[linux-2.6-block.git] / arch / powerpc / platforms / pseries / dtl.c

/*
 * Virtual Processor Dispatch Trace Log
 *
 * (C) Copyright IBM Corporation 2009
 *
 * Author: Jeremy Kerr <jk@ozlabs.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/smp.h>
#include <linux/uaccess.h>
#include <asm/firmware.h>
#include <asm/lppaca.h>
#include <asm/debugfs.h>
#include <asm/plpar_wrappers.h>
#include <asm/machdep.h>

struct dtl {
	struct dtl_entry	*buf;
	struct dentry		*file;
	int			cpu;
	int			buf_entries;
	u64			last_idx;
	spinlock_t		lock;
};
static DEFINE_PER_CPU(struct dtl, cpu_dtl);

static u8 dtl_event_mask = DTL_LOG_ALL;


/*
 * Size of per-cpu log buffers. Firmware requires that the buffer does
 * not cross a 4k boundary.
 */
static int dtl_buf_entries = N_DISPATCH_LOG;

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
struct dtl_ring {
	u64	write_index;
	struct dtl_entry *write_ptr;
	struct dtl_entry *buf;
	struct dtl_entry *buf_end;
};

static DEFINE_PER_CPU(struct dtl_ring, dtl_rings);

static atomic_t dtl_count;

/*
 * The cpu accounting code controls the DTL ring buffer, and we get
 * given entries as they are processed.
 */
static void consume_dtle(struct dtl_entry *dtle, u64 index)
{
	struct dtl_ring *dtlr = this_cpu_ptr(&dtl_rings);
	struct dtl_entry *wp = dtlr->write_ptr;
	struct lppaca *vpa = local_paca->lppaca_ptr;

	if (!wp)
		return;

	*wp = *dtle;
	barrier();

	/* check for hypervisor ring buffer overflow, ignore this entry if so */
	if (index + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx))
		return;

	++wp;
	if (wp == dtlr->buf_end)
		wp = dtlr->buf;
	dtlr->write_ptr = wp;

	/* incrementing write_index makes the new entry visible */
	smp_wmb();
	++dtlr->write_index;
}

static int dtl_start(struct dtl *dtl)
{
	struct dtl_ring *dtlr = &per_cpu(dtl_rings, dtl->cpu);

	dtlr->buf = dtl->buf;
	dtlr->buf_end = dtl->buf + dtl->buf_entries;
	dtlr->write_index = 0;

	/* setting write_ptr enables logging into our buffer */
	smp_wmb();
	dtlr->write_ptr = dtl->buf;

	/* enable event logging */
	lppaca_of(dtl->cpu).dtl_enable_mask |= dtl_event_mask;

	dtl_consumer = consume_dtle;
	atomic_inc(&dtl_count);
	return 0;
}

static void dtl_stop(struct dtl *dtl)
{
	struct dtl_ring *dtlr = &per_cpu(dtl_rings, dtl->cpu);

	dtlr->write_ptr = NULL;
	smp_wmb();

	dtlr->buf = NULL;

	/* restore dtl_enable_mask */
	lppaca_of(dtl->cpu).dtl_enable_mask = DTL_LOG_PREEMPT;

	if (atomic_dec_and_test(&dtl_count))
		dtl_consumer = NULL;
}

static u64 dtl_current_index(struct dtl *dtl)
{
	return per_cpu(dtl_rings, dtl->cpu).write_index;
}

#else /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */

static int dtl_start(struct dtl *dtl)
{
	unsigned long addr;
	int ret, hwcpu;

	/* Register our dtl buffer with the hypervisor. The HV expects the
	 * buffer size to be passed in the second word of the buffer */
	((u32 *)dtl->buf)[1] = cpu_to_be32(DISPATCH_LOG_BYTES);

	hwcpu = get_hard_smp_processor_id(dtl->cpu);
	addr = __pa(dtl->buf);
	ret = register_dtl(hwcpu, addr);
	if (ret) {
		printk(KERN_WARNING "%s: DTL registration for cpu %d (hw %d) "
		       "failed with %d\n", __func__, dtl->cpu, hwcpu, ret);
		return -EIO;
	}

