Commit cb17a636 authored by Felix Beck's avatar Felix Beck Committed by Martin Schwidefsky
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[S390] zcrypt: Use of Thin Interrupts



When the machine supports AP adapter interrupts polling will be
switched off at module initialization and the driver will work in
interrupt mode.
Signed-off-by: default avatarFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 320c04c0
......@@ -17,6 +17,7 @@
#define CHSC_SCH_ISC 7 /* CHSC subchannels */
/* Adapter interrupts. */
#define QDIO_AIRQ_ISC IO_SCH_ISC /* I/O subchannel in qdio mode */
#define AP_ISC 6 /* adjunct processor (crypto) devices */
/* Functions for registration of I/O interruption subclasses */
void isc_register(unsigned int isc);
......
......@@ -5,6 +5,7 @@
* Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Ralph Wuerthner <rwuerthn@de.ibm.com>
* Felix Beck <felix.beck@de.ibm.com>
*
* Adjunct processor bus.
*
......@@ -34,6 +35,10 @@
#include <linux/mutex.h>
#include <asm/s390_rdev.h>
#include <asm/reset.h>
#include <asm/airq.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/isc.h>
#include <linux/hrtimer.h>
#include <linux/ktime.h>
......@@ -46,6 +51,7 @@ static enum hrtimer_restart ap_poll_timeout(struct hrtimer *);
static int ap_poll_thread_start(void);
static void ap_poll_thread_stop(void);
static void ap_request_timeout(unsigned long);
static inline void ap_schedule_poll_timer(void);
/*
* Module description.
......@@ -80,18 +86,28 @@ static int ap_config_time = AP_CONFIG_TIME;
static DECLARE_WORK(ap_config_work, ap_scan_bus);
/*
* Tasklet & timer for AP request polling.
* Tasklet & timer for AP request polling and interrupts
*/
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);
static void *ap_interrupt_indicator;
static struct hrtimer ap_poll_timer;
/* In LPAR poll with 4kHz frequency. Poll every 250000 nanoseconds.
* If z/VM change to 1500000 nanoseconds to adjust to z/VM polling.*/
static unsigned long long poll_timeout = 250000;
/**
* ap_using_interrupts() - Returns non-zero if interrupt support is
* available.
*/
static inline int ap_using_interrupts(void)
{
return ap_interrupt_indicator != NULL;
}
/**
* ap_intructions_available() - Test if AP instructions are available.
*
......@@ -112,6 +128,23 @@ static inline int ap_instructions_available(void)
return reg1;
}
/**
* ap_interrupts_available(): Test if AP interrupts are available.
*
* Returns 1 if AP interrupts are available.
*/
static int ap_interrupts_available(void)
{
unsigned long long facility_bits[2];
if (stfle(facility_bits, 2) <= 1)
return 0;
if (!(facility_bits[0] & (1ULL << 61)) ||
!(facility_bits[1] & (1ULL << 62)))
return 0;
return 1;
}
/**
* ap_test_queue(): Test adjunct processor queue.
* @qid: The AP queue number
......@@ -152,6 +185,80 @@ static inline struct ap_queue_status ap_reset_queue(ap_qid_t qid)
return reg1;
}
#ifdef CONFIG_64BIT
/**
* ap_queue_interruption_control(): Enable interruption for a specific AP.
* @qid: The AP queue number
* @ind: The notification indicator byte
*
* Returns AP queue status.
*/
static inline struct ap_queue_status
ap_queue_interruption_control(ap_qid_t qid, void *ind)
{
register unsigned long reg0 asm ("0") = qid | 0x03000000UL;
register unsigned long reg1_in asm ("1") = 0x0000800000000000UL | AP_ISC;
register struct ap_queue_status reg1_out asm ("1");
register void *reg2 asm ("2") = ind;
asm volatile(
".long 0xb2af0000" /* PQAP(RAPQ) */
: "+d" (reg0), "+d" (reg1_in), "=d" (reg1_out), "+d" (reg2)
:
: "cc" );
return reg1_out;
}
#endif
/**
* ap_queue_enable_interruption(): Enable interruption on an AP.
