Logo Search packages:      
Sourcecode: linux version File versions  Download package

ap_bus.c

/*
 * linux/drivers/s390/crypto/ap_bus.c
 *
 * Copyright (C) 2006 IBM Corporation
 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *          Martin Schwidefsky <schwidefsky@de.ibm.com>
 *          Ralph Wuerthner <rwuerthn@de.ibm.com>
 *
 * Adjunct processor bus.
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/notifier.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <asm/s390_rdev.h>
#include <asm/reset.h>

#include "ap_bus.h"

/* Some prototypes. */
static void ap_scan_bus(struct work_struct *);
static void ap_poll_all(unsigned long);
static void ap_poll_timeout(unsigned long);
static int ap_poll_thread_start(void);
static void ap_poll_thread_stop(void);
static void ap_request_timeout(unsigned long);

/**
 * Module description.
 */
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("Adjunct Processor Bus driver, "
               "Copyright 2006 IBM Corporation");
MODULE_LICENSE("GPL");

/**
 * Module parameter
 */
int ap_domain_index = -1;     /* Adjunct Processor Domain Index */
module_param_named(domain, ap_domain_index, int, 0000);
MODULE_PARM_DESC(domain, "domain index for ap devices");
EXPORT_SYMBOL(ap_domain_index);

static int ap_thread_flag = 1;
module_param_named(poll_thread, ap_thread_flag, int, 0000);
MODULE_PARM_DESC(poll_thread, "Turn on/off poll thread, default is 1 (on).");

static struct device *ap_root_device = NULL;
static DEFINE_SPINLOCK(ap_device_lock);
static LIST_HEAD(ap_device_list);

/**
 * Workqueue & timer for bus rescan.
 */
static struct workqueue_struct *ap_work_queue;
static struct timer_list ap_config_timer;
static int ap_config_time = AP_CONFIG_TIME;
static DECLARE_WORK(ap_config_work, ap_scan_bus);

/**
 * Tasklet & timer for AP request polling.
 */
static struct timer_list ap_poll_timer = TIMER_INITIALIZER(ap_poll_timeout,0,0);
static DECLARE_TASKLET(ap_tasklet, ap_poll_all, 0);
static atomic_t ap_poll_requests = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(ap_poll_wait);
static struct task_struct *ap_poll_kthread = NULL;
static DEFINE_MUTEX(ap_poll_thread_mutex);

/**
 * Test if ap instructions are available.
 *
 * Returns 0 if the ap instructions are installed.
 */
static inline int ap_instructions_available(void)
{
      register unsigned long reg0 asm ("0") = AP_MKQID(0,0);
      register unsigned long reg1 asm ("1") = -ENODEV;
      register unsigned long reg2 asm ("2") = 0UL;

      asm volatile(
            "   .long 0xb2af0000\n"       /* PQAP(TAPQ) */
            "0: la    %1,0\n"
            "1:\n"
            EX_TABLE(0b, 1b)
            : "+d" (reg0), "+d" (reg1), "+d" (reg2) : : "cc" );
      return reg1;
}

/**
 * Test adjunct processor queue.
 * @qid: the ap queue number
 * @queue_depth: pointer to queue depth value
 * @device_type: pointer to device type value
 *
 * Returns ap queue status structure.
 */
static inline struct ap_queue_status
ap_test_queue(ap_qid_t qid, int *queue_depth, int *device_type)
{
      register unsigned long reg0 asm ("0") = qid;
      register struct ap_queue_status reg1 asm ("1");
      register unsigned long reg2 asm ("2") = 0UL;

      asm volatile(".long 0xb2af0000"           /* PQAP(TAPQ) */
                 : "+d" (reg0), "=d" (reg1), "+d" (reg2) : : "cc");
      *device_type = (int) (reg2 >> 24);
      *queue_depth = (int) (reg2 & 0xff);
      return reg1;
}

/**
 * Reset adjunct processor queue.
 * @qid: the ap queue number
 *
 * Returns ap queue status structure.
 */
static inline struct ap_queue_status ap_reset_queue(ap_qid_t qid)
{
      register unsigned long reg0 asm ("0") = qid | 0x01000000UL;
      register struct ap_queue_status reg1 asm ("1");
      register unsigned long reg2 asm ("2") = 0UL;

      asm volatile(
            ".long 0xb2af0000"            /* PQAP(RAPQ) */
            : "+d" (reg0), "=d" (reg1), "+d" (reg2) : : "cc");
      return reg1;
}

/**
 * Send message to adjunct processor queue.
 * @qid: the ap queue number
 * @psmid: the program supplied message identifier
 * @msg: the message text
 * @length: the message length
 *
 * Returns ap queue status structure.
 *
 * Condition code 1 on NQAP can't happen because the L bit is 1.
 *
 * Condition code 2 on NQAP also means the send is incomplete,
 * because a segment boundary was reached. The NQAP is repeated.
 */
static inline struct ap_queue_status
__ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length)
{
      typedef struct { char _[length]; } msgblock;
      register unsigned long reg0 asm ("0") = qid | 0x40000000UL;
      register struct ap_queue_status reg1 asm ("1");
      register unsigned long reg2 asm ("2") = (unsigned long) msg;
      register unsigned long reg3 asm ("3") = (unsigned long) length;
      register unsigned long reg4 asm ("4") = (unsigned int) (psmid >> 32);
      register unsigned long reg5 asm ("5") = (unsigned int) psmid;

      asm volatile (
            "0: .long 0xb2ad0042\n"       /* DQAP */
            "   brc   2,0b"
            : "+d" (reg0), "=d" (reg1), "+d" (reg2), "+d" (reg3)
            : "d" (reg4), "d" (reg5), "m" (*(msgblock *) msg)
            : "cc" );
      return reg1;
}

int ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length)
{
      struct ap_queue_status status;

      status = __ap_send(qid, psmid, msg, length);
      switch (status.response_code) {
      case AP_RESPONSE_NORMAL:
            return 0;
      case AP_RESPONSE_Q_FULL:
      case AP_RESPONSE_RESET_IN_PROGRESS:
            return -EBUSY;
      default:    /* Device is gone. */
            return -ENODEV;
      }
}
EXPORT_SYMBOL(ap_send);

