linux/drivers/s390/crypto/zcrypt_cex2a.c
Harald Freudenberger 91ffc519c1 s390/zcrypt: introduce msg tracking in zcrypt functions
Introduce a new internal struct zcrypt_track with an retry counter
field and a last return code field. Fill and update these fields at
certain points during processing of an request/reply. This tracking
info is then used to
- avoid trying to resend the message forever. Now each message is
  tried to be send TRACK_AGAIN_MAX (currently 10) times and then the
  ioctl returns to userspace with errno EAGAIN.
- avoid trying to resend the message on the very same card/domain. If
  possible (more than one APQN with same quality) don't use the very
  same qid as the previous attempt when again scheduling the request.
  This is done by adding penalty weight values when the dispatching
  takes place. There is a penalty TRACK_AGAIN_CARD_WEIGHT_PENALTY for
  using the same card as previously and another penalty define
  TRACK_AGAIN_QUEUE_WEIGHT_PENALTY to be considered when the same qid
  as the previous sent attempt is calculated. Both values make it
  harder to choose the very same card/domain but not impossible. For
  example when only one APQN is available a resend can only address the
  very same APQN.

There are some more ideas for the future to extend the use of this
tracking information. For example the last response code at NQAP and
DQAP could be stored there, giving the possibility to extended tracing
and debugging about requests failing to get processed properly.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-10-07 21:49:59 +02:00

234 lines
6.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright IBM Corp. 2001, 2012
* Author(s): Robert Burroughs
* Eric Rossman (edrossma@us.ibm.com)
*
* Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
* Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Ralph Wuerthner <rwuerthn@de.ibm.com>
* MSGTYPE restruct: Holger Dengler <hd@linux.vnet.ibm.com>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/atomic.h>
#include <linux/uaccess.h>
#include <linux/mod_devicetable.h>
#include "ap_bus.h"
#include "zcrypt_api.h"
#include "zcrypt_error.h"
#include "zcrypt_cex2a.h"
#include "zcrypt_msgtype50.h"
#define CEX2A_MIN_MOD_SIZE 1 /* 8 bits */
#define CEX2A_MAX_MOD_SIZE 256 /* 2048 bits */
#define CEX3A_MIN_MOD_SIZE CEX2A_MIN_MOD_SIZE
#define CEX3A_MAX_MOD_SIZE 512 /* 4096 bits */
#define CEX2A_MAX_MESSAGE_SIZE 0x390 /* sizeof(struct type50_crb2_msg) */
#define CEX2A_MAX_RESPONSE_SIZE 0x110 /* max outputdatalength + type80_hdr */
#define CEX3A_MAX_RESPONSE_SIZE 0x210 /* 512 bit modulus
* (max outputdatalength) +
* type80_hdr*/
#define CEX3A_MAX_MESSAGE_SIZE sizeof(struct type50_crb3_msg)
#define CEX2A_CLEANUP_TIME (15*HZ)
#define CEX3A_CLEANUP_TIME CEX2A_CLEANUP_TIME
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("CEX2A/CEX3A Cryptographic Coprocessor device driver, " \
"Copyright IBM Corp. 2001, 2018");
MODULE_LICENSE("GPL");
static struct ap_device_id zcrypt_cex2a_card_ids[] = {
{ .dev_type = AP_DEVICE_TYPE_CEX2A,
.match_flags = AP_DEVICE_ID_MATCH_CARD_TYPE },
{ .dev_type = AP_DEVICE_TYPE_CEX3A,
.match_flags = AP_DEVICE_ID_MATCH_CARD_TYPE },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_card_ids);
static struct ap_device_id zcrypt_cex2a_queue_ids[] = {
{ .dev_type = AP_DEVICE_TYPE_CEX2A,
.match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
{ .dev_type = AP_DEVICE_TYPE_CEX3A,
.match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_queue_ids);
/**
* Probe function for CEX2A card devices. It always accepts the AP device
* since the bus_match already checked the card type.
* @ap_dev: pointer to the AP device.
