linux/drivers/s390/crypto/zcrypt_error.h
Harald Freudenberger c3384369bc s390/zcrypt: improve zcrypt retry behavior
This patch reworks and improves the zcrypt retry behavior:
- The zcrypt_rescan_req counter has been removed. This
  counter variable has been increased on some transport
  errors and was used as a gatekeeper for AP bus rescans.
- Rework of the zcrypt_process_rescan() function to not
  use the above counter variable any more. Instead now
  always the ap_bus_force_rescan() function is called
  (as this has been improved with a previous patch).
- As the zcrpyt_process_rescan() function is called in
  all cprb send functions in case of the first attempt
  to send failed with ENODEV now before the next attempt
  to send an cprb is started.
- Introduce a define ZCRYPT_WAIT_BINDINGS_COMPLETE_MS
  for the amount of milliseconds to have the zcrypt API
  wait for AP bindings complete. This amount has been
  reduced to 30s (was 60s). Some playing around showed
  that 30s is a really fair limit.

The result of the above together with the patches to
improve the AP scan bus functions is that after the
first loop of cprb send retries when the result is a
ENODEV the AP bus scan is always triggered (synchronous).
If the AP bus scan detects changes in the configuration,
all the send functions now retry when the first attempt
was failing with ENODEV in the hope that now a suitable
device has appeared.

About concurrency: The ap_bus_force_rescan() uses a mutex
to ensure only one active AP bus scan is running. Another
caller of this function is blocked as long as the scan is
running but does not cause yet another scan. Instead the
result of the 'other' scan is used. This affects only tasks
which run into an initial ENODEV. Tasks with successful
delivery of cprbs will never invoke the bus scan and thus
never get blocked by the mutex.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-07 14:41:15 +01:00

