[S390] split/move machine check handler code

Split machine check handler code and move it to cio and kernel code
where it belongs to. No functional change.

Signed-off-by: Heiko Carstens <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

arch/s390/include/asm/crw.h

···
+/*
+ *   Data definitions for channel report processing
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <[e-mail]>,
+ *		 Martin Schwidefsky <[e-mail]>,
+ *		 Cornelia Huck <[e-mail]>,
+ *		 Heiko Carstens <[e-mail]>,
+ */
+
+#ifndef _ASM_S390_CRW_H
+#define _ASM_S390_CRW_H
+
+#include <linux/types.h>
+
+/*
+ * Channel Report Word
+ */
+struct crw {
+	__u32 res1 :  1;   /* reserved zero */
+	__u32 slct :  1;   /* solicited */
+	__u32 oflw :  1;   /* overflow */
+	__u32 chn  :  1;   /* chained */
+	__u32 rsc  :  4;   /* reporting source code */
+	__u32 anc  :  1;   /* ancillary report */
+	__u32 res2 :  1;   /* reserved zero */
+	__u32 erc  :  6;   /* error-recovery code */
+	__u32 rsid : 16;   /* reporting-source ID */
+} __attribute__ ((packed));
+
+typedef void (*crw_handler_t)(struct crw *, struct crw *, int);
+
+extern int crw_register_handler(int rsc, crw_handler_t handler);
+extern void crw_unregister_handler(int rsc);
+extern void crw_handle_channel_report(void);
+
+#define NR_RSCS 16
+
+#define CRW_RSC_MONITOR  0x2  /* monitoring facility */
+#define CRW_RSC_SCH	 0x3  /* subchannel */
+#define CRW_RSC_CPATH	 0x4  /* channel path */
+#define CRW_RSC_CONFIG	 0x9  /* configuration-alert facility */
+#define CRW_RSC_CSS	 0xB  /* channel subsystem */
+
+#define CRW_ERC_EVENT	 0x00 /* event information pending */
+#define CRW_ERC_AVAIL	 0x01 /* available */
+#define CRW_ERC_INIT	 0x02 /* initialized */
+#define CRW_ERC_TERROR	 0x03 /* temporary error */
+#define CRW_ERC_IPARM	 0x04 /* installed parm initialized */
+#define CRW_ERC_TERM	 0x05 /* terminal */
+#define CRW_ERC_PERRN	 0x06 /* perm. error, fac. not init */
+#define CRW_ERC_PERRI	 0x07 /* perm. error, facility init */
+#define CRW_ERC_PMOD	 0x08 /* installed parameters modified */
+
+static inline int stcrw(struct crw *pcrw)
+{
+	int ccode;
+
+	asm volatile(
+		"	stcrw	0(%2)\n"
+		"	ipm	%0\n"
+		"	srl	%0,28\n"
+		: "=d" (ccode), "=m" (*pcrw)
+		: "a" (pcrw)
+		: "cc" );
+	return ccode;
+}
+
+#endif /* _ASM_S390_CRW_H */

