[RFC 1/1] MicroSemi Switchtec management interface driver

Logan Gunthorpe
2016-12-17T17:45:39Z

Microsemi's "Switchtec" line of PCI switch devices is already
supported by the kernel with standard PCI switch drivers. However, the
Switchtec device advertises a special management endpoint which
enables some additional functionality. This includes:

* Packet and Byte Counters
* Firmware Upgrades
* Event and Error logs
* Querying port link status
* Custom user firmware commands

This patch introduces the switchtec kernel module which provides
pci driver that exposes a char device. The char device provides
userspace access to this interface through read, write and (optionally)
poll calls. Currently no ioctls have been implemented but a couple
may be added in a later revision.

A short text file is provided which documents the switchtec driver
and outlines the semantics of using the char device.

A WIP userspace tool which utilizes this interface is available
at [1]. This tool takes
inspiration (and borrows some code) from nvme-cli [2].

[1] https://github.com/sbates130272/switchtec-user
[2] https://github.com/linux-nvme/nvme-cli

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Stephen Bates <stephen.bates@microsemi.com>
---
Documentation/switchtec.txt | 54 +++
MAINTAINERS | 9 +
drivers/pci/Kconfig | 1 +
drivers/pci/Makefile | 1 +
drivers/pci/switch/Kconfig | 13 +
drivers/pci/switch/Makefile | 1 +
drivers/pci/switch/switchtec.c | 824 +++++++++++++++++++++++++++++++++++++++++
drivers/pci/switch/switchtec.h | 119 ++++++
8 files changed, 1022 insertions(+)
create mode 100644 Documentation/switchtec.txt
create mode 100644 drivers/pci/switch/Kconfig
create mode 100644 drivers/pci/switch/Makefile
create mode 100644 drivers/pci/switch/switchtec.c
create mode 100644 drivers/pci/switch/switchtec.h

diff --git a/Documentation/switchtec.txt b/Documentation/switchtec.txt
new file mode 100644
index 0000000..04657ce
--- /dev/null
+++ b/Documentation/switchtec.txt
@@ -0,0 +1,54 @@
+
+Linux Switchtec Support
+========================
+
+Microsemi's "Switchtec" line of PCI switch devices is already
+supported by the kernel with standard PCI switch drivers. However, the
+Switchtec device advertises a special management endpoint which
+enables some additional functionality. This includes:
+
+ * Packet and Byte Counters
+ * Firmware Upgrades
+ * Event and Error logs
+ * Querying port link status
+ * Custom user firmware commands
+
+The switchtec kernel module implements this functionality.
+
+
+
+Interface
+=========
+
+The primary means of communicating with the Switchtec management firmware is
+through the Memory-mapped Remote Procedure Call (MRPC) interface.
+Commands are submitted to the interface with a 4-byte command
+identifier and up to 1KB of command specific data. The firmware will
+respond with a 4 bytes return code and up to 1KB of command specific
+data. The interface only processes a single command at a time.
+
+
+Userspace Interface
+===================
+
+The MRPC interface will be exposed to userspace through a simple char
+device: /dev/switchtec#, one for each management endpoint in the system.
+
+The char device has the following semantics:
+
+ * A write must consist of at least 4 bytes and no more than 1028 bytes.
+ The first four bytes will be interpreted as the command to run and
+ the remainder will be used as the input data. A write will send the
+ command to the firmware to begin processing.
+
+ * Each write must be followed by exactly one read. Any double write will
+ produce an error and any read that doesn't follow a write will
+ produce an error.
+
+ * A read will block until the firmware completes the command and return
+ the four bytes of status plus up to 1024 bytes of output data. (The
+ length will be specified by the size parameter of the read call --
+ reading less than 4 bytes will produce an error.
+
+ * The poll call will also be supported for userspace applications that
+ need to do other things while waiting for the command to complete.
