[S390] zfcpdump support.

s390 machines provide hardware support for creating Linux dumps on SCSI
disks. For creating a dump a special purpose dump Linux is used. The first
32 MB of memory are saved by the hardware before the dump Linux is
booted. Via an SCLP interface, the saved memory can be accessed from
Linux. This patch exports memory and registers of the crashed Linux to
userspace via a debugfs file. For more information refer to
Documentation/s390/zfcpdump.txt, which is included in this patch.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 150 insertions, 82 deletions

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index a83cf1fdd8f5..06833ac2b115 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -29,36 +29,21 @@
 #define SCCB_LOADPARM (&s390_readinfo_sccb.loadparm)
 #define SCCB_FLAG (s390_readinfo_sccb.flags)
 
-enum ipl_type {
-	IPL_TYPE_NONE	 = 1,
-	IPL_TYPE_UNKNOWN = 2,
-	IPL_TYPE_CCW	 = 4,
-	IPL_TYPE_FCP	 = 8,
-	IPL_TYPE_NSS	 = 16,
-};
-
-#define IPL_NONE_STR	 "none"
-#define IPL_UNKNOWN_STR  "unknown"
-#define IPL_CCW_STR	 "ccw"
-#define IPL_FCP_STR	 "fcp"
-#define IPL_NSS_STR	 "nss"
-
-/*
- * Must be in data section since the bss section
- * is not cleared when these are accessed.
- */
-static u16 ipl_devno __attribute__((__section__(".data"))) = 0;
-u32 ipl_flags __attribute__((__section__(".data"))) = 0;
+#define IPL_UNKNOWN_STR		"unknown"
+#define IPL_CCW_STR		"ccw"
+#define IPL_FCP_STR		"fcp"
+#define IPL_FCP_DUMP_STR	"fcp_dump"
+#define IPL_NSS_STR		"nss"
 
 static char *ipl_type_str(enum ipl_type type)
 {
 	switch (type) {
-	case IPL_TYPE_NONE:
-		return IPL_NONE_STR;
 	case IPL_TYPE_CCW:
 		return IPL_CCW_STR;
 	case IPL_TYPE_FCP:
 		return IPL_FCP_STR;
+	case IPL_TYPE_FCP_DUMP:
+		return IPL_FCP_DUMP_STR;
 	case IPL_TYPE_NSS:
 		return IPL_NSS_STR;
 	case IPL_TYPE_UNKNOWN:
@@ -67,15 +52,55 @@ static char *ipl_type_str(enum ipl_type type)
 	}
 }
 
+enum dump_type {
+	DUMP_TYPE_NONE	= 1,
+	DUMP_TYPE_CCW	= 2,
+	DUMP_TYPE_FCP	= 4,
+};
+
+#define DUMP_NONE_STR	 "none"
+#define DUMP_CCW_STR	 "ccw"
+#define DUMP_FCP_STR	 "fcp"
+
+static char *dump_type_str(enum dump_type type)
+{
+	switch (type) {
+	case DUMP_TYPE_NONE:
+		return DUMP_NONE_STR;
+	case DUMP_TYPE_CCW:
+		return DUMP_CCW_STR;
+	case DUMP_TYPE_FCP:
+		return DUMP_FCP_STR;
+	default:
+		return NULL;
+	}
+}
+
+/*
+ * Must be in data section since the bss section
+ * is not cleared when these are accessed.
+ */
+static u16 ipl_devno __attribute__((__section__(".data"))) = 0;
+u32 ipl_flags __attribute__((__section__(".data"))) = 0;
+
 enum ipl_method {
-	IPL_METHOD_NONE,
-	IPL_METHOD_CCW_CIO,
-	IPL_METHOD_CCW_DIAG,
-	IPL_METHOD_CCW_VM,
-	IPL_METHOD_FCP_RO_DIAG,
-	IPL_METHOD_FCP_RW_DIAG,
-	IPL_METHOD_FCP_RO_VM,
-	IPL_METHOD_NSS,
+	REIPL_METHOD_CCW_CIO,
+	REIPL_METHOD_CCW_DIAG,
+	REIPL_METHOD_CCW_VM,
+	REIPL_METHOD_FCP_RO_DIAG,
+	REIPL_METHOD_FCP_RW_DIAG,
+	REIPL_METHOD_FCP_RO_VM,
+	REIPL_METHOD_FCP_DUMP,
+	REIPL_METHOD_NSS,
+	REIPL_METHOD_DEFAULT,
+};
+
+enum dump_method {
+	DUMP_METHOD_NONE,
+	DUMP_METHOD_CCW_CIO,
+	DUMP_METHOD_CCW_DIAG,
+	DUMP_METHOD_CCW_VM,
+	DUMP_METHOD_FCP_DIAG,
 };
 
