IB/ipath: sysfs and ipathfs support for core driver

The ipathfs filesystem contains files that are not appropriate for
sysfs, because they contain binary data.  The hierarchy is simple; the
top-level directory contains driver-wide attribute files, while numbered
subdirectories contain per-device attribute files.

Our userspace code currently expects this filesystem to be mounted on
/ipathfs, but a final location has not yet been chosen.

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

1 files changed, 605 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
new file mode 100644
index 00000000000..e274120567e
--- /dev/null
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -0,0 +1,605 @@
+/*
+ * Copyright (c) 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.
+ */
+
+#include <linux/version.h>
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/pci.h>
+
+#include "ipath_kernel.h"
+
+#define IPATHFS_MAGIC 0x726a77
+
+static struct super_block *ipath_super;
+
+static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
+			 int mode, struct file_operations *fops,
+			 void *data)
+{
+	int error;
+	struct inode *inode = new_inode(dir->i_sb);
+
+	if (!inode) {
+		error = -EPERM;
+		goto bail;
+	}
+
+	inode->i_mode = mode;
+	inode->i_uid = 0;
+	inode->i_gid = 0;
+	inode->i_blksize = PAGE_CACHE_SIZE;
+	inode->i_blocks = 0;
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	inode->u.generic_ip = data;
+	if ((mode & S_IFMT) == S_IFDIR) {
+		inode->i_op = &simple_dir_inode_operations;
+		inode->i_nlink++;
+		dir->i_nlink++;
+	}
+
+	inode->i_fop = fops;
+
+	d_instantiate(dentry, inode);
+	error = 0;
+
+bail:
+	return error;
+}
+
+static int create_file(const char *name, mode_t mode,
+		       struct dentry *parent, struct dentry **dentry,
+		       struct file_operations *fops, void *data)
+{
+	int error;
+
+	*dentry = NULL;
+	mutex_lock(&parent->d_inode->i_mutex);
+	*dentry = lookup_one_len(name, parent, strlen(name));
+	if (!IS_ERR(dentry))
+		error = ipathfs_mknod(parent->d_inode, *dentry,
+				      mode, fops, data);
+	else
+		error = PTR_ERR(dentry);
+	mutex_unlock(&parent->d_inode->i_mutex);
+
+	return error;
+}
+
+static ssize_t atomic_stats_read(struct file *file, char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
+				       sizeof ipath_stats);
+}
+
+static struct file_operations atomic_stats_ops = {
+	.read = atomic_stats_read,
+};
+
+#define NUM_COUNTERS sizeof(struct infinipath_counters) / sizeof(u64)
+
+static ssize_t atomic_counters_read(struct file *file, char __user *buf,
+				    size_t count, loff_t *ppos)
+{
+	u64 counters[NUM_COUNTERS];
+	u16 i;
+	struct ipath_devdata *dd;
+
+	dd = file->f_dentry->d_inode->u.generic_ip;
+
+	for (i = 0; i < NUM_COUNTERS; i++)
+		counters[i] = ipath_snap_cntr(dd, i);
+
+	return simple_read_from_buffer(buf, count, ppos, counters,
+				       sizeof counters);
+}
+
+static struct file_operations atomic_counters_ops = {
+	.read = atomic_counters_read,
+};
+
+static ssize_t atomic_node_info_read(struct file *file, char __user *buf,
+				     size_t count, loff_t *ppos)
+{
+	u32 nodeinfo[10];
+	struct ipath_devdata *dd;
+	u64 guid;
+
+	dd = file->f_dentry->d_inode->u.generic_ip;
+
+	guid = be64_to_cpu(dd->ipath_guid);
+
+	nodeinfo[0] =			/* BaseVersion is SMA */
+		/* ClassVersion is SMA */
+		(1 << 8)		/* NodeType  */
+		| (1 << 0);		/* NumPorts */
+	nodeinfo[1] = (u32) (guid >> 32);
+	nodeinfo[2] = (u32) (guid & 0xffffffff);
