linux/drivers/s390/char/sclp.c
Michael Holzheu 62b7494209 [S390] pm: power management support for SCLP drivers.
The SCLP base driver defines a new notifier call back for all upper level SCLP
drivers, like the SCLP console, etc. This guarantees that in suspend first the
upper level drivers are suspended and afterwards the SCLP base driver. For
resume it is the other way round. The SCLP base driver itself registers a
new platform device at the platform bus and gets PM notifications via
the dev_pm_ops.

In suspend, the SCLP base driver switches off the receiver and sender mask
This is done in sclp_deactivate(). After suspend all new requests will be
rejected with -EIO and no more interrupts will be received, because the masks
are switched off. For resume the sender and receiver masks are reset in
the sclp_reactivate() function.

When the SCLP console is suspended, all new messages are cached in the
sclp console buffers. In resume, all the cached messages are written to the
console. In addition to that we have an early resume function that removes
the cached messages from the suspend image.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-16 10:31:16 +02:00

1130 lines
30 KiB
C

/*
* 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/module.h>
#include <linux/err.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/suspend.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <asm/types.h>
#include <asm/s390_ext.h>
#include "sclp.h"
#define SCLP_HEADER "sclp: "
/* Structure for register_early_external_interrupt. */
static ext_int_info_t ext_int_info_hwc;
/* 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 struct list_head sclp_reg_list;
/* List of queued requests. */
static struct list_head sclp_req_queue;
/* Data for read and and init requests. */
static struct sclp_req sclp_read_req;
static struct sclp_req sclp_init_req;
static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
/* Suspend request */
static DECLARE_COMPLETION(sclp_request_queue_flushed);
static void sclp_suspend_req_cb(struct sclp_req *req, void *data)
{
complete(&sclp_request_queue_flushed);
}
static struct sclp_req sclp_suspend_req;
/* Timer for request retries. */
static struct timer_list sclp_request_timer;
/* Internal state: is the driver initialized? */
static volatile enum sclp_init_state_t {
sclp_init_state_uninitialized,
sclp_init_state_initializing,
sclp_init_state_initialized
} sclp_init_state = sclp_init_state_uninitialized;
/* 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;
/* Internal state: is the driver suspended? */
static enum sclp_suspend_state_t {
sclp_suspend_state_running,
sclp_suspend_state_suspended,
} sclp_suspend_state = sclp_suspend_state_running;
/* 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_process_queue(void);
static void __sclp_make_read_req(void);
static int sclp_init_mask(int calculate);
static int sclp_init(void);
/* Perform service call. Return 0 on success, non-zero otherwise. */
int
sclp_service_call(sclp_cmdw_t command, void *sccb)
{
int cc;
asm volatile(
" .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */
" ipm %0\n"
" srl %0,28"
: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
: "cc", "memory");
if (cc == 3)
return -EIO;
if (cc == 2)
return -EBUSY;
return 0;
}
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 (*function)(unsigned long),
unsigned long data)
{
del_timer(&sclp_request_timer);
sclp_request_timer.function = function;
sclp_request_timer.data = data;
sclp_request_timer.expires = jiffies + time;
add_timer(&sclp_request_timer);
}
/* Request timeout handler. Restart the request queue. If DATA is non-zero,
* force restart of running request. */
static void
sclp_request_timeout(unsigned long data)
{
unsigned long flags;
spin_lock_irqsave(&sclp_lock, flags);
if (data) {
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, 0);
}
spin_unlock_irqrestore(&sclp_lock, flags);
sclp_process_queue();
}
/* 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(req->command, req->sccb);
req->start_count++;
if (rc == 0) {
/* Sucessfully 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, 1);
return 0;
} else if (rc == -EBUSY) {
/* Try again later */
__sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
sclp_request_timeout, 0);
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);
if (!req->sccb)
goto do_post;
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, 0);
break;
}
do_post:
/* Post-processing for aborted request */