 enum shutdown_action {
@@ -107,15 +132,15 @@ static int diag308_set_works = 0;
 static int reipl_capabilities = IPL_TYPE_UNKNOWN;
 
 static enum ipl_type reipl_type = IPL_TYPE_UNKNOWN;
-static enum ipl_method reipl_method = IPL_METHOD_NONE;
+static enum ipl_method reipl_method = REIPL_METHOD_DEFAULT;
 static struct ipl_parameter_block *reipl_block_fcp;
 static struct ipl_parameter_block *reipl_block_ccw;
 
 static char reipl_nss_name[NSS_NAME_SIZE + 1];
 
-static int dump_capabilities = IPL_TYPE_NONE;
-static enum ipl_type dump_type = IPL_TYPE_NONE;
-static enum ipl_method dump_method = IPL_METHOD_NONE;
+static int dump_capabilities = DUMP_TYPE_NONE;
+static enum dump_type dump_type = DUMP_TYPE_NONE;
+static enum dump_method dump_method = DUMP_METHOD_NONE;
 static struct ipl_parameter_block *dump_block_fcp;
 static struct ipl_parameter_block *dump_block_ccw;
 
@@ -134,6 +159,7 @@ int diag308(unsigned long subcode, void *addr)
 		: "d" (subcode) : "cc", "memory");
 	return _rc;
 }
+EXPORT_SYMBOL_GPL(diag308);
 
 /* SYSFS */
 
@@ -197,7 +223,7 @@ static void make_attrs_ro(struct attribute **attrs)
  * ipl section
  */
 
-static enum ipl_type ipl_get_type(void)
+static __init enum ipl_type get_ipl_type(void)
 {
 	struct ipl_parameter_block *ipl = IPL_PARMBLOCK_START;
 
@@ -211,12 +237,44 @@ static enum ipl_type ipl_get_type(void)
 		return IPL_TYPE_UNKNOWN;
 	if (ipl->hdr.pbt != DIAG308_IPL_TYPE_FCP)
 		return IPL_TYPE_UNKNOWN;
+	if (ipl->ipl_info.fcp.opt == DIAG308_IPL_OPT_DUMP)
+		return IPL_TYPE_FCP_DUMP;
 	return IPL_TYPE_FCP;
 }
 
+void __init setup_ipl_info(void)
+{
+	ipl_info.type = get_ipl_type();
+	switch (ipl_info.type) {
+	case IPL_TYPE_CCW:
+		ipl_info.data.ccw.dev_id.devno = ipl_devno;
+		ipl_info.data.ccw.dev_id.ssid = 0;
+		break;
+	case IPL_TYPE_FCP:
+	case IPL_TYPE_FCP_DUMP:
+		ipl_info.data.fcp.dev_id.devno =
+			IPL_PARMBLOCK_START->ipl_info.fcp.devno;
+		ipl_info.data.fcp.dev_id.ssid = 0;
+		ipl_info.data.fcp.wwpn = IPL_PARMBLOCK_START->ipl_info.fcp.wwpn;
+		ipl_info.data.fcp.lun = IPL_PARMBLOCK_START->ipl_info.fcp.lun;
+		break;
+	case IPL_TYPE_NSS:
+		strncpy(ipl_info.data.nss.name, kernel_nss_name,
+			sizeof(ipl_info.data.nss.name));
+		break;
+	case IPL_TYPE_UNKNOWN:
+	default:
+		/* We have no info to copy */
+		break;
+	}
+}
+
+struct ipl_info ipl_info;
+EXPORT_SYMBOL_GPL(ipl_info);
+
 static ssize_t ipl_type_show(struct subsystem *subsys, char *page)
 {
-	return sprintf(page, "%s\n", ipl_type_str(ipl_get_type()));
+	return sprintf(page, "%s\n", ipl_type_str(ipl_info.type));
 }
 
 static struct subsys_attribute sys_ipl_type_attr = __ATTR_RO(ipl_type);
@@ -225,10 +283,11 @@ static ssize_t sys_ipl_device_show(struct subsystem *subsys, char *page)
 {
 	struct ipl_parameter_block *ipl = IPL_PARMBLOCK_START;
 
