pc-bios/s390-ccw Really big EAV ECKD DASD handling

For EAV ECKD DASD, the cylinder count will have the magic value
0xfffeU. Therefore, use the block number to test for valid eckd
addresses instead.
Signed-off-by: NEugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

pc-bios/s390-ccw/bootmap.c

@@ -93,11 +93,23 @@ static inline void verify_boot_info(BootInfo *bip)
                "Bad block size in zIPL section of the 1st record.");
 }
 
-static bool eckd_valid_address(BootMapPointer *p)
+static block_number_t eckd_block_num(BootMapPointer *p)
 {
+    const uint64_t sectors = virtio_get_sectors();
+    const uint64_t heads = virtio_get_heads();
     const uint64_t cylinder = p->eckd.cylinder
                             + ((p->eckd.head & 0xfff0) << 12);
     const uint64_t head = p->eckd.head & 0x000f;
+    const block_number_t block = sectors * heads * cylinder
+                               + sectors * head
+                               + p->eckd.sector
+                               - 1; /* block nr starts with zero */
+    return block;
+}
+
+static bool eckd_valid_address(BootMapPointer *p)
+{
+    const uint64_t head = p->eckd.head & 0x000f;
 
     if (head >= virtio_get_heads()
         ||  p->eckd.sector > virtio_get_sectors()
@@ -105,27 +117,14 @@ static bool eckd_valid_address(BootMapPointer *p)
         return false;
     }
 
-    if (!virtio_guessed_disk_nature() && cylinder >= virtio_get_cylinders()) {
+    if (!virtio_guessed_disk_nature() &&
+        eckd_block_num(p) >= virtio_get_blocks()) {
         return false;
     }
 
     return true;
 }
 
-static block_number_t eckd_block_num(BootMapPointer *p)
-{
-    const uint64_t sectors = virtio_get_sectors();
-    const uint64_t heads = virtio_get_heads();
-    const uint64_t cylinder = p->eckd.cylinder
-                            + ((p->eckd.head & 0xfff0) << 12);
-    const uint64_t head = p->eckd.head & 0x000f;
-    const block_number_t block = sectors * heads * cylinder
-                               + sectors * head
-                               + p->eckd.sector
-                               - 1; /* block nr starts with zero */
-    return block;
-}
-
 static block_number_t load_eckd_segments(block_number_t blk, uint64_t *address)
 {
     block_number_t block_nr;

pc-bios/s390-ccw/virtio.c

@@ -340,11 +340,6 @@ int virtio_get_block_size(void)
     return blk_cfg.blk_size << blk_cfg.physical_block_exp;
 }
 
-uint16_t virtio_get_cylinders(void)
-{
-    return blk_cfg.geometry.cylinders;
-}
-
 uint8_t virtio_get_heads(void)
 {
     return blk_cfg.geometry.heads;
@@ -355,6 +350,12 @@ uint8_t virtio_get_sectors(void)
     return blk_cfg.geometry.sectors;
 }
 
+uint64_t virtio_get_blocks(void)
+{
+    return blk_cfg.capacity /
+           (virtio_get_block_size() / VIRTIO_SECTOR_SIZE);
+}
+
 void virtio_setup_block(struct subchannel_id schid)
 {
     struct vq_info_block info;

pc-bios/s390-ccw/virtio.h

@@ -192,9 +192,9 @@ extern bool virtio_disk_is_scsi(void);
 extern bool virtio_disk_is_eckd(void);
 extern bool virtio_ipl_disk_is_valid(void);
 extern int virtio_get_block_size(void);
-extern uint16_t virtio_get_cylinders(void);
 extern uint8_t virtio_get_heads(void);
 extern uint8_t virtio_get_sectors(void);
+extern uint64_t virtio_get_blocks(void);
 extern int virtio_read_many(ulong sector, void *load_addr, int sec_num);
 
 #define VIRTIO_SECTOR_SIZE 512