[S390] kernel: Append scpdata to kernel boot command line

Append scpdata to the kernel boot command line. If scpdata starts
with the equal sign (=), the kernel boot command line is replaced.
(For consistency with zIPL and IPL PARM parameters.)

To use scpdata for the kernel boot command line, scpdata must consist
of ascii characters only. If scpdata contains other characters,
scpdata is not appended to the kernel boot command line.
In addition, re-IPL is extended for setting scpdata for the next
Linux reboot.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 25 insertions, 10 deletions

diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index cae14c499511..21f3799fe27c 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -81,6 +81,8 @@ asm(
         "       br      14\n"
         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n");
 
+static __initdata char upper_command_line[COMMAND_LINE_SIZE];
+
 static noinline __init void create_kernel_nss(void)
 {
         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
@@ -90,7 +92,6 @@ static noinline __init void create_kernel_nss(void)
         int response;
         size_t len;
         char *savesys_ptr;
-        char upper_command_line[COMMAND_LINE_SIZE];
         char defsys_cmd[DEFSYS_CMD_SIZE];
         char savesys_cmd[SAVESYS_CMD_SIZE];
 
@@ -367,21 +368,35 @@ static __init void rescue_initrd(void)
 }
 
 /* Set up boot command line */
-static void __init setup_boot_command_line(void)
+static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 {
-        char *parm = NULL;
+        char *parm, *delim;
+        size_t rc, len;
+
+        len = strlen(boot_command_line);
 
+        delim = boot_command_line + len;        /* '\0' character position */
+        parm  = boot_command_line + len + 1;    /* append right after '\0' */
+
+        rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
+        if (rc) {
+                if (*parm == '=')
+                        memmove(boot_command_line, parm + 1, rc);
+                else
+                        *delim = ' ';           /* replace '\0' with space */
+        }
+}
+
+static void __init setup_boot_command_line(void)
+{
         /* copy arch command line */
         strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 
         /* append IPL PARM data to the boot command line */
-        if (MACHINE_IS_VM) {
-                parm = boot_command_line + strlen(boot_command_line);
-                *parm++ = ' ';
-                get_ipl_vmparm(parm);
-                if (parm[0] == '=')
-                        memmove(boot_command_line, parm + 1, strlen(parm));
-        }
+        if (MACHINE_IS_VM)
+                append_to_cmdline(append_ipl_vmparm);
+
+        append_to_cmdline(append_ipl_scpdata);
 }