--- /dev/null
+/*
+ * 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/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/irq.h>
+
+#include "sclp.h"
+
+#define SCLP_HEADER "sclp: "
+
+/* 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);
+
+/* 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 */
+int sclp_console_drop = 0;
+/* Number of times the console dropped buffer pages */
+unsigned long sclp_console_full;
+
+static void sclp_suspend_req_cb(struct sclp_req *req, void *data)
+{
+ complete(&sclp_request_queue_flushed);
+}
+
+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)
+{
+ int drop, rc;
+
+ rc = kstrtoint(str, 0, &drop);
+ if (!rc && drop)
+ sclp_console_drop = 1;
+ return 1;
+}
+
+__setup("sclp_con_drop=", sclp_setup_console_drop);
+
+static struct sclp_req sclp_suspend_req;
+
+/* 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 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 = 4; /* Initialize for program check handling */
+
+ asm volatile(
+ "0: .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */
+ "1: ipm %0\n"
+ " srl %0,28\n"
+ "2:\n"
+ EX_TABLE(0b, 2b)
+ EX_TABLE(1b, 2b)
+ : "+&d" (cc) : "d" (command), "a" (__pa(sccb))
+ : "cc", "memory");
+ if (cc == 4)
+ return -EINVAL;
+ 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();
+}
+
+/*
+ * 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(unsigned long data)
+{
+ unsigned long flags, expires_next;
+ struct sclp_req *req;
+
+ do {
+ req = __sclp_req_queue_remove_expired_req();
+ 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);
+}
+
+/* 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) {
+ /* 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, 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;
+ 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) {
+ 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 = -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 == (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(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;
+ 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_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_sync &= 0xffff00a0;
+ cr0_sync |= 0x00000200;
+ __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 (timer_pending(&sclp_request_timer) &&
+ get_tod_clock_fast() > 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(®->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;
+
+ 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(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(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 != (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_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(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. */
+ 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);
+ if (sclp_init_req.status == SCLP_REQ_DONE &&
+ sccb->header.response_code == 0x20) {
+ rc = 0;
+ break;
+ } else
+ rc = -EBUSY;
+ }
+ 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
+};
+
+/*
+ * 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 const struct dev_pm_ops sclp_pm_ops = {
+ .freeze = sclp_freeze,
+ .thaw = sclp_thaw,
+ .restore = sclp_restore,
+};
+
+static ssize_t sclp_show_console_pages(struct device_driver *dev, char *buf)
+{
+ return sprintf(buf, "%i\n", sclp_console_pages);
+}
+
+static DRIVER_ATTR(con_pages, S_IRUSR, sclp_show_console_pages, NULL);
+
+static ssize_t sclp_show_con_drop(struct device_driver *dev, char *buf)
+{
+ return sprintf(buf, "%i\n", sclp_console_drop);
+}
+
+static DRIVER_ATTR(con_drop, S_IRUSR, sclp_show_con_drop, NULL);
+
+static ssize_t sclp_show_console_full(struct device_driver *dev, char *buf)
+{
+ return sprintf(buf, "%lu\n", sclp_console_full);
+}
+
+static DRIVER_ATTR(con_full, S_IRUSR, sclp_show_console_full, NULL);
+
+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",
+ .pm = &sclp_pm_ops,
+ .groups = sclp_drv_attr_groups,
+ },
+};
+
+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);
+ init_timer(&sclp_queue_timer);
+ sclp_queue_timer.function = sclp_req_queue_timeout;
+ /* 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;
+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 = PTR_ERR_OR_ZERO(sclp_pdev);
+ 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);
Code Review / kvmfornfv.git / blobdiff