hvCall_inst.c

Go to the documentation of this file.

/*
 * Copyright (C) 2006 Mike Kravetz IBM Corporation
 *
 * Hypervisor Call Instrumentation
 *
 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/percpu.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/cpumask.h>
#include <asm/hvcall.h>
#include <asm/firmware.h>
#include <asm/cputable.h>
#include <asm/trace.h>

DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);

/*
 * Routines for displaying the statistics in debugfs
 */
static void *hc_start(struct seq_file *m, loff_t *pos)
{
    if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))
        return (void *)(unsigned long)(*pos + 1);

    return NULL;
}

static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
{
    ++*pos;

    return hc_start(m, pos);
}

static void hc_stop(struct seq_file *m, void *p)
{
}

static int hc_show(struct seq_file *m, void *p)
{
    unsigned long h_num = (unsigned long)p;
    struct hcall_stats *hs = m->private;

    if (hs[h_num].num_calls) {
        if (cpu_has_feature(CPU_FTR_PURR))
            seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,
                   hs[h_num].num_calls,
                   hs[h_num].tb_total,
                   hs[h_num].purr_total);
        else
            seq_printf(m, "%lu %lu %lu\n", h_num<<2,
                   hs[h_num].num_calls,
                   hs[h_num].tb_total);
    }

    return 0;
}

static const struct seq_operations hcall_inst_seq_ops = {
        .start = hc_start,
        .next  = hc_next,
        .stop  = hc_stop,
        .show  = hc_show
};

static int hcall_inst_seq_open(struct inode *inode, struct file *file)
{
    int rc;
    struct seq_file *seq;

    rc = seq_open(file, &hcall_inst_seq_ops);
    seq = file->private_data;
    seq->private = file->f_path.dentry->d_inode->i_private;

    return rc;
}

static const struct file_operations hcall_inst_seq_fops = {
    .open = hcall_inst_seq_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = seq_release,
};

#define HCALL_ROOT_DIR      "hcall_inst"
#define CPU_NAME_BUF_SIZE   32


static void probe_hcall_entry(void *ignored, unsigned long opcode, unsigned long *args)
{
    struct hcall_stats *h;

    if (opcode > MAX_HCALL_OPCODE)
        return;

    h = &__get_cpu_var(hcall_stats)[opcode / 4];
    h->tb_start = mftb();
    h->purr_start = mfspr(SPRN_PURR);
}

static void probe_hcall_exit(void *ignored, unsigned long opcode, unsigned long retval,
                 unsigned long *retbuf)
{
    struct hcall_stats *h;

    if (opcode > MAX_HCALL_OPCODE)
        return;

    h = &__get_cpu_var(hcall_stats)[opcode / 4];
    h->num_calls++;
    h->tb_total += mftb() - h->tb_start;
    h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
}

static int __init hcall_inst_init(void)
{
    struct dentry *hcall_root;
    struct dentry *hcall_file;
    char cpu_name_buf[CPU_NAME_BUF_SIZE];
    int cpu;

    if (!firmware_has_feature(FW_FEATURE_LPAR))
        return 0;

    if (register_trace_hcall_entry(probe_hcall_entry, NULL))
        return -EINVAL;

    if (register_trace_hcall_exit(probe_hcall_exit, NULL)) {
        unregister_trace_hcall_entry(probe_hcall_entry, NULL);
        return -EINVAL;
    }

    hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
    if (!hcall_root)
        return -ENOMEM;

    for_each_possible_cpu(cpu) {
        snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
        hcall_file = debugfs_create_file(cpu_name_buf, S_IRUGO,
                         hcall_root,
                         per_cpu(hcall_stats, cpu),
                         &hcall_inst_seq_fops);
        if (!hcall_file)
            return -ENOMEM;
    }

    return 0;
}
__initcall(hcall_inst_init);