diff --git a/MAINTAINERS b/MAINTAINERS
index 63cefa6..1e21505 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9288,6 +9288,15 @@ S: Maintained
F: Documentation/devicetree/bindings/pci/aardvark-pci.txt
F: drivers/pci/host/pci-aardvark.c

+PCI DRIVER FOR MICROSEMI SWITCHTEC
+M: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
+M: Stephen Bates <stephen.bates@microsemi.com>
+M: Logan Gunthorpe <logang@deltatee.com>
+L: linux-pci@vger.kernel.org
+S: Maintained
+F: Documentation/switchtec.txt
+F: drivers/pci/switch/switchtec*
+
PCI DRIVER FOR NVIDIA TEGRA
M: Thierry Reding <thierry.reding@gmail.com>
L: linux-tegra@vger.kernel.org
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 6555eb7..f72e8c5 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -133,3 +133,4 @@ config PCI_HYPERV

source "drivers/pci/hotplug/Kconfig"
source "drivers/pci/host/Kconfig"
+source "drivers/pci/switch/Kconfig"
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 8db5079..15b46dd 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -68,3 +68,4 @@ ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG

# PCI host controller drivers
obj-y += host/
+obj-y += switch/
diff --git a/drivers/pci/switch/Kconfig b/drivers/pci/switch/Kconfig
new file mode 100644
index 0000000..97f8979
--- /dev/null
+++ b/drivers/pci/switch/Kconfig
@@ -0,0 +1,13 @@
+menu "PCI switch controller drivers"
+ depends on PCI
+
+config PCI_SW_SWITCHTEC
+ tristate "MicroSemi Switchtec PCIe Switch Management Driver"
+ help
+ Enables support for the management interface for the MicroSemi
+ Switchtec series of PCIe switches. Supports userspace access
+ to submit MRPC commands to the switch via /dev/switchtecX
+ devices. See <file:Documentation/switchtec.txt> for more
+ information.
+
+endmenu
diff --git a/drivers/pci/switch/Makefile b/drivers/pci/switch/Makefile
new file mode 100644
index 0000000..37d8cfb
--- /dev/null
+++ b/drivers/pci/switch/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_PCI_SW_SWITCHTEC) += switchtec.o
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
new file mode 100644
index 0000000..bd05b29
--- /dev/null
+++ b/drivers/pci/switch/switchtec.c
@@ -0,0 +1,824 @@
+/*
+ * Microsemi Switchtec(tm) PCIe Management Driver
+ * Copyright (c) 2016, 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 "switchtec.h"
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+
+MODULE_DESCRIPTION("Microsemi Switchtec(tm) PCI-E Management Driver");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Microsemi Corporation");
+
+static int switchtec_major;
+static struct class *switchtec_class;
+static DEFINE_IDA(switchtec_minor_ida);
+
+static int __match_devt(struct device *dev, const void *data)
+{
+ const dev_t *devt = data;
+
+ return dev->devt == *devt;
+}
+
+static struct device *switchtec_dev_find(dev_t dev_t)
+{
+ return class_find_device(switchtec_class, NULL, &dev_t, __match_devt);
+}
+
+struct switchtec_user {
+ struct switchtec_dev *stdev;
+
+ enum mrpc_state {
+ MRPC_IDLE = 0,
+ MRPC_QUEUED,
+ MRPC_RUNNING,
+ MRPC_DONE,
+ } state;
+
+ struct completion comp;
+ struct kref kref;
+ struct list_head list;
+
+ u32 cmd;
+ u32 status;
+ u32 return_code;
+ size_t data_len;
+ unsigned char data[SWITCHTEC_MRPC_PAYLOAD_SIZE];
+};
+
+static void stuser_free(struct kref *kref)
+{
+ struct switchtec_user *stuser;
+
+ stuser = container_of(kref, struct switchtec_user, kref);
+
+ kfree(stuser);
+}
+
+static void stuser_init(struct switchtec_user *stuser,
