With enabled movable BARs, bridge windows are recalculated during each PCI
rescan. There may be fixed BARs below a bridge: these areas are represented
by the .fixed_range field in struct pci_bus.
When choosing a start address for a bridge window, it should be not just a
lowest possible address: this window must cover every underlying fixed BAR.
If a size of the bridge window is equal to its fixed range, it can only be
assigned to the start of this range. But if a bridge window size is larger,
its lowest possible address equals to (fixed_range.end - bus_size + 1).
Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@xxxxxxxxx>
---
drivers/pci/bus.c | 2 +-
drivers/pci/setup-res.c | 30 ++++++++++++++++++++++++++++--
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 3cef835b375f..c716210b62c5 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -192,7 +192,7 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
* this is an already-configured bridge window, its start
* overrides "min".
*/
- if (avail.start)
+ if (min_used < avail.start)
min_used = avail.start;
max = avail.end;
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 432f3b084f94..ee192e731119 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -247,11 +247,27 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
int resno, resource_size_t size, resource_size_t align)
{
struct resource *res = dev->resource + resno;
+ struct resource *fixed_range = NULL;
resource_size_t min;
int ret;
min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
+ if (pci_can_move_bars && dev->subordinate && resno >= PCI_BRIDGE_RESOURCES) {
+ struct pci_bus *child_bus = dev->subordinate;
+ int win_no = resno - PCI_BRIDGE_RESOURCES;
+
+ fixed_range = &child_bus->fixed_range[win_no];
+ if (pci_fixed_range_valid(fixed_range)) {
+ if (size <= resource_size(fixed_range))
+ min = fixed_range->start;
+ else
+ min = fixed_range->end - size + 1;
+ } else {
+ fixed_range = NULL;
+ }
+ }
+
/*
* First, try exact prefetching match. Even if a 64-bit
* prefetchable bridge window is below 4GB, we can't put a 32-bit
@@ -263,7 +279,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
pcibios_align_resource, dev);
if (ret == 0)
- return 0;
+ goto check_fixed;
/*
* If the prefetchable window is only 32 bits wide, we can put
@@ -275,7 +291,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
IORESOURCE_PREFETCH,
pcibios_align_resource, dev);
if (ret == 0)
- return 0;
+ goto check_fixed;
}
/*
@@ -288,6 +304,16 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
pcibios_align_resource, dev);
+check_fixed:
+ if (ret == 0 && fixed_range &&
+ (res->start > fixed_range->start ||
+ res->end < fixed_range->end)) {
+ dev_err(&bus->dev, "fixed area %pR for %s doesn't fit in the allocated %pR",
+ fixed_range, dev_name(&dev->dev), res);
+ release_resource(res);
+ return -1;
+ }
+
return ret;
}
--
2.24.1
