Commit d0c72d6e authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

PCI: Push realloc check into pbus_size_mem() 



pbus_size_mem() and calculate_memsize() input both min_size and add_size.
They are given the same value if realloc_head is NULL and min_size is 0
otherwise. Both are used in calculate_memsize() to enforce a lower bound to
the size.

The interface between __pci_bus_size_bridges() and the forementioned
functions can be simplied by pushing the realloc check into
pbus_size_mem().

There are only two possible cases:

  1) when calculating size0, add_size parameter given to
     calculate_memsize() is always 0 which implies only min_size
     matters.

  2) when calculating size1, realloc_head is not NULL which implies
     min_size=0 so only add_size matters.

Drop min_size parameter from pbus_size_mem() and check realloc_head when
calling calculate_memsize(). Drop add_size from calculate_memsize() and use
only min_size within max() to enforce the lower bound.

calculate_iosize() is a bit more complicated than calculate_memsize() and
is therefore left as is, but pbus_size_io() can still input only min_size
similar to pbus_size_mem().

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/20251219174036.16738-7-ilpo.jarvinen@linux.intel.com
parent f909e3ee

drivers/pci/setup-bus.c

+12 −22
Original line number Diff line number Diff line
@@ -1069,14 +1069,10 @@ static resource_size_t calculate_iosize(resource_size_t size, 


static resource_size_t calculate_memsize(resource_size_t size,

					 resource_size_t min_size,

					 resource_size_t add_size,

					 resource_size_t children_add_size,

					 resource_size_t align)

{

	if (size < min_size)

		size = min_size;



	size = max(size, add_size) + children_add_size;

	size = max(size, min_size) + children_add_size;

	return ALIGN(size, align);

}
@@ -1115,8 +1111,7 @@ static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type) 
 * pbus_size_io() - Size the I/O window of a given bus

 *

 * @bus:		The bus

 * @min_size:		The minimum I/O window that must be allocated

 * @add_size:		Additional optional I/O window

 * @add_size:		Additional I/O window

 * @realloc_head:	Track the additional I/O window on this list

 *

 * Sizing the I/O windows of the PCI-PCI bridge is trivial, since these
@@ -1124,8 +1119,7 @@ static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type) 
 * devices are limited to 256 bytes.  We must be careful with the ISA

 * aliasing though.

 */

static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,

			 resource_size_t add_size,

static void pbus_size_io(struct pci_bus *bus, resource_size_t add_size,

			 struct list_head *realloc_head)

{

	struct pci_dev *dev;
@@ -1170,7 +1164,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, 
		}

	}



	size0 = calculate_iosize(size, min_size, size1, 0, 0,

	size0 = calculate_iosize(size, realloc_head ? 0 : add_size, size1, 0, 0,

			resource_size(b_res), min_align);



	if (size0)
@@ -1178,7 +1172,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, 


	size1 = size0;

	if (realloc_head && (add_size > 0 || children_add_size > 0)) {

		size1 = calculate_iosize(size, min_size, size1, add_size,

		size1 = calculate_iosize(size, 0, size1, add_size,

					 children_add_size, resource_size(b_res),

					 min_align);

	}
@@ -1269,8 +1263,7 @@ static resource_size_t calculate_head_align(resource_size_t *aligns, 
 *

 * @bus:		The bus

 * @type:		The type of bridge resource

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

 * @add_size:		Additional optional memory window

 * @add_size:		Additional memory window

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

 *

 * Calculate the size of the bus resource for @type and minimal alignment
@@ -1283,7 +1276,6 @@ static resource_size_t calculate_head_align(resource_size_t *aligns, 
 * supplied.

 */

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)

{
@@ -1363,7 +1355,8 @@ static void pbus_size_mem(struct pci_bus *bus, unsigned long type, 
	win_align = window_alignment(bus, b_res->flags);

	min_align = calculate_head_align(aligns, max_order);

	min_align = max(min_align, win_align);

	size0 = calculate_memsize(size, min_size, 0, 0, win_align);

	size0 = calculate_memsize(size, realloc_head ? 0 : add_size,

				  0, win_align);



	if (size0) {

		resource_set_range(b_res, min_align, size0);
@@ -1372,7 +1365,7 @@ static void pbus_size_mem(struct pci_bus *bus, unsigned long type, 


	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,

		size1 = calculate_memsize(size, add_size, children_add_size,

					  win_align);

	}
@@ -1550,20 +1543,17 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head) 
		}

		fallthrough;

	default:

		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,

			     additional_io_size, realloc_head);

		pbus_size_io(bus, additional_io_size, realloc_head);



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

			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);

		}



		pbus_size_mem(bus, IORESOURCE_MEM,

			      realloc_head ? 0 : additional_mmio_size,

			      additional_mmio_size, realloc_head);

		pbus_size_mem(bus, IORESOURCE_MEM, additional_mmio_size,

			      realloc_head);

		break;

	}

}