+ struct switchtec_dev *stdev)
+{
+ stuser->stdev = stdev;
+ kref_init(&stuser->kref);
+ INIT_LIST_HEAD(&stuser->list);
+ init_completion(&stuser->comp);
+}
+
+static void stuser_put(struct switchtec_user *stuser)
+{
+ kref_put(&stuser->kref, stuser_free);
+}
+
+static void stuser_set_state(struct switchtec_user *stuser,
+ enum mrpc_state state)
+{
+ const char * const state_names[] = {
+ [MRPC_IDLE] = "IDLE",
+ [MRPC_QUEUED] = "QUEUED",
+ [MRPC_RUNNING] = "RUNNING",
+ [MRPC_DONE] = "DONE",
+ };
+
+ stuser->state = state;
+
+ dev_dbg(stdev_dev(stuser->stdev), "stuser state %p -> %s",
+ stuser, state_names[state]);
+}
+
+static void mrpc_complete_cmd(struct switchtec_dev *stdev);
+
+static void mrpc_cmd_submit(struct switchtec_dev *stdev)
+{
+ /* requires the mrpc_mutex to already be held when called */
+
+ struct switchtec_user *stuser;
+
+ if (stdev->mrpc_busy)
+ return;
+
+ if (list_empty(&stdev->mrpc_queue))
+ return;
+
+ stuser = list_entry(stdev->mrpc_queue.next, struct switchtec_user,
+ list);
+
+ stuser_set_state(stuser, MRPC_RUNNING);
+ stdev->mrpc_busy = 1;
+ memcpy_toio(&stdev->mmio_mrpc->input_data,
+ stuser->data, stuser->data_len);
+ iowrite32(stuser->cmd, &stdev->mmio_mrpc->cmd);
+
+ stuser->status = ioread32(&stdev->mmio_mrpc->status);
+ if (stuser->status != SWITCHTEC_MRPC_STATUS_INPROGRESS)
+ mrpc_complete_cmd(stdev);
+
+ schedule_delayed_work(&stdev->mrpc_timeout,
+ msecs_to_jiffies(500));
+}
+
+static void mrpc_queue_cmd(struct switchtec_user *stuser)
+{
+ /* requires the mrpc_mutex to already be held when called */
+
+ struct switchtec_dev *stdev = stuser->stdev;
+
+ kref_get(&stuser->kref);
+ stuser_set_state(stuser, MRPC_QUEUED);
+ init_completion(&stuser->comp);
+ list_add_tail(&stuser->list, &stdev->mrpc_queue);
+
+ mrpc_cmd_submit(stdev);
+}
+
+static void mrpc_complete_cmd(struct switchtec_dev *stdev)
+{
+ /* requires the mrpc_mutex to already be held when called */
+ struct switchtec_user *stuser;
+
+ if (list_empty(&stdev->mrpc_queue))
+ return;
+
+ stuser = list_entry(stdev->mrpc_queue.next, struct switchtec_user,
+ list);
+
+ stuser->status = ioread32(&stdev->mmio_mrpc->status);
+ if (stuser->status == SWITCHTEC_MRPC_STATUS_INPROGRESS)
+ return;
+
+ stuser_set_state(stuser, MRPC_DONE);
+ stuser->return_code = 0;
+
+ if (stuser->status != SWITCHTEC_MRPC_STATUS_DONE)
+ goto out;
+
+ stuser->return_code = ioread32(&stdev->mmio_mrpc->ret_value);
+ if (stuser->return_code != 0)
+ goto out;
+
+ memcpy_fromio(stuser->data, &stdev->mmio_mrpc->output_data,
+ sizeof(stuser->data));
+
+out:
+ complete_all(&stuser->comp);
+ list_del_init(&stuser->list);
+ stuser_put(stuser);
+ stdev->mrpc_busy = 0;
+
+ mrpc_cmd_submit(stdev);
+}
+
+static void mrpc_event_work(struct work_struct *work)
+{
+ struct switchtec_dev *stdev;
+
+ stdev = container_of(work, struct switchtec_dev, mrpc_work);
+
+ dev_dbg(stdev_dev(stdev), "%s\n", __func__);
+
+ mutex_lock(&stdev->mrpc_mutex);
+ cancel_delayed_work(&stdev->mrpc_timeout);
+ mrpc_complete_cmd(stdev);
+ mutex_unlock(&stdev->mrpc_mutex);
+}
+
+static void mrpc_timeout_work(struct work_struct *work)
+{
+ struct switchtec_dev *stdev;
+ u32 status;
+
+ stdev = container_of(work, struct switchtec_dev, mrpc_timeout.work);
+
+ dev_dbg(stdev_dev(stdev), "%s\n", __func__);
+
+ mutex_lock(&stdev->mrpc_mutex);
+
+ status = ioread32(&stdev->mmio_mrpc->status);
+ if (status == SWITCHTEC_MRPC_STATUS_INPROGRESS) {
