IB/ipath: chip initialisation code, and diag support

ipath_init_chip.c sets up an InfiniPath device for use.

ipath_diag.c permits userspace diagnostic tools to read and write a
chip's registers.  It is different in purpose from the mmap interfaces
to the /sys/bus/pci resource files.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_diag.c

@@ -0,0 +1,379 @@
+/*
+ * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * This file contains support for diagnostic functions.  It is accessed by
+ * opening the ipath_diag device, normally minor number 129.  Diagnostic use
+ * of the InfiniPath chip may render the chip or board unusable until the
+ * driver is unloaded, or in some cases, until the system is rebooted.
+ *
+ * Accesses to the chip through this interface are not similar to going
+ * through the /sys/bus/pci resource mmap interface.
+ */
+
+#include <linux/pci.h>
+#include <asm/uaccess.h>
+
+#include "ipath_common.h"
+#include "ipath_kernel.h"
+#include "ips_common.h"
+#include "ipath_layer.h"
+
+int ipath_diag_inuse;
+static int diag_set_link;
+
+static int ipath_diag_open(struct inode *in, struct file *fp);
+static int ipath_diag_release(struct inode *in, struct file *fp);
+static ssize_t ipath_diag_read(struct file *fp, char __user *data,
+			       size_t count, loff_t *off);
+static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
+				size_t count, loff_t *off);
+
+static struct file_operations diag_file_ops = {
+	.owner = THIS_MODULE,
+	.write = ipath_diag_write,
+	.read = ipath_diag_read,
+	.open = ipath_diag_open,
+	.release = ipath_diag_release
+};
+
+static struct cdev *diag_cdev;
+static struct class_device *diag_class_dev;
+
+int ipath_diag_init(void)
+{
+	return ipath_cdev_init(IPATH_DIAG_MINOR, "ipath_diag",
+			       &diag_file_ops, &diag_cdev, &diag_class_dev);
+}
+
+void ipath_diag_cleanup(void)
+{
+	ipath_cdev_cleanup(&diag_cdev, &diag_class_dev);
+}
+
+/**
+ * ipath_read_umem64 - read a 64-bit quantity from the chip into user space
+ * @dd: the infinipath device
+ * @uaddr: the location to store the data in user memory
+ * @caddr: the source chip address (full pointer, not offset)
+ * @count: number of bytes to copy (multiple of 32 bits)
+ *
+ * This function also localizes all chip memory accesses.
+ * The copy should be written such that we read full cacheline packets
+ * from the chip.  This is usually used for a single qword
+ *
+ * NOTE:  This assumes the chip address is 64-bit aligned.
+ */
+static int ipath_read_umem64(struct ipath_devdata *dd, void __user *uaddr,
+			     const void __iomem *caddr, size_t count)
+{
+	const u64 __iomem *reg_addr = caddr;
+	const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
+	int ret;
+
+	/* not very efficient, but it works for now */
+	if (reg_addr < dd->ipath_kregbase ||
+	    reg_end > dd->ipath_kregend) {
+		ret = -EINVAL;
+		goto bail;
+	}
+	while (reg_addr < reg_end) {
+		u64 data = readq(reg_addr);
+		if (copy_to_user(uaddr, &data, sizeof(u64))) {
+			ret = -EFAULT;
+			goto bail;
+		}
+		reg_addr++;
+		uaddr++;
+	}
+	ret = 0;
+bail:
+	return ret;
+}
+
+/**
+ * ipath_write_umem64 - write a 64-bit quantity to the chip from user space
+ * @dd: the infinipath device
+ * @caddr: the destination chip address (full pointer, not offset)
+ * @uaddr: the source of the data in user memory
+ * @count: the number of bytes to copy (multiple of 32 bits)
+ *
+ * This is usually used for a single qword
+ * NOTE:  This assumes the chip address is 64-bit aligned.
+ */
+
+static int ipath_write_umem64(struct ipath_devdata *dd, void __iomem *caddr,
+			      const void __user *uaddr, size_t count)
+{
+	u64 __iomem *reg_addr = caddr;
+	const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
+	int ret;
+
+	/* not very efficient, but it works for now */
+	if (reg_addr < dd->ipath_kregbase ||
+	    reg_end > dd->ipath_kregend) {
+		ret = -EINVAL;
+		goto bail;
+	}
+	while (reg_addr < reg_end) {
+		u64 data;
+		if (copy_from_user(&data, uaddr, sizeof(data))) {
+			ret = -EFAULT;
+			goto bail;
+		}
+		writeq(data, reg_addr);
+
+		reg_addr++;
+		uaddr++;
+	}
+	ret = 0;
+bail:
+	return ret;
+}
+
+/**
+ * ipath_read_umem32 - read a 32-bit quantity from the chip into user space
+ * @dd: the infinipath device
+ * @uaddr: the location to store the data in user memory
+ * @caddr: the source chip address (full pointer, not offset)
+ * @count: number of bytes to copy
+ *
+ * read 32 bit values, not 64 bit; for memories that only
+ * support 32 bit reads; usually a single dword.
+ */
+static int ipath_read_umem32(struct ipath_devdata *dd, void __user *uaddr,
+			     const void __iomem *caddr, size_t count)
+{
+	const u32 __iomem *reg_addr = caddr;
+	const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
