// SPDX-License-Identifier: GPL-2.0
/*
* core function to access sclp interface
*
* Copyright IBM Corp. 1999, 2009
*
* Author(s): Martin Peschke <mpeschke@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/panic_notifier.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/reboot.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <asm/types.h>
#include <asm/irq.h>
#include <asm/debug.h>
#include "sclp.h"
#define SCLP_HEADER "sclp: "
struct sclp_trace_entry {
char id[4] __nonstring;
u32 a;
u64 b;
};
#define SCLP_TRACE_ENTRY_SIZE sizeof(struct sclp_trace_entry)
#define SCLP_TRACE_MAX_SIZE 128
#define SCLP_TRACE_EVENT_MAX_SIZE 64
/* Debug trace area intended for all entries in abbreviated form. */
DEFINE_STATIC_DEBUG_INFO(sclp_debug, "sclp", 8, 1, SCLP_TRACE_ENTRY_SIZE,
&debug_hex_ascii_view);
/* Error trace area intended for full entries relating to failed requests. */
DEFINE_STATIC_DEBUG_INFO(sclp_debug_err, "sclp_err", 4, 1,
SCLP_TRACE_ENTRY_SIZE, &debug_hex_ascii_view);
/* Lock to protect internal data consistency. */
static DEFINE_SPINLOCK(sclp_lock);
/* Mask of events that we can send to the sclp interface. */
static sccb_mask_t sclp_receive_mask;
/* Mask of events that we can receive from the sclp interface. */
static sccb_mask_t sclp_send_mask;
/* List of registered event listeners and senders. */
static LIST_HEAD(sclp_reg_list);
/* List of queued requests. */
static LIST_HEAD(sclp_req_queue);
/* Data for read and init requests. */
static struct sclp_req sclp_read_req;
static struct sclp_req sclp_init_req;
static void *sclp_read_sccb;
static struct init_sccb *sclp_init_sccb;
/* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */
int sclp_console_pages = SCLP_CONSOLE_PAGES;
/* Flag to indicate if buffer pages are dropped on buffer full condition */
bool sclp_console_drop = true;
/* Number of times the console dropped buffer pages */
unsigned long sclp_console_full;
/* The currently active SCLP command word. */
static sclp_cmdw_t active_cmd;
static inline void sclp_trace(int prio, char *id, u32 a, u64 b, bool err)
{
struct sclp_trace_entry e;
memset(&e, 0, sizeof(e));
strncpy(e.id, id, sizeof(e.id));
e.a = a;
e.b = b;
debug_event(&sclp_debug, prio, &e, sizeof(e));
if (err)
debug_event(&sclp_debug_err, 0, &e, sizeof(e));
}
static inline int no_zeroes_len(void *data, int len)
{
char *d = data;
/* Minimize trace area usage by not tracing trailing zeroes. */
while (len > SCLP_TRACE_ENTRY_SIZE && d[len - 1] == 0)
len--;
return len;
}
static inline void sclp_trace_bin(int prio, void *d, int len, int errlen)
{
debug_event(&sclp_debug, prio, d, no_zeroes_len(d, len));
if (errlen)
debug_event(&sclp_debug_err, 0, d, no_zeroes_len(d, errlen));
}
static inline int abbrev_len(sclp_cmdw_t cmd, struct sccb_header *sccb)
{
struct evbuf_header *evbuf = (struct evbuf_header *)(sccb + 1);
int len = sccb->length, limit = SCLP_TRACE_MAX_SIZE;
/* Full SCCB tracing if debug level is set to max. */
if (sclp_debug.level == DEBUG_MAX_LEVEL)
return len;
/* Minimal tracing for console writes. */
if (cmd == SCLP_CMDW_WRITE_EVENT_DATA &&
(evbuf->type == EVTYP_MSG || evbuf->type == EVTYP_VT220MSG))
limit = SCLP_TRACE_ENTRY_SIZE;
return min(len, limit);
}
static inline void sclp_trace_sccb(int prio, char *id, u32 a, u64 b,
sclp_cmdw_t cmd, struct sccb_header *sccb,
bool err)
{
sclp_trace(prio, id, a, b, err);
if (sccb) {
sclp_trace_bin(prio + 1, sccb, abbrev_len(cmd, sccb),
err ? sccb->length : 0);
}
}
static inline void sclp_trace_evbuf(int prio, char *id, u32 a, u64 b,
struct evbuf_header *evbuf, bool err)
{
sclp_trace(prio, id, a, b, err);
sclp_trace_bin(prio + 1, evbuf,
min((int)evbuf->length, (int)SCLP_TRACE_EVENT_MAX_SIZE),
err ? evbuf->length : 0);
}
static inline void sclp_trace_req(int prio, char *id, struct sclp_req *req,
bool err)
{
struct sccb_header *sccb = req->sccb;
union {
struct {
u16 status;
u16 response;
u16 timeout;
u16 start_count;
};
u64 b;
} summary;
summary.status = req->status;
summary.response = sccb ? sccb->response_code : 0;
summary.timeout = (u16)req->queue_timeout;
summary.start_count = (u16)req->start_count;
sclp_trace(prio, id, __pa(sccb), summary.b, err);
