s390: add support for ipl devices in subchannel sets > 0

Allow to ipl from CCW based devices residing in any subchannel set.
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/cio.h

@@ -312,6 +312,7 @@ extern void css_schedule_reprobe(void);
 extern void reipl_ccw_dev(struct ccw_dev_id *id);
 
 struct cio_iplinfo {
+	u8 ssid;
 	u16 devno;
 	int is_qdio;
 };

arch/s390/include/asm/ipl.h

@@ -64,7 +64,8 @@ struct ipl_block_fcp {
 
 struct ipl_block_ccw {
 	u8  reserved1[84];
-	u8  reserved2[2];
+	u16 reserved2 : 13;
+	u8  ssid : 3;
 	u16 devno;
 	u8  vm_flags;
 	u8  reserved3[3];

arch/s390/kernel/ipl.c

@@ -121,6 +121,7 @@ static char *dump_type_str(enum dump_type type)
  * Must be in data section since the bss section
  * is not cleared when these are accessed.
  */
+static u8 ipl_ssid __attribute__((__section__(".data"))) = 0;
 static u16 ipl_devno __attribute__((__section__(".data"))) = 0;
 u32 ipl_flags __attribute__((__section__(".data"))) = 0;
 
@@ -197,6 +198,33 @@ static ssize_t sys_##_prefix##_##_name##_show(struct kobject *kobj,	\
 	return snprintf(page, PAGE_SIZE, _format, ##args);		\
 }
 
+#define IPL_ATTR_CCW_STORE_FN(_prefix, _name, _ipl_blk)			\
+static ssize_t sys_##_prefix##_##_name##_store(struct kobject *kobj,	\
+		struct kobj_attribute *attr,				\
+		const char *buf, size_t len)				\
+{									\
+	unsigned long long ssid, devno;					\
+									\
+	if (sscanf(buf, "0.%llx.%llx\n", &ssid, &devno) != 2)		\
+		return -EINVAL;						\
+									\
+	if (ssid > __MAX_SSID || devno > __MAX_SUBCHANNEL)		\
+		return -EINVAL;						\
+									\
+	_ipl_blk.ssid = ssid;						\
+	_ipl_blk.devno = devno;						\
+	return len;							\
+}
+
+#define DEFINE_IPL_CCW_ATTR_RW(_prefix, _name, _ipl_blk)		\
+IPL_ATTR_SHOW_FN(_prefix, _name, "0.%x.%04x\n",				\
+		 _ipl_blk.ssid, _ipl_blk.devno);			\
+IPL_ATTR_CCW_STORE_FN(_prefix, _name, _ipl_blk);			\
+static struct kobj_attribute sys_##_prefix##_##_name##_attr =		\
+	__ATTR(_name, (S_IRUGO | S_IWUSR),				\
+	       sys_##_prefix##_##_name##_show,				\
+	       sys_##_prefix##_##_name##_store)				\
+
 #define DEFINE_IPL_ATTR_RO(_prefix, _name, _format, _value)		\
 IPL_ATTR_SHOW_FN(_prefix, _name, _format, _value)			\
 static struct kobj_attribute sys_##_prefix##_##_name##_attr =		\
@@ -395,7 +423,7 @@ static ssize_t sys_ipl_device_show(struct kobject *kobj,
 
 	switch (ipl_info.type) {
 	case IPL_TYPE_CCW:
-		return sprintf(page, "0.0.%04x\n", ipl_devno);
+		return sprintf(page, "0.%x.%04x\n", ipl_ssid, ipl_devno);
 	case IPL_TYPE_FCP:
 	case IPL_TYPE_FCP_DUMP:
 		return sprintf(page, "0.0.%04x\n", ipl->ipl_info.fcp.devno);
@@ -807,9 +835,7 @@ static struct attribute_group reipl_fcp_attr_group = {
 };
 
 /* CCW reipl device attributes */
-
-DEFINE_IPL_ATTR_RW(reipl_ccw, device, "0.0.%04llx\n", "0.0.%llx\n",
-	reipl_block_ccw->ipl_info.ccw.devno);
+DEFINE_IPL_CCW_ATTR_RW(reipl_ccw, device, reipl_block_ccw->ipl_info.ccw);
 
 /* NSS wrapper */
 static ssize_t reipl_nss_loadparm_show(struct kobject *kobj,
@@ -1049,8 +1075,8 @@ static void __reipl_run(void *unused)
 
 	switch (reipl_method) {
 	case REIPL_METHOD_CCW_CIO:
+		devid.ssid  = reipl_block_ccw->ipl_info.ccw.ssid;
 		devid.devno = reipl_block_ccw->ipl_info.ccw.devno;
-		devid.ssid  = 0;
 		reipl_ccw_dev(&devid);
 		break;
 	case REIPL_METHOD_CCW_VM:
@@ -1185,6 +1211,7 @@ static int __init reipl_ccw_init(void)
 
 	reipl_block_ccw_init(reipl_block_ccw);
 	if (ipl_info.type == IPL_TYPE_CCW) {
+		reipl_block_ccw->ipl_info.ccw.ssid = ipl_ssid;
 		reipl_block_ccw->ipl_info.ccw.devno = ipl_devno;
 		reipl_block_ccw_fill_parms(reipl_block_ccw);
 	}
@@ -1329,9 +1356,7 @@ static struct attribute_group dump_fcp_attr_group = {
 };
 
