Patch "PCI: endpoint: Add helper to get first unreserved BAR" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    PCI: endpoint: Add helper to get first unreserved BAR

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pci-endpoint-add-helper-to-get-first-unreserved-bar.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a15ca4dc80ee6fe71010ff55e80ab03771f66da6
Author: Kishon Vijay Abraham I <kishon@xxxxxx>
Date:   Mon Jan 14 16:45:05 2019 +0530

    PCI: endpoint: Add helper to get first unreserved BAR
    
    [ Upstream commit 1e9efe6c9976552e88c6e6feaca3a78b8cf5aaf6 ]
    
    Add a helper function pci_epc_get_first_free_bar() to get the first
    unreserved BAR that can be used for endpoint function.
    
    Tested-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
    Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
    Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
    Stable-dep-of: 7e6689b34a81 ("PCI: rockchip: Set address alignment for endpoint mode")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 5a099479d9aba..e4712a0f249cb 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -83,6 +83,29 @@ struct pci_epc *pci_epc_get(const char *epc_name)
 }
 EXPORT_SYMBOL_GPL(pci_epc_get);
 
+/**
+ * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
+ * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
+ *
+ * Invoke to get the first unreserved BAR that can be used for endpoint
+ * function. For any incorrect value in reserved_bar return '0'.
+ */
+unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
+					*epc_features)
+{
+	int free_bar;
+
+	if (!epc_features)
+		return 0;
+
+	free_bar = ffz(epc_features->reserved_bar);
+	if (free_bar > 5)
+		return 0;
+
+	return free_bar;
+}
+EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
+
 /**
  * pci_epc_get_features() - get the features supported by EPC
  * @epc: the features supported by *this* EPC device will be returned
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index fcd5e50475468..dcaecf715b1cf 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -183,6 +183,8 @@ int pci_epc_start(struct pci_epc *epc);
 void pci_epc_stop(struct pci_epc *epc);
 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 						    u8 func_no);
+unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
+					*epc_features);
 struct pci_epc *pci_epc_get(const char *epc_name);
 void pci_epc_put(struct pci_epc *epc);