = pbus_select_window(bus, res);
+               if (!res)
+                       return false;
+               if (!res->parent)
+                       continue;
 
-                               if (find_resource_space(res, &gap, size, &constraint) == 0) {
-                                       gap.flags = type;
-                                       pci_dbg(bus->self,
-                                               "Assigned bridge window %pR to %pR free space at %pR\n",
-                                               res, &bus->busn_res, &gap);
-                                       return true;
-                               }
-                       }
+               if (resource_size(res) >= size) {
+                       struct resource gap = {};
 
-                       if (bus->self) {
-                               pci_info(bus->self,
-                                        "Assigned bridge window %pR to %pR cannot fit 0x%llx required for %s bridging to %pR\n",
-                                        res, &bus->busn_res,
-                                        (unsigned long long)size,
-                                        pci_name(downstream->self),
-                                        &downstream->busn_res);
+                       if (find_resource_space(res, &gap, size, &constraint) == 0) {
+                               gap.flags = res->flags;
+                               pci_dbg(bus->self,
+                                       "Assigned bridge window %pR to %pR free space at %pR\n",
+                                       res, &bus->busn_res, &gap);
+                               return true;
                        }
+               }
 
-                       return false;
+               if (bus->self) {
+                       pci_info(bus->self,
+                                "Assigned bridge window %pR to %pR cannot fit 0x%llx required for %s bridging to %pR\n",
+                                res, &bus->busn_res,
+                                (unsigned long long)size,
+                                pci_name(downstream->self),
+                                &downstream->busn_res);
                }
+
+               return false;
        }
 
        return true;
@@ -1395,8 +1396,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                b_res->flags &= ~IORESOURCE_DISABLED;
 
        if (bus->self && size0 &&
-           !pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type,
-                                          size0, min_align)) {
+           !pbus_upstream_space_available(bus, b_res, size0, min_align)) {
                relaxed_align = 1ULL << (max_order + __ffs(SZ_1M));
                relaxed_align = max(relaxed_align, win_align);
                min_align = min(min_align, relaxed_align);
@@ -1411,8 +1411,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                                          resource_size(b_res), add_align);
 
                if (bus->self && size1 &&
-                   !pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type,
-                                                  size1, add_align)) {
+                   !pbus_upstream_space_available(bus, b_res, size1, add_align)) {
                        relaxed_align = 1ULL << (max_order + __ffs(SZ_1M));
                        relaxed_align = max(relaxed_align, win_align);
                        min_align = min(min_align, relaxed_align);