+ schedule_delayed_work(&stdev->mrpc_timeout,
+ msecs_to_jiffies(500));
+ goto out;
+ }
+
+ mrpc_complete_cmd(stdev);
+
+out:
+ mutex_unlock(&stdev->mrpc_mutex);
+}
+
+static int switchtec_register_dev(struct switchtec_dev *stdev)
+{
+ int rc;
+ int minor;
+ struct device *dev;
+ dev_t devt;
+
+ minor = ida_simple_get(&switchtec_minor_ida, 0, 0,
+ GFP_KERNEL);
+ if (minor < 0)
+ return minor;
+
+ devt = MKDEV(switchtec_major, minor);
+ dev = device_create(switchtec_class, &stdev->pdev->dev,
+ devt, stdev, "switchtec%d", minor);
+ if (IS_ERR(dev)) {
+ rc = PTR_ERR(dev);
+ goto err_create;
+ }
+
+ stdev->dev = dev;
+
+ return 0;
+
+err_create:
+ ida_simple_remove(&switchtec_minor_ida, minor);
+
+ return rc;
+}
+
+static void switchtec_unregister_dev(struct switchtec_dev *stdev)
+{
+ device_unregister(stdev_dev(stdev));
+ ida_simple_remove(&switchtec_minor_ida, MINOR(stdev_dev(stdev)->devt));
+}
+
+static void stdev_free(struct kref *kref)
+{
+ struct switchtec_dev *stdev;
+ struct switchtec_user *stuser, *temp;
+
+ stdev = container_of(kref, struct switchtec_dev, kref);
+
+ if (!stdev->dev)
+ goto free_and_exit;
+
+ get_device(stdev_dev(stdev));
+
+ dev_dbg(stdev_dev(stdev), "%s\n", __func__);
+
+ cancel_delayed_work(&stdev->mrpc_timeout);
+ mutex_lock(&stdev->mrpc_mutex);
+
+ list_for_each_entry_safe(stuser, temp, &stdev->mrpc_queue, list) {
+ stuser->status = SWITCHTEC_MRPC_STATUS_INTERRUPTED;
+ list_del_init(&stuser->list);
+ stuser_put(stuser);
+ }
+
+ mutex_unlock(&stdev->mrpc_mutex);
+
+ switchtec_unregister_dev(stdev);
+ put_device(stdev_dev(stdev));
+
+free_and_exit:
+ kfree(stdev);
+}
+
+static void stdev_init(struct switchtec_dev *stdev,
+ struct pci_dev *pdev)
+{
+ stdev->pdev = pdev;
+ kref_init(&stdev->kref);
+ INIT_LIST_HEAD(&stdev->mrpc_queue);
+ mutex_init(&stdev->mrpc_mutex);
+ stdev->mrpc_busy = 0;
+ INIT_WORK(&stdev->mrpc_work, mrpc_event_work);
+ INIT_DELAYED_WORK(&stdev->mrpc_timeout, mrpc_timeout_work);
+}
+
+static void stdev_put(struct switchtec_dev *stdev)
+{
+ kref_put(&stdev->kref, stdev_free);
+}
+
+static int stdev_is_alive(struct switchtec_dev *stdev)
+{
+ return stdev->mmio != NULL;
+}
+
+static int switchtec_dev_open(struct inode *inode, struct file *filp)
+{
+ struct device *dev;
+ struct switchtec_dev *stdev;
+ struct switchtec_user *stuser;
+ int rc;
+
+ dev = switchtec_dev_find(inode->i_rdev);
+ if (!dev)
+ return -ENXIO;
+
+ device_lock(dev);
+ stdev = dev_get_drvdata(dev);
+ if (!stdev) {
+ rc = -ENXIO;
+ goto err_unlock_exit;
+ }
+
+ kref_get(&stdev->kref);
+
+ stuser = kzalloc(sizeof(*stuser), GFP_KERNEL);
+ if (!stuser) {
+ rc = -ENOMEM;
+ goto err_unlock_exit;
+ }
+
+ stuser_init(stuser, stdev);
+ filp->private_data = stuser;
+
+ dev_dbg(stdev_dev(stdev), "%s: %p\n", __func__, stuser);
+
+ device_unlock(dev);
+ nonseekable_open(inode, filp);
+ return 0;
+
+err_unlock_exit:
+ device_unlock(dev);
+ put_device(dev);
+ return rc;
+}
+
+static int switchtec_dev_release(struct inode *inode, struct file *filp)
+{
+ struct switchtec_user *stuser = filp->private_data;
+ struct switchtec_dev *stdev = stuser->stdev;
+ struct device *dev = stdev_dev(stdev);
+
+ dev_dbg(dev, "%s: %p\n", __func__, stuser);
+
+ stuser_put(stuser);
+ stdev_put(stdev);
+ put_device(dev);
+
+ return 0;
+}
+
+static ssize_t switchtec_dev_write(struct file *filp, const char __user *data,
+ size_t size, loff_t *off)
+{
+ struct switchtec_user *stuser = filp->private_data;
