[PATCH v17 20/34] pc-bios/s390-ccw: Refactor zipl_run()

Refactor to enhance readability before enabling secure IPL in later
patches.

Signed-off-by: Zhuoying Cai <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Reviewed-by: Jared Rossi <[email protected]>
Reviewed-by: Collin Walling <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
---
 pc-bios/s390-ccw/bootmap.c | 54 ++++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 420ee32eff..2cf5c9eee3 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -674,12 +674,42 @@ static int zipl_load_segment(ComponentEntry *entry)
     return 0;
 }
 
+static int zipl_run_normal(ComponentEntry **entry_ptr, const uint8_t *tmp_sec)
+{
+    ComponentEntry *entry = *entry_ptr;
+
+    while (entry->component_type == ZIPL_COMP_ENTRY_LOAD ||
+           entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
+
+        /* Secure boot is off, so we skip signature entries */
+        if (entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
+            entry++;
+            continue;
+        }
+
+        if (zipl_load_segment(entry)) {
+            return -1;
+        }
+
+        entry++;
+
+        if ((uint8_t *)&entry[1] > tmp_sec + MAX_SECTOR_SIZE) {
+            puts("Wrong entry value");
+            return -EINVAL;
+        }
+    }
+
+    *entry_ptr = entry;
+    return 0;
+}
+
 /* Run a zipl program */
 static int zipl_run(ScsiBlockPtr *pte)
 {
     ComponentHeader *header;
     ComponentEntry *entry;
     uint8_t tmp_sec[MAX_SECTOR_SIZE];
+    int rc;
 
     if (virtio_read(pte->blockno, tmp_sec)) {
         puts("Cannot read header");
@@ -700,25 +730,10 @@ static int zipl_run(ScsiBlockPtr *pte)
 
     /* Load image(s) into RAM */
     entry = (ComponentEntry *)(&header[1]);
-    while (entry->component_type == ZIPL_COMP_ENTRY_LOAD ||
-           entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
-
-        /* We don't support secure boot yet, so we skip signature entries */
-        if (entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
-            entry++;
-            continue;
-        }
 
-        if (zipl_load_segment(entry)) {
-            return -1;
-        }
-
-        entry++;
-
-        if ((uint8_t *)(&entry[1]) > (tmp_sec + MAX_SECTOR_SIZE)) {
-            puts("Wrong entry value");
-            return -EINVAL;
-        }
+    rc = zipl_run_normal(&entry, tmp_sec);
+    if (rc) {
+        return rc;
     }
 
     if (entry->component_type != ZIPL_COMP_ENTRY_EXEC) {
@@ -726,10 +741,9 @@ static int zipl_run(ScsiBlockPtr *pte)
         return -EINVAL;
     }
 
-    /* should not return */
     write_reset_psw(entry->compdat.load_psw);
     jump_to_IPL_code(0);
-    return -1;
+    return -1; /* should not return */
 }
 
 static int ipl_scsi(void)
-- 
2.55.0