* @qid: The AP queue number
* @ind: the notification indicator byte
*
* Enables interruption on AP queue via ap_queue_interruption_control(). Based
* on the return value it waits a while and tests the AP queue if interrupts
* have been switched on using ap_test_queue().
*/
static int ap_queue_enable_interruption(ap_qid_t qid, void *ind)
{
#ifdef CONFIG_64BIT
struct ap_queue_status status;
int t_depth, t_device_type, rc, i;
rc = -EBUSY;
status = ap_queue_interruption_control(qid, ind);
for (i = 0; i < AP_MAX_RESET; i++) {
switch (status.response_code) {
case AP_RESPONSE_NORMAL:
if (status.int_enabled)
return 0;
break;
case AP_RESPONSE_RESET_IN_PROGRESS:
case AP_RESPONSE_BUSY:
break;
case AP_RESPONSE_Q_NOT_AVAIL:
case AP_RESPONSE_DECONFIGURED:
case AP_RESPONSE_CHECKSTOPPED:
case AP_RESPONSE_INVALID_ADDRESS:
return -ENODEV;
case AP_RESPONSE_OTHERWISE_CHANGED:
if (status.int_enabled)
return 0;
break;
default:
break;
}
if (i < AP_MAX_RESET - 1) {
udelay(5);
status = ap_test_queue(qid, &t_depth, &t_device_type);
}
}
return rc;
#else
return -EINVAL;
#endif
}
/**
* __ap_send(): Send message to adjunct processor queue.
* @qid: The AP queue number
......@@ -295,6 +402,11 @@ static int ap_query_queue(ap_qid_t qid, int *queue_depth, int *device_type)
case AP_RESPONSE_CHECKSTOPPED:
rc = -ENODEV;
break;
case AP_RESPONSE_INVALID_ADDRESS:
rc = -ENODEV;
break;
case AP_RESPONSE_OTHERWISE_CHANGED:
break;
case AP_RESPONSE_BUSY:
break;
default:
......@@ -345,6 +457,15 @@ static int ap_init_queue(ap_qid_t qid)
status = ap_test_queue(qid, &dummy, &dummy);
}
}
if (rc == 0 && ap_using_interrupts()) {
rc = ap_queue_enable_interruption(qid, ap_interrupt_indicator);
/* If interruption mode is supported by the machine,
* but an AP can not be enabled for interruption then
* the AP will be discarded. */
if (rc)
pr_err("Registering adapter interrupts for "
"AP %d failed\n", AP_QID_DEVICE(qid));
}
return rc;
}
......@@ -599,6 +720,14 @@ 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_interrupts_show(struct bus_type *bus, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n",
ap_using_interrupts() ? 1 : 0);
}
static BUS_ATTR(ap_interrupts, 0444, ap_interrupts_show, NULL);
static ssize_t ap_config_time_store(struct bus_type *bus,
const char *buf, size_t count)
{
......@@ -653,7 +782,8 @@ static ssize_t poll_timeout_store(struct bus_type *bus, const char *buf,
ktime_t hr_time;
/* 120 seconds = maximum poll interval */
if (sscanf(buf, "%llu\n", &time) != 1 || time < 1 || time > 120000000000)
if (sscanf(buf, "%llu\n", &time) != 1 || time < 1 ||
time > 120000000000ULL)
return -EINVAL;
poll_timeout = time;
hr_time = ktime_set(0, poll_timeout);
......@@ -672,6 +802,7 @@ static struct bus_attribute *const ap_bus_attrs[] = {
&bus_attr_ap_domain,
&bus_attr_config_time,
&bus_attr_poll_thread,
&bus_attr_ap_interrupts,
&bus_attr_poll_timeout,
NULL,
};
......@@ -814,6 +945,11 @@ out:
return rc;
}
static void ap_interrupt_handler(void *unused1, void *unused2)
{
tasklet_schedule(&ap_tasklet);
}
/**
* __ap_scan_bus(): Scan the AP bus.
