1 files changed, 80 insertions, 21 deletions

diff --git a/drivers/s390/char/sclp_sdias.c b/drivers/s390/char/sclp_sdias.c
index fa733ecd3d70..69e6c50d4cfb 100644
--- a/drivers/s390/char/sclp_sdias.c
+++ b/drivers/s390/char/sclp_sdias.c
@@ -8,6 +8,7 @@
 #define KMSG_COMPONENT "sclp_sdias"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
+#include <linux/completion.h>
 #include <linux/sched.h>
 #include <asm/sclp.h>
 #include <asm/debug.h>
@@ -62,15 +63,29 @@ struct sdias_sccb {
 } __attribute__((packed));
 
 static struct sdias_sccb sccb __attribute__((aligned(4096)));
+static struct sdias_evbuf sdias_evbuf;
 
-static int sclp_req_done;
-static wait_queue_head_t sdias_wq;
+static DECLARE_COMPLETION(evbuf_accepted);
+static DECLARE_COMPLETION(evbuf_done);
 static DEFINE_MUTEX(sdias_mutex);
 
+/*
+ * Called by SCLP base when read event data has been completed (async mode only)
+ */
+static void sclp_sdias_receiver_fn(struct evbuf_header *evbuf)
+{
+        memcpy(&sdias_evbuf, evbuf,
+               min_t(unsigned long, sizeof(sdias_evbuf), evbuf->length));
+        complete(&evbuf_done);
+        TRACE("sclp_sdias_receiver_fn done\n");
+}
+
+/*
+ * Called by SCLP base when sdias event has been accepted
+ */
 static void sdias_callback(struct sclp_req *request, void *data)
 {
-        sclp_req_done = 1;
-        wake_up(&sdias_wq); /* Inform caller, that request is complete */
+        complete(&evbuf_accepted);
         TRACE("callback done\n");
 }
 
@@ -80,7 +95,6 @@ static int sdias_sclp_send(struct sclp_req *req)
         int rc;
 
         for (retries = SDIAS_RETRIES; retries; retries--) {
-                sclp_req_done = 0;
                 TRACE("add request\n");
                 rc = sclp_add_request(req);
                 if (rc) {
@@ -91,16 +105,31 @@ static int sdias_sclp_send(struct sclp_req *req)
                         continue;
                 }
                 /* initiated, wait for completion of service call */
-                wait_event(sdias_wq, (sclp_req_done == 1));
+                wait_for_completion(&evbuf_accepted);
                 if (req->status == SCLP_REQ_FAILED) {
                         TRACE("sclp request failed\n");
-                        rc = -EIO;
                         continue;
                 }
+                /* if not accepted, retry */
+                if (!(sccb.evbuf.hdr.flags & 0x80)) {
+                        TRACE("sclp request failed: flags=%x\n",
+                              sccb.evbuf.hdr.flags);
+                        continue;
+                }
+                /*
+                 * for the sync interface the response is in the initial sccb
+                 */
+                if (!sclp_sdias_register.receiver_fn) {
+                        memcpy(&sdias_evbuf, &sccb.evbuf, sizeof(sdias_evbuf));
+                        TRACE("sync request done\n");
+                        return 0;
+                }
+                /* otherwise we wait for completion */
+                wait_for_completion(&evbuf_done);
                 TRACE("request done\n");
-                break;
+                return 0;
         }
-        return rc;
+        return -EIO;
 }
 
 /*
@@ -140,13 +169,12 @@ int sclp_sdias_blk_count(void)
                 goto out;
         }
 
-        switch (sccb.evbuf.event_status) {
+        switch (sdias_evbuf.event_status) {
                 case 0:
-                        rc = sccb.evbuf.blk_cnt;
+                        rc = sdias_evbuf.blk_cnt;
                         break;
                 default:
-                        pr_err("SCLP error: %x\n",
-                               sccb.evbuf.event_status);
+                        pr_err("SCLP error: %x\n", sdias_evbuf.event_status);
                         rc = -EIO;
                         goto out;
         }
@@ -211,18 +239,18 @@ int sclp_sdias_copy(void *dest, int start_blk, int nr_blks)
                 goto out;
         }
 
-        switch (sccb.evbuf.event_status) {
+        switch (sdias_evbuf.event_status) {
                 case EVSTATE_ALL_STORED:
                         TRACE("all stored\n");
                 case EVSTATE_PART_STORED:
-                        TRACE("part stored: %i\n", sccb.evbuf.blk_cnt);
+                        TRACE("part stored: %i\n", sdias_evbuf.blk_cnt);
                         break;
                 case EVSTATE_NO_DATA:
                         TRACE("no data\n");
                 default:
                         pr_err("Error from SCLP while copying hsa. "
                                "Event status = %x\n",
-                               sccb.evbuf.event_status);
+                               sdias_evbuf.event_status);
                         rc = -EIO;
         }
 out:
@@ -230,19 +258,50 @@ out:
         return rc;
 }
 
-int __init sclp_sdias_init(void)
+static int __init sclp_sdias_register_check(void)
 {
         int rc;
 
+        rc = sclp_register(&sclp_sdias_register);
+        if (rc)
+                return rc;
+        if (sclp_sdias_blk_count() == 0) {
+                sclp_unregister(&sclp_sdias_register);
+                return -ENODEV;
+        }
+        return 0;
+}
+
+static int __init sclp_sdias_init_sync(void)
+{
+        TRACE("Try synchronous mode\n");
+        sclp_sdias_register.receive_mask = 0;
+        sclp_sdias_register.receiver_fn = NULL;
+        return sclp_sdias_register_check();
+}
+
+static int __init sclp_sdias_init_async(void)
+{
+        TRACE("Try asynchronous mode\n");
+        sclp_sdias_register.receive_mask = EVTYP_SDIAS_MASK;
+        sclp_sdias_register.receiver_fn = sclp_sdias_receiver_fn;
+        return sclp_sdias_register_check();
+}
+
+int __init sclp_sdias_init(void)
+{
         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
                 return 0;
         sdias_dbf = debug_register("dump_sdias", 4, 1, 4 * sizeof(long));
         debug_register_view(sdias_dbf, &debug_sprintf_view);
         debug_set_level(sdias_dbf, 6);
-        rc = sclp_register(&sclp_sdias_register);
-        if (rc)
-                return rc;
-        init_waitqueue_head(&sdias_wq);
+        if (sclp_sdias_init_sync() == 0)
+                goto out;
+        if (sclp_sdias_init_async() == 0)
+                goto out;
+        TRACE("init failed\n");
+        return -ENODEV;
+out:
         TRACE("init done\n");
         return 0;
 }