From: David Daney <david.daney@xxxxxxxxxx>
There are two problems with the bus_max calculation:
1) The u8 data type can overflow for large config space windows.
2) The calculation is incorrect for a bus range that doesn't start at
zero.
Since the configuration space is relative to bus zero, make bus_max
just be the size of the config window scaled by bus_shift. Then clamp
it to a maximum of 255, per PCI. Use a data type of int to avoid
overflow problems.
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
drivers/pci/host/pci-host-generic.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index cd6f898..fce5bf7 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -164,7 +164,7 @@ out_release_res:
static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
{
int err;
- u8 bus_max;
+ int bus_max;
resource_size_t busn;
struct resource *bus_range;
struct device *dev = pci->host.dev.parent;
@@ -177,8 +177,9 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
}
/* Limit the bus-range to fit within reg */
- bus_max = pci->cfg.bus_range->start +
- (resource_size(&pci->cfg.res) >> pci->cfg.ops.bus_shift) - 1;
+ bus_max = (resource_size(&pci->cfg.res) >> pci->cfg.ops.bus_shift) - 1;
+ if (bus_max > 255)
+ bus_max = 255;
pci->cfg.bus_range->end = min_t(resource_size_t,
pci->cfg.bus_range->end, bus_max);
--
1.7.11.7
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