	/* set our initial buffer indices */
	lppaca_of(dtl->cpu).dtl_idx = 0;

	/* ensure that our updates to the lppaca fields have occurred before
	 * we actually enable the logging */
	smp_wmb();

	/* enable event logging */
	lppaca_of(dtl->cpu).dtl_enable_mask = dtl_event_mask;

	return 0;
}

static void dtl_stop(struct dtl *dtl)
{
	int hwcpu = get_hard_smp_processor_id(dtl->cpu);

	lppaca_of(dtl->cpu).dtl_enable_mask = 0x0;

	unregister_dtl(hwcpu);
}

static u64 dtl_current_index(struct dtl *dtl)
{
	return be64_to_cpu(lppaca_of(dtl->cpu).dtl_idx);
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */

static int dtl_enable(struct dtl *dtl)
{
	long int n_entries;
	long int rc;
	struct dtl_entry *buf = NULL;

	if (!dtl_cache)
		return -ENOMEM;

	/* only allow one reader */
	if (dtl->buf)
		return -EBUSY;

	n_entries = dtl_buf_entries;
	buf = kmem_cache_alloc_node(dtl_cache, GFP_KERNEL, cpu_to_node(dtl->cpu));
	if (!buf) {
		printk(KERN_WARNING "%s: buffer alloc failed for cpu %d\n",
				__func__, dtl->cpu);
		return -ENOMEM;
	}

	spin_lock(&dtl->lock);
	rc = -EBUSY;
	if (!dtl->buf) {
		/* store the original allocation size for use during read */
		dtl->buf_entries = n_entries;
		dtl->buf = buf;
		dtl->last_idx = 0;
		rc = dtl_start(dtl);
		if (rc)
			dtl->buf = NULL;
	}
	spin_unlock(&dtl->lock);

	if (rc)
		kmem_cache_free(dtl_cache, buf);
	return rc;
}

static void dtl_disable(struct dtl *dtl)
{
	spin_lock(&dtl->lock);
	dtl_stop(dtl);
	kmem_cache_free(dtl_cache, dtl->buf);
	dtl->buf = NULL;
	dtl->buf_entries = 0;
	spin_unlock(&dtl->lock);
}

/* file interface */

static int dtl_file_open(struct inode *inode, struct file *filp)
{
	struct dtl *dtl = inode->i_private;
	int rc;

	rc = dtl_enable(dtl);
	if (rc)
		return rc;

	filp->private_data = dtl;
	return 0;
}

static int dtl_file_release(struct inode *inode, struct file *filp)
{
	struct dtl *dtl = inode->i_private;
	dtl_disable(dtl);
	return 0;
}

static ssize_t dtl_file_read(struct file *filp, char __user *buf, size_t len,
		loff_t *pos)
{
	long int rc, n_read, n_req, read_size;
	struct dtl *dtl;
	u64 cur_idx, last_idx, i;

	if ((len % sizeof(struct dtl_entry)) != 0)
		return -EINVAL;

	dtl = filp->private_data;

	/* requested number of entries to read */
	n_req = len / sizeof(struct dtl_entry);

	/* actual number of entries read */
	n_read = 0;

	spin_lock(&dtl->lock);

	cur_idx = dtl_current_index(dtl);
	last_idx = dtl->last_idx;

	if (last_idx + dtl->buf_entries <= cur_idx)
		last_idx = cur_idx - dtl->buf_entries + 1;

	if (last_idx + n_req > cur_idx)
		n_req = cur_idx - last_idx;

	if (n_req > 0)
		dtl->last_idx = last_idx + n_req;

	spin_unlock(&dtl->lock);

	if (n_req <= 0)
		return 0;

	i = last_idx % dtl->buf_entries;

	/* read the tail of the buffer if we've wrapped */
	if (i + n_req > dtl->buf_entries) {
		read_size = dtl->buf_entries - i;

		rc = copy_to_user(buf, &dtl->buf[i],
				read_size * sizeof(struct dtl_entry));
		if (rc)
			return -EFAULT;

		i = 0;
		n_req -= read_size;
		n_read += read_size;
		buf += read_size * sizeof(struct dtl_entry);
	}