}
static inline void sclp_trace_register(int prio, char *id, u32 a, u64 b,
struct sclp_register *reg)
{
struct {
u64 receive;
u64 send;
} d;
d.receive = reg->receive_mask;
d.send = reg->send_mask;
sclp_trace(prio, id, a, b, false);
sclp_trace_bin(prio, &d, sizeof(d), 0);
}
static int __init sclp_setup_console_pages(char *str)
{
int pages, rc;
rc = kstrtoint(str, 0, &pages);
if (!rc && pages >= SCLP_CONSOLE_PAGES)
sclp_console_pages = pages;
return 1;
}
__setup("sclp_con_pages=", sclp_setup_console_pages);
static int __init sclp_setup_console_drop(char *str)
{
return kstrtobool(str, &sclp_console_drop) == 0;
}
__setup("sclp_con_drop=", sclp_setup_console_drop);
/* Timer for request retries. */
static struct timer_list sclp_request_timer;
/* Timer for queued requests. */
static struct timer_list sclp_queue_timer;
/* Internal state: is a request active at the sclp? */
static volatile enum sclp_running_state_t {
sclp_running_state_idle,
sclp_running_state_running,
sclp_running_state_reset_pending
} sclp_running_state = sclp_running_state_idle;
/* Internal state: is a read request pending? */
static volatile enum sclp_reading_state_t {
sclp_reading_state_idle,
sclp_reading_state_reading
} sclp_reading_state = sclp_reading_state_idle;
/* Internal state: is the driver currently serving requests? */
static volatile enum sclp_activation_state_t {
sclp_activation_state_active,
sclp_activation_state_deactivating,
sclp_activation_state_inactive,
sclp_activation_state_activating
} sclp_activation_state = sclp_activation_state_active;
/* Internal state: is an init mask request pending? */
static volatile enum sclp_mask_state_t {
sclp_mask_state_idle,
sclp_mask_state_initializing
} sclp_mask_state = sclp_mask_state_idle;
/* Maximum retry counts */
#define SCLP_INIT_RETRY 3
#define SCLP_MASK_RETRY 3
/* Timeout intervals in seconds.*/
#define SCLP_BUSY_INTERVAL 10
#define SCLP_RETRY_INTERVAL 30
static void sclp_request_timeout(bool force_restart);
static void sclp_process_queue(void);
static void __sclp_make_read_req(void);
static int sclp_init_mask(int calculate);
static int sclp_init(void);
static void
__sclp_queue_read_req(void)
{
if (sclp_reading_state == sclp_reading_state_idle) {
sclp_reading_state = sclp_reading_state_reading;
__sclp_make_read_req();
/* Add request to head of queue */
list_add(&sclp_read_req.list, &sclp_req_queue);
}
}
/* Set up request retry timer. Called while sclp_lock is locked. */
static inline void
__sclp_set_request_timer(unsigned long time, void (*cb)(struct timer_list *))
{
del_timer(&sclp_request_timer);
sclp_request_timer.function = cb;
sclp_request_timer.expires = jiffies + time;
add_timer(&sclp_request_timer);
}
static void sclp_request_timeout_restart(struct timer_list *unused)
{
sclp_request_timeout(true);
}
static void sclp_request_timeout_normal(struct timer_list *unused)
{
sclp_request_timeout(false);
}
/* Request timeout handler. Restart the request queue. If force_restart,
* force restart of running request. */
static void sclp_request_timeout(bool force_restart)
{
unsigned long flags;
/* TMO: A timeout occurred (a=force_restart) */
sclp_trace(2, "TMO", force_restart, 0, true);
spin_lock_irqsave(&sclp_lock, flags);
if (force_restart) {
if (sclp_running_state == sclp_running_state_running) {
/* Break running state and queue NOP read event request
* to get a defined interface state. */
__sclp_queue_read_req();
sclp_running_state = sclp_running_state_idle;
}
} else {
__sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
sclp_request_timeout_normal);
}
spin_unlock_irqrestore(&sclp_lock, flags);
sclp_process_queue();
}
/*
* Returns the expire value in jiffies of the next pending request timeout,
* if any. Needs to be called with sclp_lock.
*/
static unsigned long __sclp_req_queue_find_next_timeout(void)
{
unsigned long expires_next = 0;
struct sclp_req *req;
list_for_each_entry(req, &sclp_req_queue, list) {
if (!req->queue_expires)
continue;
if (!expires_next ||
(time_before(req->queue_expires, expires_next)))
expires_next = req->queue_expires;
}
return expires_next;
}
/*
* Returns expired request, if any, and removes it from the list.
