/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -596,6 +596,14 @@ int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 	if (!epc_features)
 		return -EINVAL;
 
+	if (epf_bar->num_submap && !epf_bar->submap)
+		return -EINVAL;
+
+	if (epf_bar->num_submap &&
+	    !(epc_features->dynamic_inbound_mapping &&
+	      epc_features->subrange_mapping))
+		return -EINVAL;
+
 	if (epc_features->bar[bar].type == BAR_RESIZABLE &&
 	    (epf_bar->size < SZ_1M || (u64)epf_bar->size > (SZ_128G * 1024)))
 		return -EINVAL;
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 4c8516756c568..c021c7af175fd 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -227,6 +227,9 @@ struct pci_epc_bar_desc {
  *                           inbound mappings for an already configured BAR
  *                           (i.e. allow calling pci_epc_set_bar() again
  *                           without first calling pci_epc_clear_bar())
+ * @subrange_mapping: indicate if the EPC device can map inbound subranges for a
+ *                    BAR. This feature depends on @dynamic_inbound_mapping
+ *                    feature.
  * @msi_capable: indicate if the endpoint function has MSI capability
  * @msix_capable: indicate if the endpoint function has MSI-X capability
  * @intx_capable: indicate if the endpoint can raise INTx interrupts
@@ -236,6 +239,7 @@ struct pci_epc_bar_desc {
 struct pci_epc_features {
 	unsigned int	linkup_notifier : 1;
 	unsigned int	dynamic_inbound_mapping : 1;
+	unsigned int	subrange_mapping : 1;
 	unsigned int	msi_capable : 1;
 	unsigned int	msix_capable : 1;
 	unsigned int	intx_capable : 1;
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 48f68c4dcfa5e..7737a7c03260d 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -110,6 +110,22 @@ struct pci_epf_driver {
 
 #define to_pci_epf_driver(drv) container_of_const((drv), struct pci_epf_driver, driver)
 
+/**
+ * struct pci_epf_bar_submap - BAR subrange for inbound mapping
+ * @phys_addr: target physical/DMA address for this subrange
+ * @size: the size of the subrange to be mapped
+ *
+ * When pci_epf_bar.num_submap is >0, pci_epf_bar.submap describes the
+ * complete BAR layout. This allows an EPC driver to program multiple
+ * inbound translation windows for a single BAR when supported by the
+ * controller. The array order defines the BAR layout (submap[0] at offset
+ * 0, and each immediately follows the previous one).
+ */
+struct pci_epf_bar_submap {
+	dma_addr_t	phys_addr;
+	size_t		size;
+};
+
 /**
  * struct pci_epf_bar - represents the BAR of EPF device
  * @phys_addr: physical address that should be mapped to the BAR
@@ -119,6 +135,9 @@ struct pci_epf_driver {
  *            requirement
  * @barno: BAR number
  * @flags: flags that are set for the BAR
+ * @num_submap: number of entries in @submap
+ * @submap: array of subrange descriptors allocated by the caller. See
+ *          struct pci_epf_bar_submap for the semantics in detail.
  */
 struct pci_epf_bar {
 	dma_addr_t	phys_addr;
@@ -127,6 +146,10 @@ struct pci_epf_bar {
 	size_t		mem_size;
 	enum pci_barno	barno;
 	int		flags;
+
+	/* Optional sub-range mapping */
+	unsigned int	num_submap;
+	struct pci_epf_bar_submap	*submap;
 };
 
 /**
-- 
2.51.0[PATCH 6.19 395/781] PCI: endpoint: Add BAR subrange mapping supportGreg Kroah-Hartman <gregkh@linuxfoundation.org> undefinedstable@vger.kernel.org undefined undefined undefined undefined undefined undefinedŇ
†™U