list_del(&req->list);
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_suspend_req || req == &sclp_init_req)
return 1;
if (sclp_suspend_state != sclp_suspend_state_running)
return 0;
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;
}
req->status = SCLP_REQ_QUEUED;
req->start_count = 0;
list_add_tail(&req->list, &sclp_req_queue);
rc = 0;
/* Start if request is first in list */
if (sclp_running_state == sclp_running_state_idle &&
req->list.prev == &sclp_req_queue) {
if (!req->sccb) {
list_del(&req->list);
rc = -ENODATA;
goto out;
}
rc = __sclp_start_request(req);
if (rc)
list_del(&req->list);
}
out:
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 & (1 << (32 - evbuf->type)))
break;
else
reg = NULL;
}
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 = -ENOSYS;
}
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 == (u32) (addr_t) req->sccb)
return req;
}
return NULL;
}
/* 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(__u16 code)
{
struct sclp_req *req;
u32 finished_sccb;
u32 evbuf_pending;
spin_lock(&sclp_lock);
finished_sccb = S390_lowcore.ext_params & 0xfffffff8;
evbuf_pending = S390_lowcore.ext_params & 0x3;
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;
if (req->callback) {
spin_unlock(&sclp_lock);
req->callback(req, req->callback_data);
spin_lock(&sclp_lock);
}
}
sclp_running_state = sclp_running_state_idle;
}
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;
u64 timeout;
int irq_context;
/* 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_clock() +
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_sync &= 0xffff00a0;
cr0_sync |= 0x00000200;
__ctl_load(cr0_sync, 0, 0);
__raw_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 (timer_pending(&sclp_request_timer) &&
get_clock() > timeout &&
del_timer(&sclp_request_timer))
sclp_request_timer.function(sclp_request_timer.data);
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);
}
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)
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;
sccb_mask_t sclp_receive_mask;
sccb_mask_t sclp_send_mask;
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;
scbuf = (struct sclp_statechangebuf *) evbuf;
if (scbuf->mask_length != sizeof(sccb_mask_t))
return;
spin_lock_irqsave(&sclp_lock, flags);
if (scbuf->validity_sclp_receive_mask)
sclp_receive_mask = scbuf->sclp_receive_mask;
if (scbuf->validity_sclp_send_mask)
sclp_send_mask = scbuf->sclp_send_mask;
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;
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;
reg->pm_event_posted = 0;
list_add(&reg->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(&reg->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;
spin_lock_irqsave(&sclp_lock, flags);
list_del(&reg->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);
struct init_sccb {
struct sccb_header header;
u16 _reserved;
u16 mask_length;
sccb_mask_t receive_mask;
sccb_mask_t send_mask;
sccb_mask_t sclp_receive_mask;
sccb_mask_t sclp_send_mask;
} __attribute__((packed));
/* Prepare init mask request. Called while sclp_lock is locked. */
static inline void
__sclp_make_init_req(u32 receive_mask, u32 send_mask)
{
struct init_sccb *sccb;
sccb = (struct init_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(struct init_sccb);
sccb->mask_length = sizeof(sccb_mask_t);
sccb->receive_mask = receive_mask;
sccb->send_mask = send_mask;
sccb->sclp_receive_mask = 0;
sccb->sclp_send_mask = 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 = (struct init_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->sclp_receive_mask;
sclp_send_mask = sccb->sclp_send_mask;
} 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(__u16 code)
{
u32 finished_sccb;
finished_sccb = S390_lowcore.ext_params & 0xfffffff8;
/* Is this the interrupt we are waiting for? */
if (finished_sccb == 0)
return;
if (finished_sccb != (u32) (addr_t) 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(unsigned long data)
{
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_early_external_interrupt(0x2401, sclp_check_handler,
&ext_int_info_hwc);
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(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, 0);
spin_unlock_irqrestore(&sclp_lock, flags);
/* Enable service-signal interruption - needs to happen
* with IRQs enabled. */
ctl_set_bit(0, 9);
/* Wait for signal from interrupt or timeout */
sclp_sync_wait();
/* Disable service-signal interruption - needs to happen
