Commit ae88d0b9 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

PCI: Use pbus_select_window_for_type() during mem window sizing 



__pci_bus_size_bridges() goes to great lengths of helping pbus_size_mem()
in which types it should put into a particular bridge window, requiring
passing up to three resource type into pbus_size_mem().

Instead of having complex logic in __pci_bus_size_bridges() and a
non-straightforward interface between those functions, use
pbus_select_window_for_type() and pbus_select_window() to find the correct
bridge window and compare if the resources belong to that window.

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/20250829131113.36754-20-ilpo.jarvinen@linux.intel.com
parent 13016e15

drivers/pci/setup-bus.c

+24 −87
Original line number Diff line number Diff line
@@ -1284,24 +1284,22 @@ static bool pbus_upstream_space_available(struct pci_bus *bus, 
 * pbus_size_mem() - Size the memory window of a given bus

 *

 * @bus:		The bus

 * @mask:		Mask the resource flag, then compare it with type

 * @type:		The type of free resource from bridge

 * @type2:		Second match type

 * @type3:		Third match type

 * @type:		The type of bridge resource

 * @min_size:		The minimum memory window that must be allocated

 * @add_size:		Additional optional memory window

 * @realloc_head:	Track the additional memory window on this list

 *

 * Calculate the size of the bus and minimal alignment which guarantees

 * that all child resources fit in this size.

 * Calculate the size of the bus resource for @type and minimal alignment

 * which guarantees that all child resources fit in this size.

 *

 * Return -ENOSPC if there's no available bus resource of the desired

 * type.  Otherwise, set the bus resource start/end to indicate the

 * required size, add things to realloc_head (if supplied), and return 0.

 * Set the bus resource start/end to indicate the required size if there an

 * available unassigned bus resource of the desired @type.

 *

 * Add optional resource requests to the @realloc_head list if it is

 * supplied.

 */

static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,

			 unsigned long type, unsigned long type2,

			 unsigned long type3, resource_size_t min_size,

static void pbus_size_mem(struct pci_bus *bus, unsigned long type,

			 resource_size_t min_size,

			 resource_size_t add_size,

			 struct list_head *realloc_head)

{
@@ -1309,19 +1307,18 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, 
	resource_size_t min_align, win_align, align, size, size0, size1 = 0;

	resource_size_t aligns[28]; /* Alignments from 1MB to 128TB */

	int order, max_order;

	struct resource *b_res = find_bus_resource_of_type(bus,

					mask | IORESOURCE_PREFETCH, type);

	struct resource *b_res = pbus_select_window_for_type(bus, type);

	resource_size_t children_add_size = 0;

	resource_size_t children_add_align = 0;

	resource_size_t add_align = 0;

	resource_size_t relaxed_align;



	if (!b_res)

		return -ENOSPC;

		return;



	/* If resource is already assigned, nothing more to do */

	if (b_res->parent)

		return 0;

		return;



	memset(aligns, 0, sizeof(aligns));

	max_order = 0;
@@ -1338,11 +1335,9 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, 
			if (!pdev_resources_assignable(dev) ||

			    !pdev_resource_should_fit(dev, r))

				continue;



			if ((r->flags & mask) != type &&

			    (r->flags & mask) != type2 &&

			    (r->flags & mask) != type3)

			if (b_res != pbus_select_window(bus, r))

				continue;



			r_size = resource_size(r);



			/* Put SRIOV requested res to the optional list */
@@ -1428,7 +1423,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, 
			pci_info(bus->self, "disabling bridge window %pR to %pR (unused)\n",

				 b_res, &bus->busn_res);

		b_res->flags |= IORESOURCE_DISABLED;

		return 0;

		return;

	}



	resource_set_range(b_res, min_align, size0);
@@ -1441,7 +1436,6 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, 
			   (unsigned long long) (size1 - size0),

			   (unsigned long long) add_align);

	}

	return 0;

}



unsigned long pci_cardbus_resource_alignment(struct resource *res)
@@ -1546,12 +1540,11 @@ static void pci_bus_size_cardbus(struct pci_bus *bus, 
void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)

{

	struct pci_dev *dev;

	unsigned long mask, prefmask, type2 = 0, type3 = 0;

	resource_size_t additional_io_size = 0, additional_mmio_size = 0,

			additional_mmio_pref_size = 0;

	struct resource *pref;

	struct pci_host_bridge *host;

	int hdr_type, ret;

	int hdr_type;



	list_for_each_entry(dev, &bus->devices, bus_list) {

		struct pci_bus *b = dev->subordinate;
@@ -1601,71 +1594,15 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head) 
		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,

			     additional_io_size, realloc_head);



		/*

		 * If there's a 64-bit prefetchable MMIO window, compute

		 * the size required to put all 64-bit prefetchable

		 * resources in it.

		 */

		mask = IORESOURCE_MEM;

		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;

		if (pref && (pref->flags & IORESOURCE_MEM_64)) {

			prefmask |= IORESOURCE_MEM_64;

			ret = pbus_size_mem(bus, prefmask, prefmask,

				prefmask, prefmask,

		if (pref) {

			pbus_size_mem(bus,

				      IORESOURCE_MEM | IORESOURCE_PREFETCH |

				      (pref->flags & IORESOURCE_MEM_64),

				      realloc_head ? 0 : additional_mmio_pref_size,

				      additional_mmio_pref_size, realloc_head);



			/*

			 * If successful, all non-prefetchable resources

			 * and any 32-bit prefetchable resources will go in

			 * the non-prefetchable window.

			 */

			if (ret == 0) {

				mask = prefmask;

				type2 = prefmask & ~IORESOURCE_MEM_64;

				type3 = prefmask & ~IORESOURCE_PREFETCH;

			}

		}



		/*

		 * If there is no 64-bit prefetchable window, compute the

		 * size required to put all prefetchable resources in the

		 * 32-bit prefetchable window (if there is one).

		 */

		if (!type2) {

			prefmask &= ~IORESOURCE_MEM_64;

			ret = pbus_size_mem(bus, prefmask, prefmask,

				prefmask, prefmask,

				realloc_head ? 0 : additional_mmio_pref_size,

				additional_mmio_pref_size, realloc_head);



			/*

			 * If successful, only non-prefetchable resources

			 * will go in the non-prefetchable window.

			 */

			if (ret == 0)

				mask = prefmask;

			else

				additional_mmio_size += additional_mmio_pref_size;



			type2 = type3 = IORESOURCE_MEM;

		}



		/*

		 * Compute the size required to put everything else in the

		 * non-prefetchable window. This includes:

		 *

		 *   - all non-prefetchable resources

		 *   - 32-bit prefetchable resources if there's a 64-bit

		 *     prefetchable window or no prefetchable window at all

		 *   - 64-bit prefetchable resources if there's no prefetchable

		 *     window at all

		 *

		 * Note that the strategy in __pci_assign_resource() must match

		 * that used here. Specifically, we cannot put a 32-bit

		 * prefetchable resource in a 64-bit prefetchable window.

		 */

		pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,

		pbus_size_mem(bus, IORESOURCE_MEM,

			      realloc_head ? 0 : additional_mmio_size,

			      additional_mmio_size, realloc_head);

		break;