Commit de3ffa30 authored by Jon Derrick's avatar Jon Derrick Committed by Bjorn Helgaas
Browse files

PCI: Equalize hotplug memory and io for occupied and empty slots 



Currently, a hotplug bridge will be given hpmemsize additional memory
and hpiosize additional io if available, in order to satisfy any future
hotplug allocation requirements.

These calculations don't consider the current memory/io size of the
hotplug bridge/slot, so hotplug bridges/slots which have downstream
devices will be allocated their current allocation in addition to the
hpmemsize value.

This makes for possibly undesirable results with a mix of unoccupied and
occupied slots (ex, with hpmemsize=2M):

  02:03.0 PCI bridge: <-- Occupied
	  Memory behind bridge: d6200000-d64fffff [size=3M]
  02:04.0 PCI bridge: <-- Unoccupied
	  Memory behind bridge: d6500000-d66fffff [size=2M]

This change considers the current allocation size when using the
hpmemsize/hpiosize parameters to make the reservations predictable for
the mix of unoccupied and occupied slots:

  02:03.0 PCI bridge: <-- Occupied
	  Memory behind bridge: d6200000-d63fffff [size=2M]
  02:04.0 PCI bridge: <-- Unoccupied
	  Memory behind bridge: d6400000-d65fffff [size=2M]

Signed-off-by: default avatarJon Derrick <jonathan.derrick@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 26ad34d5

drivers/pci/setup-bus.c

+15 −13
Original line number Diff line number Diff line
@@ -811,6 +811,8 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus, 
static resource_size_t calculate_iosize(resource_size_t size,

		resource_size_t min_size,

		resource_size_t size1,

		resource_size_t add_size,

		resource_size_t children_add_size,

		resource_size_t old_size,

		resource_size_t align)

{
@@ -823,15 +825,18 @@ static resource_size_t calculate_iosize(resource_size_t size, 
#if defined(CONFIG_ISA) || defined(CONFIG_EISA)

	size = (size & 0xff) + ((size & ~0xffUL) << 2);

#endif

	size = ALIGN(size + size1, align);

	size = size + size1;

	if (size < old_size)

		size = old_size;



	size = ALIGN(max(size, add_size) + children_add_size, align);

	return size;

}



static resource_size_t calculate_memsize(resource_size_t size,

		resource_size_t min_size,

		resource_size_t size1,

		resource_size_t add_size,

		resource_size_t children_add_size,

		resource_size_t old_size,

		resource_size_t align)

{
@@ -841,7 +846,8 @@ static resource_size_t calculate_memsize(resource_size_t size, 
		old_size = 0;

	if (size < old_size)

		size = old_size;

	size = ALIGN(size + size1, align);



	size = ALIGN(max(size, add_size) + children_add_size, align);

	return size;

}
@@ -930,12 +936,10 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, 
		}

	}



	size0 = calculate_iosize(size, min_size, size1,

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

			resource_size(b_res), min_align);

	if (children_add_size > add_size)

		add_size = children_add_size;

	size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :

		calculate_iosize(size, min_size, add_size + size1,

	size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 :

		calculate_iosize(size, min_size, size1, add_size, children_add_size,

			resource_size(b_res), min_align);

	if (!size0 && !size1) {

		if (b_res->start || b_res->end)
@@ -1079,12 +1083,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, 


	min_align = calculate_mem_align(aligns, max_order);

	min_align = max(min_align, window_alignment(bus, b_res->flags));

	size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);

	size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), min_align);

	add_align = max(min_align, add_align);

	if (children_add_size > add_size)

		add_size = children_add_size;

	size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :

		calculate_memsize(size, min_size, add_size,

	size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 :

		calculate_memsize(size, min_size, add_size, children_add_size,

				resource_size(b_res), add_align);

	if (!size0 && !size1) {

		if (b_res->start || b_res->end)

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