+ struct switchtec_dev *stdev = stuser->stdev;
+ int rc;
+
+ if (!stdev_is_alive(stdev))
+ return -ENXIO;
+
+ if (size < sizeof(stuser->cmd) ||
+ size > sizeof(stuser->cmd) + SWITCHTEC_MRPC_PAYLOAD_SIZE)
+ return -EINVAL;
+
+ if (mutex_lock_interruptible(&stdev->mrpc_mutex))
+ return -EINTR;
+
+ if (stuser->state != MRPC_IDLE) {
+ rc = -EBADE;
+ goto out;
+ }
+
+ rc = copy_from_user(&stuser->cmd, data, sizeof(stuser->cmd));
+ if (rc) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ data += sizeof(stuser->cmd);
+ rc = copy_from_user(&stuser->data, data, size - sizeof(stuser->cmd));
+ if (rc) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ stuser->data_len = size - sizeof(stuser->cmd);
+
+ mrpc_queue_cmd(stuser);
+
+ rc = size;
+
+out:
+ mutex_unlock(&stdev->mrpc_mutex);
+
+ return rc;
+}
+
+static ssize_t switchtec_dev_read(struct file *filp, char __user *data,
+ size_t size, loff_t *off)
+{
+ struct switchtec_user *stuser = filp->private_data;
+ struct switchtec_dev *stdev = stuser->stdev;
+ int rc;
+
+ if (!stdev_is_alive(stdev))
+ return -ENXIO;
+
+ if (size < sizeof(stuser->cmd) ||
+ size >= sizeof(stuser->cmd) + SWITCHTEC_MRPC_PAYLOAD_SIZE)
+ return -EINVAL;
+
+ if (stuser->state == MRPC_IDLE)
+ return -EBADE;
+
+ if (filp->f_flags & O_NONBLOCK) {
+ if (!try_wait_for_completion(&stuser->comp))
+ return -EAGAIN;
+ } else {
+ rc = wait_for_completion_interruptible(&stuser->comp);
+ if (rc < 0)
+ return rc;
+ }
+
+ if (mutex_lock_interruptible(&stdev->mrpc_mutex))
+ return -EINTR;
+
+ if (stuser->state != MRPC_DONE)
+ return -EBADE;
+
+ rc = copy_to_user(data, &stuser->return_code,
+ sizeof(stuser->return_code));
+ if (rc) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ data += sizeof(stuser->return_code);
+ rc = copy_to_user(data, &stuser->data,
+ size - sizeof(stuser->return_code));
+ if (rc) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ stuser_set_state(stuser, MRPC_IDLE);
+
+ if (stuser->status == SWITCHTEC_MRPC_STATUS_DONE)
+ rc = size;
+ else if (stuser->status == SWITCHTEC_MRPC_STATUS_INTERRUPTED)
+ rc = -ENXIO;
+ else
+ rc = -EBADMSG;
+
+out:
+ mutex_unlock(&stdev->mrpc_mutex);
+
+ return rc;
+}
+
+static unsigned int switchtec_dev_poll(struct file *filp, poll_table *wait)
+{
+ struct switchtec_user *stuser = filp->private_data;
+ struct switchtec_dev *stdev = stuser->stdev;
+
+ poll_wait(filp, &stuser->comp.wait, wait);
+
+ if (!stdev_is_alive(stdev))
+ return POLLERR;
+
+ if (stuser->state == MRPC_IDLE)
+ return POLLERR;
+ else if (try_wait_for_completion(&stuser->comp))
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+}
+
+static const struct file_operations switchtec_fops = {
+ .owner = THIS_MODULE,
+ .open = switchtec_dev_open,
+ .release = switchtec_dev_release,
+ .write = switchtec_dev_write,
+ .read = switchtec_dev_read,
+ .poll = switchtec_dev_poll,
+};
+
+static irqreturn_t switchtec_event_isr(int irq, void *dev)
+{
+ struct switchtec_dev *stdev = dev;
+ u32 summary;
+
+ summary = ioread32(&stdev->mmio_part_cfg->part_event_summary);
+
+ if (summary & SWITCHTEC_PART_CFG_EVENT_MRPC_CMP) {
+ schedule_work(&stdev->mrpc_work);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static int switchtec_init_msix_isr(struct switchtec_dev *stdev)
+{
+ struct pci_dev *pdev = stdev_pdev(stdev);
+ int rc, i, msix_count, node;
+
+ node = dev_to_node(&pdev->dev);
+
+ stdev->msix = kzalloc_node(4 * sizeof(*stdev->msix),
+ GFP_KERNEL, node);
+ if (!stdev->msix)
+ return -ENOMEM;
