Commit 00a47e7e authored by Eugene (jno) Dvurechenski's avatar Eugene (jno) Dvurechenski Committed by Christian Borntraeger

pc-bios/s390-ccw: handle more ECKD DASD block sizes

Using dasdfmt(8) to format a DASD allows to choose a block size.
There are four supported values: 512, 1024, 2048, and 4096 bytes
per block. Each block size leads to selection of new count of
sectors per track. The head count remains always the same: 15.

This empiric knowledge is used to detect ECKD DASD to IPL from.
Signed-off-by: default avatarEugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 92cb0557
......@@ -299,14 +299,35 @@ bool virtio_disk_is_scsi(void)
&& (virtio_get_block_size() == 512);
}
/*
* Other supported value pairs, if any, would need to be added here.
* Note: head count is always 15.
*/
static inline u8 virtio_eckd_sectors_for_block_size(int size)
{
switch (size) {
case 512:
return 49;
case 1024:
return 33;
case 2048:
return 21;
case 4096:
return 12;
}
return 0;
}
bool virtio_disk_is_eckd(void)
{
const int block_size = virtio_get_block_size();
if (guessed_disk_nature) {
return (virtio_get_block_size() == 4096);
return (block_size == 4096);
}
return (blk_cfg.geometry.heads == 15)
&& (blk_cfg.geometry.sectors == 12)
&& (virtio_get_block_size() == 4096);
&& (blk_cfg.geometry.sectors ==
virtio_eckd_sectors_for_block_size(block_size));
}
bool virtio_ipl_disk_is_valid(void)
......
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