// SPDX-License-Identifier: GPL-2.0 /* * core function to access sclp interface * * Copyright IBM Corp. 1999, 2009 * * Author(s): Martin Peschke * Martin Schwidefsky */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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)); strtomem(e.id, 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; struct ctlreg cr0, cr0_sync; unsigned long flags; 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(); local_ctl_store(0, &cr0); cr0_sync.val = cr0.val & ~CR0_IRQ_SUBCLASS_MASK; cr0_sync.val |= 1UL << (63 - 54); local_ctl_load(0, &cr0_sync); arch_local_irq_enable_external(); /* 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(); local_ctl_load(0, &cr0); 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, .priority = INT_MIN, }; 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: list_del(&sclp_state_change_event.list); 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);