arch/s390/include/asm/nmi.h

···
+/*
+ *   Machine check handler definitions
+ *
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <[e-mail]>,
+ *		 Martin Schwidefsky <[e-mail]>,
+ *		 Cornelia Huck <[e-mail]>,
+ *		 Heiko Carstens <[e-mail]>,
+ */
+
+#ifndef _ASM_S390_NMI_H
+#define _ASM_S390_NMI_H
+
+#include <linux/types.h>
+
+struct mci {
+	__u32 sd :  1; /* 00 system damage */
+	__u32 pd :  1; /* 01 instruction-processing damage */
+	__u32 sr :  1; /* 02 system recovery */
+	__u32	 :  1; /* 03 */
+	__u32 cd :  1; /* 04 timing-facility damage */
+	__u32 ed :  1; /* 05 external damage */
+	__u32	 :  1; /* 06 */
+	__u32 dg :  1; /* 07 degradation */
+	__u32 w  :  1; /* 08 warning pending */
+	__u32 cp :  1; /* 09 channel-report pending */
+	__u32 sp :  1; /* 10 service-processor damage */
+	__u32 ck :  1; /* 11 channel-subsystem damage */
+	__u32	 :  2; /* 12-13 */
+	__u32 b  :  1; /* 14 backed up */
+	__u32	 :  1; /* 15 */
+	__u32 se :  1; /* 16 storage error uncorrected */
+	__u32 sc :  1; /* 17 storage error corrected */
+	__u32 ke :  1; /* 18 storage-key error uncorrected */
+	__u32 ds :  1; /* 19 storage degradation */
+	__u32 wp :  1; /* 20 psw mwp validity */
+	__u32 ms :  1; /* 21 psw mask and key validity */
+	__u32 pm :  1; /* 22 psw program mask and cc validity */
+	__u32 ia :  1; /* 23 psw instruction address validity */
+	__u32 fa :  1; /* 24 failing storage address validity */
+	__u32	 :  1; /* 25 */
+	__u32 ec :  1; /* 26 external damage code validity */
+	__u32 fp :  1; /* 27 floating point register validity */
+	__u32 gr :  1; /* 28 general register validity */
+	__u32 cr :  1; /* 29 control register validity */
+	__u32	 :  1; /* 30 */
+	__u32 st :  1; /* 31 storage logical validity */
+	__u32 ie :  1; /* 32 indirect storage error */
+	__u32 ar :  1; /* 33 access register validity */
+	__u32 da :  1; /* 34 delayed access exception */
+	__u32	 :  7; /* 35-41 */
+	__u32 pr :  1; /* 42 tod programmable register validity */
+	__u32 fc :  1; /* 43 fp control register validity */
+	__u32 ap :  1; /* 44 ancillary report */
+	__u32	 :  1; /* 45 */
+	__u32 ct :  1; /* 46 cpu timer validity */
+	__u32 cc :  1; /* 47 clock comparator validity */
+	__u32	 : 16; /* 47-63 */
+};
+
+struct pt_regs;
+
+extern void s390_handle_mcck(void);
+extern void s390_do_machine_check(struct pt_regs *regs);
+
+#endif /* _ASM_S390_NMI_H */

arch/s390/kernel/Makefile

···
 obj-y	:=  bitmap.o traps.o time.o process.o base.o early.o setup.o \
 	    processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o \
 	    s390_ext.o debug.o irq.o ipl.o dis.o diag.o mem_detect.o \
-	    vdso.o vtime.o sysinfo.o
+	    vdso.o vtime.o sysinfo.o nmi.o
 
 obj-y	+= $(if $(CONFIG_64BIT),entry64.o,entry.o)
 obj-y	+= $(if $(CONFIG_64BIT),reipl64.o,reipl.o)

arch/s390/kernel/process.c

···
 #include <asm/processor.h>
 #include <asm/irq.h>
 #include <asm/timer.h>
+#include <asm/nmi.h>
 #include "entry.h"
 
 asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
···
 	return sf->gprs[8];
 }
 
-extern void s390_handle_mcck(void);
 /*
  * The idle loop on a S390...
  */

arch/s390/kvm/kvm-s390.c

···
 #include <linux/timer.h>
 #include <asm/lowcore.h>
 #include <asm/pgtable.h>
-
+#include <asm/nmi.h>
 #include "kvm-s390.h"
 #include "gaccess.h"
 
···
 {
 	return -EINVAL; /* not implemented yet */
 }
-
-extern void s390_handle_mcck(void);
 
 static void __vcpu_run(struct kvm_vcpu *vcpu)
 {

drivers/s390/Makefile

···
 # Makefile for the S/390 specific device drivers
 #
 
-obj-y += s390mach.o
 obj-y += cio/ block/ char/ crypto/ net/ scsi/ kvm/
 
 drivers-y += drivers/s390/built-in.o

drivers/s390/cio/Makefile

···
 #
 
 obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o isc.o scsw.o \
-	fcx.o itcw.o
+	fcx.o itcw.o crw.o
 ccw_device-objs += device.o device_fsm.o device_ops.o
 ccw_device-objs += device_id.o device_pgid.o device_status.o
 obj-y += ccw_device.o cmf.o

drivers/s390/cio/chp.c

···
 #include <linux/errno.h>
 #include <asm/chpid.h>
 #include <asm/sclp.h>
+#include <asm/crw.h>
 