+	/* PortGUID == SystemImageGUID for us */
+	nodeinfo[3] = nodeinfo[1];
+	/* PortGUID == SystemImageGUID for us */
+	nodeinfo[4] = nodeinfo[2];
+	/* PortGUID == NodeGUID for us */
+	nodeinfo[5] = nodeinfo[3];
+	/* PortGUID == NodeGUID for us */
+	nodeinfo[6] = nodeinfo[4];
+	nodeinfo[7] = (4 << 16) /* we support 4 pkeys */
+		| (dd->ipath_deviceid << 0);
+	/* our chip version as 16 bits major, 16 bits minor */
+	nodeinfo[8] = dd->ipath_minrev | (dd->ipath_majrev << 16);
+	nodeinfo[9] = (dd->ipath_unit << 24) | (dd->ipath_vendorid << 0);
+
+	return simple_read_from_buffer(buf, count, ppos, nodeinfo,
+				       sizeof nodeinfo);
+}
+
+static struct file_operations atomic_node_info_ops = {
+	.read = atomic_node_info_read,
+};
+
+static ssize_t atomic_port_info_read(struct file *file, char __user *buf,
+				     size_t count, loff_t *ppos)
+{
+	u32 portinfo[13];
+	u32 tmp, tmp2;
+	struct ipath_devdata *dd;
+
+	dd = file->f_dentry->d_inode->u.generic_ip;
+
+	/* so we only initialize non-zero fields. */
+	memset(portinfo, 0, sizeof portinfo);
+
+	/*
+	 * Notimpl yet M_Key (64)
+	 * Notimpl yet GID (64)
+	 */
+
+	portinfo[4] = (dd->ipath_lid << 16);
+
+	/*
+	 * Notimpl yet SMLID (should we store this in the driver, in case
+	 * SMA dies?)  CapabilityMask is 0, we don't support any of these
+	 * DiagCode is 0; we don't store any diag info for now Notimpl yet
+	 * M_KeyLeasePeriod (we don't support M_Key)
+	 */
+
+	/* LocalPortNum is whichever port number they ask for */
+	portinfo[7] = (dd->ipath_unit << 24)
+		/* LinkWidthEnabled */
+		| (2 << 16)
+		/* LinkWidthSupported (really 2, but not IB valid) */
+		| (3 << 8)
+		/* LinkWidthActive */
+		| (2 << 0);
+	tmp = dd->ipath_lastibcstat & IPATH_IBSTATE_MASK;
+	tmp2 = 5;
+	if (tmp == IPATH_IBSTATE_INIT)
+		tmp = 2;
+	else if (tmp == IPATH_IBSTATE_ARM)
+		tmp = 3;
+	else if (tmp == IPATH_IBSTATE_ACTIVE)
+		tmp = 4;
+	else {
+		tmp = 0;	/* down */
+		tmp2 = tmp & 0xf;
+	}
+
+	portinfo[8] = (1 << 28)	/* LinkSpeedSupported */
+		| (tmp << 24)	/* PortState */
+		| (tmp2 << 20)	/* PortPhysicalState */
+		| (2 << 16)
+
+		/* LinkDownDefaultState */
+		/* M_KeyProtectBits == 0 */
+		/* NotImpl yet LMC == 0 (we can support all values) */
+		| (1 << 4)	/* LinkSpeedActive */
+		| (1 << 0);	/* LinkSpeedEnabled */
+	switch (dd->ipath_ibmtu) {
+	case 4096:
+		tmp = 5;
+		break;
+	case 2048:
+		tmp = 4;
+		break;
+	case 1024:
+		tmp = 3;
+		break;
+	case 512:
+		tmp = 2;
+		break;
+	case 256:
+		tmp = 1;
+		break;
+	default:		/* oops, something is wrong */
+		ipath_dbg("Problem, ipath_ibmtu 0x%x not a valid IB MTU, "
+			  "treat as 2048\n", dd->ipath_ibmtu);
+		tmp = 4;
+		break;
+	}
+	portinfo[9] = (tmp << 28)
+		/* NeighborMTU */
+		/* Notimpl MasterSMSL */
+		| (1 << 20)
+
+		/* VLCap */
+		/* Notimpl InitType (actually, an SMA decision) */
+		/* VLHighLimit is 0 (only one VL) */
+		; /* VLArbitrationHighCap is 0 (only one VL) */
+	portinfo[10] = 	/* VLArbitrationLowCap is 0 (only one VL) */
+		/* InitTypeReply is SMA decision */
+		(5 << 16)	/* MTUCap 4096 */
+		| (7 << 13)	/* VLStallCount */
+		| (0x1f << 8)	/* HOQLife */
+		| (1 << 4)
+
+		/* OperationalVLs 0 */
+		/* PartitionEnforcementInbound */
+		/* PartitionEnforcementOutbound not enforced */
+		/* FilterRawinbound not enforced */
+		;		/* FilterRawOutbound not enforced */
+	/* M_KeyViolations are not counted by hardware, SMA can count */
+	tmp = ipath_read_creg32(dd, dd->ipath_cregs->cr_errpkey);