/*
 * Receive message from adjunct processor queue.
 * @qid: the ap queue number
 * @psmid: pointer to program supplied message identifier
 * @msg: the message text
 * @length: the message length
 *
 * Returns ap queue status structure.
 *
 * Condition code 1 on DQAP means the receive has taken place
 * but only partially.  The response is incomplete, hence the
 * DQAP is repeated.
 *
 * Condition code 2 on DQAP also means the receive is incomplete,
 * this time because a segment boundary was reached. Again, the
 * DQAP is repeated.
 *
 * Note that gpr2 is used by the DQAP instruction to keep track of
 * any 'residual' length, in case the instruction gets interrupted.
 * Hence it gets zeroed before the instruction.
 */
static inline struct ap_queue_status
__ap_recv(ap_qid_t qid, unsigned long long *psmid, void *msg, size_t length)
{
      typedef struct { char _[length]; } msgblock;
      register unsigned long reg0 asm("0") = qid | 0x80000000UL;
      register struct ap_queue_status reg1 asm ("1");
      register unsigned long reg2 asm("2") = 0UL;
      register unsigned long reg4 asm("4") = (unsigned long) msg;
      register unsigned long reg5 asm("5") = (unsigned long) length;
      register unsigned long reg6 asm("6") = 0UL;
      register unsigned long reg7 asm("7") = 0UL;


      asm volatile(
            "0: .long 0xb2ae0064\n"
            "   brc   6,0b\n"
            : "+d" (reg0), "=d" (reg1), "+d" (reg2),
            "+d" (reg4), "+d" (reg5), "+d" (reg6), "+d" (reg7),
            "=m" (*(msgblock *) msg) : : "cc" );
      *psmid = (((unsigned long long) reg6) << 32) + reg7;
      return reg1;
}

int ap_recv(ap_qid_t qid, unsigned long long *psmid, void *msg, size_t length)
{
      struct ap_queue_status status;

      status = __ap_recv(qid, psmid, msg, length);
      switch (status.response_code) {
      case AP_RESPONSE_NORMAL:
            return 0;
      case AP_RESPONSE_NO_PENDING_REPLY:
            if (status.queue_empty)
                  return -ENOENT;
            return -EBUSY;
      case AP_RESPONSE_RESET_IN_PROGRESS:
            return -EBUSY;
      default:
            return -ENODEV;
      }
}
EXPORT_SYMBOL(ap_recv);

/**
 * Check if an AP queue is available. The test is repeated for
 * AP_MAX_RESET times.
 * @qid: the ap queue number
 * @queue_depth: pointer to queue depth value
 * @device_type: pointer to device type value
 */
static int ap_query_queue(ap_qid_t qid, int *queue_depth, int *device_type)
{
      struct ap_queue_status status;
      int t_depth, t_device_type, rc, i;

      rc = -EBUSY;
      for (i = 0; i < AP_MAX_RESET; i++) {
            status = ap_test_queue(qid, &t_depth, &t_device_type);
            switch (status.response_code) {
            case AP_RESPONSE_NORMAL:
                  *queue_depth = t_depth + 1;
                  *device_type = t_device_type;
                  rc = 0;
                  break;
            case AP_RESPONSE_Q_NOT_AVAIL:
                  rc = -ENODEV;
                  break;
            case AP_RESPONSE_RESET_IN_PROGRESS:
                  break;
            case AP_RESPONSE_DECONFIGURED:
                  rc = -ENODEV;
                  break;
            case AP_RESPONSE_CHECKSTOPPED:
                  rc = -ENODEV;
                  break;
            case AP_RESPONSE_BUSY:
                  break;
            default:
                  BUG();
            }
            if (rc != -EBUSY)
                  break;
            if (i < AP_MAX_RESET - 1)
                  udelay(5);
      }
      return rc;
}

/**
 * Reset an AP queue and wait for it to become available again.
 * @qid: the ap queue number
 */
static int ap_init_queue(ap_qid_t qid)
{
      struct ap_queue_status status;
      int rc, dummy, i;

      rc = -ENODEV;
      status = ap_reset_queue(qid);
      for (i = 0; i < AP_MAX_RESET; i++) {
            switch (status.response_code) {
            case AP_RESPONSE_NORMAL:
                  if (status.queue_empty)
                        rc = 0;
                  break;
            case AP_RESPONSE_Q_NOT_AVAIL:
            case AP_RESPONSE_DECONFIGURED:
            case AP_RESPONSE_CHECKSTOPPED:
                  i = AP_MAX_RESET; /* return with -ENODEV */
                  break;
            case AP_RESPONSE_RESET_IN_PROGRESS:
                  rc = -EBUSY;
            case AP_RESPONSE_BUSY:
            default:
                  break;
            }
            if (rc != -ENODEV && rc != -EBUSY)
                  break;
            if (i < AP_MAX_RESET - 1) {
                  udelay(5);
                  status = ap_test_queue(qid, &dummy, &dummy);
            }
      }
      return rc;
}

