[S390] Convert memory detection into C code.
Hopefully this will make it more maintainable and less error prone.
Code makes use of search_exception_tables(). Since it calls this
function before the kernel exeception table is sorted, there is an
early call to sort_main_extable().
This way it's easy to use the already present infrastructure of fixup
sections. Also this would allows to easily convert the rest of
head[31|64].S into C code.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp_info.c b/drivers/s390/char/sclp_info.c
new file mode 100644
index 0000000..7bcbe64
--- /dev/null
+++ b/drivers/s390/char/sclp_info.c
@@ -0,0 +1,57 @@
+/*
+ * drivers/s390/char/sclp_info.c
+ *
+ * Copyright IBM Corp. 2007
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <asm/sclp.h>
+#include "sclp.h"
+
+struct sclp_readinfo_sccb s390_readinfo_sccb;
+
+void __init sclp_readinfo_early(void)
+{
+ sclp_cmdw_t command;
+ struct sccb_header *sccb;
+ int ret;
+
+ __ctl_set_bit(0, 9); /* enable service signal subclass mask */
+
+ sccb = &s390_readinfo_sccb.header;
+ command = SCLP_CMDW_READ_SCP_INFO_FORCED;
+ while (1) {
+ u16 response;
+
+ memset(&s390_readinfo_sccb, 0, sizeof(s390_readinfo_sccb));
+ sccb->length = sizeof(s390_readinfo_sccb);
+ sccb->control_mask[2] = 0x80;
+
+ ret = sclp_service_call(command, &s390_readinfo_sccb);
+
+ if (ret == -EIO)
+ goto out;
+ if (ret == -EBUSY)
+ continue;
+
+ __load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
+ PSW_MASK_WAIT | PSW_DEFAULT_KEY);
+ local_irq_disable();
+ barrier();
+
+ response = sccb->response_code;
+
+ if (response == 0x10)
+ break;
+
+ if (response != 0x1f0 || command == SCLP_CMDW_READ_SCP_INFO)
+ break;
+
+ command = SCLP_CMDW_READ_SCP_INFO;
+ }
+out:
+ __ctl_clear_bit(0, 9); /* disable service signal subclass mask */
+}