+
+ for (i = 0; i < 4; ++i)
+ stdev->msix[i].entry = i;
+
+ msix_count = pci_enable_msix_range(pdev, stdev->msix, 1, 4);
+ if (msix_count < 0) {
+ rc = msix_count;
+ goto err_msix_enable;
+ }
+
+ stdev->event_irq = ioread32(&stdev->mmio_part_cfg->vep_vector_number);
+ if (stdev->event_irq < 0 || stdev->event_irq >= msix_count) {
+ rc = -EFAULT;
+ goto err_msix_request;
+ }
+
+ rc = request_irq(stdev->msix[stdev->event_irq].vector,
+ switchtec_event_isr, 0,
+ "switchtec_event_isr", stdev);
+
+ if (rc)
+ goto err_msix_request;
+
+ dev_dbg(stdev_pdev_dev(stdev), "Using msix interrupts: event_irq=%d\n",
+ stdev->event_irq);
+ return 0;
+
+err_msix_request:
+ pci_disable_msix(pdev);
+err_msix_enable:
+ kfree(stdev->msix);
+ return rc;
+}
+
+static void switchtec_deinit_msix_isr(struct switchtec_dev *stdev)
+{
+ free_irq(stdev->msix[stdev->event_irq].vector, stdev);
+ pci_disable_msix(stdev_pdev(stdev));
+ kfree(stdev->msix);
+}
+
+static int switchtec_init_msi_isr(struct switchtec_dev *stdev)
+{
+ int rc;
+ struct pci_dev *pdev = stdev_pdev(stdev);
+
+ stdev->msix = NULL;
+
+ /* Try to set up msi irq */
+ rc = pci_enable_msi_range(pdev, 1, 4);
+ if (rc < 0)
+ goto err_msi_enable;
+
+ stdev->event_irq = ioread32(&stdev->mmio_part_cfg->vep_vector_number);
+ if (stdev->event_irq < 0 || stdev->event_irq >= 4) {
+ rc = -EFAULT;
+ goto err_msi_request;
+ }
+
+ rc = request_irq(pdev->irq + stdev->event_irq, switchtec_event_isr, 0,
+ "switchtec_event_isr", stdev);
+ if (rc)
+ goto err_msi_request;
+
+ dev_dbg(stdev_pdev_dev(stdev), "Using msi interrupts: event_irq=%d\n",
+ stdev->event_irq);
+ return 0;
+
+err_msi_request:
+ pci_disable_msi(pdev);
+err_msi_enable:
+ return rc;
+}
+
+static void switchtec_deinit_msi_isr(struct switchtec_dev *stdev)
+{
+ struct pci_dev *pdev = stdev_pdev(stdev);
+
+ free_irq(pdev->irq + stdev->event_irq, stdev);
+ pci_disable_msi(pdev);
+}
+
+static void switchtec_deinit_isr(struct switchtec_dev *stdev)
+{
+ if (stdev->msix)
+ switchtec_deinit_msix_isr(stdev);
+ else
+ switchtec_deinit_msi_isr(stdev);
+}
+
+static int switchtec_init_isr(struct switchtec_dev *stdev)
+{
+ int ret;
+
+ ret = switchtec_init_msix_isr(stdev);
+ if (ret)
+ ret = switchtec_init_msi_isr(stdev);
+
+ return ret;
+}
+
+static int switchtec_init_pci(struct switchtec_dev *stdev,
+ struct pci_dev *pdev)
+{
+ int rc;
+ int partition;
+
+ pci_set_drvdata(pdev, stdev);
+
+ rc = pci_enable_device(pdev);
+ if (rc)
+ goto err_pci_enable;
+
+ rc = pci_request_regions(pdev, KBUILD_MODNAME);
+ if (rc)
+ goto err_pci_regions;
+
+ pci_set_master(pdev);
+
+ stdev->mmio = pci_iomap(pdev, 0, 0);
+ if (!stdev->mmio) {
+ rc = -EIO;
+ goto err_iomap;
+ }
+
+ stdev->mmio_mrpc = stdev->mmio + SWITCHTEC_GAS_MRPC_OFFSET;
+ stdev->mmio_ntb = stdev->mmio + SWITCHTEC_GAS_NTB_OFFSET;
+ partition = ioread8(&stdev->mmio_ntb->partition_id);
+ stdev->mmio_part_cfg = stdev->mmio + SWITCHTEC_GAS_PART_CFG_OFFSET +
+ sizeof(struct part_cfg_regs) * partition;
+
+ return 0;
+
+err_iomap:
+ pci_clear_master(pdev);
+ pci_release_regions(pdev);
+err_pci_regions:
+ pci_disable_device(pdev);
+err_pci_enable:
+ pci_set_drvdata(pdev, NULL);
+ return rc;
+}
+
+static void switchtec_deinit_pci(struct switchtec_dev *stdev)
+{
+ struct pci_dev *pdev = stdev_pdev(stdev);
+
+ pci_iounmap(pdev, stdev->mmio);
+ stdev->mmio = NULL;
+
+ pci_clear_master(pdev);
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+ pci_set_drvdata(pdev, NULL);
+}
+
