PCI: endpoint: Drop only_64bit on reserved BARs

The definition of a reserved BAR is that EPF drivers should not touch
them.

The definition of only_64bit is that the EPF driver must configure this
BAR as 64-bit. (An EPF driver is not allowed to choose if this BAR should
be configured as 32-bit or 64-bit.)

Thus, it does not make sense to put only_64bit of a BAR that EPF drivers
are not allow to touch.

Drop the only_64bit property from hardware descriptions that are of type
reserved BAR.
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20240216134524.1142149-3-cassel@kernel.orgSigned-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/pci/controller/dwc/pci-keystone.c

@@ -924,7 +924,7 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = true,
-	.bar[BAR_0] = { .type = BAR_RESERVED, .only_64bit = true, },
+	.bar[BAR_0] = { .type = BAR_RESERVED, },
 	.bar[BAR_1] = { .type = BAR_RESERVED, },
 	.bar[BAR_2] = { .type = BAR_FIXED, .fixed_size = SZ_1M, },
 	.bar[BAR_3] = { .type = BAR_FIXED, .fixed_size = SZ_64K, },

drivers/pci/controller/dwc/pcie-uniphier-ep.c

@@ -415,7 +415,7 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {
 		.bar[BAR_1] = { .type = BAR_RESERVED, },
 		.bar[BAR_2] = { .only_64bit = true, },
 		.bar[BAR_3] = { .type = BAR_RESERVED, },
-		.bar[BAR_4] = { .type = BAR_RESERVED, .only_64bit = true, },
+		.bar[BAR_4] = { .type = BAR_RESERVED, },
 		.bar[BAR_5] = { .type = BAR_RESERVED, },
 	},
 };

drivers/pci/endpoint/pci-epc-core.c

@@ -120,13 +120,6 @@ enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
 		/* If the BAR is not reserved, return it. */
 		if (epc_features->bar[i].type != BAR_RESERVED)
 			return i;
-
-		/*
-		 * If the BAR is reserved, and marked as 64-bit only, then the
-		 * succeeding BAR is also reserved.
-		 */
-		if (epc_features->bar[i].only_64bit)
-			i++;
 	}
 
 	return NO_BAR;

include/linux/pci-epc.h

@@ -164,6 +164,11 @@ enum pci_epc_bar_type {
  *		should be configured as 32-bit or 64-bit, the EPF driver must
  *		configure this BAR as 64-bit. Additionally, the BAR succeeding
  *		this BAR must be set to type BAR_RESERVED.
+ *
+ *		only_64bit should not be set on a BAR of type BAR_RESERVED.
+ *		(If BARx is a 64-bit BAR that an EPF driver is not allowed to
+ *		touch, then both BARx and BARx+1 must be set to type
+ *		BAR_RESERVED.)
  */
 struct pci_epc_bar_desc {
 	enum pci_epc_bar_type type;