+	int ret;
+
+	if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
+	    reg_end > (u32 __iomem *) dd->ipath_kregend) {
+		ret = -EINVAL;
+		goto bail;
+	}
+	/* not very efficient, but it works for now */
+	while (reg_addr < reg_end) {
+		u32 data = readl(reg_addr);
+		if (copy_to_user(uaddr, &data, sizeof(data))) {
+			ret = -EFAULT;
+			goto bail;
+		}
+
+		reg_addr++;
+		uaddr++;
+	}
+	ret = 0;
+bail:
+	return ret;
+}
+
+/**
+ * ipath_write_umem32 - write a 32-bit quantity to the chip from user space
+ * @dd: the infinipath device
+ * @caddr: the destination chip address (full pointer, not offset)
+ * @uaddr: the source of the data in user memory
+ * @count: number of bytes to copy
+ *
+ * write 32 bit values, not 64 bit; for memories that only
+ * support 32 bit write; usually a single dword.
+ */
+
+static int ipath_write_umem32(struct ipath_devdata *dd, void __iomem *caddr,
+			      const void __user *uaddr, size_t count)
+{
+	u32 __iomem *reg_addr = caddr;
+	const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
+	int ret;
+
+	if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
+	    reg_end > (u32 __iomem *) dd->ipath_kregend) {
+		ret = -EINVAL;
+		goto bail;
+	}
+	while (reg_addr < reg_end) {
+		u32 data;
+		if (copy_from_user(&data, uaddr, sizeof(data))) {
+			ret = -EFAULT;
+			goto bail;
+		}
+		writel(data, reg_addr);
+
+		reg_addr++;
+		uaddr++;
+	}
+	ret = 0;
+bail:
+	return ret;
+}
+
+static int ipath_diag_open(struct inode *in, struct file *fp)
+{
+	struct ipath_devdata *dd;
+	int unit = 0; /* XXX this is bogus */
+	unsigned long flags;
+	int ret;
+
+	dd = ipath_lookup(unit);
+
+	mutex_lock(&ipath_mutex);
+	spin_lock_irqsave(&ipath_devs_lock, flags);
+
+	if (ipath_diag_inuse) {
+		ret = -EBUSY;
+		goto bail;
+	}
+
+	list_for_each_entry(dd, &ipath_dev_list, ipath_list) {
+		/*
+		 * we need at least one infinipath device to be present
+		 * (don't use INITTED, because we want to be able to open
+		 * even if device is in freeze mode, which cleared INITTED).
+		 * There is a small amount of risk to this, which is why we
+		 * also verify kregbase is set.
+		 */
+
+		if (!(dd->ipath_flags & IPATH_PRESENT) ||
+		    !dd->ipath_kregbase)
+			continue;
+
+		ipath_diag_inuse = 1;
+		diag_set_link = 0;
+		ret = 0;
+		goto bail;
+	}
+
+	ret = -ENODEV;
+
+bail:
+	spin_unlock_irqrestore(&ipath_devs_lock, flags);
+	mutex_unlock(&ipath_mutex);
+
+	/* Only expose a way to reset the device if we
+	   make it into diag mode. */
+	if (ret == 0)
+		ipath_expose_reset(&dd->pcidev->dev);
+
+	return ret;
+}
+
+static int ipath_diag_release(struct inode *i, struct file *f)
+{
+	mutex_lock(&ipath_mutex);
+	ipath_diag_inuse = 0;
+	mutex_unlock(&ipath_mutex);
+	return 0;
+}
+
+static ssize_t ipath_diag_read(struct file *fp, char __user *data,
+			       size_t count, loff_t *off)
+{
+	int unit = 0; /* XXX provide for reads on other units some day */
+	struct ipath_devdata *dd;
+	void __iomem *kreg_base;
+	ssize_t ret;
+
+	dd = ipath_lookup(unit);
+	if (!dd) {
+		ret = -ENODEV;
+		goto bail;
+	}
+
+	kreg_base = dd->ipath_kregbase;
+
+	if (count == 0)
+		ret = 0;
+	else if ((count % 4) || (*off % 4))
+		/* address or length is not 32-bit aligned, hence invalid */
+		ret = -EINVAL;
+	else if ((count % 8) || (*off % 8))
+		/* address or length not 64-bit aligned; do 32-bit reads */
+		ret = ipath_read_umem32(dd, data, kreg_base + *off, count);
+	else
+		ret = ipath_read_umem64(dd, data, kreg_base + *off, count);
+
+	if (ret >= 0) {
+		*off += count;
+		ret = count;
+	}
+
+bail:
+	return ret;
+}
+
+static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
+				size_t count, loff_t *off)
+{
+	int unit = 0; /* XXX this is bogus */
+	struct ipath_devdata *dd;
+	void __iomem *kreg_base;
+	ssize_t ret;
+
+	dd = ipath_lookup(unit);
+	if (!dd) {
+		ret = -ENODEV;
+		goto bail;
+	}
+	kreg_base = dd->ipath_kregbase;
+
+	if (count == 0)
+		ret = 0;
+	else if ((count % 4) || (*off % 4))
+		/* address or length is not 32-bit aligned, hence invalid */
+		ret = -EINVAL;
+	else if ((count % 8) || (*off % 8))
+		/* address or length not 64-bit aligned; do 32-bit writes */
+		ret = ipath_write_umem32(dd, kreg_base + *off, data, count);
+	else
+		ret = ipath_write_umem64(dd, kreg_base + *off, data, count);
+
+	if (ret >= 0) {
+		*off += count;
+		ret = count;
+	}
+
+bail:
+	return ret;
+}
+
+void ipath_diag_bringup_link(struct ipath_devdata *dd)
+{
+	if (diag_set_link || (dd->ipath_flags & IPATH_LINKACTIVE))
+		return;
+
+	diag_set_link = 1;
+	ipath_cdbg(VERBOSE, "Trying to set to set link active for "
+		   "diag pkt\n");
+	ipath_layer_set_linkstate(dd, IPATH_IB_LINKARM);
+	ipath_layer_set_linkstate(dd, IPATH_IB_LINKACTIVE);
+}