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