[POWERPC] powerpc: Instrument Hypervisor Calls

Add instrumentation for hypervisor calls on pseries.  Call statistics
include number of calls, wall time and cpu cycles (if available) and
are made available via debugfs.  Instrumentation code is behind the
HCALL_STATS config option and has no impact if not enabled.

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 129 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/hvCall_inst.c b/arch/powerpc/platforms/pseries/hvCall_inst.c
new file mode 100644
index 000000000000..641e6511cf06
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/hvCall_inst.c
@@ -0,0 +1,129 @@
+/*
+ * 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>
+
+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)
+                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 = (struct hcall_stats *)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 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_dentry->d_inode->u.generic_ip;
+
+        return rc;
+}
+
+static 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 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;
+
+        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);