/**
 * Arm request timeout if a AP device was idle and a new request is submitted.
 */
static void ap_increase_queue_count(struct ap_device *ap_dev)
{
      int timeout = ap_dev->drv->request_timeout;

      ap_dev->queue_count++;
      if (ap_dev->queue_count == 1) {
            mod_timer(&ap_dev->timeout, jiffies + timeout);
            ap_dev->reset = AP_RESET_ARMED;
      }
}

/**
 * AP device is still alive, re-schedule request timeout if there are still
 * pending requests.
 */
static void ap_decrease_queue_count(struct ap_device *ap_dev)
{
      int timeout = ap_dev->drv->request_timeout;

      ap_dev->queue_count--;
      if (ap_dev->queue_count > 0)
            mod_timer(&ap_dev->timeout, jiffies + timeout);
      else
            /**
             * The timeout timer should to be disabled now - since
             * del_timer_sync() is very expensive, we just tell via the
             * reset flag to ignore the pending timeout timer.
             */
            ap_dev->reset = AP_RESET_IGNORE;
}

/**
 * AP device related attributes.
 */
static ssize_t ap_hwtype_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      return snprintf(buf, PAGE_SIZE, "%d\n", ap_dev->device_type);
}
static DEVICE_ATTR(hwtype, 0444, ap_hwtype_show, NULL);

static ssize_t ap_depth_show(struct device *dev, struct device_attribute *attr,
                       char *buf)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      return snprintf(buf, PAGE_SIZE, "%d\n", ap_dev->queue_depth);
}
static DEVICE_ATTR(depth, 0444, ap_depth_show, NULL);

static ssize_t ap_request_count_show(struct device *dev,
                             struct device_attribute *attr,
                             char *buf)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      int rc;

      spin_lock_bh(&ap_dev->lock);
      rc = snprintf(buf, PAGE_SIZE, "%d\n", ap_dev->total_request_count);
      spin_unlock_bh(&ap_dev->lock);
      return rc;
}

static DEVICE_ATTR(request_count, 0444, ap_request_count_show, NULL);

static ssize_t ap_modalias_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
      return sprintf(buf, "ap:t%02X", to_ap_dev(dev)->device_type);
}

static DEVICE_ATTR(modalias, 0444, ap_modalias_show, NULL);

static struct attribute *ap_dev_attrs[] = {
      &dev_attr_hwtype.attr,
      &dev_attr_depth.attr,
      &dev_attr_request_count.attr,
      &dev_attr_modalias.attr,
      NULL
};
static struct attribute_group ap_dev_attr_group = {
      .attrs = ap_dev_attrs
};

/**
 * AP bus driver registration/unregistration.
 */
static int ap_bus_match(struct device *dev, struct device_driver *drv)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      struct ap_driver *ap_drv = to_ap_drv(drv);
      struct ap_device_id *id;

      /**
       * Compare device type of the device with the list of
       * supported types of the device_driver.
       */
      for (id = ap_drv->ids; id->match_flags; id++) {
            if ((id->match_flags & AP_DEVICE_ID_MATCH_DEVICE_TYPE) &&
                (id->dev_type != ap_dev->device_type))
                  continue;
            return 1;
      }
      return 0;
}

/**
 * uevent function for AP devices. It sets up a single environment
 * variable DEV_TYPE which contains the hardware device type.
 */
static int ap_uevent (struct device *dev, struct kobj_uevent_env *env)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      int retval = 0;

      if (!ap_dev)
            return -ENODEV;

      /* Set up DEV_TYPE environment variable. */
      retval = add_uevent_var(env, "DEV_TYPE=%04X", ap_dev->device_type);
      if (retval)
            return retval;

      /* Add MODALIAS= */
      retval = add_uevent_var(env, "MODALIAS=ap:t%02X", ap_dev->device_type);

      return retval;
}

static struct bus_type ap_bus_type = {
      .name = "ap",
      .match = &ap_bus_match,
      .uevent = &ap_uevent,
};

static int ap_device_probe(struct device *dev)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      struct ap_driver *ap_drv = to_ap_drv(dev->driver);
      int rc;

      ap_dev->drv = ap_drv;
      spin_lock_bh(&ap_device_lock);
      list_add(&ap_dev->list, &ap_device_list);
      spin_unlock_bh(&ap_device_lock);
      rc = ap_drv->probe ? ap_drv->probe(ap_dev) : -ENODEV;
      return rc;
}

