summary refs log tree commit diff stats
path: root/pc-bios/s390-ccw/main.c
diff options
context:
space:
mode:
Diffstat (limited to 'pc-bios/s390-ccw/main.c')
-rw-r--r--pc-bios/s390-ccw/main.c172
1 files changed, 106 insertions, 66 deletions
diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 146a50760b..43c792cf95 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -51,6 +51,60 @@ unsigned int get_loadparm_index(void)
     return atoui(loadparm_str);
 }
 
+static int is_dev_possibly_bootable(int dev_no, int sch_no)
+{
+    bool is_virtio;
+    Schib schib;
+    int r;
+
+    blk_schid.sch_no = sch_no;
+    r = stsch_err(blk_schid, &schib);
+    if (r == 3 || r == -EIO) {
+        return -ENODEV;
+    }
+    if (!schib.pmcw.dnv) {
+        return false;
+    }
+
+    enable_subchannel(blk_schid);
+    cutype = cu_type(blk_schid);
+
+    /*
+     * Note: we always have to run virtio_is_supported() here to make
+     * sure that the vdev.senseid data gets pre-initialized correctly
+     */
+    is_virtio = virtio_is_supported(blk_schid);
+
+    /* No specific devno given, just return whether the device is possibly bootable */
+    if (dev_no < 0) {
+        switch (cutype) {
+        case CU_TYPE_VIRTIO:
+            if (is_virtio) {
+                /*
+                 * Skip net devices since no IPLB is created and therefore
+                 * no network bootloader has been loaded
+                 */
+                if (virtio_get_device_type() != VIRTIO_ID_NET) {
+                    return true;
+                }
+            }
+            return false;
+        case CU_TYPE_DASD_3990:
+        case CU_TYPE_DASD_2107:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    /* Caller asked for a specific devno */
+    if (schib.pmcw.dev == dev_no) {
+        return true;
+    }
+
+    return false;
+}
+
 /*
  * Find the subchannel connected to the given device (dev_no) and fill in the
  * subchannel information block (schib) with the connected subchannel's info.
@@ -62,53 +116,14 @@ unsigned int get_loadparm_index(void)
  */
 static bool find_subch(int dev_no)
 {
-    Schib schib;
     int i, r;
-    bool is_virtio;
 
     for (i = 0; i < 0x10000; i++) {
-        blk_schid.sch_no = i;
-        r = stsch_err(blk_schid, &schib);
-        if ((r == 3) || (r == -EIO)) {
+        r = is_dev_possibly_bootable(dev_no, i);
+        if (r < 0) {
             break;
         }
-        if (!schib.pmcw.dnv) {
-            continue;
-        }
-
-        enable_subchannel(blk_schid);
-        cutype = cu_type(blk_schid);
-
-        /*
-         * Note: we always have to run virtio_is_supported() here to make
-         * sure that the vdev.senseid data gets pre-initialized correctly
-         */
-        is_virtio = virtio_is_supported(blk_schid);
-
-        /* No specific devno given, just return 1st possibly bootable device */
-        if (dev_no < 0) {
-            switch (cutype) {
-            case CU_TYPE_VIRTIO:
-                if (is_virtio) {
-                    /*
-                     * Skip net devices since no IPLB is created and therefore
-                     * no network bootloader has been loaded
-                     */
-                    if (virtio_get_device_type() != VIRTIO_ID_NET) {
-                        return true;
-                    }
-                }
-                continue;
-            case CU_TYPE_DASD_3990:
-            case CU_TYPE_DASD_2107:
-                return true;
-            default:
-                continue;
-            }
-        }
-
-        /* Caller asked for a specific devno */
-        if (schib.pmcw.dev == dev_no) {
+        if (r == true) {
             return true;
         }
     }
@@ -167,20 +182,8 @@ static void boot_setup(void)
 static void find_boot_device(void)
 {
     VDev *vdev = virtio_get_device();
-    int ssid;
     bool found;
 
-    if (!have_iplb) {
-        for (ssid = 0; ssid < 0x3; ssid++) {
-            blk_schid.ssid = ssid;
-            found = find_subch(-1);
-            if (found) {
-                return;
-            }
-        }
-        panic("Could not find a suitable boot device (none specified)\n");
-    }
-
     switch (iplb.pbt) {
     case S390_IPL_TYPE_CCW:
         debug_print_int("device no. ", iplb.ccw.devno);
@@ -203,7 +206,7 @@ static void find_boot_device(void)
     IPL_assert(found, "Boot device not found\n");
 }
 
-static void virtio_setup(void)
+static int virtio_setup(void)
 {
     VDev *vdev = virtio_get_device();
     QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;
@@ -218,31 +221,68 @@ static void virtio_setup(void)
         sclp_print("Network boot device detected\n");
         vdev->netboot_start_addr = qipl.netboot_start_addr;
     } else {
-        virtio_blk_setup_device(blk_schid);
+        int ret = virtio_blk_setup_device(blk_schid);
+        if (ret) {
+            return ret;
+        }
         IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
     }
+
+    return 0;
 }
 
-int main(void)
+static void ipl_boot_device(void)
 {
-    sclp_setup();
-    css_setup();
-    boot_setup();
-    find_boot_device();
-    enable_subchannel(blk_schid);
-
     switch (cutype) {
     case CU_TYPE_DASD_3990:
     case CU_TYPE_DASD_2107:
         dasd_ipl(blk_schid, cutype); /* no return */
         break;
     case CU_TYPE_VIRTIO:
-        virtio_setup();
-        zipl_load(); /* no return */
+        if (virtio_setup() == 0) {
+            zipl_load();             /* Only returns in case of errors */
+        }
         break;
     default:
         print_int("Attempting to boot from unexpected device type", cutype);
-        panic("");
+        panic("\nBoot failed.\n");
+    }
+}
+
+/*
+ * No boot device has been specified, so we have to scan through the
+ * channels to find one.
+ */
+static void probe_boot_device(void)
+{
+    int ssid, sch_no, ret;
+
+    for (ssid = 0; ssid < 0x3; ssid++) {
+        blk_schid.ssid = ssid;
+        for (sch_no = 0; sch_no < 0x10000; sch_no++) {
+            ret = is_dev_possibly_bootable(-1, sch_no);
+            if (ret < 0) {
+                break;
+            }
+            if (ret == true) {
+                ipl_boot_device();      /* Only returns if unsuccessful */
+            }
+        }
+    }
+
+    sclp_print("Could not find a suitable boot device (none specified)\n");
+}
+
+int main(void)
+{
+    sclp_setup();
+    css_setup();
+    boot_setup();
+    if (have_iplb) {
+        find_boot_device();
+        ipl_boot_device();
+    } else {
+        probe_boot_device();
     }
 
     panic("Failed to load OS from hard disk\n");