	/* .. and now the head */
	rc = copy_to_user(buf, &dtl->buf[i], n_req * sizeof(struct dtl_entry));
	if (rc)
		return -EFAULT;

	n_read += n_req;

	return n_read * sizeof(struct dtl_entry);
}

static const struct file_operations dtl_fops = {
	.open		= dtl_file_open,
	.release	= dtl_file_release,
	.read		= dtl_file_read,
	.llseek		= no_llseek,
};

static struct dentry *dtl_dir;

static int dtl_setup_file(struct dtl *dtl)
{
	char name[10];

	sprintf(name, "cpu-%d", dtl->cpu);

	dtl->file = debugfs_create_file(name, 0400, dtl_dir, dtl, &dtl_fops);
	if (!dtl->file)
		return -ENOMEM;

	return 0;
}

static int dtl_init(void)
{
	struct dentry *event_mask_file, *buf_entries_file;
	int rc, i;

	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
		return -ENODEV;

	/* set up common debugfs structure */

	rc = -ENOMEM;
	dtl_dir = debugfs_create_dir("dtl", powerpc_debugfs_root);
	if (!dtl_dir) {
		printk(KERN_WARNING "%s: can't create dtl root dir\n",
				__func__);
		goto err;
	}

	event_mask_file = debugfs_create_x8("dtl_event_mask", 0600,
				dtl_dir, &dtl_event_mask);
	buf_entries_file = debugfs_create_u32("dtl_buf_entries", 0400,
				dtl_dir, &dtl_buf_entries);

	if (!event_mask_file || !buf_entries_file) {
		printk(KERN_WARNING "%s: can't create dtl files\n", __func__);
		goto err_remove_dir;
	}

	/* set up the per-cpu log structures */
	for_each_possible_cpu(i) {
		struct dtl *dtl = &per_cpu(cpu_dtl, i);
		spin_lock_init(&dtl->lock);
		dtl->cpu = i;

		rc = dtl_setup_file(dtl);
		if (rc)
			goto err_remove_dir;
	}

	return 0;