-#include "../s390mach.h"
 #include "cio.h"
 #include "css.h"
 #include "ioasm.h"
···
 	struct chp_id chpid;
 	int ret;
 
-	ret = s390_register_crw_handler(CRW_RSC_CPATH, chp_process_crw);
+	ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 	if (ret)
 		return ret;
 	chp_wq = create_singlethread_workqueue("cio_chp");
 	if (!chp_wq) {
-		s390_unregister_crw_handler(CRW_RSC_CPATH);
+		crw_unregister_handler(CRW_RSC_CPATH);
 		return -ENOMEM;
 	}
 	INIT_WORK(&cfg_work, cfg_func);

drivers/s390/cio/chsc.c

···
 #include <asm/cio.h>
 #include <asm/chpid.h>
 #include <asm/chsc.h>
+#include <asm/crw.h>
 
-#include "../s390mach.h"
 #include "css.h"
 #include "cio.h"
 #include "cio_debug.h"
···
 			      "chsc machine checks!\n");
 		return -ENOMEM;
 	}
-	ret = s390_register_crw_handler(CRW_RSC_CSS, chsc_process_crw);
+	ret = crw_register_handler(CRW_RSC_CSS, chsc_process_crw);
 	if (ret)
 		kfree(sei_page);
 	return ret;
···
 
 void __init chsc_free_sei_area(void)
 {
-	s390_unregister_crw_handler(CRW_RSC_CSS);
+	crw_unregister_handler(CRW_RSC_CSS);
 	kfree(sei_page);
 }
 

drivers/s390/cio/cio.c

···
 #include <asm/isc.h>
 #include <asm/cpu.h>
 #include <asm/fcx.h>
+#include <asm/nmi.h>
+#include <asm/crw.h>
 #include "cio.h"
 #include "css.h"
 #include "chsc.h"
···
 #include "blacklist.h"
 #include "cio_debug.h"
 #include "chp.h"
-#include "../s390mach.h"
 
 debug_info_t *cio_debug_msg_id;
 debug_info_t *cio_debug_trace_id;

