[PATCH RFC 1/2] drivers: pci: fix window allocation order wrt bus_range filtering

[Lorenzo Pieralisi]

The number of windows allocated for the host bridge depends on the
bus resource. Instead of first allocating the windows and then
limit the bus resource, this patch reshuffles the code so that if any
limitation is applied to the bus resource it is taken into account in
the windows allocation.

Cc: Will Deacon <will.deacon at arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
---
 drivers/pci/host/pci-host-generic.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index 3d2076f..1e1a80f 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -276,17 +276,17 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
 		return err;
 	}
 
-	pci->cfg.win = devm_kcalloc(dev, resource_size(&pci->cfg.bus_range),
-				    sizeof(*pci->cfg.win), GFP_KERNEL);
-	if (!pci->cfg.win)
-		return -ENOMEM;
-
 	/* 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;
 	pci->cfg.bus_range.end = min_t(resource_size_t, pci->cfg.bus_range.end,
 				       bus_max);
 
+	pci->cfg.win = devm_kcalloc(dev, resource_size(&pci->cfg.bus_range),
+				    sizeof(*pci->cfg.win), GFP_KERNEL);
+	if (!pci->cfg.win)
+		return -ENOMEM;
+
 	/* Map our Configuration Space windows */
 	if (!devm_request_mem_region(dev, pci->cfg.res.start,
 				     resource_size(&pci->cfg.res),
-- 
2.1.2