-	switch (ipl_get_type()) {
+	switch (ipl_info.type) {
 	case IPL_TYPE_CCW:
 		return sprintf(page, "0.0.%04x\n", ipl_devno);
 	case IPL_TYPE_FCP:
+	case IPL_TYPE_FCP_DUMP:
 		return sprintf(page, "0.0.%04x\n", ipl->ipl_info.fcp.devno);
 	default:
 		return 0;
@@ -485,23 +544,29 @@ static int reipl_set_type(enum ipl_type type)
 	switch(type) {
 	case IPL_TYPE_CCW:
 		if (MACHINE_IS_VM)
-			reipl_method = IPL_METHOD_CCW_VM;
+			reipl_method = REIPL_METHOD_CCW_VM;
 		else
-			reipl_method = IPL_METHOD_CCW_CIO;
+			reipl_method = REIPL_METHOD_CCW_CIO;
 		break;
 	case IPL_TYPE_FCP:
 		if (diag308_set_works)
-			reipl_method = IPL_METHOD_FCP_RW_DIAG;
+			reipl_method = REIPL_METHOD_FCP_RW_DIAG;
 		else if (MACHINE_IS_VM)
-			reipl_method = IPL_METHOD_FCP_RO_VM;
+			reipl_method = REIPL_METHOD_FCP_RO_VM;
 		else
-			reipl_method = IPL_METHOD_FCP_RO_DIAG;
+			reipl_method = REIPL_METHOD_FCP_RO_DIAG;
+		break;
+	case IPL_TYPE_FCP_DUMP:
+		reipl_method = REIPL_METHOD_FCP_DUMP;
 		break;
 	case IPL_TYPE_NSS:
-		reipl_method = IPL_METHOD_NSS;
+		reipl_method = REIPL_METHOD_NSS;
+		break;
+	case IPL_TYPE_UNKNOWN:
+		reipl_method = REIPL_METHOD_DEFAULT;
 		break;
 	default:
-		reipl_method = IPL_METHOD_NONE;
+		BUG();
 	}
 	reipl_type = type;
 	return 0;
@@ -579,22 +644,22 @@ static struct attribute_group dump_ccw_attr_group = {
 
 /* dump type */
 
-static int dump_set_type(enum ipl_type type)
+static int dump_set_type(enum dump_type type)
 {
 	if (!(dump_capabilities & type))
 		return -EINVAL;
 	switch(type) {
-	case IPL_TYPE_CCW:
+	case DUMP_TYPE_CCW:
 		if (MACHINE_IS_VM)
-			dump_method = IPL_METHOD_CCW_VM;
+			dump_method = DUMP_METHOD_CCW_VM;
 		else
-			dump_method = IPL_METHOD_CCW_CIO;
+			dump_method = DUMP_METHOD_CCW_CIO;
 		break;
-	case IPL_TYPE_FCP:
-		dump_method = IPL_METHOD_FCP_RW_DIAG;
+	case DUMP_TYPE_FCP:
+		dump_method = DUMP_METHOD_FCP_DIAG;
 		break;
 	default:
-		dump_method = IPL_METHOD_NONE;
+		dump_method = DUMP_METHOD_NONE;
 	}
 	dump_type = type;
 	return 0;
@@ -602,7 +667,7 @@ static int dump_set_type(enum ipl_type type)
 
 static ssize_t dump_type_show(struct subsystem *subsys, char *page)
 {
-	return sprintf(page, "%s\n", ipl_type_str(dump_type));
+	return sprintf(page, "%s\n", dump_type_str(dump_type));
 }
 
 static ssize_t dump_type_store(struct subsystem *subsys, const char *buf,
@@ -610,12 +675,12 @@ static ssize_t dump_type_store(struct subsystem *subsys, const char *buf,
 {
 	int rc = -EINVAL;
 
-	if (strncmp(buf, IPL_NONE_STR, strlen(IPL_NONE_STR)) == 0)
-		rc = dump_set_type(IPL_TYPE_NONE);
-	else if (strncmp(buf, IPL_CCW_STR, strlen(IPL_CCW_STR)) == 0)
-		rc = dump_set_type(IPL_TYPE_CCW);
-	else if (strncmp(buf, IPL_FCP_STR, strlen(IPL_FCP_STR)) == 0)
-		rc = dump_set_type(IPL_TYPE_FCP);
+	if (strncmp(buf, DUMP_NONE_STR, strlen(DUMP_NONE_STR)) == 0)
+		rc = dump_set_type(DUMP_TYPE_NONE);
+	else if (strncmp(buf, DUMP_CCW_STR, strlen(DUMP_CCW_STR)) == 0)
+		rc = dump_set_type(DUMP_TYPE_CCW);
+	else if (strncmp(buf, DUMP_FCP_STR, strlen(DUMP_FCP_STR)) == 0)
+		rc = dump_set_type(DUMP_TYPE_FCP);
 	return (rc != 0) ? rc : len;
 }
 
