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: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Jon Derrick 2018-09-25 12:39:06 -06:00 committed by Bjorn Helgaas
parent 26ad34d510
commit de3ffa3011

View File

@ -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)