*/
static struct sclp_req *__sclp_req_queue_remove_expired_req(void)
{
unsigned long flags, now;
struct sclp_req *req;
spin_lock_irqsave(&sclp_lock, flags);
now = jiffies;
/* Don't need list_for_each_safe because we break out after list_del */
list_for_each_entry(req, &sclp_req_queue, list) {
if (!req->queue_expires)
continue;
if (time_before_eq(req->queue_expires, now)) {
if (req->status == SCLP_REQ_QUEUED) {
req->status = SCLP_REQ_QUEUED_TIMEOUT;
list_del(&req->list);
goto out;
}
}
}
req = NULL;
out:
spin_unlock_irqrestore(&sclp_lock, flags);
return req;
}
/*
* Timeout handler for queued requests. Removes request from list and
* invokes callback. This timer can be set per request in situations where
* waiting too long would be harmful to the system, e.g. during SE reboot.
*/
static void sclp_req_queue_timeout(struct timer_list *unused)
{
unsigned long flags, expires_next;
struct sclp_req *req;
do {
req = __sclp_req_queue_remove_expired_req();
if (req) {
/* RQTM: Request timed out (a=sccb, b=summary) */
sclp_trace_req(2, "RQTM", req, true);
}
if (req && req->callback)
req->callback(req, req->callback_data);
} while (req);
spin_lock_irqsave(&sclp_lock, flags);
expires_next = __sclp_req_queue_find_next_timeout();
if (expires_next)
mod_timer(&sclp_queue_timer, expires_next);
spin_unlock_irqrestore(&sclp_lock, flags);
}
static int sclp_service_call_trace(sclp_cmdw_t command, void *sccb)
{
static u64 srvc_count;
int rc;
/* SRV1: Service call about to be issued (a=command, b=sccb address) */
sclp_trace_sccb(0, "SRV1", command, (u64)sccb, command, sccb, false);
rc = sclp_service_call(command, sccb);
/* SRV2: Service call was issued (a=rc, b=SRVC sequence number) */
sclp_trace(0, "SRV2", -rc, ++srvc_count, rc != 0);
if (rc == 0)
active_cmd = command;
return rc;
}
/* Try to start a request. Return zero if the request was successfully
* started or if it will be started at a later time. Return non-zero otherwise.
* Called while sclp_lock is locked. */
static int
__sclp_start_request(struct sclp_req *req)
{
int rc;
if (sclp_running_state != sclp_running_state_idle)
return 0;
del_timer(&sclp_request_timer);
rc = sclp_service_call_trace(req->command, req->sccb);
req->start_count++;
if (rc == 0) {
/* Successfully started request */
req->status = SCLP_REQ_RUNNING;
sclp_running_state = sclp_running_state_running;
__sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
sclp_request_timeout_restart);
return 0;
} else if (rc == -EBUSY) {
/* Try again later */
__sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
sclp_request_timeout_normal);
return 0;
}
/* Request failed */
req->status = SCLP_REQ_FAILED;
return rc;
}
/* Try to start queued requests. */
static void
sclp_process_queue(void)
{
struct sclp_req *req;
int rc;
unsigned long flags;
spin_lock_irqsave(&sclp_lock, flags);
if (sclp_running_state != sclp_running_state_idle) {
spin_unlock_irqrestore(&sclp_lock, flags);
return;
}
del_timer(&sclp_request_timer);
while (!list_empty(&sclp_req_queue)) {
req = list_entry(sclp_req_queue.next, struct sclp_req, list);
rc = __sclp_start_request(req);
if (rc == 0)
break;
/* Request failed */
if (req->start_count > 1) {
/* Cannot abort already submitted request - could still
* be active at the SCLP */
__sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
sclp_request_timeout_normal);
break;
}
/* Post-processing for aborted request */
list_del(&req->list);
/* RQAB: Request aborted (a=sccb, b=summary) */
sclp_trace_req(2, "RQAB", req, true);
if (req->callback) {
spin_unlock_irqrestore(&sclp_lock, flags);
req->callback(req, req->callback_data);
spin_lock_irqsave(&sclp_lock, flags);
}
}
spin_unlock_irqrestore(&sclp_lock, flags);
}
static int __sclp_can_add_request(struct sclp_req *req)
{
if (req == &sclp_init_req)
return 1;
if (sclp_init_state != sclp_init_state_initialized)
return 0;
if (sclp_activation_state != sclp_activation_state_active)
return 0;
return 1;
}
/* Queue a new request. Return zero on success, non-zero otherwise. */
int