+	/* P_KeyViolations are counted by hardware. */
+	portinfo[11] = ((tmp & 0xffff) << 0);
+	portinfo[12] =
+		/* Q_KeyViolations are not counted by hardware */
+		(1 << 8)
+
+		/* GUIDCap */
+		/* SubnetTimeOut handled by SMA */
+		/* RespTimeValue handled by SMA */
+		;
+	/* LocalPhyErrors are programmed to max */
+	portinfo[12] |= (0xf << 20)
+		| (0xf << 16)   /* OverRunErrors are programmed to max */
+		;
+
+	return simple_read_from_buffer(buf, count, ppos, portinfo,
+				       sizeof portinfo);
+}
+
+static struct file_operations atomic_port_info_ops = {
+	.read = atomic_port_info_read,
+};
+
+static ssize_t flash_read(struct file *file, char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	struct ipath_devdata *dd;
+	ssize_t ret;
+	loff_t pos;
+	char *tmp;
+
+	pos = *ppos;
+
+	if ( pos < 0) {
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	if (pos >= sizeof(struct ipath_flash)) {
+		ret = 0;
+		goto bail;
+	}
+
+	if (count > sizeof(struct ipath_flash) - pos)
+		count = sizeof(struct ipath_flash) - pos;
+
+	tmp = kmalloc(count, GFP_KERNEL);
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+
+	dd = file->f_dentry->d_inode->u.generic_ip;
+	if (ipath_eeprom_read(dd, pos, tmp, count)) {
+		ipath_dev_err(dd, "failed to read from flash\n");
+		ret = -ENXIO;
+		goto bail_tmp;
+	}
+
+	if (copy_to_user(buf, tmp, count)) {
+		ret = -EFAULT;
+		goto bail_tmp;
+	}
+
+	*ppos = pos + count;
+	ret = count;
+
+bail_tmp:
+	kfree(tmp);
+
+bail:
+	return ret;
+}
+
+static ssize_t flash_write(struct file *file, const char __user *buf,
+			   size_t count, loff_t *ppos)
+{
+	struct ipath_devdata *dd;
+	ssize_t ret;
+	loff_t pos;
+	char *tmp;
+
+	pos = *ppos;
+
+	if ( pos < 0) {
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	if (pos >= sizeof(struct ipath_flash)) {
+		ret = 0;
+		goto bail;
+	}
+
+	if (count > sizeof(struct ipath_flash) - pos)
+		count = sizeof(struct ipath_flash) - pos;
+
+	tmp = kmalloc(count, GFP_KERNEL);
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+
+	if (copy_from_user(tmp, buf, count)) {
+		ret = -EFAULT;
+		goto bail_tmp;
+	}
+
+	dd = file->f_dentry->d_inode->u.generic_ip;
+	if (ipath_eeprom_write(dd, pos, tmp, count)) {
+		ret = -ENXIO;
+		ipath_dev_err(dd, "failed to write to flash\n");
+		goto bail_tmp;
+	}
+
+	*ppos = pos + count;
+	ret = count;
+
+bail_tmp:
+	kfree(tmp);
+
+bail:
+	return ret;
+}
+
+static struct file_operations flash_ops = {
+	.read = flash_read,
+	.write = flash_write,
+};
+
+static int create_device_files(struct super_block *sb,
+			       struct ipath_devdata *dd)
+{
+	struct dentry *dir, *tmp;
+	char unit[10];
+	int ret;
+
+	snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
+	ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
+			  (struct file_operations *) &simple_dir_operations,
+			  dd);
+	if (ret) {
+		printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
+		goto bail;
+	}
+
+	ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
+			  &atomic_counters_ops, dd);
+	if (ret) {
+		printk(KERN_ERR "create_file(%s/atomic_counters) "
+		       "failed: %d\n", unit, ret);
+		goto bail;
+	}
+
+	ret = create_file("node_info", S_IFREG|S_IRUGO, dir, &tmp,
+			  &atomic_node_info_ops, dd);
+	if (ret) {
+		printk(KERN_ERR "create_file(%s/node_info) "
+		       "failed: %d\n", unit, ret);
+		goto bail;
+	}
+
+	ret = create_file("port_info", S_IFREG|S_IRUGO, dir, &tmp,
+			  &atomic_port_info_ops, dd);