* @dev: Pointer to device
......@@ -928,6 +1064,8 @@ ap_config_timeout(unsigned long ptr)
*/
static inline void ap_schedule_poll_timer(void)
{
if (ap_using_interrupts())
return;
if (hrtimer_is_queued(&ap_poll_timer))
return;
hrtimer_start(&ap_poll_timer, ktime_set(0, poll_timeout),
......@@ -1207,6 +1345,12 @@ static void ap_poll_all(unsigned long dummy)
unsigned long flags;
struct ap_device *ap_dev;
/* Reset the indicator if interrupts are used. Thus new interrupts can
* be received. Doing it in the beginning of the tasklet is therefor
* important that no requests on any AP get lost.
*/
if (ap_using_interrupts())
xchg((u8 *)ap_interrupt_indicator, 0);
do {
flags = 0;
spin_lock(&ap_device_lock);
......@@ -1268,6 +1412,8 @@ static int ap_poll_thread_start(void)
{
int rc;
if (ap_using_interrupts())
return 0;
mutex_lock(&ap_poll_thread_mutex);
if (!ap_poll_kthread) {
ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
......@@ -1301,8 +1447,12 @@ static void ap_request_timeout(unsigned long data)
{
struct ap_device *ap_dev = (struct ap_device *) data;
if (ap_dev->reset == AP_RESET_ARMED)
if (ap_dev->reset == AP_RESET_ARMED) {
ap_dev->reset = AP_RESET_DO;
if (ap_using_interrupts())
tasklet_schedule(&ap_tasklet);
}
}
static void ap_reset_domain(void)
......@@ -1345,6 +1495,16 @@ int __init ap_module_init(void)
printk(KERN_WARNING "AP instructions not installed.\n");
return -ENODEV;
}
if (ap_interrupts_available()) {
isc_register(AP_ISC);
ap_interrupt_indicator = s390_register_adapter_interrupt(
&ap_interrupt_handler, NULL, AP_ISC);
if (IS_ERR(ap_interrupt_indicator)) {
ap_interrupt_indicator = NULL;
isc_unregister(AP_ISC);
}
}
register_reset_call(&ap_reset_call);
/* Create /sys/bus/ap. */
......@@ -1408,6 +1568,10 @@ out_bus:
bus_unregister(&ap_bus_type);
out:
unregister_reset_call(&ap_reset_call);
if (ap_using_interrupts()) {
s390_unregister_adapter_interrupt(ap_interrupt_indicator, AP_ISC);
isc_unregister(AP_ISC);
}
return rc;
}
......@@ -1443,6 +1607,10 @@ void ap_module_exit(void)
bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
bus_unregister(&ap_bus_type);
unregister_reset_call(&ap_reset_call);
if (ap_using_interrupts()) {
s390_unregister_adapter_interrupt(ap_interrupt_indicator, AP_ISC);
isc_unregister(AP_ISC);
}
}
#ifndef CONFIG_ZCRYPT_MONOLITHIC
......
......@@ -5,6 +5,7 @@
* Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Ralph Wuerthner <rwuerthn@de.ibm.com>
* Felix Beck <felix.beck@de.ibm.com>
*
* Adjunct processor bus header file.
*
......@@ -67,7 +68,8 @@ struct ap_queue_status {
unsigned int queue_empty : 1;
unsigned int replies_waiting : 1;
unsigned int queue_full : 1;
unsigned int pad1 : 5;
unsigned int pad1 : 4;
unsigned int int_enabled : 1;
unsigned int response_code : 8;
unsigned int pad2 : 16;
};
......@@ -78,6 +80,8 @@ struct ap_queue_status {
#define AP_RESPONSE_DECONFIGURED 0x03
#define AP_RESPONSE_CHECKSTOPPED 0x04
#define AP_RESPONSE_BUSY 0x05
#define AP_RESPONSE_INVALID_ADDRESS 0x06
#define AP_RESPONSE_OTHERWISE_CHANGED 0x07
#define AP_RESPONSE_Q_FULL 0x10
#define AP_RESPONSE_NO_PENDING_REPLY 0x10
#define AP_RESPONSE_INDEX_TOO_BIG 0x11
......
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