*/
static int zcrypt_cex2a_card_probe(struct ap_device *ap_dev)
{
/*
* Normalized speed ratings per crypto adapter
* MEX_1k, MEX_2k, MEX_4k, CRT_1k, CRT_2k, CRT_4k, RNG, SECKEY
*/
static const int CEX2A_SPEED_IDX[] = {
800, 1000, 2000, 900, 1200, 2400, 0, 0};
static const int CEX3A_SPEED_IDX[] = {
400, 500, 1000, 450, 550, 1200, 0, 0};
struct ap_card *ac = to_ap_card(&ap_dev->device);
struct zcrypt_card *zc;
int rc = 0;
zc = zcrypt_card_alloc();
if (!zc)
return -ENOMEM;
zc->card = ac;
ac->private = zc;
if (ac->ap_dev.device_type == AP_DEVICE_TYPE_CEX2A) {
zc->min_mod_size = CEX2A_MIN_MOD_SIZE;
zc->max_mod_size = CEX2A_MAX_MOD_SIZE;
zc->speed_rating = CEX2A_SPEED_IDX;
zc->max_exp_bit_length = CEX2A_MAX_MOD_SIZE;
zc->type_string = "CEX2A";
zc->user_space_type = ZCRYPT_CEX2A;
} else if (ac->ap_dev.device_type == AP_DEVICE_TYPE_CEX3A) {
zc->min_mod_size = CEX2A_MIN_MOD_SIZE;
zc->max_mod_size = CEX2A_MAX_MOD_SIZE;
zc->max_exp_bit_length = CEX2A_MAX_MOD_SIZE;
if (ap_test_bit(&ac->functions, AP_FUNC_MEX4K) &&
ap_test_bit(&ac->functions, AP_FUNC_CRT4K)) {
zc->max_mod_size = CEX3A_MAX_MOD_SIZE;
zc->max_exp_bit_length = CEX3A_MAX_MOD_SIZE;
}
zc->speed_rating = CEX3A_SPEED_IDX;
zc->type_string = "CEX3A";
zc->user_space_type = ZCRYPT_CEX3A;
} else {
zcrypt_card_free(zc);
return -ENODEV;
}
zc->online = 1;
rc = zcrypt_card_register(zc);
if (rc) {
ac->private = NULL;
zcrypt_card_free(zc);
}
return rc;
}
/**
* This is called to remove the CEX2A card driver information
* if an AP card device is removed.
*/
static void zcrypt_cex2a_card_remove(struct ap_device *ap_dev)
{
struct zcrypt_card *zc = to_ap_card(&ap_dev->device)->private;
if (zc)
zcrypt_card_unregister(zc);
}
static struct ap_driver zcrypt_cex2a_card_driver = {
.probe = zcrypt_cex2a_card_probe,
.remove = zcrypt_cex2a_card_remove,
.ids = zcrypt_cex2a_card_ids,
.flags = AP_DRIVER_FLAG_DEFAULT,
};
/**
* Probe function for CEX2A queue devices. It always accepts the AP device
* since the bus_match already checked the queue type.
* @ap_dev: pointer to the AP device.
*/
static int zcrypt_cex2a_queue_probe(struct ap_device *ap_dev)
{
struct ap_queue *aq = to_ap_queue(&ap_dev->device);
struct zcrypt_queue *zq = NULL;
int rc;
switch (ap_dev->device_type) {
case AP_DEVICE_TYPE_CEX2A:
zq = zcrypt_queue_alloc(CEX2A_MAX_RESPONSE_SIZE);
if (!zq)
return -ENOMEM;
break;
case AP_DEVICE_TYPE_CEX3A:
zq = zcrypt_queue_alloc(CEX3A_MAX_RESPONSE_SIZE);
if (!zq)
return -ENOMEM;
break;
}
if (!zq)
return -ENODEV;
zq->ops = zcrypt_msgtype(MSGTYPE50_NAME, MSGTYPE50_VARIANT_DEFAULT);
zq->queue = aq;
zq->online = 1;
atomic_set(&zq->load, 0);
ap_queue_init_state(aq);
ap_queue_init_reply(aq, &zq->reply);
aq->request_timeout = CEX2A_CLEANUP_TIME,
aq->private = zq;
rc = zcrypt_queue_register(zq);
if (rc) {
aq->private = NULL;
zcrypt_queue_free(zq);
}
return rc;
}
/**
* This is called to remove the CEX2A queue driver information
* if an AP queue device is removed.
*/
static void zcrypt_cex2a_queue_remove(struct ap_device *ap_dev)
{
struct ap_queue *aq = to_ap_queue(&ap_dev->device);
struct zcrypt_queue *zq = aq->private;
if (zq)
zcrypt_queue_unregister(zq);
}
static struct ap_driver zcrypt_cex2a_queue_driver = {
.probe = zcrypt_cex2a_queue_probe,
.remove = zcrypt_cex2a_queue_remove,
.ids = zcrypt_cex2a_queue_ids,
.flags = AP_DRIVER_FLAG_DEFAULT,
};
int __init zcrypt_cex2a_init(void)
{
int rc;
rc = ap_driver_register(&zcrypt_cex2a_card_driver,
THIS_MODULE, "cex2acard");
if (rc)
return rc;
rc = ap_driver_register(&zcrypt_cex2a_queue_driver,
THIS_MODULE, "cex2aqueue");
if (rc)
ap_driver_unregister(&zcrypt_cex2a_card_driver);
return rc;
}
void __exit zcrypt_cex2a_exit(void)
{
ap_driver_unregister(&zcrypt_cex2a_queue_driver);
ap_driver_unregister(&zcrypt_cex2a_card_driver);
}
module_init(zcrypt_cex2a_init);
module_exit(zcrypt_cex2a_exit);