/*
   * arch/s390/appldata/appldata_os.c
   *
   * Data gathering module for Linux-VM Monitor Stream, Stage 1.
   * Collects misc. OS related data (CPU utilization, running processes).
   *

   * Copyright (C) 2003,2006 IBM Corporation, IBM Deutschland Entwicklung GmbH.

   *

   * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>

   */

  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/errno.h>
  #include <linux/kernel_stat.h>
  #include <linux/netdevice.h>
  #include <linux/sched.h>

  #include <asm/appldata.h>

  #include <asm/smp.h>
  
  #include "appldata.h"
  
  
  #define MY_PRINT_NAME	"appldata_os"		/* for debug messages, etc. */
  #define LOAD_INT(x) ((x) >> FSHIFT)
  #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
  
  /*
   * OS data
   *
   * This is accessed as binary data by z/VM. If changes to it can't be avoided,
   * the structure version (product ID, see appldata_base.c) needs to be changed
   * as well and all documentation and z/VM applications using it must be
   * updated.
   *
   * The record layout is documented in the Linux for zSeries Device Drivers
   * book:
   * http://oss.software.ibm.com/developerworks/opensource/linux390/index.shtml
   */
  struct appldata_os_per_cpu {
  	u32 per_cpu_user;	/* timer ticks spent in user mode   */
  	u32 per_cpu_nice;	/* ... spent with modified priority */
  	u32 per_cpu_system;	/* ... spent in kernel mode         */
  	u32 per_cpu_idle;	/* ... spent in idle mode           */

  	/* New in 2.6 */

  	u32 per_cpu_irq;	/* ... spent in interrupts          */
  	u32 per_cpu_softirq;	/* ... spent in softirqs            */
  	u32 per_cpu_iowait;	/* ... spent while waiting for I/O  */

  
  	/* New in modification level 01 */
  	u32 per_cpu_steal;	/* ... stolen by hypervisor	    */
  	u32 cpu_id;		/* number of this CPU		    */

  } __attribute__((packed));

  
  struct appldata_os_data {
  	u64 timestamp;
  	u32 sync_count_1;	/* after VM collected the record data, */
  	u32 sync_count_2;	/* sync_count_1 and sync_count_2 should be the
  				   same. If not, the record has been updated on
  				   the Linux side while VM was collecting the
  				   (possibly corrupt) data */
  
  	u32 nr_cpus;		/* number of (virtual) CPUs        */
  	u32 per_cpu_size;	/* size of the per-cpu data struct */
  	u32 cpu_offset;		/* offset of the first per-cpu data struct */
  
  	u32 nr_running;		/* number of runnable threads      */
  	u32 nr_threads;		/* number of threads               */
  	u32 avenrun[3];		/* average nr. of running processes during */
  				/* the last 1, 5 and 15 minutes */

  	/* New in 2.6 */

  	u32 nr_iowait;		/* number of blocked threads
  				   (waiting for I/O)               */

  
  	/* per cpu data */
  	struct appldata_os_per_cpu os_cpu[0];

  } __attribute__((packed));

  
  static struct appldata_os_data *appldata_os_data;

  static struct appldata_ops ops = {
  	.ctl_nr    = CTL_APPLDATA_OS,
  	.name	   = "os",
  	.record_nr = APPLDATA_RECORD_OS_ID,
  	.owner	   = THIS_MODULE,
  	.mod_lvl   = {0xF0, 0xF1},		/* EBCDIC "01" */
  };

  
  static inline void appldata_print_debug(struct appldata_os_data *os_data)
  {
  	int a0, a1, a2, i;
  
  	P_DEBUG("--- OS - RECORD ---
  ");
  	P_DEBUG("nr_threads   = %u
  ", os_data->nr_threads);
  	P_DEBUG("nr_running   = %u
  ", os_data->nr_running);
  	P_DEBUG("nr_iowait    = %u
  ", os_data->nr_iowait);
  	P_DEBUG("avenrun(int) = %8x / %8x / %8x
  ", os_data->avenrun[0],
  		os_data->avenrun[1], os_data->avenrun[2]);
  	a0 = os_data->avenrun[0];
  	a1 = os_data->avenrun[1];
  	a2 = os_data->avenrun[2];
  	P_DEBUG("avenrun(float) = %d.%02d / %d.%02d / %d.%02d
  ",
  		LOAD_INT(a0), LOAD_FRAC(a0), LOAD_INT(a1), LOAD_FRAC(a1),
  		LOAD_INT(a2), LOAD_FRAC(a2));
  
  	P_DEBUG("nr_cpus = %u
  ", os_data->nr_cpus);
  	for (i = 0; i < os_data->nr_cpus; i++) {
  		P_DEBUG("cpu%u : user = %u, nice = %u, system = %u, "

  			"idle = %u, irq = %u, softirq = %u, iowait = %u, "
  			"steal = %u
  ",
  				os_data->os_cpu[i].cpu_id,

  				os_data->os_cpu[i].per_cpu_user,
  				os_data->os_cpu[i].per_cpu_nice,
  				os_data->os_cpu[i].per_cpu_system,
  				os_data->os_cpu[i].per_cpu_idle,
  				os_data->os_cpu[i].per_cpu_irq,
  				os_data->os_cpu[i].per_cpu_softirq,

  				os_data->os_cpu[i].per_cpu_iowait,
  				os_data->os_cpu[i].per_cpu_steal);