/**
 * Flush all requests from the request/pending queue of an AP device.
 * @ap_dev: pointer to the AP device.
 */
static void __ap_flush_queue(struct ap_device *ap_dev)
{
      struct ap_message *ap_msg, *next;

      list_for_each_entry_safe(ap_msg, next, &ap_dev->pendingq, list) {
            list_del_init(&ap_msg->list);
            ap_dev->pendingq_count--;
            ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
      }
      list_for_each_entry_safe(ap_msg, next, &ap_dev->requestq, list) {
            list_del_init(&ap_msg->list);
            ap_dev->requestq_count--;
            ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
      }
}

void ap_flush_queue(struct ap_device *ap_dev)
{
      spin_lock_bh(&ap_dev->lock);
      __ap_flush_queue(ap_dev);
      spin_unlock_bh(&ap_dev->lock);
}
EXPORT_SYMBOL(ap_flush_queue);

static int ap_device_remove(struct device *dev)
{
      struct ap_device *ap_dev = to_ap_dev(dev);
      struct ap_driver *ap_drv = ap_dev->drv;

      ap_flush_queue(ap_dev);
      del_timer_sync(&ap_dev->timeout);
      if (ap_drv->remove)
            ap_drv->remove(ap_dev);
      spin_lock_bh(&ap_device_lock);
      list_del_init(&ap_dev->list);
      spin_unlock_bh(&ap_device_lock);
      spin_lock_bh(&ap_dev->lock);
      atomic_sub(ap_dev->queue_count, &ap_poll_requests);
      spin_unlock_bh(&ap_dev->lock);
      return 0;
}

int ap_driver_register(struct ap_driver *ap_drv, struct module *owner,
                   char *name)
{
      struct device_driver *drv = &ap_drv->driver;

      drv->bus = &ap_bus_type;
      drv->probe = ap_device_probe;
      drv->remove = ap_device_remove;
      drv->owner = owner;
      drv->name = name;
      return driver_register(drv);
}
EXPORT_SYMBOL(ap_driver_register);

void ap_driver_unregister(struct ap_driver *ap_drv)
{
      driver_unregister(&ap_drv->driver);
}
EXPORT_SYMBOL(ap_driver_unregister);

/**
 * AP bus attributes.
 */
static ssize_t ap_domain_show(struct bus_type *bus, char *buf)
{
      return snprintf(buf, PAGE_SIZE, "%d\n", ap_domain_index);
}

static BUS_ATTR(ap_domain, 0444, ap_domain_show, NULL);

static ssize_t ap_config_time_show(struct bus_type *bus, char *buf)
{
      return snprintf(buf, PAGE_SIZE, "%d\n", ap_config_time);
}

static ssize_t ap_config_time_store(struct bus_type *bus,
                            const char *buf, size_t count)
{
      int time;

      if (sscanf(buf, "%d\n", &time) != 1 || time < 5 || time > 120)
            return -EINVAL;
      ap_config_time = time;
      if (!timer_pending(&ap_config_timer) ||
          !mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ)) {
            ap_config_timer.expires = jiffies + ap_config_time * HZ;
            add_timer(&ap_config_timer);
      }
      return count;
}

static BUS_ATTR(config_time, 0644, ap_config_time_show, ap_config_time_store);

static ssize_t ap_poll_thread_show(struct bus_type *bus, char *buf)
{
      return snprintf(buf, PAGE_SIZE, "%d\n", ap_poll_kthread ? 1 : 0);
}

static ssize_t ap_poll_thread_store(struct bus_type *bus,
                            const char *buf, size_t count)
{
      int flag, rc;

      if (sscanf(buf, "%d\n", &flag) != 1)
            return -EINVAL;
      if (flag) {
            rc = ap_poll_thread_start();
            if (rc)
                  return rc;
      }
      else
            ap_poll_thread_stop();
      return count;
}

static BUS_ATTR(poll_thread, 0644, ap_poll_thread_show, ap_poll_thread_store);

static struct bus_attribute *const ap_bus_attrs[] = {
      &bus_attr_ap_domain,
      &bus_attr_config_time,
      &bus_attr_poll_thread,
      NULL
};

/**
 * Pick one of the 16 ap domains.
 */
static int ap_select_domain(void)
{
      int queue_depth, device_type, count, max_count, best_domain;
      int rc, i, j;

      /**
       * We want to use a single domain. Either the one specified with
       * the "domain=" parameter or the domain with the maximum number
       * of devices.
       */
      if (ap_domain_index >= 0 && ap_domain_index < AP_DOMAINS)
            /* Domain has already been selected. */
            return 0;
      best_domain = -1;
      max_count = 0;
      for (i = 0; i < AP_DOMAINS; i++) {
            count = 0;
            for (j = 0; j < AP_DEVICES; j++) {
                  ap_qid_t qid = AP_MKQID(j, i);
                  rc = ap_query_queue(qid, &queue_depth, &device_type);
                  if (rc)
                        continue;
                  count++;
            }
            if (count > max_count) {
                  max_count = count;
                  best_domain = i;
            }
      }
      if (best_domain >= 0){
            ap_domain_index = best_domain;
            return 0;
      }
      return -ENODEV;
}