+static int switchtec_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct switchtec_dev *stdev;
+ int rc, node;
+
+ node = dev_to_node(&pdev->dev);
+
+ stdev = kzalloc_node(sizeof(*stdev), GFP_KERNEL, node);
+ if (!stdev) {
+ rc = -ENOMEM;
+ goto err_stdev;
+ }
+
+ stdev_init(stdev, pdev);
+
+ rc = switchtec_init_pci(stdev, pdev);
+ if (rc)
+ goto err_init_pci;
+
+ rc = switchtec_init_isr(stdev);
+ if (rc) {
+ dev_err(stdev_pdev_dev(stdev), "failed to init isr.\n");
+ goto err_init_isr;
+ }
+
+ rc = switchtec_register_dev(stdev);
+ if (rc)
+ goto err_register_dev;
+
+ dev_info(stdev_dev(stdev), "Management device registered.\n");
+
+ return 0;
+
+err_register_dev:
+ switchtec_deinit_isr(stdev);
+err_init_isr:
+ switchtec_deinit_pci(stdev);
+err_init_pci:
+ stdev_put(stdev);
+err_stdev:
+ return rc;
+}
+
+static void switchtec_pci_remove(struct pci_dev *pdev)
+{
+ struct switchtec_dev *stdev = pci_get_drvdata(pdev);
+
+ switchtec_deinit_isr(stdev);
+ switchtec_deinit_pci(stdev);
+ stdev_put(stdev);
+}
+
+#define SWITCHTEC_PCI_DEVICE(device_id) \
+ { \
+ .vendor = MICROSEMI_VENDOR_ID, \
+ .device = device_id, \
+ .subvendor = PCI_ANY_ID, \
+ .subdevice = PCI_ANY_ID, \
+ .class = MICROSEMI_MGMT_CLASSCODE, \
+ .class_mask = 0xFFFFFFFF, \
+ }, \
+ { \
+ .vendor = MICROSEMI_VENDOR_ID, \
+ .device = device_id, \
+ .subvendor = PCI_ANY_ID, \
+ .subdevice = PCI_ANY_ID, \
+ .class = MICROSEMI_NTB_CLASSCODE, \
+ .class_mask = 0xFFFFFFFF, \
+ }
+
+static const struct pci_device_id switchtec_pci_tbl[] = {
+ SWITCHTEC_PCI_DEVICE(0x8531), //PFX 24xG3
+ SWITCHTEC_PCI_DEVICE(0x8532), //PFX 32xG3
+ SWITCHTEC_PCI_DEVICE(0x8533), //PFX 48xG3
+ SWITCHTEC_PCI_DEVICE(0x8534), //PFX 64xG3
+ SWITCHTEC_PCI_DEVICE(0x8535), //PFX 80xG3
+ SWITCHTEC_PCI_DEVICE(0x8536), //PFX 96xG3
+ SWITCHTEC_PCI_DEVICE(0x8543), //PSX 48xG3
+ SWITCHTEC_PCI_DEVICE(0x8544), //PSX 64xG3
+ SWITCHTEC_PCI_DEVICE(0x8545), //PSX 80xG3
+ SWITCHTEC_PCI_DEVICE(0x8546), //PSX 96xG3
+ {0}
+};
+MODULE_DEVICE_TABLE(pci, switchtec_pci_tbl);
+
+static struct pci_driver switchtec_pci_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = switchtec_pci_tbl,
+ .probe = switchtec_pci_probe,
+ .remove = switchtec_pci_remove,
+};
+
+static int __init switchtec_init(void)
+{
+ int rc;
+
+ rc = register_chrdev(0, "switchtec", &switchtec_fops);
+ if (rc < 0)
+ return rc;
+ switchtec_major = rc;
+
+ switchtec_class = class_create(THIS_MODULE, "switchtec");
+ if (IS_ERR(switchtec_class)) {
+ rc = PTR_ERR(switchtec_class);
+ goto err_create_class;
+ }
+
+ rc = pci_register_driver(&switchtec_pci_driver);
+ if (rc)
+ goto err_pci_register;
+
+ pr_info(KBUILD_MODNAME ": loaded.\n");
+
+ return 0;
+
+err_pci_register:
+ class_destroy(switchtec_class);
+
+err_create_class:
+ unregister_chrdev(switchtec_major, "switchtec");
+
+ return rc;
+}
+module_init(switchtec_init);
+
+static void __exit switchtec_exit(void)
+{
+ pci_unregister_driver(&switchtec_pci_driver);
+ class_destroy(switchtec_class);
+ unregister_chrdev(switchtec_major, "switchtec");
+ ida_destroy(&switchtec_minor_ida);
+
+ pr_info(KBUILD_MODNAME ": unloaded.\n");
+}
+module_exit(switchtec_exit);
diff --git a/drivers/pci/switch/switchtec.h b/drivers/pci/switch/switchtec.h
new file mode 100644
index 0000000..10a9909
--- /dev/null
+++ b/drivers/pci/switch/switchtec.h
@@ -0,0 +1,119 @@
+/*
+ * Microsemi Switchtec PCIe Driver
+ * Copyright (c) 2016, 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.
