[PATCH v3 4/6] PCI: endpoint: Cleanup get_msix() callback

[Niklas Cassel <cassel@kernel.org>]

The kdoc for pci_epc_get_msix() says:
"Invoke to get the number of MSI-X interrupts allocated by the RC"
the kdoc for the callback pci_epc_ops->get_msix() says:
"ops to get the number of MSI-X interrupts allocated by the RC from the
MSI-X capability register"

pci_epc_ops->get_msix() does however return the number of interrupts
in the encoding as defined by the Table Size field.

Nowhere in the kdoc does it say that the returned number of interrupts
is in Table Size encoding.

Thus, it is very confusing that the wrapper function (pci_epc_get_msix())
and the callback function (pci_epc_ops->get_msix()) don't return the same
value.

Cleanup the API so that the wrapper function and the callback function
will have the same semantics, i.e. return the number of interrupts,
regardless of the internal encoding of that value.

Cc: <stable+noautosel@kernel.org> # this is simply a cleanup
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/pci/controller/cadence/pcie-cadence-ep.c | 2 +-
 drivers/pci/controller/dwc/pcie-designware-ep.c  | 2 +-
 drivers/pci/endpoint/pci-epc-core.c              | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index 78b4d009cd04..569cb7481d45 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -281,7 +281,7 @@ static int cdns_pcie_ep_get_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
 
 	val &= PCI_MSIX_FLAGS_QSIZE;
 
-	return val;
+	return val + 1;
 }
 
 static int cdns_pcie_ep_set_msix(struct pci_epc *epc, u8 fn, u8 vfn,
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 03597551f4cd..307c862588a4 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -575,7 +575,7 @@ static int dw_pcie_ep_get_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
 
 	val &= PCI_MSIX_FLAGS_QSIZE;
 
-	return val;
+	return val + 1;
 }
 
 static int dw_pcie_ep_set_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index cc1456bd188e..092b14918b46 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -355,7 +355,7 @@ int pci_epc_get_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
 	if (interrupt < 0)
 		return 0;
 
-	return interrupt + 1;
+	return interrupt;
 }
 EXPORT_SYMBOL_GPL(pci_epc_get_msix);
 
-- 
2.49.0