/**
 * Find the device type if query queue returned a device type of 0.
 * @ap_dev: pointer to the AP device.
 */
static int ap_probe_device_type(struct ap_device *ap_dev)
{
      static unsigned char msg[] = {
            0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x58,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x01,0x00,0x43,0x43,0x41,0x2d,0x41,0x50,
            0x50,0x4c,0x20,0x20,0x20,0x01,0x01,0x01,
            0x00,0x00,0x00,0x00,0x50,0x4b,0x00,0x00,
            0x00,0x00,0x01,0x1c,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x05,0xb8,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x70,0x00,0x41,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x54,0x32,0x01,0x00,0xa0,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0xb8,0x05,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x0a,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
            0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,
            0x49,0x43,0x53,0x46,0x20,0x20,0x20,0x20,
            0x50,0x4b,0x0a,0x00,0x50,0x4b,0x43,0x53,
            0x2d,0x31,0x2e,0x32,0x37,0x00,0x11,0x22,
            0x33,0x44,0x55,0x66,0x77,0x88,0x99,0x00,
            0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88,
            0x99,0x00,0x11,0x22,0x33,0x44,0x55,0x66,
            0x77,0x88,0x99,0x00,0x11,0x22,0x33,0x44,
            0x55,0x66,0x77,0x88,0x99,0x00,0x11,0x22,
            0x33,0x44,0x55,0x66,0x77,0x88,0x99,0x00,
            0x11,0x22,0x33,0x5d,0x00,0x5b,0x00,0x77,
            0x88,0x1e,0x00,0x00,0x57,0x00,0x00,0x00,
            0x00,0x04,0x00,0x00,0x4f,0x00,0x00,0x00,
            0x03,0x02,0x00,0x00,0x40,0x01,0x00,0x01,
            0xce,0x02,0x68,0x2d,0x5f,0xa9,0xde,0x0c,
            0xf6,0xd2,0x7b,0x58,0x4b,0xf9,0x28,0x68,
            0x3d,0xb4,0xf4,0xef,0x78,0xd5,0xbe,0x66,
            0x63,0x42,0xef,0xf8,0xfd,0xa4,0xf8,0xb0,
            0x8e,0x29,0xc2,0xc9,0x2e,0xd8,0x45,0xb8,
            0x53,0x8c,0x6f,0x4e,0x72,0x8f,0x6c,0x04,
            0x9c,0x88,0xfc,0x1e,0xc5,0x83,0x55,0x57,
            0xf7,0xdd,0xfd,0x4f,0x11,0x36,0x95,0x5d,
      };
      struct ap_queue_status status;
      unsigned long long psmid;
      char *reply;
      int rc, i;

      reply = (void *) get_zeroed_page(GFP_KERNEL);
      if (!reply) {
            rc = -ENOMEM;
            goto out;
      }

      status = __ap_send(ap_dev->qid, 0x0102030405060708ULL,
                     msg, sizeof(msg));
      if (status.response_code != AP_RESPONSE_NORMAL) {
            rc = -ENODEV;
            goto out_free;
      }

      /* Wait for the test message to complete. */
      for (i = 0; i < 6; i++) {
            mdelay(300);
            status = __ap_recv(ap_dev->qid, &psmid, reply, 4096);
            if (status.response_code == AP_RESPONSE_NORMAL &&
                psmid == 0x0102030405060708ULL)
                  break;
      }
      if (i < 6) {
            /* Got an answer. */
            if (reply[0] == 0x00 && reply[1] == 0x86)
                  ap_dev->device_type = AP_DEVICE_TYPE_PCICC;
            else
                  ap_dev->device_type = AP_DEVICE_TYPE_PCICA;
            rc = 0;
      } else
            rc = -ENODEV;

out_free:
      free_page((unsigned long) reply);
out:
      return rc;
}

/**
 * Scan the ap bus for new devices.
 */
static int __ap_scan_bus(struct device *dev, void *data)
{
      return to_ap_dev(dev)->qid == (ap_qid_t)(unsigned long) data;
}

static void ap_device_release(struct device *dev)
{
      struct ap_device *ap_dev = to_ap_dev(dev);

      kfree(ap_dev);
}

static void ap_scan_bus(struct work_struct *unused)
{
      struct ap_device *ap_dev;
      struct device *dev;
      ap_qid_t qid;
      int queue_depth, device_type;
      int rc, i;

      if (ap_select_domain() != 0)
            return;
      for (i = 0; i < AP_DEVICES; i++) {
            qid = AP_MKQID(i, ap_domain_index);
            dev = bus_find_device(&ap_bus_type, NULL,
                              (void *)(unsigned long)qid,
                              __ap_scan_bus);
            rc = ap_query_queue(qid, &queue_depth, &device_type);
            if (dev) {
                  if (rc == -EBUSY) {
                        set_current_state(TASK_UNINTERRUPTIBLE);
                        schedule_timeout(AP_RESET_TIMEOUT);
                        rc = ap_query_queue(qid, &queue_depth,
                                        &device_type);
                  }
                  ap_dev = to_ap_dev(dev);
                  spin_lock_bh(&ap_dev->lock);
                  if (rc || ap_dev->unregistered) {
                        spin_unlock_bh(&ap_dev->lock);
                        device_unregister(dev);
                        put_device(dev);
                        continue;
                  }
                  spin_unlock_bh(&ap_dev->lock);
                  put_device(dev);
                  continue;
            }
            if (rc)
                  continue;
            rc = ap_init_queue(qid);
            if (rc)
                  continue;
            ap_dev = kzalloc(sizeof(*ap_dev), GFP_KERNEL);
            if (!ap_dev)
                  break;
            ap_dev->qid = qid;
            ap_dev->queue_depth = queue_depth;
            ap_dev->unregistered = 1;
            spin_lock_init(&ap_dev->lock);
            INIT_LIST_HEAD(&ap_dev->pendingq);
            INIT_LIST_HEAD(&ap_dev->requestq);
            INIT_LIST_HEAD(&ap_dev->list);
            setup_timer(&ap_dev->timeout, ap_request_timeout,
                      (unsigned long) ap_dev);
            if (device_type == 0)
                  ap_probe_device_type(ap_dev);
            else
                  ap_dev->device_type = device_type;

            ap_dev->device.bus = &ap_bus_type;
            ap_dev->device.parent = ap_root_device;
            snprintf(ap_dev->device.bus_id, BUS_ID_SIZE, "card%02x",
                   AP_QID_DEVICE(ap_dev->qid));
            ap_dev->device.release = ap_device_release;
            rc = device_register(&ap_dev->device);
            if (rc) {
                  kfree(ap_dev);
                  continue;
            }
            /* Add device attributes. */
            rc = sysfs_create_group(&ap_dev->device.kobj,
                              &ap_dev_attr_group);
            if (!rc) {
                  spin_lock_bh(&ap_dev->lock);
                  ap_dev->unregistered = 0;
                  spin_unlock_bh(&ap_dev->lock);
            }
            else
                  device_unregister(&ap_dev->device);
      }
}

static void
ap_config_timeout(unsigned long ptr)
{
      queue_work(ap_work_queue, &ap_config_work);
      ap_config_timer.expires = jiffies + ap_config_time * HZ;
      add_timer(&ap_config_timer);
}