sclp_add_request(struct sclp_req *req)
{
unsigned long flags;
int rc;
spin_lock_irqsave(&sclp_lock, flags);
if (!__sclp_can_add_request(req)) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EIO;
}
/* RQAD: Request was added (a=sccb, b=caller) */
sclp_trace(2, "RQAD", __pa(req->sccb), _RET_IP_, false);
req->status = SCLP_REQ_QUEUED;
req->start_count = 0;
list_add_tail(&req->list, &sclp_req_queue);
rc = 0;
if (req->queue_timeout) {
req->queue_expires = jiffies + req->queue_timeout * HZ;
if (!timer_pending(&sclp_queue_timer) ||
time_after(sclp_queue_timer.expires, req->queue_expires))
mod_timer(&sclp_queue_timer, req->queue_expires);
} else
req->queue_expires = 0;
/* Start if request is first in list */
if (sclp_running_state == sclp_running_state_idle &&
req->list.prev == &sclp_req_queue) {
rc = __sclp_start_request(req);
if (rc)
list_del(&req->list);
}
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
EXPORT_SYMBOL(sclp_add_request);
/* Dispatch events found in request buffer to registered listeners. Return 0
* if all events were dispatched, non-zero otherwise. */
static int
sclp_dispatch_evbufs(struct sccb_header *sccb)
{
unsigned long flags;
struct evbuf_header *evbuf;
struct list_head *l;
struct sclp_register *reg;
int offset;
int rc;
spin_lock_irqsave(&sclp_lock, flags);
rc = 0;
for (offset = sizeof(struct sccb_header); offset < sccb->length;
offset += evbuf->length) {
evbuf = (struct evbuf_header *) ((addr_t) sccb + offset);
/* Check for malformed hardware response */
if (evbuf->length == 0)
break;
/* Search for event handler */
reg = NULL;
list_for_each(l, &sclp_reg_list) {
reg = list_entry(l, struct sclp_register, list);
if (reg->receive_mask & SCLP_EVTYP_MASK(evbuf->type))
break;
else
reg = NULL;
}
/* EVNT: Event callback (b=receiver) */
sclp_trace_evbuf(2, "EVNT", 0, reg ? (u64)reg->receiver_fn : 0,
evbuf, !reg);
if (reg && reg->receiver_fn) {
spin_unlock_irqrestore(&sclp_lock, flags);
reg->receiver_fn(evbuf);
spin_lock_irqsave(&sclp_lock, flags);
} else if (reg == NULL)
rc = -EOPNOTSUPP;
}
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
/* Read event data request callback. */
static void
sclp_read_cb(struct sclp_req *req, void *data)
{
unsigned long flags;
struct sccb_header *sccb;
sccb = (struct sccb_header *) req->sccb;
if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 ||
sccb->response_code == 0x220))
sclp_dispatch_evbufs(sccb);
spin_lock_irqsave(&sclp_lock, flags);
sclp_reading_state = sclp_reading_state_idle;
spin_unlock_irqrestore(&sclp_lock, flags);
}
/* Prepare read event data request. Called while sclp_lock is locked. */
static void __sclp_make_read_req(void)
{
struct sccb_header *sccb;
sccb = (struct sccb_header *) sclp_read_sccb;
clear_page(sccb);
memset(&sclp_read_req, 0, sizeof(struct sclp_req));
sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA;
sclp_read_req.status = SCLP_REQ_QUEUED;
sclp_read_req.start_count = 0;
sclp_read_req.callback = sclp_read_cb;
sclp_read_req.sccb = sccb;
sccb->length = PAGE_SIZE;
sccb->function_code = 0;
sccb->control_mask[2] = 0x80;
}
/* Search request list for request with matching sccb. Return request if found,
* NULL otherwise. Called while sclp_lock is locked. */
static inline struct sclp_req *
__sclp_find_req(u32 sccb)
{
struct list_head *l;
struct sclp_req *req;
list_for_each(l, &sclp_req_queue) {
req = list_entry(l, struct sclp_req, list);
if (sccb == __pa(req->sccb))
return req;
}
return NULL;
}
static bool ok_response(u32 sccb_int, sclp_cmdw_t cmd)
{
struct sccb_header *sccb = (struct sccb_header *)__va(sccb_int);
struct evbuf_header *evbuf;
u16 response;
if (!sccb)
return true;
/* Check SCCB response. */
response = sccb->response_code & 0xff;
if (response != 0x10 && response != 0x20)
return false;
/* Check event-processed flag on outgoing events. */
if (cmd == SCLP_CMDW_WRITE_EVENT_DATA) {
evbuf = (struct evbuf_header *)(sccb + 1);
if (!(evbuf->flags & 0x80))
return false;
}
return true;
}
/* Handler for external interruption. Perform request post-processing.
