s390/sclp: do not use static sccbs
The sccbs for init/read/sdias/early have to be located below 2 GB, and
they are currently defined as a static buffer.
With a relocatable kernel that could reside at any place in memory, this
will no longer guarantee the location below 2 GB, so use a dynamic
GFP_DMA allocation instead.
The sclp_early_sccb buffer needs special handling, as it can be used
very early, and by both the decompressor and also the decompressed
kernel. Therefore, a fixed 4 KB buffer is introduced at 0x11000, the
former PARMAREA_END. The new PARMAREA_END is now 0x12000, and it is
renamed to HEAD_END, as it is rather the end of head.S and not the end
of the parmarea.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index 42c23a5..fbdd3ea 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -337,10 +337,8 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
* load memory in head.S will be accessed, e.g. to register the next
* command line. If the next kernel were smaller the current kernel
* will panic at load.
- *
- * 0x11000 = sizeof(head.S)
*/
- if (buf_len < 0x11000)
+ if (buf_len < HEAD_END)
return -ENOEXEC;
return kexec_image_probe_default(image, buf, buf_len);