/**
 * Set up the timer to run the poll tasklet
 */
static inline void ap_schedule_poll_timer(void)
{
      if (timer_pending(&ap_poll_timer))
            return;
      mod_timer(&ap_poll_timer, jiffies + AP_POLL_TIME);
}

/**
 * Receive pending reply messages from an AP device.
 * @ap_dev: pointer to the AP device
 * @flags: pointer to control flags, bit 2^0 is set if another poll is
 *       required, bit 2^1 is set if the poll timer needs to get armed
 * Returns 0 if the device is still present, -ENODEV if not.
 */
static int ap_poll_read(struct ap_device *ap_dev, unsigned long *flags)
{
      struct ap_queue_status status;
      struct ap_message *ap_msg;

      if (ap_dev->queue_count <= 0)
            return 0;
      status = __ap_recv(ap_dev->qid, &ap_dev->reply->psmid,
                     ap_dev->reply->message, ap_dev->reply->length);
      switch (status.response_code) {
      case AP_RESPONSE_NORMAL:
            atomic_dec(&ap_poll_requests);
            ap_decrease_queue_count(ap_dev);
            list_for_each_entry(ap_msg, &ap_dev->pendingq, list) {
                  if (ap_msg->psmid != ap_dev->reply->psmid)
                        continue;
                  list_del_init(&ap_msg->list);
                  ap_dev->pendingq_count--;
                  ap_dev->drv->receive(ap_dev, ap_msg, ap_dev->reply);
                  break;
            }
            if (ap_dev->queue_count > 0)
                  *flags |= 1;
            break;
      case AP_RESPONSE_NO_PENDING_REPLY:
            if (status.queue_empty) {
                  /* The card shouldn't forget requests but who knows. */
                  atomic_sub(ap_dev->queue_count, &ap_poll_requests);
                  ap_dev->queue_count = 0;
                  list_splice_init(&ap_dev->pendingq, &ap_dev->requestq);
                  ap_dev->requestq_count += ap_dev->pendingq_count;
                  ap_dev->pendingq_count = 0;
            } else
                  *flags |= 2;
            break;
      default:
            return -ENODEV;
      }
      return 0;
}

/**
 * Send messages from the request queue to an AP device.
 * @ap_dev: pointer to the AP device
 * @flags: pointer to control flags, bit 2^0 is set if another poll is
 *       required, bit 2^1 is set if the poll timer needs to get armed
 * Returns 0 if the device is still present, -ENODEV if not.
 */
static int ap_poll_write(struct ap_device *ap_dev, unsigned long *flags)
{
      struct ap_queue_status status;
      struct ap_message *ap_msg;

      if (ap_dev->requestq_count <= 0 ||
          ap_dev->queue_count >= ap_dev->queue_depth)
            return 0;
      /* Start the next request on the queue. */
      ap_msg = list_entry(ap_dev->requestq.next, struct ap_message, list);
      status = __ap_send(ap_dev->qid, ap_msg->psmid,
                     ap_msg->message, ap_msg->length);
      switch (status.response_code) {
      case AP_RESPONSE_NORMAL:
            atomic_inc(&ap_poll_requests);
            ap_increase_queue_count(ap_dev);
            list_move_tail(&ap_msg->list, &ap_dev->pendingq);
            ap_dev->requestq_count--;
            ap_dev->pendingq_count++;
            if (ap_dev->queue_count < ap_dev->queue_depth &&
                ap_dev->requestq_count > 0)
                  *flags |= 1;
            *flags |= 2;
            break;
      case AP_RESPONSE_Q_FULL:
      case AP_RESPONSE_RESET_IN_PROGRESS:
            *flags |= 2;
            break;
      case AP_RESPONSE_MESSAGE_TOO_BIG:
            return -EINVAL;
      default:
            return -ENODEV;
      }
      return 0;
}

/**
 * Poll AP device for pending replies and send new messages. If either
 * ap_poll_read or ap_poll_write returns -ENODEV unregister the device.
 * @ap_dev: pointer to the bus device
 * @flags: pointer to control flags, bit 2^0 is set if another poll is
 *       required, bit 2^1 is set if the poll timer needs to get armed
 * Returns 0.
 */
static inline int ap_poll_queue(struct ap_device *ap_dev, unsigned long *flags)
{
      int rc;

      rc = ap_poll_read(ap_dev, flags);
      if (rc)
            return rc;
      return ap_poll_write(ap_dev, flags);
}