* Prepare read event data request if necessary. Start processing of next
* request on queue. */
static void sclp_interrupt_handler(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct sclp_req *req;
u32 finished_sccb;
u32 evbuf_pending;
inc_irq_stat(IRQEXT_SCP);
spin_lock(&sclp_lock);
finished_sccb = param32 & 0xfffffff8;
evbuf_pending = param32 & 0x3;
/* INT: Interrupt received (a=intparm, b=cmd) */
sclp_trace_sccb(0, "INT", param32, active_cmd, active_cmd,
(struct sccb_header *)__va(finished_sccb),
!ok_response(finished_sccb, active_cmd));
if (finished_sccb) {
del_timer(&sclp_request_timer);
sclp_running_state = sclp_running_state_reset_pending;
req = __sclp_find_req(finished_sccb);
if (req) {
/* Request post-processing */
list_del(&req->list);
req->status = SCLP_REQ_DONE;
/* RQOK: Request success (a=sccb, b=summary) */
sclp_trace_req(2, "RQOK", req, false);
if (req->callback) {
spin_unlock(&sclp_lock);
req->callback(req, req->callback_data);
spin_lock(&sclp_lock);
}
} else {
/* UNEX: Unexpected SCCB completion (a=sccb address) */
sclp_trace(0, "UNEX", finished_sccb, 0, true);
}
sclp_running_state = sclp_running_state_idle;
active_cmd = 0;
}
if (evbuf_pending &&
sclp_activation_state == sclp_activation_state_active)
__sclp_queue_read_req();
spin_unlock(&sclp_lock);
sclp_process_queue();
}
/* Convert interval in jiffies to TOD ticks. */
static inline u64
sclp_tod_from_jiffies(unsigned long jiffies)
{
return (u64) (jiffies / HZ) << 32;
}
/* Wait until a currently running request finished. Note: while this function
* is running, no timers are served on the calling CPU. */
void
sclp_sync_wait(void)
{
unsigned long long old_tick;
unsigned long flags;
unsigned long cr0, cr0_sync;
static u64 sync_count;
u64 timeout;
int irq_context;
/* SYN1: Synchronous wait start (a=runstate, b=sync count) */
sclp_trace(4, "SYN1", sclp_running_state, ++sync_count, false);
/* We'll be disabling timer interrupts, so we need a custom timeout
* mechanism */
timeout = 0;
if (timer_pending(&sclp_request_timer)) {
/* Get timeout TOD value */
timeout = get_tod_clock_fast() +
sclp_tod_from_jiffies(sclp_request_timer.expires -
jiffies);
}
local_irq_save(flags);
/* Prevent bottom half from executing once we force interrupts open */
irq_context = in_interrupt();
if (!irq_context)
local_bh_disable();
/* Enable service-signal interruption, disable timer interrupts */
old_tick = local_tick_disable();
trace_hardirqs_on();
__ctl_store(cr0, 0, 0);
cr0_sync = cr0 & ~CR0_IRQ_SUBCLASS_MASK;
cr0_sync |= 1UL << (63 - 54);
__ctl_load(cr0_sync, 0, 0);
__arch_local_irq_stosm(0x01);
/* Loop until driver state indicates finished request */
while (sclp_running_state != sclp_running_state_idle) {
/* Check for expired request timer */
if (get_tod_clock_fast() > timeout && del_timer(&sclp_request_timer))
sclp_request_timer.function(&sclp_request_timer);
cpu_relax();
}
local_irq_disable();
__ctl_load(cr0, 0, 0);
if (!irq_context)
_local_bh_enable();
local_tick_enable(old_tick);
local_irq_restore(flags);
/* SYN2: Synchronous wait end (a=runstate, b=sync_count) */
sclp_trace(4, "SYN2", sclp_running_state, sync_count, false);
}
EXPORT_SYMBOL(sclp_sync_wait);
/* Dispatch changes in send and receive mask to registered listeners. */
static void
sclp_dispatch_state_change(void)
{
struct list_head *l;
struct sclp_register *reg;
unsigned long flags;
sccb_mask_t receive_mask;
sccb_mask_t send_mask;
do {
spin_lock_irqsave(&sclp_lock, flags);
reg = NULL;
list_for_each(l, &sclp_reg_list) {
reg = list_entry(l, struct sclp_register, list);
receive_mask = reg->send_mask & sclp_receive_mask;
send_mask = reg->receive_mask & sclp_send_mask;
if (reg->sclp_receive_mask != receive_mask ||
reg->sclp_send_mask != send_mask) {
reg->sclp_receive_mask = receive_mask;
reg->sclp_send_mask = send_mask;
break;
} else
reg = NULL;
}
spin_unlock_irqrestore(&sclp_lock, flags);
if (reg && reg->state_change_fn) {
/* STCG: State-change callback (b=callback) */
sclp_trace(2, "STCG", 0, (u64)reg->state_change_fn,
false);
reg->state_change_fn(reg);
}
} while (reg);
}
struct sclp_statechangebuf {
struct evbuf_header header;
u8 validity_sclp_active_facility_mask : 1;
u8 validity_sclp_receive_mask : 1;
u8 validity_sclp_send_mask : 1;
u8 validity_read_data_function_mask : 1;
u16 _zeros : 12;
u16 mask_length;
u64 sclp_active_facility_mask;
u8 masks[2 * 1021 + 4]; /* variable length */
/*
* u8 sclp_receive_mask[mask_length];
* u8 sclp_send_mask[mask_length];
* u32 read_data_function_mask;
*/
} __attribute__((packed));
/* State change event callback. Inform listeners of changes. */
static void
sclp_state_change_cb(struct evbuf_header *evbuf)
{
unsigned long flags;
struct sclp_statechangebuf *scbuf;
BUILD_BUG_ON(sizeof(struct sclp_statechangebuf) > PAGE_SIZE);
scbuf = (struct sclp_statechangebuf *) evbuf;
spin_lock_irqsave(&sclp_lock, flags);
if (scbuf->validity_sclp_receive_mask)
sclp_receive_mask = sccb_get_recv_mask(scbuf);
if (scbuf->validity_sclp_send_mask)
sclp_send_mask = sccb_get_send_mask(scbuf);
spin_unlock_irqrestore(&sclp_lock, flags);
if (scbuf->validity_sclp_active_facility_mask)
sclp.facilities = scbuf->sclp_active_facility_mask;
sclp_dispatch_state_change();
}
static struct sclp_register sclp_state_change_event = {
.receive_mask = EVTYP_STATECHANGE_MASK,
.receiver_fn = sclp_state_change_cb
};
/* Calculate receive and send mask of currently registered listeners.