drivers/s390/cio/crw.c

···
+/*
+ *   Channel report handling code
+ *
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <[e-mail]>,
+ *		 Martin Schwidefsky <[e-mail]>,
+ *		 Cornelia Huck <[e-mail]>,
+ *		 Heiko Carstens <[e-mail]>,
+ */
+
+#include <linux/semaphore.h>
+#include <linux/kthread.h>
+#include <linux/init.h>
+#include <asm/crw.h>
+
+static struct semaphore crw_semaphore;
+static crw_handler_t crw_handlers[NR_RSCS];
+
+/**
+ * crw_register_handler() - register a channel report word handler
+ * @rsc: reporting source code to handle
+ * @handler: handler to be registered
+ *
+ * Returns %0 on success and a negative error value otherwise.
+ */
+int crw_register_handler(int rsc, crw_handler_t handler)
+{
+	if ((rsc < 0) || (rsc >= NR_RSCS))
+		return -EINVAL;
+	if (!cmpxchg(&crw_handlers[rsc], NULL, handler))
+		return 0;
+	return -EBUSY;
+}
+
+/**
+ * crw_unregister_handler() - unregister a channel report word handler
+ * @rsc: reporting source code to handle
+ */
+void crw_unregister_handler(int rsc)
+{
+	if ((rsc < 0) || (rsc >= NR_RSCS))
+		return;
+	xchg(&crw_handlers[rsc], NULL);
+	synchronize_sched();
+}
+
+/*
+ * Retrieve CRWs and call function to handle event.
+ */
+static int crw_collect_info(void *unused)
+{
+	struct crw crw[2];
+	int ccode;
+	unsigned int chain;
+	int ignore;
+
+repeat:
+	ignore = down_interruptible(&crw_semaphore);
+	chain = 0;
+	while (1) {
+		if (unlikely(chain > 1)) {
+			struct crw tmp_crw;
+
+			printk(KERN_WARNING"%s: Code does not support more "
+			       "than two chained crws; please report to "
+			       "[e-mail]!\n", __func__);
+			ccode = stcrw(&tmp_crw);
+			printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
+			       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
+			       __func__, tmp_crw.slct, tmp_crw.oflw,
+			       tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
+			       tmp_crw.erc, tmp_crw.rsid);
+			printk(KERN_WARNING"%s: This was crw number %x in the "
+			       "chain\n", __func__, chain);
+			if (ccode != 0)
+				break;
+			chain = tmp_crw.chn ? chain + 1 : 0;
+			continue;
+		}
+		ccode = stcrw(&crw[chain]);
+		if (ccode != 0)
+			break;
+		printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
+		       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
+		       crw[chain].slct, crw[chain].oflw, crw[chain].chn,
+		       crw[chain].rsc, crw[chain].anc, crw[chain].erc,
+		       crw[chain].rsid);
+		/* Check for overflows. */
+		if (crw[chain].oflw) {
+			int i;
+
+			pr_debug("%s: crw overflow detected!\n", __func__);
+			for (i = 0; i < NR_RSCS; i++) {
+				if (crw_handlers[i])
+					crw_handlers[i](NULL, NULL, 1);
+			}
+			chain = 0;
+			continue;
+		}
+		if (crw[0].chn && !chain) {
+			chain++;
+			continue;
+		}
+		if (crw_handlers[crw[chain].rsc])
+			crw_handlers[crw[chain].rsc](&crw[0],
+						     chain ? &crw[1] : NULL,
+						     0);
+		/* chain is always 0 or 1 here. */
+		chain = crw[chain].chn ? chain + 1 : 0;
+	}
+	goto repeat;
+	return 0;
+}
+
+void crw_handle_channel_report(void)
+{
+	up(&crw_semaphore);
+}
+
+/*
+ * Separate initcall needed for semaphore initialization since
+ * crw_handle_channel_report might be called before crw_machine_check_init.
+ */
+static int __init crw_init_semaphore(void)
+{
+	init_MUTEX_LOCKED(&crw_semaphore);
+	return 0;
+}
+pure_initcall(crw_init_semaphore);
+
+/*
+ * Machine checks for the channel subsystem must be enabled
+ * after the channel subsystem is initialized
+ */
+static int __init crw_machine_check_init(void)
+{
+	struct task_struct *task;
+
+	task = kthread_run(crw_collect_info, NULL, "kmcheck");
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	ctl_set_bit(14, 28);	/* enable channel report MCH */
+	return 0;
+}
+device_initcall(crw_machine_check_init);

drivers/s390/cio/css.c

···
 #include <linux/list.h>
 #include <linux/reboot.h>
 #include <asm/isc.h>
+#include <asm/crw.h>
 
-#include "../s390mach.h"
 #include "css.h"
 #include "cio.h"
 #include "cio_debug.h"
···
 	if (ret)
 		goto out;
 
-	ret = s390_register_crw_handler(CRW_RSC_SCH, css_process_crw);
+	ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
 	if (ret)
 		goto out;
 