/**
 * Queue a message to a device.
 * @ap_dev: pointer to the AP device
 * @ap_msg: the message to be queued
 */
static int __ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
{
      struct ap_queue_status status;

      if (list_empty(&ap_dev->requestq) &&
          ap_dev->queue_count < ap_dev->queue_depth) {
            status = __ap_send(ap_dev->qid, ap_msg->psmid,
                           ap_msg->message, ap_msg->length);
            switch (status.response_code) {
            case AP_RESPONSE_NORMAL:
                  list_add_tail(&ap_msg->list, &ap_dev->pendingq);
                  atomic_inc(&ap_poll_requests);
                  ap_dev->pendingq_count++;
                  ap_increase_queue_count(ap_dev);
                  ap_dev->total_request_count++;
                  break;
            case AP_RESPONSE_Q_FULL:
            case AP_RESPONSE_RESET_IN_PROGRESS:
                  list_add_tail(&ap_msg->list, &ap_dev->requestq);
                  ap_dev->requestq_count++;
                  ap_dev->total_request_count++;
                  return -EBUSY;
            case AP_RESPONSE_MESSAGE_TOO_BIG:
                  ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-EINVAL));
                  return -EINVAL;
            default:    /* Device is gone. */
                  ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
                  return -ENODEV;
            }
      } else {
            list_add_tail(&ap_msg->list, &ap_dev->requestq);
            ap_dev->requestq_count++;
            ap_dev->total_request_count++;
            return -EBUSY;
      }
      ap_schedule_poll_timer();
      return 0;
}

void ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
{
      unsigned long flags;
      int rc;

      spin_lock_bh(&ap_dev->lock);
      if (!ap_dev->unregistered) {
            /* Make room on the queue by polling for finished requests. */
            rc = ap_poll_queue(ap_dev, &flags);
            if (!rc)
                  rc = __ap_queue_message(ap_dev, ap_msg);
            if (!rc)
                  wake_up(&ap_poll_wait);
            if (rc == -ENODEV)
                  ap_dev->unregistered = 1;
      } else {
            ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
            rc = -ENODEV;
      }
      spin_unlock_bh(&ap_dev->lock);
      if (rc == -ENODEV)
            device_unregister(&ap_dev->device);
}
EXPORT_SYMBOL(ap_queue_message);

/**
 * Cancel a crypto request. This is done by removing the request
 * from the devive pendingq or requestq queue. Note that the
 * request stays on the AP queue. When it finishes the message
 * reply will be discarded because the psmid can't be found.
 * @ap_dev: AP device that has the message queued
 * @ap_msg: the message that is to be removed
 */
void ap_cancel_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
{
      struct ap_message *tmp;

      spin_lock_bh(&ap_dev->lock);
      if (!list_empty(&ap_msg->list)) {
            list_for_each_entry(tmp, &ap_dev->pendingq, list)
                  if (tmp->psmid == ap_msg->psmid) {
                        ap_dev->pendingq_count--;
                        goto found;
                  }
            ap_dev->requestq_count--;
      found:
            list_del_init(&ap_msg->list);
      }
      spin_unlock_bh(&ap_dev->lock);
}
EXPORT_SYMBOL(ap_cancel_message);

/**
 * AP receive polling for finished AP requests
 */
static void ap_poll_timeout(unsigned long unused)
{
      tasklet_schedule(&ap_tasklet);
}

/**
 * Reset a not responding AP device and move all requests from the
 * pending queue to the request queue.
 */
static void ap_reset(struct ap_device *ap_dev)
{
      int rc;

      ap_dev->reset = AP_RESET_IGNORE;
      atomic_sub(ap_dev->queue_count, &ap_poll_requests);
      ap_dev->queue_count = 0;
      list_splice_init(&ap_dev->pendingq, &ap_dev->requestq);
      ap_dev->requestq_count += ap_dev->pendingq_count;
      ap_dev->pendingq_count = 0;
      rc = ap_init_queue(ap_dev->qid);
      if (rc == -ENODEV)
            ap_dev->unregistered = 1;
}

/**
 * Poll all AP devices on the bus in a round robin fashion. Continue
 * polling until bit 2^0 of the control flags is not set. If bit 2^1
 * of the control flags has been set arm the poll timer.
 */
static int __ap_poll_all(struct ap_device *ap_dev, unsigned long *flags)
{
      spin_lock(&ap_dev->lock);
      if (!ap_dev->unregistered) {
            if (ap_poll_queue(ap_dev, flags))
                  ap_dev->unregistered = 1;
            if (ap_dev->reset == AP_RESET_DO)
                  ap_reset(ap_dev);
      }
      spin_unlock(&ap_dev->lock);
      return 0;
}

static void ap_poll_all(unsigned long dummy)
{
      unsigned long flags;
      struct ap_device *ap_dev;

      do {
            flags = 0;
            spin_lock(&ap_device_lock);
            list_for_each_entry(ap_dev, &ap_device_list, list) {
                  __ap_poll_all(ap_dev, &flags);
            }
            spin_unlock(&ap_device_lock);
      } while (flags & 1);
      if (flags & 2)
            ap_schedule_poll_timer();
}