 /* CCW dump device attributes */
-
-DEFINE_IPL_ATTR_RW(dump_ccw, device, "0.0.%04llx\n", "0.0.%llx\n",
-		   dump_block_ccw->ipl_info.ccw.devno);
+DEFINE_IPL_CCW_ATTR_RW(dump_ccw, device, dump_block_ccw->ipl_info.ccw);
 
 static struct attribute *dump_ccw_attrs[] = {
 	&sys_dump_ccw_device_attr.attr,
@@ -1411,8 +1436,8 @@ static void __dump_run(void *unused)
 
 	switch (dump_method) {
 	case DUMP_METHOD_CCW_CIO:
+		devid.ssid  = dump_block_ccw->ipl_info.ccw.ssid;
 		devid.devno = dump_block_ccw->ipl_info.ccw.devno;
-		devid.ssid  = 0;
 		reipl_ccw_dev(&devid);
 		break;
 	case DUMP_METHOD_CCW_VM:
@@ -1932,14 +1957,14 @@ void __init setup_ipl(void)
 	ipl_info.type = get_ipl_type();
 	switch (ipl_info.type) {
 	case IPL_TYPE_CCW:
+		ipl_info.data.ccw.dev_id.ssid = ipl_ssid;
 		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.ssid = 0;
 		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;
@@ -1971,6 +1996,7 @@ void __init ipl_save_parameters(void)
 	if (cio_get_iplinfo(&iplinfo))
 		return;
 
+	ipl_ssid = iplinfo.ssid;
 	ipl_devno = iplinfo.devno;
 	ipl_flags |= IPL_DEVNO_VALID;
 	if (!iplinfo.is_qdio)

drivers/s390/cio/chsc.c

@@ -1080,28 +1080,10 @@ void __init chsc_init_cleanup(void)
 	free_page((unsigned long)sei_page);
 }
 
-int chsc_enable_facility(int operation_code)
+int __chsc_enable_facility(struct chsc_sda_area *sda_area, int operation_code)
 {
-	unsigned long flags;
 	int ret;
-	struct {
-		struct chsc_header request;
-		u8 reserved1:4;
-		u8 format:4;
-		u8 reserved2;
-		u16 operation_code;
-		u32 reserved3;
-		u32 reserved4;
-		u32 operation_data_area[252];
-		struct chsc_header response;
-		u32 reserved5:4;
-		u32 format2:4;
-		u32 reserved6:24;
-	} __attribute__ ((packed)) *sda_area;
 
-	spin_lock_irqsave(&chsc_page_lock, flags);
-	memset(chsc_page, 0, PAGE_SIZE);
-	sda_area = chsc_page;
 	sda_area->request.length = 0x0400;
 	sda_area->request.code = 0x0031;
 	sda_area->operation_code = operation_code;
@@ -1119,10 +1101,25 @@ int chsc_enable_facility(int operation_code)
 	default:
 		ret = chsc_error_from_response(sda_area->response.code);
 	}
+out:
+	return ret;
+}
+
+int chsc_enable_facility(int operation_code)
+{
+	struct chsc_sda_area *sda_area;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&chsc_page_lock, flags);
+	memset(chsc_page, 0, PAGE_SIZE);
+	sda_area = chsc_page;
+
+	ret = __chsc_enable_facility(sda_area, operation_code);
 	if (ret != 0)
 		CIO_CRW_EVENT(2, "chsc: sda (oc=%x) failed (rc=%04x)\n",
 			      operation_code, sda_area->response.code);
-out:
+
 	spin_unlock_irqrestore(&chsc_page_lock, flags);
 	return ret;
 }

drivers/s390/cio/chsc.h

@@ -115,6 +115,20 @@ struct chsc_scpd {
 	u8 data[PAGE_SIZE - 20];
 } __attribute__ ((packed));
 
+struct chsc_sda_area {
+	struct chsc_header request;
+	u8 :4;
+	u8 format:4;
+	u8 :8;
+	u16 operation_code;
+	u32 :32;
+	u32 :32;
+	u32 operation_data_area[252];
+	struct chsc_header response;
+	u32 :4;
+	u32 format2:4;
+	u32 :24;
+} __packed __aligned(PAGE_SIZE);
 
 extern int chsc_get_ssd_info(struct subchannel_id schid,
 			     struct chsc_ssd_info *ssd);
@@ -122,6 +136,7 @@ extern int chsc_determine_css_characteristics(void);
 extern int chsc_init(void);
 extern void chsc_init_cleanup(void);
 
+int __chsc_enable_facility(struct chsc_sda_area *sda_area, int operation_code);
 extern int chsc_enable_facility(int);
 struct channel_subsystem;
 extern int chsc_secm(struct channel_subsystem *, int);

drivers/s390/cio/cio.c

@@ -925,18 +925,32 @@ void reipl_ccw_dev(struct ccw_dev_id *devid)
 
 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 {
+	static struct chsc_sda_area sda_area __initdata;
 	struct subchannel_id schid;
 	struct schib schib;
 
 	schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 	if (!schid.one)
 		return -ENODEV;
+
+	if (schid.ssid) {
+		/*
+		 * Firmware should have already enabled MSS but whoever started
+		 * the kernel might have initiated a channel subsystem reset.
+		 * Ensure that MSS is enabled.
+		 */
+		memset(&sda_area, 0, sizeof(sda_area));
+		if (__chsc_enable_facility(&sda_area, CHSC_SDA_OC_MSS))
+			return -ENODEV;
+	}
 	if (stsch_err(schid, &schib))
 		return -ENODEV;
 	if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
 		return -ENODEV;
 	if (!schib.pmcw.dnv)
 		return -ENODEV;
+
+	iplinfo->ssid = schid.ssid;
 	iplinfo->devno = schib.pmcw.dev;
 	iplinfo->is_qdio = schib.pmcw.qf;
 	return 0;