* Called while sclp_lock is locked. */
static inline void
__sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask)
{
struct list_head *l;
struct sclp_register *t;
*receive_mask = 0;
*send_mask = 0;
list_for_each(l, &sclp_reg_list) {
t = list_entry(l, struct sclp_register, list);
*receive_mask |= t->receive_mask;
*send_mask |= t->send_mask;
}
}
/* Register event listener. Return 0 on success, non-zero otherwise. */
int
sclp_register(struct sclp_register *reg)
{
unsigned long flags;
sccb_mask_t receive_mask;
sccb_mask_t send_mask;
int rc;
/* REG: Event listener registered (b=caller) */
sclp_trace_register(2, "REG", 0, _RET_IP_, reg);
rc = sclp_init();
if (rc)
return rc;
spin_lock_irqsave(&sclp_lock, flags);
/* Check event mask for collisions */
__sclp_get_mask(&receive_mask, &send_mask);
if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EBUSY;
}
/* Trigger initial state change callback */
reg->sclp_receive_mask = 0;
reg->sclp_send_mask = 0;
list_add(®->list, &sclp_reg_list);
spin_unlock_irqrestore(&sclp_lock, flags);
rc = sclp_init_mask(1);
if (rc) {
spin_lock_irqsave(&sclp_lock, flags);
list_del(®->list);
spin_unlock_irqrestore(&sclp_lock, flags);
}
return rc;
}
EXPORT_SYMBOL(sclp_register);
/* Unregister event listener. */
void
sclp_unregister(struct sclp_register *reg)
{
unsigned long flags;
/* UREG: Event listener unregistered (b=caller) */
sclp_trace_register(2, "UREG", 0, _RET_IP_, reg);
spin_lock_irqsave(&sclp_lock, flags);
list_del(®->list);
spin_unlock_irqrestore(&sclp_lock, flags);
sclp_init_mask(1);
}
EXPORT_SYMBOL(sclp_unregister);
/* Remove event buffers which are marked processed. Return the number of
* remaining event buffers. */
int
sclp_remove_processed(struct sccb_header *sccb)
{
struct evbuf_header *evbuf;
int unprocessed;
u16 remaining;
evbuf = (struct evbuf_header *) (sccb + 1);
unprocessed = 0;
remaining = sccb->length - sizeof(struct sccb_header);
while (remaining > 0) {
remaining -= evbuf->length;
if (evbuf->flags & 0x80) {
sccb->length -= evbuf->length;
memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length),
remaining);
} else {
unprocessed++;
evbuf = (struct evbuf_header *)
((addr_t) evbuf + evbuf->length);
}
}
return unprocessed;
}
EXPORT_SYMBOL(sclp_remove_processed);
/* Prepare init mask request. Called while sclp_lock is locked. */
static inline void
__sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask)
{
struct init_sccb *sccb = sclp_init_sccb;
clear_page(sccb);
memset(&sclp_init_req, 0, sizeof(struct sclp_req));
sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK;
sclp_init_req.status = SCLP_REQ_FILLED;
sclp_init_req.start_count = 0;
sclp_init_req.callback = NULL;
sclp_init_req.callback_data = NULL;
sclp_init_req.sccb = sccb;
sccb->header.length = sizeof(*sccb);
if (sclp_mask_compat_mode)
sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
else
sccb->mask_length = sizeof(sccb_mask_t);
sccb_set_recv_mask(sccb, receive_mask);
sccb_set_send_mask(sccb, send_mask);
sccb_set_sclp_recv_mask(sccb, 0);
sccb_set_sclp_send_mask(sccb, 0);
}
/* Start init mask request. If calculate is non-zero, calculate the mask as
* requested by registered listeners. Use zero mask otherwise. Return 0 on
* success, non-zero otherwise. */
static int
sclp_init_mask(int calculate)
{
unsigned long flags;
struct init_sccb *sccb = sclp_init_sccb;
sccb_mask_t receive_mask;
sccb_mask_t send_mask;
int retry;
int rc;
unsigned long wait;
spin_lock_irqsave(&sclp_lock, flags);
/* Check if interface is in appropriate state */
if (sclp_mask_state != sclp_mask_state_idle) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EBUSY;
}
if (sclp_activation_state == sclp_activation_state_inactive) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EINVAL;
}
sclp_mask_state = sclp_mask_state_initializing;
/* Determine mask */
if (calculate)
__sclp_get_mask(&receive_mask, &send_mask);
else {