  	}
  
  	P_DEBUG("sync_count_1 = %u
  ", os_data->sync_count_1);
  	P_DEBUG("sync_count_2 = %u
  ", os_data->sync_count_2);
  	P_DEBUG("timestamp    = %lX
  ", os_data->timestamp);
  }
  
  /*
   * appldata_get_os_data()
   *
   * gather OS data
   */
  static void appldata_get_os_data(void *data)
  {

  	int i, j, rc;

  	struct appldata_os_data *os_data;

  	unsigned int new_size;

  
  	os_data = data;
  	os_data->sync_count_1++;

  	os_data->nr_threads = nr_threads;
  	os_data->nr_running = nr_running();
  	os_data->nr_iowait  = nr_iowait();
  	os_data->avenrun[0] = avenrun[0] + (FIXED_1/200);
  	os_data->avenrun[1] = avenrun[1] + (FIXED_1/200);
  	os_data->avenrun[2] = avenrun[2] + (FIXED_1/200);
  
  	j = 0;
  	for_each_online_cpu(i) {
  		os_data->os_cpu[j].per_cpu_user =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.user);

  		os_data->os_cpu[j].per_cpu_nice =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.nice);

  		os_data->os_cpu[j].per_cpu_system =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.system);

  		os_data->os_cpu[j].per_cpu_idle =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.idle);

  		os_data->os_cpu[j].per_cpu_irq =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.irq);

  		os_data->os_cpu[j].per_cpu_softirq =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.softirq);

  		os_data->os_cpu[j].per_cpu_iowait =

  			cputime_to_jiffies(kstat_cpu(i).cpustat.iowait);

  		os_data->os_cpu[j].per_cpu_steal =
  			cputime_to_jiffies(kstat_cpu(i).cpustat.steal);
  		os_data->os_cpu[j].cpu_id = i;

  		j++;
  	}

  	os_data->nr_cpus = j;
  
  	new_size = sizeof(struct appldata_os_data) +
  		   (os_data->nr_cpus * sizeof(struct appldata_os_per_cpu));
  	if (ops.size != new_size) {
  		if (ops.active) {
  			rc = appldata_diag(APPLDATA_RECORD_OS_ID,
  					   APPLDATA_START_INTERVAL_REC,
  					   (unsigned long) ops.data, new_size,
  					   ops.mod_lvl);
  			if (rc != 0) {
  				P_ERROR("os: START NEW DIAG 0xDC failed, "
  					"return code: %d, new size = %i
  ", rc,
  					new_size);
  				P_INFO("os: stopping old record now
  ");
  			} else
  				P_INFO("os: new record size = %i
  ", new_size);
  
  			rc = appldata_diag(APPLDATA_RECORD_OS_ID,
  					   APPLDATA_STOP_REC,
  					   (unsigned long) ops.data, ops.size,
  					   ops.mod_lvl);
  			if (rc != 0)
  				P_ERROR("os: STOP OLD DIAG 0xDC failed, "
  					"return code: %d, old size = %i
  ", rc,
  					ops.size);
  			else
  				P_INFO("os: old record size = %i stopped
  ",
  					ops.size);
  		}
  		ops.size = new_size;
  	}

  	os_data->timestamp = get_clock();
  	os_data->sync_count_2++;
  #ifdef APPLDATA_DEBUG
  	appldata_print_debug(os_data);
  #endif
  }

  /*
   * appldata_os_init()
   *
   * init data, register ops
   */
  static int __init appldata_os_init(void)
  {

  	int rc, max_size;

  	max_size = sizeof(struct appldata_os_data) +
  		   (NR_CPUS * sizeof(struct appldata_os_per_cpu));
  	if (max_size > APPLDATA_MAX_REC_SIZE) {
  		P_ERROR("Max. size of OS record = %i, bigger than maximum "
  			"record size (%i)
  ", max_size, APPLDATA_MAX_REC_SIZE);

  		rc = -ENOMEM;
  		goto out;
  	}

  	P_DEBUG("max. sizeof(os) = %i, sizeof(os_cpu) = %lu
  ", max_size,

  		sizeof(struct appldata_os_per_cpu));

  	appldata_os_data = kzalloc(max_size, GFP_DMA);

  	if (appldata_os_data == NULL) {
  		P_ERROR("No memory for %s!
  ", ops.name);
  		rc = -ENOMEM;
  		goto out;
  	}

  
  	appldata_os_data->per_cpu_size = sizeof(struct appldata_os_per_cpu);
  	appldata_os_data->cpu_offset   = offsetof(struct appldata_os_data,
  							os_cpu);
  	P_DEBUG("cpu offset = %u
  ", appldata_os_data->cpu_offset);
  
  	ops.data = appldata_os_data;

  	ops.callback  = &appldata_get_os_data;

  	rc = appldata_register_ops(&ops);
  	if (rc != 0) {
  		P_ERROR("Error registering ops, rc = %i
  ", rc);
  		kfree(appldata_os_data);
  	} else {
  		P_DEBUG("%s-ops registered!
  ", ops.name);
  	}
  out:
  	return rc;
  }
  
  /*
   * appldata_os_exit()
   *
   * unregister ops
   */
  static void __exit appldata_os_exit(void)
  {
  	appldata_unregister_ops(&ops);
  	kfree(appldata_os_data);
  	P_DEBUG("%s-ops unregistered!
  ", ops.name);
  }
  
  
  module_init(appldata_os_init);
  module_exit(appldata_os_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Gerald Schaefer");
  MODULE_DESCRIPTION("Linux-VM Monitor Stream, OS statistics");