@@ -664,14 +729,14 @@ void do_reipl(void)
 	char loadparm[LOADPARM_LEN + 1];
 
 	switch (reipl_method) {
-	case IPL_METHOD_CCW_CIO:
+	case REIPL_METHOD_CCW_CIO:
 		devid.devno = reipl_block_ccw->ipl_info.ccw.devno;
-		if (ipl_get_type() == IPL_TYPE_CCW && devid.devno == ipl_devno)
+		if (ipl_info.type == IPL_TYPE_CCW && devid.devno == ipl_devno)
 			diag308(DIAG308_IPL, NULL);
 		devid.ssid  = 0;
 		reipl_ccw_dev(&devid);
 		break;
-	case IPL_METHOD_CCW_VM:
+	case REIPL_METHOD_CCW_VM:
 		reipl_get_ascii_loadparm(loadparm);
 		if (strlen(loadparm) == 0)
 			sprintf(buf, "IPL %X",
@@ -681,30 +746,32 @@ void do_reipl(void)
 				reipl_block_ccw->ipl_info.ccw.devno, loadparm);
 		__cpcmd(buf, NULL, 0, NULL);
 		break;
-	case IPL_METHOD_CCW_DIAG:
+	case REIPL_METHOD_CCW_DIAG:
 		diag308(DIAG308_SET, reipl_block_ccw);
 		diag308(DIAG308_IPL, NULL);
 		break;
-	case IPL_METHOD_FCP_RW_DIAG:
+	case REIPL_METHOD_FCP_RW_DIAG:
 		diag308(DIAG308_SET, reipl_block_fcp);
 		diag308(DIAG308_IPL, NULL);
 		break;
-	case IPL_METHOD_FCP_RO_DIAG:
+	case REIPL_METHOD_FCP_RO_DIAG:
 		diag308(DIAG308_IPL, NULL);
 		break;
-	case IPL_METHOD_FCP_RO_VM:
+	case REIPL_METHOD_FCP_RO_VM:
 		__cpcmd("IPL", NULL, 0, NULL);
 		break;
-	case IPL_METHOD_NSS:
+	case REIPL_METHOD_NSS:
 		sprintf(buf, "IPL %s", reipl_nss_name);
 		__cpcmd(buf, NULL, 0, NULL);
 		break;
-	case IPL_METHOD_NONE:
-	default:
+	case REIPL_METHOD_DEFAULT:
 		if (MACHINE_IS_VM)
 			__cpcmd("IPL", NULL, 0, NULL);
 		diag308(DIAG308_IPL, NULL);
 		break;
+	case REIPL_METHOD_FCP_DUMP:
+	default:
+		break;
 	}
 	signal_processor(smp_processor_id(), sigp_stop_and_store_status);
 }
@@ -715,28 +782,28 @@ static void do_dump(void)
 	static char buf[100];
 