···
 out_bus:
 	bus_unregister(&css_bus_type);
 out:
-	s390_unregister_crw_handler(CRW_RSC_CSS);
+	crw_unregister_handler(CRW_RSC_CSS);
 	chsc_free_sei_area();
 	kfree(slow_subchannel_set);
 	pr_alert("The CSS device driver initialization failed with "

drivers/s390/s390mach.c arch/s390/kernel/nmi.c

···
 /*
- *  drivers/s390/s390mach.c
- *   S/390 machine check handler
+ *   Machine check handler
  *
- *    Copyright IBM Corp. 2000,2008
- *    Author(s): Ingo Adlung ([e-mail])
- *		 Martin Schwidefsky ([e-mail])
- *		 Cornelia Huck <[e-mail]>
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <[e-mail]>,
+ *		 Martin Schwidefsky <[e-mail]>,
+ *		 Cornelia Huck <[e-mail]>,
+ *		 Heiko Carstens <[e-mail]>,
  */
 
 #include <linux/init.h>
-#include <linux/sched.h>
 #include <linux/errno.h>
-#include <linux/workqueue.h>
 #include <linux/time.h>
-#include <linux/device.h>
-#include <linux/kthread.h>
-#include <asm/etr.h>
+#include <linux/module.h>
 #include <asm/lowcore.h>
-#include <asm/cio.h>
+#include <asm/smp.h>
+#include <asm/etr.h>
 #include <asm/cpu.h>
-#include "s390mach.h"
-
-static struct semaphore m_sem;
-
-static NORET_TYPE void
-s390_handle_damage(char *msg)
-{
-#ifdef CONFIG_SMP
-	smp_send_stop();
-#endif
-	disabled_wait((unsigned long) __builtin_return_address(0));
-	for(;;);
-}
-
-static crw_handler_t crw_handlers[NR_RSCS];
-
-/**
- * s390_register_crw_handler() - register a channel report word handler
- * @rsc: reporting source code to handle
- * @handler: handler to be registered
- *
- * Returns %0 on success and a negative error value otherwise.
- */
-int s390_register_crw_handler(int rsc, crw_handler_t handler)
-{
-	if ((rsc < 0) || (rsc >= NR_RSCS))
-		return -EINVAL;
-	if (!cmpxchg(&crw_handlers[rsc], NULL, handler))
-		return 0;
-	return -EBUSY;
-}
-
-/**
- * s390_unregister_crw_handler() - unregister a channel report word handler
- * @rsc: reporting source code to handle
- */
-void s390_unregister_crw_handler(int rsc)
-{
-	if ((rsc < 0) || (rsc >= NR_RSCS))
-		return;
-	xchg(&crw_handlers[rsc], NULL);
-	synchronize_sched();
-}
-
-/*
- * Retrieve CRWs and call function to handle event.
- */
-static int s390_collect_crw_info(void *param)
-{
-	struct crw crw[2];
-	int ccode;
-	struct semaphore *sem;
-	unsigned int chain;
-	int ignore;
-
-	sem = (struct semaphore *)param;
-repeat:
-	ignore = down_interruptible(sem);
-	chain = 0;
-	while (1) {
-		if (unlikely(chain > 1)) {
-			struct crw tmp_crw;
-
-			printk(KERN_WARNING"%s: Code does not support more "
-			       "than two chained crws; please report to "
-			       "[e-mail]!\n", __func__);
-			ccode = stcrw(&tmp_crw);
-			printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
-			       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
-			       __func__, tmp_crw.slct, tmp_crw.oflw,
-			       tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
-			       tmp_crw.erc, tmp_crw.rsid);
-			printk(KERN_WARNING"%s: This was crw number %x in the "
-			       "chain\n", __func__, chain);
-			if (ccode != 0)
-				break;
-			chain = tmp_crw.chn ? chain + 1 : 0;
-			continue;
-		}
-		ccode = stcrw(&crw[chain]);
-		if (ccode != 0)
-			break;
-		printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
-		       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
-		       crw[chain].slct, crw[chain].oflw, crw[chain].chn,
-		       crw[chain].rsc, crw[chain].anc, crw[chain].erc,
-		       crw[chain].rsid);
-		/* Check for overflows. */
-		if (crw[chain].oflw) {
-			int i;
-
-			pr_debug("%s: crw overflow detected!\n", __func__);
-			for (i = 0; i < NR_RSCS; i++) {
-				if (crw_handlers[i])
-					crw_handlers[i](NULL, NULL, 1);
-			}
-			chain = 0;
-			continue;
-		}
-		if (crw[0].chn && !chain) {
-			chain++;
-			continue;
-		}
-		if (crw_handlers[crw[chain].rsc])
-			crw_handlers[crw[chain].rsc](&crw[0],
-						     chain ? &crw[1] : NULL,
-						     0);
-		/* chain is always 0 or 1 here. */
-		chain = crw[chain].chn ? chain + 1 : 0;
-	}
-	goto repeat;
-	return 0;
-}
+#include <asm/nmi.h>
+#include <asm/crw.h>
 
