Commit 13016e15 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

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: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-19-ilpo.jarvinen@linux.intel.com
parent da078810

drivers/pci/setup-bus.c

+32 −33
Original line number Diff line number Diff line
@@ -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 = {
@@ -1241,21 +1242,22 @@ 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)

		res = pbus_select_window(bus, res);

		if (!res)

			return false;

		if (!res->parent)

			continue;



		if (resource_size(res) >= size) {

			struct resource gap = {};



			if (find_resource_space(res, &gap, size, &constraint) == 0) {

					gap.flags = type;

				gap.flags = res->flags;

				pci_dbg(bus->self,

					"Assigned bridge window %pR to %pR free space at %pR\n",

					res, &bus->busn_res, &gap);
@@ -1274,7 +1276,6 @@ static bool pbus_upstream_space_available(struct pci_bus *bus, unsigned long mas 


		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);