This is a note to let you know that I've just added the patch titled
PCI: Equalize hotplug memory and io for occupied and empty slots
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-equalize-hotplug-memory-and-io-for-occupied-and-.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d1812bbc036ea102a7b8cff2ca667cd3107247bd
Author: Jon Derrick <jonathan.derrick@xxxxxxxxx>
Date: Tue Sep 25 12:39:06 2018 -0600
PCI: Equalize hotplug memory and io for occupied and empty slots
[ Upstream commit de3ffa301142bf8802a7b0de17f9985acde5c223 ]
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@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Stable-dep-of: 903534fa7d30 ("PCI: Fix resource double counting on remove & rescan")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 87c8190de622f..7f58360b42b7e 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -774,6 +774,8 @@ 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)
{
@@ -786,15 +788,18 @@ 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)
{
@@ -804,7 +809,8 @@ 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;
}
@@ -893,12 +899,10 @@ 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)
@@ -1042,12 +1046,10 @@ 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)