receive_mask = 0;
send_mask = 0;
}
rc = -EIO;
for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) {
/* Prepare request */
__sclp_make_init_req(receive_mask, send_mask);
spin_unlock_irqrestore(&sclp_lock, flags);
if (sclp_add_request(&sclp_init_req)) {
/* Try again later */
wait = jiffies + SCLP_BUSY_INTERVAL * HZ;
while (time_before(jiffies, wait))
sclp_sync_wait();
spin_lock_irqsave(&sclp_lock, flags);
continue;
}
while (sclp_init_req.status != SCLP_REQ_DONE &&
sclp_init_req.status != SCLP_REQ_FAILED)
sclp_sync_wait();
spin_lock_irqsave(&sclp_lock, flags);
if (sclp_init_req.status == SCLP_REQ_DONE &&
sccb->header.response_code == 0x20) {
/* Successful request */
if (calculate) {
sclp_receive_mask = sccb_get_sclp_recv_mask(sccb);
sclp_send_mask = sccb_get_sclp_send_mask(sccb);
} else {
sclp_receive_mask = 0;
sclp_send_mask = 0;
}
spin_unlock_irqrestore(&sclp_lock, flags);
sclp_dispatch_state_change();
spin_lock_irqsave(&sclp_lock, flags);
rc = 0;
break;
}
}
sclp_mask_state = sclp_mask_state_idle;
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
/* Deactivate SCLP interface. On success, new requests will be rejected,
* events will no longer be dispatched. Return 0 on success, non-zero
* otherwise. */
int
sclp_deactivate(void)
{
unsigned long flags;
int rc;
spin_lock_irqsave(&sclp_lock, flags);
/* Deactivate can only be called when active */
if (sclp_activation_state != sclp_activation_state_active) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EINVAL;
}
sclp_activation_state = sclp_activation_state_deactivating;
spin_unlock_irqrestore(&sclp_lock, flags);
rc = sclp_init_mask(0);
spin_lock_irqsave(&sclp_lock, flags);
if (rc == 0)
sclp_activation_state = sclp_activation_state_inactive;
else
sclp_activation_state = sclp_activation_state_active;
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
EXPORT_SYMBOL(sclp_deactivate);
/* Reactivate SCLP interface after sclp_deactivate. On success, new
* requests will be accepted, events will be dispatched again. Return 0 on
* success, non-zero otherwise. */
int
sclp_reactivate(void)
{
unsigned long flags;
int rc;
spin_lock_irqsave(&sclp_lock, flags);
/* Reactivate can only be called when inactive */
if (sclp_activation_state != sclp_activation_state_inactive) {
spin_unlock_irqrestore(&sclp_lock, flags);
return -EINVAL;
}
sclp_activation_state = sclp_activation_state_activating;
spin_unlock_irqrestore(&sclp_lock, flags);
rc = sclp_init_mask(1);
spin_lock_irqsave(&sclp_lock, flags);
if (rc == 0)
sclp_activation_state = sclp_activation_state_active;
else
sclp_activation_state = sclp_activation_state_inactive;
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
EXPORT_SYMBOL(sclp_reactivate);
/* Handler for external interruption used during initialization. Modify
* request state to done. */
static void sclp_check_handler(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
u32 finished_sccb;
inc_irq_stat(IRQEXT_SCP);
finished_sccb = param32 & 0xfffffff8;
/* Is this the interrupt we are waiting for? */
if (finished_sccb == 0)
return;
if (finished_sccb != __pa(sclp_init_sccb))
panic("sclp: unsolicited interrupt for buffer at 0x%x\n",
finished_sccb);
spin_lock(&sclp_lock);
if (sclp_running_state == sclp_running_state_running) {
sclp_init_req.status = SCLP_REQ_DONE;
sclp_running_state = sclp_running_state_idle;
}
spin_unlock(&sclp_lock);
}
/* Initial init mask request timed out. Modify request state to failed. */
static void
sclp_check_timeout(struct timer_list *unused)
{
unsigned long flags;
spin_lock_irqsave(&sclp_lock, flags);
if (sclp_running_state == sclp_running_state_running) {
sclp_init_req.status = SCLP_REQ_FAILED;
sclp_running_state = sclp_running_state_idle;
}
spin_unlock_irqrestore(&sclp_lock, flags);
}
/* Perform a check of the SCLP interface. Return zero if the interface is
* available and there are no pending requests from a previous instance.