err_remove_dir:
	debugfs_remove_recursive(dtl_dir);
err:
	return rc;
}
machine_arch_initcall(pseries, dtl_init);
Commit	Line	Data
fc59a3fc JK	1	/*
	2	* Virtual Processor Dispatch Trace Log
	3	*
	4	* (C) Copyright IBM Corporation 2009
	5	*
	6	* Author: Jeremy Kerr <jk@ozlabs.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2, or (at your option)
	11	* any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	21	*/
	22
5a0e3ad6	23	#include <linux/slab.h>
872e439a	24	#include <linux/spinlock.h>
fc59a3fc	25	#include <asm/smp.h>
7c0f6ba6	26	#include <linux/uaccess.h>
b71a0c29	27	#include <asm/firmware.h>
cf9efce0	28	#include <asm/lppaca.h>
7644d581	29	#include <asm/debugfs.h>
212bebb4	30	#include <asm/plpar_wrappers.h>
8e83e905	31	#include <asm/machdep.h>
fc59a3fc	32
fc59a3fc JK	33	struct dtl {
	34	struct dtl_entry *buf;
	35	struct dentry *file;
	36	int cpu;
	37	int buf_entries;
	38	u64 last_idx;
872e439a	39	spinlock_t lock;
fc59a3fc	40	};
6b7487fc	41	static DEFINE_PER_CPU(struct dtl, cpu_dtl);
fc59a3fc	42
515bbc8a	43	static u8 dtl_event_mask = DTL_LOG_ALL;
fc59a3fc JK	44
	45
	46	/*
af442a1b NA	47	* Size of per-cpu log buffers. Firmware requires that the buffer does
af442a1b NA	48	* not cross a 4k boundary.
fc59a3fc	49	*/
af442a1b	50	static int dtl_buf_entries = N_DISPATCH_LOG;
fc59a3fc	51
abf917cd	52	#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
872e439a PM	53	struct dtl_ring {
	54	u64 write_index;
	55	struct dtl_entry *write_ptr;
	56	struct dtl_entry *buf;
	57	struct dtl_entry *buf_end;
872e439a PM	58	};
	59
	60	static DEFINE_PER_CPU(struct dtl_ring, dtl_rings);
	61
	62	static atomic_t dtl_count;
	63
	64	/*
	65	* The cpu accounting code controls the DTL ring buffer, and we get
	66	* given entries as they are processed.
	67	*/
	68	static void consume_dtle(struct dtl_entry *dtle, u64 index)
fc59a3fc	69	{
69111bac	70	struct dtl_ring *dtlr = this_cpu_ptr(&dtl_rings);
872e439a PM	71	struct dtl_entry *wp = dtlr->write_ptr;
872e439a PM	72	struct lppaca *vpa = local_paca->lppaca_ptr;
fc59a3fc	73
872e439a PM	74	if (!wp)
872e439a PM	75	return;
fc59a3fc	76
872e439a PM	77	wp = dtle;
872e439a PM	78	barrier();
fc59a3fc	79
872e439a	80	/* check for hypervisor ring buffer overflow, ignore this entry if so */
7ffcf8ec	81	if (index + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx))
872e439a PM	82	return;
	83
	84	++wp;
	85	if (wp == dtlr->buf_end)
	86	wp = dtlr->buf;
	87	dtlr->write_ptr = wp;
	88
	89	/* incrementing write_index makes the new entry visible */
	90	smp_wmb();
	91	++dtlr->write_index;
	92	}
	93
	94	static int dtl_start(struct dtl *dtl)
	95	{
	96	struct dtl_ring *dtlr = &per_cpu(dtl_rings, dtl->cpu);
	97
	98	dtlr->buf = dtl->buf;
	99	dtlr->buf_end = dtl->buf + dtl->buf_entries;
	100	dtlr->write_index = 0;
	101
	102	/* setting write_ptr enables logging into our buffer */
	103	smp_wmb();
	104	dtlr->write_ptr = dtl->buf;
	105
	106	/* enable event logging */
872e439a PM	107	lppaca_of(dtl->cpu).dtl_enable_mask \|= dtl_event_mask;
	108
	109	dtl_consumer = consume_dtle;
	110	atomic_inc(&dtl_count);
	111	return 0;
	112	}
	113
	114	static void dtl_stop(struct dtl *dtl)
	115	{
	116	struct dtl_ring *dtlr = &per_cpu(dtl_rings, dtl->cpu);
	117
	118	dtlr->write_ptr = NULL;
	119	smp_wmb();
	120
	121	dtlr->buf = NULL;
	122
	123	/* restore dtl_enable_mask */
5b3306f0	124	lppaca_of(dtl->cpu).dtl_enable_mask = DTL_LOG_PREEMPT;
872e439a PM	125
	126	if (atomic_dec_and_test(&dtl_count))
	127	dtl_consumer = NULL;
	128	}
	129
	130	static u64 dtl_current_index(struct dtl *dtl)
