IB/ipath: sysfs and ipathfs support for core driver

/*

 * 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);

}