/**
 * AP bus poll thread. The purpose of this thread is to poll for
 * finished requests in a loop if there is a "free" cpu - that is
 * a cpu that doesn't have anything better to do. The polling stops
 * as soon as there is another task or if all messages have been
 * delivered.
 */
static int ap_poll_thread(void *data)
{
      DECLARE_WAITQUEUE(wait, current);
      unsigned long flags;
      int requests;
      struct ap_device *ap_dev;

      set_user_nice(current, 19);
      while (1) {
            if (need_resched()) {
                  schedule();
                  continue;
            }
            add_wait_queue(&ap_poll_wait, &wait);
            set_current_state(TASK_INTERRUPTIBLE);
            if (kthread_should_stop())
                  break;
            requests = atomic_read(&ap_poll_requests);
            if (requests <= 0)
                  schedule();
            set_current_state(TASK_RUNNING);
            remove_wait_queue(&ap_poll_wait, &wait);

            flags = 0;
            spin_lock_bh(&ap_device_lock);
            list_for_each_entry(ap_dev, &ap_device_list, list) {
                  __ap_poll_all(ap_dev, &flags);
            }
            spin_unlock_bh(&ap_device_lock);
      }
      set_current_state(TASK_RUNNING);
      remove_wait_queue(&ap_poll_wait, &wait);
      return 0;
}

static int ap_poll_thread_start(void)
{
      int rc;

      mutex_lock(&ap_poll_thread_mutex);
      if (!ap_poll_kthread) {
            ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
            rc = IS_ERR(ap_poll_kthread) ? PTR_ERR(ap_poll_kthread) : 0;
            if (rc)
                  ap_poll_kthread = NULL;
      }
      else
            rc = 0;
      mutex_unlock(&ap_poll_thread_mutex);
      return rc;
}

static void ap_poll_thread_stop(void)
{
      mutex_lock(&ap_poll_thread_mutex);
      if (ap_poll_kthread) {
            kthread_stop(ap_poll_kthread);
            ap_poll_kthread = NULL;
      }
      mutex_unlock(&ap_poll_thread_mutex);
}

/**
 * Handling of request timeouts
 */
static void ap_request_timeout(unsigned long data)
{
      struct ap_device *ap_dev = (struct ap_device *) data;

      if (ap_dev->reset == AP_RESET_ARMED)
            ap_dev->reset = AP_RESET_DO;
}

static void ap_reset_domain(void)
{
      int i;

      if (ap_domain_index != -1)
            for (i = 0; i < AP_DEVICES; i++)
                  ap_reset_queue(AP_MKQID(i, ap_domain_index));
}

static void ap_reset_all(void)
{
      int i, j;

      for (i = 0; i < AP_DOMAINS; i++)
            for (j = 0; j < AP_DEVICES; j++)
                  ap_reset_queue(AP_MKQID(j, i));
}

static struct reset_call ap_reset_call = {
      .fn = ap_reset_all,
};

/**
 * The module initialization code.
 */
int __init ap_module_init(void)
{
      int rc, i;

      if (ap_domain_index < -1 || ap_domain_index >= AP_DOMAINS) {
            printk(KERN_WARNING "Invalid param: domain = %d. "
                   " Not loading.\n", ap_domain_index);
            return -EINVAL;
      }
      if (ap_instructions_available() != 0) {
            printk(KERN_WARNING "AP instructions not installed.\n");
            return -ENODEV;
      }
      register_reset_call(&ap_reset_call);

      /* Create /sys/bus/ap. */
      rc = bus_register(&ap_bus_type);
      if (rc)
            goto out;
      for (i = 0; ap_bus_attrs[i]; i++) {
            rc = bus_create_file(&ap_bus_type, ap_bus_attrs[i]);
            if (rc)
                  goto out_bus;
      }

      /* Create /sys/devices/ap. */
      ap_root_device = s390_root_dev_register("ap");
      rc = IS_ERR(ap_root_device) ? PTR_ERR(ap_root_device) : 0;
      if (rc)
            goto out_bus;

      ap_work_queue = create_singlethread_workqueue("kapwork");
      if (!ap_work_queue) {
            rc = -ENOMEM;
            goto out_root;
      }

      if (ap_select_domain() == 0)
            ap_scan_bus(NULL);

      /* Setup the ap bus rescan timer. */
      init_timer(&ap_config_timer);
      ap_config_timer.function = ap_config_timeout;
      ap_config_timer.data = 0;
      ap_config_timer.expires = jiffies + ap_config_time * HZ;
      add_timer(&ap_config_timer);

      /* Start the low priority AP bus poll thread. */
      if (ap_thread_flag) {
            rc = ap_poll_thread_start();
            if (rc)
                  goto out_work;
      }

      return 0;

out_work:
      del_timer_sync(&ap_config_timer);
      del_timer_sync(&ap_poll_timer);
      destroy_workqueue(ap_work_queue);
out_root:
      s390_root_dev_unregister(ap_root_device);
out_bus:
      while (i--)
            bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
      bus_unregister(&ap_bus_type);
out:
      unregister_reset_call(&ap_reset_call);
      return rc;
}

static int __ap_match_all(struct device *dev, void *data)
{
      return 1;
}

/**
 * The module termination code
 */
void ap_module_exit(void)
{
      int i;
      struct device *dev;

      ap_reset_domain();
      ap_poll_thread_stop();
      del_timer_sync(&ap_config_timer);
      del_timer_sync(&ap_poll_timer);
      destroy_workqueue(ap_work_queue);
      tasklet_kill(&ap_tasklet);
      s390_root_dev_unregister(ap_root_device);
      while ((dev = bus_find_device(&ap_bus_type, NULL, NULL,
                __ap_match_all)))
      {
            device_unregister(dev);
            put_device(dev);
      }
      for (i = 0; ap_bus_attrs[i]; i++)
            bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
      bus_unregister(&ap_bus_type);
      unregister_reset_call(&ap_reset_call);
}

#ifndef CONFIG_ZCRYPT_MONOLITHIC
module_init(ap_module_init);
module_exit(ap_module_exit);
#endif

Generated by  Doxygen 1.6.0   Back to index