	131	{
	132	return per_cpu(dtl_rings, dtl->cpu).write_index;
	133	}
	134
abf917cd	135	#else /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
872e439a PM	136
	137	static int dtl_start(struct dtl *dtl)
	138	{
	139	unsigned long addr;
	140	int ret, hwcpu;
fc59a3fc JK	141
	142	/* Register our dtl buffer with the hypervisor. The HV expects the
	143	* buffer size to be passed in the second word of the buffer */
db787af1	144	((u32 *)dtl->buf)[1] = cpu_to_be32(DISPATCH_LOG_BYTES);
fc59a3fc JK	145
	146	hwcpu = get_hard_smp_processor_id(dtl->cpu);
	147	addr = __pa(dtl->buf);
	148	ret = register_dtl(hwcpu, addr);
	149	if (ret) {
	150	printk(KERN_WARNING "%s: DTL registration for cpu %d (hw %d) "
	151	"failed with %d\n", __func__, dtl->cpu, hwcpu, ret);
fc59a3fc JK	152	return -EIO;
	153	}
	154
	155	/* set our initial buffer indices */
872e439a	156	lppaca_of(dtl->cpu).dtl_idx = 0;
fc59a3fc	157
82631f5d JK	158	/* ensure that our updates to the lppaca fields have occurred before
	159	* we actually enable the logging */
	160	smp_wmb();
	161
fc59a3fc	162	/* enable event logging */
8154c5d2	163	lppaca_of(dtl->cpu).dtl_enable_mask = dtl_event_mask;
fc59a3fc JK	164
	165	return 0;
	166	}
	167
872e439a	168	static void dtl_stop(struct dtl *dtl)
fc59a3fc JK	169	{
	170	int hwcpu = get_hard_smp_processor_id(dtl->cpu);
	171
8154c5d2	172	lppaca_of(dtl->cpu).dtl_enable_mask = 0x0;
fc59a3fc	173
b1301797	174	unregister_dtl(hwcpu);
872e439a PM	175	}
	176
	177	static u64 dtl_current_index(struct dtl *dtl)
	178	{
9258227e	179	return be64_to_cpu(lppaca_of(dtl->cpu).dtl_idx);
872e439a	180	}
abf917cd	181	#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
fc59a3fc	182
872e439a PM	183	static int dtl_enable(struct dtl *dtl)
	184	{
	185	long int n_entries;
	186	long int rc;
	187	struct dtl_entry *buf = NULL;
	188
af442a1b NA	189	if (!dtl_cache)
	190	return -ENOMEM;
	191
872e439a PM	192	/* only allow one reader */
	193	if (dtl->buf)
	194	return -EBUSY;
	195
	196	n_entries = dtl_buf_entries;
af442a1b	197	buf = kmem_cache_alloc_node(dtl_cache, GFP_KERNEL, cpu_to_node(dtl->cpu));
872e439a PM	198	if (!buf) {
	199	printk(KERN_WARNING "%s: buffer alloc failed for cpu %d\n",
	200	__func__, dtl->cpu);
	201	return -ENOMEM;
	202	}
	203
	204	spin_lock(&dtl->lock);
	205	rc = -EBUSY;
	206	if (!dtl->buf) {
	207	/* store the original allocation size for use during read */
	208	dtl->buf_entries = n_entries;
	209	dtl->buf = buf;
	210	dtl->last_idx = 0;
	211	rc = dtl_start(dtl);
	212	if (rc)
	213	dtl->buf = NULL;
	214	}
	215	spin_unlock(&dtl->lock);
	216
	217	if (rc)
af442a1b	218	kmem_cache_free(dtl_cache, buf);
872e439a PM	219	return rc;
	220	}
	221
	222	static void dtl_disable(struct dtl *dtl)
	223	{
	224	spin_lock(&dtl->lock);
	225	dtl_stop(dtl);
af442a1b	226	kmem_cache_free(dtl_cache, dtl->buf);
fc59a3fc JK	227	dtl->buf = NULL;
fc59a3fc JK	228	dtl->buf_entries = 0;
872e439a	229	spin_unlock(&dtl->lock);
fc59a3fc JK	230	}
	231
	232	/* file interface */
	233
	234	static int dtl_file_open(struct inode inode, struct file filp)
	235	{
	236	struct dtl *dtl = inode->i_private;
	237	int rc;
	238
	239	rc = dtl_enable(dtl);
	240	if (rc)
	241	return rc;
	242
	243	filp->private_data = dtl;
	244	return 0;
	245	}
	246
	247	static int dtl_file_release(struct inode inode, struct file filp)
	248	{
	249	struct dtl *dtl = inode->i_private;
	250	dtl_disable(dtl);
	251	return 0;
	252	}
	253
	254	static ssize_t dtl_file_read(struct file filp, char __user buf, size_t len,
	255	loff_t *pos)
