NTB: switchtec_ntb: Introduce initial NTB driver

Seeing the Switchtec NTB hardware shares the same endpoint as the
management endpoint we utilize the class_interface API to register
an NTB driver for every Switchtec device in the system that has the
NTB class code.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

diff --git a/MAINTAINERS b/MAINTAINERS
index 07d288f..2d78153 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10348,6 +10348,7 @@ F:      Documentation/ABI/testing/sysfs-class-switchtec
 F:     drivers/pci/switch/switchtec*
 F:     include/uapi/linux/switchtec_ioctl.h
 F:     include/linux/switchtec.h
+F:     drivers/ntb/hw/mscc/
 
 PCI DRIVER FOR MVEBU (Marvell Armada 370 and Armada XP SOC support)
 M:     Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

diff --git a/drivers/ntb/hw/Kconfig b/drivers/ntb/hw/Kconfig
index a89243c..e51b581 100644 (file)
--- a/drivers/ntb/hw/Kconfig
+++ b/drivers/ntb/hw/Kconfig
@@ -1,3 +1,4 @@
 source "drivers/ntb/hw/amd/Kconfig"
 source "drivers/ntb/hw/idt/Kconfig"
 source "drivers/ntb/hw/intel/Kconfig"
+source "drivers/ntb/hw/mscc/Kconfig"

diff --git a/drivers/ntb/hw/Makefile b/drivers/ntb/hw/Makefile
index 87332c3..923c442 100644 (file)
--- a/drivers/ntb/hw/Makefile
+++ b/drivers/ntb/hw/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_NTB_AMD)  += amd/
 obj-$(CONFIG_NTB_IDT)  += idt/
 obj-$(CONFIG_NTB_INTEL)        += intel/
+obj-$(CONFIG_NTB_SWITCHTEC) += mscc/

diff --git a/drivers/ntb/hw/mscc/Kconfig b/drivers/ntb/hw/mscc/Kconfig
new file mode 100644 (file)
index 0000000..013ed67
--- /dev/null
+++ b/drivers/ntb/hw/mscc/Kconfig
@@ -0,0 +1,9 @@
+config NTB_SWITCHTEC
+       tristate "MicroSemi Switchtec Non-Transparent Bridge Support"
+       select PCI_SW_SWITCHTEC
+       help
+        Enables NTB support for Switchtec PCI switches. This also
+        selects the Switchtec management driver as they share the same
+        hardware interface.
+
+        If unsure, say N.

diff --git a/drivers/ntb/hw/mscc/Makefile b/drivers/ntb/hw/mscc/Makefile
new file mode 100644 (file)
index 0000000..064686e
--- /dev/null
+++ b/drivers/ntb/hw/mscc/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_SWITCHTEC) += ntb_hw_switchtec.o

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
new file mode 100644 (file)
index 0000000..253efba
--- /dev/null
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -0,0 +1,81 @@
+/*
+ * Microsemi Switchtec(tm) PCIe Management Driver
+ * Copyright (c) 2017, Microsemi Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/switchtec.h>
+#include <linux/module.h>
+
+MODULE_DESCRIPTION("Microsemi Switchtec(tm) NTB Driver");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Microsemi Corporation");
+
+struct switchtec_ntb {
+       struct switchtec_dev *stdev;
+};
+
+static int switchtec_ntb_add(struct device *dev,
+                            struct class_interface *class_intf)
+{
+       struct switchtec_dev *stdev = to_stdev(dev);
+       struct switchtec_ntb *sndev;
+
+       stdev->sndev = NULL;
+
+       if (stdev->pdev->class != MICROSEMI_NTB_CLASSCODE)
+               return -ENODEV;
+
+       sndev = kzalloc_node(sizeof(*sndev), GFP_KERNEL, dev_to_node(dev));
+       if (!sndev)
+               return -ENOMEM;
+
+       sndev->stdev = stdev;
+
+       stdev->sndev = sndev;
+       dev_info(dev, "NTB device registered");
+
+       return 0;
+}
+
+void switchtec_ntb_remove(struct device *dev,
+                         struct class_interface *class_intf)
+{
+       struct switchtec_dev *stdev = to_stdev(dev);
+       struct switchtec_ntb *sndev = stdev->sndev;
+
+       if (!sndev)
+               return;
+
+       stdev->sndev = NULL;
+       kfree(sndev);
+       dev_info(dev, "ntb device unregistered");
+}
+
+static struct class_interface switchtec_interface  = {
+       .add_dev = switchtec_ntb_add,
+       .remove_dev = switchtec_ntb_remove,
+};
+
+static int __init switchtec_ntb_init(void)
+{
+       switchtec_interface.class = switchtec_class;
+       return class_interface_register(&switchtec_interface);
+}
+module_init(switchtec_ntb_init);
+
+static void __exit switchtec_ntb_exit(void)
+{
+       class_interface_unregister(&switchtec_interface);
+}
+module_exit(switchtec_ntb_exit);

diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index 807569e..58edc24 100644 (file)
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -1275,6 +1275,9 @@ static int switchtec_pci_probe(struct pci_dev *pdev,
        struct switchtec_dev *stdev;
        int rc;
 
+       if (pdev->class == MICROSEMI_NTB_CLASSCODE)
+               request_module_nowait("ntb_hw_switchtec");
+
        stdev = stdev_create(pdev);
        if (IS_ERR(stdev))
                return PTR_ERR(stdev);

diff --git a/include/linux/switchtec.h b/include/linux/switchtec.h
index d815994..09d73d0 100644 (file)
--- a/include/linux/switchtec.h
+++ b/include/linux/switchtec.h
@@ -320,6 +320,8 @@ struct pff_csr_regs {
        u32 reserved4[174];
 } __packed;
 
+struct switchtec_ntb;
+
 struct switchtec_dev {
        struct pci_dev *pdev;
        struct device dev;
@@ -357,6 +359,8 @@ struct switchtec_dev {
        struct work_struct link_event_work;
        void (*link_notifier)(struct switchtec_dev *stdev);
        u8 link_event_count[SWITCHTEC_MAX_PFF_CSR];
+
+       struct switchtec_ntb *sndev;
 };
 
 static inline struct switchtec_dev *to_stdev(struct device *dev)