[PATCH 2/8] pci: Calculate right add_size
From: Yinghai Lu
Date: Sat Oct 15 2011 - 21:32:16 EST
During debug one SRIOV enabled hotplug, found add_size is not passed properly.
the device have devices under two level bridges..
+-[0000:80]-+-00.0-[81-8f]--
| +-01.0-[90-9f]--
| +-02.0-[a0-af]----00.0-[a1-a3]--+-02.0-[a2]--+-00.0 Oracle Corporation Device
| | \-03.0-[a3]--+-00.0 Oracle Corporation Device
so later parent bridge will not try to add big range.
[ 557.455077] pci 0000:a0:00.0: BAR 14: assigned [mem 0xf9000000-0xf93fffff]
[ 557.461974] pci 0000:a0:00.0: BAR 15: assigned [mem 0xf6000000-0xf61fffff pref]
[ 557.469340] pci 0000:a1:02.0: BAR 14: assigned [mem 0xf9000000-0xf91fffff]
[ 557.476231] pci 0000:a1:02.0: BAR 15: assigned [mem 0xf6000000-0xf60fffff pref]
[ 557.483582] pci 0000:a1:03.0: BAR 14: assigned [mem 0xf9200000-0xf93fffff]
[ 557.490468] pci 0000:a1:03.0: BAR 15: assigned [mem 0xf6100000-0xf61fffff pref]
[ 557.497833] pci 0000:a1:03.0: BAR 14: can't assign mem (size 0x200000)
[ 557.504378] pci 0000:a1:03.0: failed to add optional resources res=[mem 0xf9200000-0xf93fffff]
[ 557.513026] pci 0000:a1:02.0: BAR 14: can't assign mem (size 0x200000)
[ 557.519578] pci 0000:a1:02.0: failed to add optional resources res=[mem 0xf9000000-0xf91fffff]
it turns out We did not calculate size1 properly.
static resource_size_t calculate_memsize(resource_size_t size,
resource_size_t min_size,
resource_size_t size1,
resource_size_t old_size,
resource_size_t align)
{
if (size < min_size)
size = min_size;
if (old_size == 1 )
old_size = 0;
if (size < old_size)
size = old_size;
size = ALIGN(size + size1, align);
return size;
}
We should not pass add_size with min_size in calculate_memsize.
that will make add_size not contribute final add_size.
Just pass add_size with size1 to calculate_memsize()
With this change, We should have chance to remove extra addon in pci_reassign_resource...
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/setup-bus.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -612,7 +616,7 @@ static void pbus_size_io(struct pci_bus
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,
+ calculate_iosize(size, min_size, add_size + size1,
resource_size(b_res), 4096);
if (!size0 && !size1) {
if (b_res->start || b_res->end)
@@ -726,7 +734,7 @@ static int pbus_size_mem(struct pci_bus
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, 0,
+ calculate_memsize(size, min_size, add_size,
resource_size(b_res), min_align);
if (!size0 && !size1) {
if (b_res->start || b_res->end)
Index: linux-2.6/drivers/pci/setup-res.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-res.c
+++ linux-2.6/drivers/pci/setup-res.c
@@ -232,11 +232,12 @@ int pci_reassign_resource(struct pci_dev
return -EINVAL;
}
- new_size = resource_size(res) + addsize + min_align;
+ /* already aligned with min_align */
+ new_size = resource_size(res) + addsize;
ret = _pci_assign_resource(dev, resno, new_size, min_align);
if (!ret) {
res->flags &= ~IORESOURCE_STARTALIGN;
- dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);
+ dev_info(&dev->dev, "BAR %d: reassigned %pR\n", resno, res);
if (resno < PCI_BRIDGE_RESOURCES)
pci_update_resource(dev, resno);
}
--
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