	256	{
872e439a	257	long int rc, n_read, n_req, read_size;
fc59a3fc	258	struct dtl *dtl;
872e439a	259	u64 cur_idx, last_idx, i;
fc59a3fc JK	260
	261	if ((len % sizeof(struct dtl_entry)) != 0)
	262	return -EINVAL;
	263
	264	dtl = filp->private_data;
	265
	266	/* requested number of entries to read */
	267	n_req = len / sizeof(struct dtl_entry);
	268
	269	/* actual number of entries read */
	270	n_read = 0;
	271
872e439a PM	272	spin_lock(&dtl->lock);
	273
	274	cur_idx = dtl_current_index(dtl);
fc59a3fc JK	275	last_idx = dtl->last_idx;
fc59a3fc JK	276
872e439a PM	277	if (last_idx + dtl->buf_entries <= cur_idx)
	278	last_idx = cur_idx - dtl->buf_entries + 1;
	279
	280	if (last_idx + n_req > cur_idx)
	281	n_req = cur_idx - last_idx;
fc59a3fc	282
872e439a PM	283	if (n_req > 0)
	284	dtl->last_idx = last_idx + n_req;
	285
	286	spin_unlock(&dtl->lock);
	287
	288	if (n_req <= 0)
	289	return 0;
	290
	291	i = last_idx % dtl->buf_entries;
fc59a3fc JK	292
fc59a3fc JK	293	/* read the tail of the buffer if we've wrapped */
872e439a PM	294	if (i + n_req > dtl->buf_entries) {
872e439a PM	295	read_size = dtl->buf_entries - i;
fc59a3fc	296
872e439a	297	rc = copy_to_user(buf, &dtl->buf[i],
fc59a3fc JK	298	read_size * sizeof(struct dtl_entry));
	299	if (rc)
	300	return -EFAULT;
	301
872e439a	302	i = 0;
fc59a3fc JK	303	n_req -= read_size;
	304	n_read += read_size;
	305	buf += read_size * sizeof(struct dtl_entry);
	306	}
	307
	308	/* .. and now the head */
872e439a	309	rc = copy_to_user(buf, &dtl->buf[i], n_req * sizeof(struct dtl_entry));
fc59a3fc JK	310	if (rc)
	311	return -EFAULT;
	312
872e439a	313	n_read += n_req;
fc59a3fc JK	314
	315	return n_read * sizeof(struct dtl_entry);
	316	}
	317
828c0950	318	static const struct file_operations dtl_fops = {
fc59a3fc JK	319	.open = dtl_file_open,
	320	.release = dtl_file_release,
	321	.read = dtl_file_read,
	322	.llseek = no_llseek,
	323	};
	324
	325	static struct dentry *dtl_dir;
	326
	327	static int dtl_setup_file(struct dtl *dtl)
	328	{
	329	char name[10];
	330
	331	sprintf(name, "cpu-%d", dtl->cpu);
	332
	333	dtl->file = debugfs_create_file(name, 0400, dtl_dir, dtl, &dtl_fops);
	334	if (!dtl->file)
	335	return -ENOMEM;
	336
	337	return 0;
	338	}
	339
	340	static int dtl_init(void)
	341	{
	342	struct dentry event_mask_file, buf_entries_file;
	343	int rc, i;
	344
	345	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
	346	return -ENODEV;
	347
	348	/* set up common debugfs structure */
	349
	350	rc = -ENOMEM;
	351	dtl_dir = debugfs_create_dir("dtl", powerpc_debugfs_root);
	352	if (!dtl_dir) {
	353	printk(KERN_WARNING "%s: can't create dtl root dir\n",
	354	__func__);
	355	goto err;
	356	}
	357
	358	event_mask_file = debugfs_create_x8("dtl_event_mask", 0600,
	359	dtl_dir, &dtl_event_mask);
af442a1b	360	buf_entries_file = debugfs_create_u32("dtl_buf_entries", 0400,
fc59a3fc JK	361	dtl_dir, &dtl_buf_entries);
	362
	363	if (!event_mask_file \|\| !buf_entries_file) {
	364	printk(KERN_WARNING "%s: can't create dtl files\n", __func__);
	365	goto err_remove_dir;
	366	}
	367
	368	/* set up the per-cpu log structures */
	369	for_each_possible_cpu(i) {
6b7487fc	370	struct dtl *dtl = &per_cpu(cpu_dtl, i);
872e439a	371	spin_lock_init(&dtl->lock);
fc59a3fc JK	372	dtl->cpu = i;
	373
	374	rc = dtl_setup_file(dtl);
	375	if (rc)
	376	goto err_remove_dir;
	377	}
	378
	379	return 0;
	380
	381	err_remove_dir:
	382	debugfs_remove_recursive(dtl_dir);
	383	err:
	384	return rc;
	385	}
8e83e905	386	machine_arch_initcall(pseries, dtl_init);