[PATCH v7 02/18] PCI: endpoint: Make *_get_first_free_bar() take into account 64 bit BAR

Kishon Vijay Abraham I
2020-09-30T15:35:57Z

pci_epc_get_first_free_bar() uses only "reserved_bar" member in
epc_features to get the first unreserved BAR. However if the
reserved BAR is also a 64-bit BAR, then the next BAR shouldn't be
returned (since 64-bit BAR uses two BARs).

Make pci_epc_get_first_free_bar() take into account 64 bit BAR while
returning the first free unreserved BAR.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/pci/endpoint/pci-epc-core.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index cadd3db0cbb0..25e57672e1a1 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -93,12 +93,20 @@ EXPORT_SYMBOL_GPL(pci_epc_get);
unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
*epc_features)
{
- int free_bar;
+ unsigned long free_bar;

if (!epc_features)
return 0;

- free_bar = ffz(epc_features->reserved_bar);
+ /* Find if the reserved BAR is also a 64-bit BAR */
+ free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
+
+ /* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */
+ free_bar <<= 1;
+ free_bar |= epc_features->reserved_bar;
+
+ /* Now find the free BAR */
+ free_bar = ffz(free_bar);
if (free_bar > 5)
return 0;

--
2.17.1