* with IRQs enabled. */
ctl_clear_bit(0,9);
spin_lock_irqsave(&sclp_lock, flags);
del_timer(&sclp_request_timer);
if (sclp_init_req.status == SCLP_REQ_DONE &&
sccb->header.response_code == 0x20) {
rc = 0;
break;
} else
rc = -EBUSY;
}
unregister_early_external_interrupt(0x2401, sclp_check_handler,
&ext_int_info_hwc);
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
};
/*
* Suspend/resume SCLP notifier implementation
*/
static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback)
{
struct sclp_register *reg;
unsigned long flags;
if (!rollback) {
spin_lock_irqsave(&sclp_lock, flags);
list_for_each_entry(reg, &sclp_reg_list, list)
reg->pm_event_posted = 0;
spin_unlock_irqrestore(&sclp_lock, flags);
}
do {
spin_lock_irqsave(&sclp_lock, flags);
list_for_each_entry(reg, &sclp_reg_list, list) {
if (rollback && reg->pm_event_posted)
goto found;
if (!rollback && !reg->pm_event_posted)
goto found;
}
spin_unlock_irqrestore(&sclp_lock, flags);
return;
found:
spin_unlock_irqrestore(&sclp_lock, flags);
if (reg->pm_event_fn)
reg->pm_event_fn(reg, sclp_pm_event);
reg->pm_event_posted = rollback ? 0 : 1;
} while (1);
}
/*
* Susend/resume callbacks for platform device
*/
static int sclp_freeze(struct device *dev)
{
unsigned long flags;
int rc;
sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0);
spin_lock_irqsave(&sclp_lock, flags);
sclp_suspend_state = sclp_suspend_state_suspended;
spin_unlock_irqrestore(&sclp_lock, flags);
/* Init supend data */
memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req));
sclp_suspend_req.callback = sclp_suspend_req_cb;
sclp_suspend_req.status = SCLP_REQ_FILLED;
init_completion(&sclp_request_queue_flushed);
rc = sclp_add_request(&sclp_suspend_req);
if (rc == 0)
wait_for_completion(&sclp_request_queue_flushed);
else if (rc != -ENODATA)
goto fail_thaw;
rc = sclp_deactivate();
if (rc)
goto fail_thaw;
return 0;
fail_thaw:
spin_lock_irqsave(&sclp_lock, flags);
sclp_suspend_state = sclp_suspend_state_running;
spin_unlock_irqrestore(&sclp_lock, flags);
sclp_pm_event(SCLP_PM_EVENT_THAW, 1);
return rc;
}
static int sclp_undo_suspend(enum sclp_pm_event event)
{
unsigned long flags;
int rc;
rc = sclp_reactivate();
if (rc)
return rc;
spin_lock_irqsave(&sclp_lock, flags);
sclp_suspend_state = sclp_suspend_state_running;
spin_unlock_irqrestore(&sclp_lock, flags);
sclp_pm_event(event, 0);
return 0;
}
static int sclp_thaw(struct device *dev)
{
return sclp_undo_suspend(SCLP_PM_EVENT_THAW);
}
static int sclp_restore(struct device *dev)
{
return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE);
}
static struct dev_pm_ops sclp_pm_ops = {
.freeze = sclp_freeze,
.thaw = sclp_thaw,
.restore = sclp_restore,
};
static struct platform_driver sclp_pdrv = {
.driver = {
.name = "sclp",
.owner = THIS_MODULE,
.pm = &sclp_pm_ops,
},
};
static struct platform_device *sclp_pdev;
/* 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;
/* Set up variables */
INIT_LIST_HEAD(&sclp_req_queue);
INIT_LIST_HEAD(&sclp_reg_list);
list_add(&sclp_state_change_event.list, &sclp_reg_list);
init_timer(&sclp_request_timer);
/* 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_early_external_interrupt(0x2401, sclp_interrupt_handler,
&ext_int_info_hwc);
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. */
ctl_set_bit(0, 9);
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;
fail_unlock:
spin_unlock_irqrestore(&sclp_lock, flags);
return rc;
}
/*
* SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able
* to print the panic message.
*/
static int sclp_panic_notify(struct notifier_block *self,
unsigned long event, void *data)
{
if (sclp_suspend_state == sclp_suspend_state_suspended)
sclp_undo_suspend(SCLP_PM_EVENT_THAW);
return NOTIFY_OK;
}
static struct notifier_block sclp_on_panic_nb = {
.notifier_call = sclp_panic_notify,
.priority = SCLP_PANIC_PRIO,
};
static __init int sclp_initcall(void)
{
int rc;
rc = platform_driver_register(&sclp_pdrv);
if (rc)
return rc;
sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0);
rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0;
if (rc)
goto fail_platform_driver_unregister;
rc = atomic_notifier_chain_register(&panic_notifier_list,
&sclp_on_panic_nb);
if (rc)
goto fail_platform_device_unregister;
return sclp_init();
fail_platform_device_unregister:
platform_device_unregister(sclp_pdev);
fail_platform_driver_unregister:
platform_driver_unregister(&sclp_pdrv);
return rc;
}
arch_initcall(sclp_initcall);