From: Hans-Joachim Picht <hpicht@redhat.com>
Date: Thu, 12 Mar 2009 15:24:26 +0100
Subject: [s390] extra kernel parameters via VMPARM
Message-id: 20090312142426.GJ5103@redhat.com
O-Subject: [RHEL5 U4 PATCH 9/20] FEAT: s390 - kernel: Extra kernel parameters via VMPARM (NSS part of the patch)
Bugzilla: 475530

Description
============

This feature allows the user to append or replace kernel
parameters using PARM option of the IPL command.
Parameters can be set with the IPL command on the CP/CMS
commandline or via the new "parm" sysfs attribute
for the ccw and nss reipl types.

Whereas the previous patch in this series addresses the base implementation,
this patch provides the kernel NSS part.

Bugzilla
=========

BZ 475530
https://bugzilla.redhat.com/show_bug.cgi?id=475530

Upstream status of the patch:
=============================

The patch is upstream as of git commit
a0443fbb467af5e5930b9b059b52190605f70059

Test status:
============

The patch has been tested by the IBM test department.

Please ACK.

With best regards,

	--Hans

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index febfa6f..0c71557 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -318,12 +318,37 @@ static inline void setup_zfcpdump(unsigned int console_devno) {}
 /*
  * Create a Kernel NSS if the SAVESYS= parameter is defined
 */
-#define DEFSYS_CMD_SIZE	96
+#define DEFSYS_CMD_SIZE		128
 #define SAVESYS_CMD_SIZE	32
 
 char kernel_nss_name[NSS_NAME_SIZE + 1];
 
 #ifdef CONFIG_SHARED_KERNEL
+int __init savesys_ipl_nss(char *cmd, const int cmdlen);
+
+asm(
+	"	.section .init.text,\"ax\",@progbits\n"
+	"	.align	4\n"
+	"	.type	savesys_ipl_nss, @function\n"
+	"savesys_ipl_nss:\n"
+#ifdef CONFIG_64BIT
+	"	stmg	6,15,48(15)\n"
+	"	lgr	14,3\n"
+	"	sam31\n"
+	"	diag	2,14,0x8\n"
+	"	sam64\n"
+	"	lgr	2,14\n"
+	"	lmg	6,15,48(15)\n"
+#else
+	"	stm	6,15,24(15)\n"
+	"	lr	14,3\n"
+	"	diag	2,14,0x8\n"
+	"	lr	2,14\n"
+	"	lm	6,15,24(15)\n"
+#endif
+	"	br	14\n"
+	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n");
+
 static __init void create_kernel_nss(void)
 {
 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
@@ -331,6 +356,7 @@ static __init void create_kernel_nss(void)
 	unsigned int sinitrd_pfn, einitrd_pfn;
 #endif
 	int response;
+	size_t len;
 	char *savesys_ptr;
 	char upper_command_line[COMMAND_LINE_SIZE];
 	char defsys_cmd[DEFSYS_CMD_SIZE];
@@ -340,9 +366,9 @@ static __init void create_kernel_nss(void)
 	if (!MACHINE_IS_VM)
 		return;
 
-	/* Convert COMMAND_LINE to upper case */
-	for (i = 0; i < strlen(COMMAND_LINE); i++)
-		upper_command_line[i] = toupper(COMMAND_LINE[i]);
+	/* Convert s390_command_line to upper case */
+	for (i = 0; i < strlen(s390_command_line); i++)
+		upper_command_line[i] = toupper(s390_command_line[i]);
 
 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 
@@ -375,7 +401,8 @@ static __init void create_kernel_nss(void)
 	}
 #endif
 
-	sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK", defsys_cmd, min_size);
+	sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
+		defsys_cmd, min_size);
 	sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
 		kernel_nss_name, kernel_nss_name);
 
@@ -386,13 +413,24 @@ static __init void create_kernel_nss(void)
 		return;
 	}
 
-	__cpcmd(savesys_cmd, NULL, 0, &response);
+	len = strlen(savesys_cmd);
+	ASCEBC(savesys_cmd, len);
+	response = savesys_ipl_nss(savesys_cmd, len);
 
-	if (response != strlen(savesys_cmd)) {
+	/* On success: response is equal to the command size,
+	 *	       max SAVESYS_CMD_SIZE
+	 * On error: response contains the numeric portion of cp error message.
+	 *	     for SAVESYS it will be >= 263
+	 */
+	if (response > SAVESYS_CMD_SIZE) {
 		kernel_nss_name[0] = '\0';
 		return;
 	}
 
+	/* re-setup boot command line with new ipl vm parms */
+	ipl_update_parameters();
+	setup_boot_command_line();
+
 	ipl_flags = IPL_NSS_VALID;
 }