Merge tag 'io_uring-5.15-2021-09-11' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.git] / drivers / s390 / char / sclp.c
index 792b4bf..2cf7fe1 100644 (file)
 #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);
 
@@ -54,6 +73,114 @@ 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, (u32)(addr_t)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;
@@ -162,6 +289,9 @@ 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) {
@@ -237,6 +367,12 @@ static void sclp_req_queue_timeout(struct timer_list *unused)
 
        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);
@@ -248,6 +384,25 @@ static void sclp_req_queue_timeout(struct timer_list *unused)
        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. */
@@ -259,7 +414,7 @@ __sclp_start_request(struct sclp_req *req)
        if (sclp_running_state != sclp_running_state_idle)
                return 0;
        del_timer(&sclp_request_timer);
-       rc = sclp_service_call(req->command, req->sccb);
+       rc = sclp_service_call_trace(req->command, req->sccb);
        req->start_count++;
 
        if (rc == 0) {
@@ -309,6 +464,10 @@ sclp_process_queue(void)
                }
                /* 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);
@@ -341,6 +500,10 @@ sclp_add_request(struct sclp_req *req)
                spin_unlock_irqrestore(&sclp_lock, flags);
                return -EIO;
        }
+
+       /* RQAD: Request was added (a=sccb, b=caller) */
+       sclp_trace(2, "RQAD", (u32)(addr_t)req->sccb, _RET_IP_, false);
+
        req->status = SCLP_REQ_QUEUED;
        req->start_count = 0;
        list_add_tail(&req->list, &sclp_req_queue);
@@ -394,6 +557,11 @@ sclp_dispatch_evbufs(struct sccb_header *sccb)
                        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);
@@ -455,6 +623,30 @@ __sclp_find_req(u32 sccb)
        return NULL;
 }
 
+static bool ok_response(u32 sccb_int, sclp_cmdw_t cmd)
+{
+       struct sccb_header *sccb = (struct sccb_header *)(addr_t)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. */
@@ -469,6 +661,12 @@ static void sclp_interrupt_handler(struct ext_code ext_code,
        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 *)(addr_t)finished_sccb,
+                       !ok_response(finished_sccb, active_cmd));
+
        if (finished_sccb) {
                del_timer(&sclp_request_timer);
                sclp_running_state = sclp_running_state_reset_pending;
@@ -477,13 +675,21 @@ static void sclp_interrupt_handler(struct ext_code ext_code,
                        /* 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)
@@ -507,9 +713,13 @@ 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;
@@ -547,6 +757,9 @@ sclp_sync_wait(void)
                _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);
 
@@ -576,8 +789,13 @@ sclp_dispatch_state_change(void)
                                reg = NULL;
                }
                spin_unlock_irqrestore(&sclp_lock, flags);
-               if (reg && reg->state_change_fn)
+               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);
 }
 
@@ -651,6 +869,9 @@ sclp_register(struct sclp_register *reg)
        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;
@@ -683,6 +904,9 @@ 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(&reg->list);
        spin_unlock_irqrestore(&sclp_lock, flags);
@@ -932,7 +1156,7 @@ sclp_check_interface(void)
        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);
+               rc = sclp_service_call_trace(sclp_init_req.command, sccb);
                if (rc == -EIO)
                        break;
                sclp_init_req.status = SCLP_REQ_RUNNING;