+ *
+ */
+
+#ifndef SWITCHTEC_H
+#define SWITCHTEC_H
+
+#include <linux/pci.h>
+
+#define MICROSEMI_VENDOR_ID 0x11f8
+#define MICROSEMI_NTB_CLASSCODE 0x068000
+#define MICROSEMI_MGMT_CLASSCODE 0x058000
+
+#define SWITCHTEC_MRPC_PAYLOAD_SIZE 1024
+
+enum {
+ SWITCHTEC_GAS_MRPC_OFFSET = 0x0000,
+ SWITCHTEC_GAS_TOP_CFG_OFFSET = 0x1000,
+ SWITCHTEC_GAS_SW_EVENT_OFFSET = 0x1800,
+ SWITCHTEC_GAS_PART_CFG_OFFSET = 0x4000,
+ SWITCHTEC_GAS_NTB_OFFSET = 0x10000,
+ SWITCHTEC_GAS_PFF_CSR_OFFSET = 0x134000,
+};
+
+struct mrpc_regs {
+ u8 input_data[SWITCHTEC_MRPC_PAYLOAD_SIZE];
+ u8 output_data[SWITCHTEC_MRPC_PAYLOAD_SIZE];
+ u32 cmd;
+ u32 status;
+ u32 ret_value;
+} __packed;
+
+enum mrpc_status {
+ SWITCHTEC_MRPC_STATUS_INPROGRESS = 1,
+ SWITCHTEC_MRPC_STATUS_DONE = 2,
+ SWITCHTEC_MRPC_STATUS_ERROR = 0xFF,
+ SWITCHTEC_MRPC_STATUS_INTERRUPTED = 0x100,
+};
+
+struct ntb_info_regs {
+ u8 partition_count;
+ u8 partition_id;
+ u16 reserved1;
+ u64 ep_map;
+ u16 requester_id;
+} __packed;
+
+struct part_cfg_regs {
+ u32 status;
+ u32 state;
+ u32 port_cnt;
+ u32 usp_port_mode;
+ u32 usp_pff_inst_id;
+ u32 vep_pff_inst_id;
+ u32 dsp_inst_id[47];
+ u32 reserved1[11];
+ u16 vep_vector_number;
+ u16 usp_vector_number;
+ u32 port_event_bitmap;
+ u32 reserved2[3];
+ u32 part_event_summary;
+ u32 reserved3[3];
+ u32 part_reset_event_hdr;
+ u8 part_reset_event_data[20];
+ u32 mrpc_completion_hdr;
+ u8 mrpc_completion_data[20];
+ u32 mrpc_completion_async_hdr;
+ u8 mrpc_completion_async_data[20];
+ u32 dynamic_part_binding_evt_hdr;
+ u8 dynamic_part_binding_evt_data[20];
+ u32 reserved4[159];
+} __packed;
+
+enum {
+ SWITCHTEC_PART_CFG_EVENT_MRPC_CMP = 2,
+ SWITCHTEC_PART_CFG_EVENT_MRPC_ASYNC_CMP = 4,
+};
+
+struct switchtec_dev {
+ struct pci_dev *pdev;
+ struct msix_entry *msix;
+ struct device *dev;
+ struct kref kref;
+
+ unsigned int event_irq;
+
+ void __iomem *mmio;
+ struct mrpc_regs __iomem *mmio_mrpc;
+ struct ntb_info_regs __iomem *mmio_ntb;
+ struct part_cfg_regs __iomem *mmio_part_cfg;
+
+ /*
+ * The mrpc mutex must be held when accessing the other
+ * mrpc fields
+ */
+ struct mutex mrpc_mutex;
+ struct list_head mrpc_queue;
+ int mrpc_busy;
+ struct work_struct mrpc_work;
+ struct delayed_work mrpc_timeout;
+};
+
+#define stdev_pdev(stdev) ((stdev)->pdev)
+#define stdev_pdev_dev(stdev) (&stdev_pdev(stdev)->dev)
+#define stdev_name(stdev) pci_name(stdev_pdev(stdev))
+#define stdev_dev(stdev) ((stdev)->dev)
+
+#endif
--
2.1.4