152 lines
5.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright IBM Corp. 2001, 2006
* 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>
*/
#ifndef _ZCRYPT_ERROR_H_
#define _ZCRYPT_ERROR_H_
#include <linux/atomic.h>
#include "zcrypt_debug.h"
#include "zcrypt_api.h"
#include "zcrypt_msgtype6.h"
/**
* Reply Messages
*
* Error reply messages are of two types:
* 82: Error (see below)
* 88: Error (see below)
* Both type 82 and type 88 have the same structure in the header.
*
* Request reply messages are of three known types:
* 80: Reply from a Type 50 Request (see CEX2A-RELATED STRUCTS)
* 84: Reply from a Type 4 Request (see PCICA-RELATED STRUCTS)
* 86: Reply from a Type 6 Request (see PCICC/PCIXCC/CEX2C-RELATED STRUCTS)
*
*/
struct error_hdr {
unsigned char reserved1; /* 0x00 */
unsigned char type; /* 0x82 or 0x88 */
unsigned char reserved2[2]; /* 0x0000 */
unsigned char reply_code; /* reply code */
unsigned char reserved3[3]; /* 0x000000 */
};
#define TYPE82_RSP_CODE 0x82
#define TYPE88_RSP_CODE 0x88
#define REP82_ERROR_MACHINE_FAILURE 0x10
#define REP82_ERROR_PREEMPT_FAILURE 0x12
#define REP82_ERROR_CHECKPT_FAILURE 0x14
#define REP82_ERROR_MESSAGE_TYPE 0x20
#define REP82_ERROR_INVALID_COMM_CD 0x21 /* Type 84 */
#define REP82_ERROR_INVALID_MSG_LEN 0x23
#define REP82_ERROR_RESERVD_FIELD 0x24 /* was 0x50 */
#define REP82_ERROR_FORMAT_FIELD 0x29
#define REP82_ERROR_INVALID_COMMAND 0x30
#define REP82_ERROR_MALFORMED_MSG 0x40
#define REP82_ERROR_INVALID_SPECIAL_CMD 0x41
#define REP82_ERROR_RESERVED_FIELDO 0x50 /* old value */
#define REP82_ERROR_WORD_ALIGNMENT 0x60
#define REP82_ERROR_MESSAGE_LENGTH 0x80
#define REP82_ERROR_OPERAND_INVALID 0x82
#define REP82_ERROR_OPERAND_SIZE 0x84
#define REP82_ERROR_EVEN_MOD_IN_OPND 0x85
#define REP82_ERROR_RESERVED_FIELD 0x88
#define REP82_ERROR_INVALID_DOMAIN_PENDING 0x8A
#define REP82_ERROR_FILTERED_BY_HYPERVISOR 0x8B
#define REP82_ERROR_TRANSPORT_FAIL 0x90
#define REP82_ERROR_PACKET_TRUNCATED 0xA0
#define REP82_ERROR_ZERO_BUFFER_LEN 0xB0
#define REP88_ERROR_MODULE_FAILURE 0x10
#define REP88_ERROR_MESSAGE_TYPE 0x20
#define REP88_ERROR_MESSAGE_MALFORMD 0x22
#define REP88_ERROR_MESSAGE_LENGTH 0x23
#define REP88_ERROR_RESERVED_FIELD 0x24
#define REP88_ERROR_KEY_TYPE 0x34
#define REP88_ERROR_INVALID_KEY 0x82 /* CEX2A */
#define REP88_ERROR_OPERAND 0x84 /* CEX2A */
#define REP88_ERROR_OPERAND_EVEN_MOD 0x85 /* CEX2A */
static inline int convert_error(struct zcrypt_queue *zq,
struct ap_message *reply)
{
struct error_hdr *ehdr = reply->msg;
int card = AP_QID_CARD(zq->queue->qid);
int queue = AP_QID_QUEUE(zq->queue->qid);
switch (ehdr->reply_code) {
case REP82_ERROR_INVALID_MSG_LEN: /* 0x23 */
case REP82_ERROR_RESERVD_FIELD: /* 0x24 */
case REP82_ERROR_FORMAT_FIELD: /* 0x29 */
case REP82_ERROR_MALFORMED_MSG: /* 0x40 */
case REP82_ERROR_INVALID_SPECIAL_CMD: /* 0x41 */
case REP82_ERROR_MESSAGE_LENGTH: /* 0x80 */
case REP82_ERROR_OPERAND_INVALID: /* 0x82 */
case REP82_ERROR_OPERAND_SIZE: /* 0x84 */
case REP82_ERROR_EVEN_MOD_IN_OPND: /* 0x85 */
case REP82_ERROR_INVALID_DOMAIN_PENDING: /* 0x8A */
case REP82_ERROR_FILTERED_BY_HYPERVISOR: /* 0x8B */
case REP82_ERROR_PACKET_TRUNCATED: /* 0xA0 */
case REP88_ERROR_MESSAGE_MALFORMD: /* 0x22 */
case REP88_ERROR_KEY_TYPE: /* 0x34 */
/* RY indicates malformed request */
if (ehdr->reply_code == REP82_ERROR_FILTERED_BY_HYPERVISOR &&
ehdr->type == TYPE86_RSP_CODE) {
struct {
struct type86_hdr hdr;
struct type86_fmt2_ext fmt2;
} __packed * head = reply->msg;
unsigned int apfs = *((u32 *)head->fmt2.apfs);
ZCRYPT_DBF_WARN("%s dev=%02x.%04x RY=0x%02x apfs=0x%x => rc=EINVAL\n",
__func__, card, queue,
ehdr->reply_code, apfs);
} else {
ZCRYPT_DBF_WARN("%s dev=%02x.%04x RY=0x%02x => rc=EINVAL\n",
__func__, card, queue,
ehdr->reply_code);
}
return -EINVAL;
case REP82_ERROR_MACHINE_FAILURE: /* 0x10 */
case REP82_ERROR_MESSAGE_TYPE: /* 0x20 */
case REP82_ERROR_TRANSPORT_FAIL: /* 0x90 */
/*
* Msg to wrong type or card/infrastructure failure. Return
* EAGAIN, the upper layer may do a retry on the request.
*/
/* For type 86 response show the apfs value (failure reason) */
if (ehdr->reply_code == REP82_ERROR_TRANSPORT_FAIL &&
ehdr->type == TYPE86_RSP_CODE) {
struct {
struct type86_hdr hdr;
struct type86_fmt2_ext fmt2;
} __packed * head = reply->msg;
unsigned int apfs = *((u32 *)head->fmt2.apfs);
ZCRYPT_DBF_WARN(
"%s dev=%02x.%04x RY=0x%02x apfs=0x%x => bus rescan, rc=EAGAIN\n",
__func__, card, queue, ehdr->reply_code, apfs);
} else {
ZCRYPT_DBF_WARN("%s dev=%02x.%04x RY=0x%02x => bus rescan, rc=EAGAIN\n",
__func__, card, queue,
ehdr->reply_code);
}
return -EAGAIN;
default:
/* Assume request is valid and a retry will be worth it */
ZCRYPT_DBF_WARN("%s dev=%02x.%04x RY=0x%02x => rc=EAGAIN\n",
__func__, card, queue, ehdr->reply_code);
return -EAGAIN;
}
}
#endif /* _ZCRYPT_ERROR_H_ */