* Return non-zero otherwise. */
static int
sclp_check_interface(void)
{
struct init_sccb *sccb;
unsigned long flags;
int retry;
int rc;
spin_lock_irqsave(&sclp_lock, flags);
/* Prepare init mask command */
rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
if (rc) {
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) {
__sclp_make_init_req(0, 0);
sccb = (struct init_sccb *) sclp_init_req.sccb;
rc = sclp_service_call_trace(sclp_init_req.command, sccb);
if (rc == -EIO)
break;
sclp_init_req.status = SCLP_REQ_RUNNING;
sclp_running_state = sclp_running_state_running;
__sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
sclp_check_timeout);
spin_unlock_irqrestore(&sclp_lock, flags);
/* Enable service-signal interruption - needs to happen
* with IRQs enabled. */
irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
/* Wait for signal from interrupt or timeout */
sclp_sync_wait();
/* Disable service-signal interruption - needs to happen
* with IRQs enabled. */
irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
spin_lock_irqsave(&sclp_lock, flags);
del_timer(&sclp_request_timer);
rc = -EBUSY;
if (sclp_init_req.status == SCLP_REQ_DONE) {
if (sccb->header.response_code == 0x20) {
rc = 0;
break;
} else if (sccb->header.response_code == 0x74f0) {
if (!sclp_mask_compat_mode) {
sclp_mask_compat_mode = true;
retry = 0;
}
}
}
}
unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
/* Reboot event handler. Reset send and receive mask to prevent pending SCLP
* events from interfering with rebooted system. */
static int
sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
{
sclp_deactivate();
return NOTIFY_DONE;
}
static struct notifier_block sclp_reboot_notifier = {
.notifier_call = sclp_reboot_event
};
static ssize_t con_pages_show(struct device_driver *dev, char *buf)
{
return sysfs_emit(buf, "%i\n", sclp_console_pages);
}
static DRIVER_ATTR_RO(con_pages);
static ssize_t con_drop_store(struct device_driver *dev, const char *buf, size_t count)
{
int rc;
rc = kstrtobool(buf, &sclp_console_drop);
return rc ?: count;
}
static ssize_t con_drop_show(struct device_driver *dev, char *buf)
{
return sysfs_emit(buf, "%i\n", sclp_console_drop);
}
static DRIVER_ATTR_RW(con_drop);
static ssize_t con_full_show(struct device_driver *dev, char *buf)
{
return sysfs_emit(buf, "%lu\n", sclp_console_full);
}
static DRIVER_ATTR_RO(con_full);
static struct attribute *sclp_drv_attrs[] = {
&driver_attr_con_pages.attr,
&driver_attr_con_drop.attr,
&driver_attr_con_full.attr,
NULL,
};
static struct attribute_group sclp_drv_attr_group = {
.attrs = sclp_drv_attrs,
};
static const struct attribute_group *sclp_drv_attr_groups[] = {
&sclp_drv_attr_group,
NULL,
};
static struct platform_driver sclp_pdrv = {
.driver = {
.name = "sclp",
.groups = sclp_drv_attr_groups,
},
};
/* Initialize SCLP driver. Return zero if driver is operational, non-zero
* otherwise. */
static int
sclp_init(void)
{
unsigned long flags;
int rc = 0;
spin_lock_irqsave(&sclp_lock, flags);
/* Check for previous or running initialization */
if (sclp_init_state != sclp_init_state_uninitialized)
goto fail_unlock;
sclp_init_state = sclp_init_state_initializing;
sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
BUG_ON(!sclp_read_sccb || !sclp_init_sccb);
/* Set up variables */
list_add(&sclp_state_change_event.list, &sclp_reg_list);
timer_setup(&sclp_request_timer, NULL, 0);
timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0);
/* Check interface */
spin_unlock_irqrestore(&sclp_lock, flags);
rc = sclp_check_interface();
spin_lock_irqsave(&sclp_lock, flags);
if (rc)
goto fail_init_state_uninitialized;
/* Register reboot handler */
rc = register_reboot_notifier(&sclp_reboot_notifier);
if (rc)
goto fail_init_state_uninitialized;
/* Register interrupt handler */
rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler);
if (rc)
goto fail_unregister_reboot_notifier;
sclp_init_state = sclp_init_state_initialized;
spin_unlock_irqrestore(&sclp_lock, flags);
/* Enable service-signal external interruption - needs to happen with
* IRQs enabled. */
irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
sclp_init_mask(1);
return 0;
fail_unregister_reboot_notifier:
unregister_reboot_notifier(&sclp_reboot_notifier);
fail_init_state_uninitialized:
sclp_init_state = sclp_init_state_uninitialized;
free_page((unsigned long) sclp_read_sccb);
free_page((unsigned long) sclp_init_sccb);
fail_unlock:
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
static __init int sclp_initcall(void)
{
int rc;
rc = platform_driver_register(&sclp_pdrv);
if (rc)
return rc;
return sclp_init();
}
arch_initcall(sclp_initcall);