+	if (ret) {
+		printk(KERN_ERR "create_file(%s/port_info) "
+		       "failed: %d\n", unit, ret);
+		goto bail;
+	}
+
+	ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
+			  &flash_ops, dd);
+	if (ret) {
+		printk(KERN_ERR "create_file(%s/flash) "
+		       "failed: %d\n", unit, ret);
+		goto bail;
+	}
+
+bail:
+	return ret;
+}
+
+static void remove_file(struct dentry *parent, char *name)
+{
+	struct dentry *tmp;
+
+	tmp = lookup_one_len(name, parent, strlen(name));
+
+	spin_lock(&dcache_lock);
+	spin_lock(&tmp->d_lock);
+	if (!(d_unhashed(tmp) && tmp->d_inode)) {
+		dget_locked(tmp);
+		__d_drop(tmp);
+		spin_unlock(&tmp->d_lock);
+		spin_unlock(&dcache_lock);
+		simple_unlink(parent->d_inode, tmp);
+	} else {
+		spin_unlock(&tmp->d_lock);
+		spin_unlock(&dcache_lock);
+	}
+}
+
+static int remove_device_files(struct super_block *sb,
+			       struct ipath_devdata *dd)
+{
+	struct dentry *dir, *root;
+	char unit[10];
+	int ret;
+
+	root = dget(sb->s_root);
+	mutex_lock(&root->d_inode->i_mutex);
+	snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
+	dir = lookup_one_len(unit, root, strlen(unit));
+
+	if (IS_ERR(dir)) {
+		ret = PTR_ERR(dir);
+		printk(KERN_ERR "Lookup of %s failed\n", unit);
+		goto bail;
+	}
+
+	remove_file(dir, "flash");
+	remove_file(dir, "port_info");
+	remove_file(dir, "node_info");
+	remove_file(dir, "atomic_counters");
+	d_delete(dir);
+	ret = simple_rmdir(root->d_inode, dir);
+
+bail:
+	mutex_unlock(&root->d_inode->i_mutex);
+	dput(root);
+	return ret;
+}
+
+static int ipathfs_fill_super(struct super_block *sb, void *data,
+			      int silent)
+{
+	struct ipath_devdata *dd, *tmp;
+	unsigned long flags;
+	int ret;
+
+	static struct tree_descr files[] = {
+		[1] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
+		{""},
+	};
+
+	ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
+	if (ret) {
+		printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
+		goto bail;
+	}
+
+	spin_lock_irqsave(&ipath_devs_lock, flags);
+
+	list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
+		spin_unlock_irqrestore(&ipath_devs_lock, flags);
+		ret = create_device_files(sb, dd);
+		if (ret) {
+			deactivate_super(sb);
+			goto bail;
+		}
+		spin_lock_irqsave(&ipath_devs_lock, flags);
+	}
+
+	spin_unlock_irqrestore(&ipath_devs_lock, flags);
+
+bail:
+	return ret;
+}
+
+static struct super_block *ipathfs_get_sb(struct file_system_type *fs_type,
+				        int flags, const char *dev_name,
+					void *data)
+{
+	ipath_super = get_sb_single(fs_type, flags, data,
+				    ipathfs_fill_super);
+	return ipath_super;
+}
+
+static void ipathfs_kill_super(struct super_block *s)
+{
+	kill_litter_super(s);
+	ipath_super = NULL;
+}
+
+int ipathfs_add_device(struct ipath_devdata *dd)
+{
+	int ret;
+
+	if (ipath_super == NULL) {
+		ret = 0;
+		goto bail;
+	}
+
+	ret = create_device_files(ipath_super, dd);
+
+bail:
+	return ret;
+}
+
+int ipathfs_remove_device(struct ipath_devdata *dd)
+{
+	int ret;
+
+	if (ipath_super == NULL) {
+		ret = 0;
+		goto bail;
+	}
+
+	ret = remove_device_files(ipath_super, dd);
+
+bail:
+	return ret;
+}
+
+static struct file_system_type ipathfs_fs_type = {
+	.owner =	THIS_MODULE,
+	.name =		"ipathfs",
+	.get_sb =	ipathfs_get_sb,
+	.kill_sb =	ipathfs_kill_super,
+};
+
+int __init ipath_init_ipathfs(void)
+{
+	return register_filesystem(&ipathfs_fs_type);
+}
+
+void __exit ipath_exit_ipathfs(void)
+{
+	unregister_filesystem(&ipathfs_fs_type);
+}