 	switch (dump_method) {
-	case IPL_METHOD_CCW_CIO:
+	case DUMP_METHOD_CCW_CIO:
 		smp_send_stop();
 		devid.devno = dump_block_ccw->ipl_info.ccw.devno;
 		devid.ssid  = 0;
 		reipl_ccw_dev(&devid);
 		break;
-	case IPL_METHOD_CCW_VM:
+	case DUMP_METHOD_CCW_VM:
 		smp_send_stop();
 		sprintf(buf, "STORE STATUS");
 		__cpcmd(buf, NULL, 0, NULL);
 		sprintf(buf, "IPL %X", dump_block_ccw->ipl_info.ccw.devno);
 		__cpcmd(buf, NULL, 0, NULL);
 		break;
-	case IPL_METHOD_CCW_DIAG:
+	case DUMP_METHOD_CCW_DIAG:
 		diag308(DIAG308_SET, dump_block_ccw);
 		diag308(DIAG308_DUMP, NULL);
 		break;
-	case IPL_METHOD_FCP_RW_DIAG:
+	case DUMP_METHOD_FCP_DIAG:
 		diag308(DIAG308_SET, dump_block_fcp);
 		diag308(DIAG308_DUMP, NULL);
 		break;
-	case IPL_METHOD_NONE:
+	case DUMP_METHOD_NONE:
 	default:
 		return;
 	}
@@ -777,12 +844,13 @@ static int __init ipl_init(void)
 	rc = firmware_register(&ipl_subsys);
 	if (rc)
 		return rc;
-	switch (ipl_get_type()) {
+	switch (ipl_info.type) {
 	case IPL_TYPE_CCW:
 		rc = sysfs_create_group(&ipl_subsys.kset.kobj,
 					&ipl_ccw_attr_group);
 		break;
 	case IPL_TYPE_FCP:
+	case IPL_TYPE_FCP_DUMP:
 		rc = ipl_register_fcp_files();
 		break;
 	case IPL_TYPE_NSS:
@@ -852,7 +920,7 @@ static int __init reipl_ccw_init(void)
 	/* FIXME: check for diag308_set_works when enabling diag ccw reipl */
 	if (!MACHINE_IS_VM)
 		sys_reipl_ccw_loadparm_attr.attr.mode = S_IRUGO;
-	if (ipl_get_type() == IPL_TYPE_CCW)
+	if (ipl_info.type == IPL_TYPE_CCW)
 		reipl_block_ccw->ipl_info.ccw.devno = ipl_devno;
 	reipl_capabilities |= IPL_TYPE_CCW;
 	return 0;
@@ -862,9 +930,9 @@ static int __init reipl_fcp_init(void)
 {
 	int rc;
 
-	if ((!diag308_set_works) && (ipl_get_type() != IPL_TYPE_FCP))
+	if ((!diag308_set_works) && (ipl_info.type != IPL_TYPE_FCP))
 		return 0;
-	if ((!diag308_set_works) && (ipl_get_type() == IPL_TYPE_FCP))
+	if ((!diag308_set_works) && (ipl_info.type == IPL_TYPE_FCP))
 		make_attrs_ro(reipl_fcp_attrs);
 
 	reipl_block_fcp = (void *) get_zeroed_page(GFP_KERNEL);
@@ -875,7 +943,7 @@ static int __init reipl_fcp_init(void)
 		free_page((unsigned long)reipl_block_fcp);
 		return rc;
 	}
-	if (ipl_get_type() == IPL_TYPE_FCP) {
+	if (ipl_info.type == IPL_TYPE_FCP) {
 		memcpy(reipl_block_fcp, IPL_PARMBLOCK_START, PAGE_SIZE);
 	} else {
 		reipl_block_fcp->hdr.len = IPL_PARM_BLK_FCP_LEN;
@@ -909,7 +977,7 @@ static int __init reipl_init(void)
 	rc = reipl_nss_init();
 	if (rc)
 		return rc;
-	rc = reipl_set_type(ipl_get_type());
+	rc = reipl_set_type(ipl_info.type);
 	if (rc)
 		return rc;
 	return 0;
@@ -931,7 +999,7 @@ static int __init dump_ccw_init(void)
 	dump_block_ccw->hdr.version = IPL_PARM_BLOCK_VERSION;
 	dump_block_ccw->hdr.blk0_len = IPL_PARM_BLK0_CCW_LEN;
 	dump_block_ccw->hdr.pbt = DIAG308_IPL_TYPE_CCW;
-	dump_capabilities |= IPL_TYPE_CCW;
+	dump_capabilities |= DUMP_TYPE_CCW;
 	return 0;
 }
 
@@ -956,7 +1024,7 @@ static int __init dump_fcp_init(void)
 	dump_block_fcp->hdr.blk0_len = IPL_PARM_BLK0_FCP_LEN;
 	dump_block_fcp->hdr.pbt = DIAG308_IPL_TYPE_FCP;
 	dump_block_fcp->ipl_info.fcp.opt = DIAG308_IPL_OPT_DUMP;
-	dump_capabilities |= IPL_TYPE_FCP;
+	dump_capabilities |= DUMP_TYPE_FCP;
 	return 0;
 }
 
@@ -995,7 +1063,7 @@ static int __init dump_init(void)
 	rc = dump_fcp_init();
 	if (rc)
 		return rc;
-	dump_set_type(IPL_TYPE_NONE);
+	dump_set_type(DUMP_TYPE_NONE);
 	return 0;
 }