PCI: hv: Add a Hyper-V PCI interface driver for software backchannel interface

This interface driver is a helper driver allows other drivers to
have a common interface with the Hyper-V PCI frontend driver.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/pci/controller/pci-hyperv-intf.c b/drivers/pci/controller/pci-hyperv-intf.c
new file mode 100644
index 000000000000..cc96be450360
--- /dev/null
+++ b/drivers/pci/controller/pci-hyperv-intf.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Author:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *
+ * This small module is a helper driver allows other drivers to
+ * have a common interface with the Hyper-V PCI frontend driver.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/hyperv.h>
+
+struct hyperv_pci_block_ops hvpci_block_ops;
+EXPORT_SYMBOL_GPL(hvpci_block_ops);
+
+int hyperv_read_cfg_blk(struct pci_dev *dev, void *buf, unsigned int buf_len,
+			unsigned int block_id, unsigned int *bytes_returned)
+{
+	if (!hvpci_block_ops.read_block)
+		return -EOPNOTSUPP;
+
+	return hvpci_block_ops.read_block(dev, buf, buf_len, block_id,
+					  bytes_returned);
+}
+EXPORT_SYMBOL_GPL(hyperv_read_cfg_blk);
+
+int hyperv_write_cfg_blk(struct pci_dev *dev, void *buf, unsigned int len,
+			 unsigned int block_id)
+{
+	if (!hvpci_block_ops.write_block)
+		return -EOPNOTSUPP;
+
+	return hvpci_block_ops.write_block(dev, buf, len, block_id);
+}
+EXPORT_SYMBOL_GPL(hyperv_write_cfg_blk);
+
+int hyperv_reg_block_invalidate(struct pci_dev *dev, void *context,
+				void (*block_invalidate)(void *context,
+							 u64 block_mask))
+{
+	if (!hvpci_block_ops.reg_blk_invalidate)
+		return -EOPNOTSUPP;
+
+	return hvpci_block_ops.reg_blk_invalidate(dev, context,
+						  block_invalidate);
+}
+EXPORT_SYMBOL_GPL(hyperv_reg_block_invalidate);
+
+static void __exit exit_hv_pci_intf(void)
+{
+}
+
+static int __init init_hv_pci_intf(void)
+{
+	return 0;
+}
+
+module_init(init_hv_pci_intf);
+module_exit(exit_hv_pci_intf);
+
+MODULE_DESCRIPTION("Hyper-V PCI Interface");
+MODULE_LICENSE("GPL v2");