 struct mcck_struct {
 	int kill_task;
···
 
 static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
 
+static NORET_TYPE void s390_handle_damage(char *msg)
+{
+	smp_send_stop();
+	disabled_wait((unsigned long) __builtin_return_address(0));
+	while (1);
+}
+
 /*
  * Main machine check handler function. Will be called with interrupts enabled
  * or disabled and machine checks enabled or disabled.
  */
-void
-s390_handle_mcck(void)
+void s390_handle_mcck(void)
 {
 	unsigned long flags;
 	struct mcck_struct mcck;
···
 	local_irq_restore(flags);
 
 	if (mcck.channel_report)
-		up(&m_sem);
+		crw_handle_channel_report();
 
 #ifdef CONFIG_MACHCHK_WARNING
 /*
···
  * returns 0 if all registers could be validated
  * returns 1 otherwise
  */
-static int
-s390_revalidate_registers(struct mci *mci)
+static int notrace s390_revalidate_registers(struct mci *mci)
 {
 	int kill_task;
 	u64 tmpclock;
···
 
 	kill_task = 0;
 	zero = 0;
-	/* General purpose registers */
-	if (!mci->gr)
+
+	if (!mci->gr) {
 		/*
 		 * General purpose registers couldn't be restored and have
 		 * unknown contents. Process needs to be terminated.
 		 */
 		kill_task = 1;
-
-	/* Revalidate floating point registers */
-	if (!mci->fp)
+	}
+	if (!mci->fp) {
 		/*
 		 * Floating point registers can't be restored and
 		 * therefore the process needs to be terminated.
 		 */
 		kill_task = 1;
-
+	}
 #ifndef CONFIG_64BIT
 	asm volatile(
 		"	ld	0,0(%0)\n"
···
 		fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
 #else
 		fpt_save_area = (void *) S390_lowcore.extended_save_area_addr;
-		fpt_creg_save_area = fpt_save_area+128;
+		fpt_creg_save_area = fpt_save_area + 128;
 #endif
-		/* Floating point control register */
 		if (!mci->fc) {
 			/*
 			 * Floating point control register can't be restored.
···
 			"	ld	15,120(%0)\n"
 			: : "a" (fpt_save_area));
 	}
-
 	/* Revalidate access registers */
 	asm volatile(
 		"	lam	0,15,0(%0)"
 		: : "a" (&S390_lowcore.access_regs_save_area));
-	if (!mci->ar)
+	if (!mci->ar) {
 		/*
 		 * Access registers have unknown contents.
 		 * Terminating task.
 		 */
 		kill_task = 1;
-
+	}
 	/* Revalidate control registers */
-	if (!mci->cr)
+	if (!mci->cr) {
 		/*
 		 * Control registers have unknown contents.
 		 * Can't recover and therefore stopping machine.
 		 */
 		s390_handle_damage("invalid control registers.");
-	else
+	} else {
 #ifdef CONFIG_64BIT
 		asm volatile(
 			"	lctlg	0,15,0(%0)"
···
 			"	lctl	0,15,0(%0)"
 			: : "a" (&S390_lowcore.cregs_save_area));
 #endif
-
+	}
 	/*
 	 * We don't even try to revalidate the TOD register, since we simply
 	 * can't write something sensible into that register.
 	 */
-
 #ifdef CONFIG_64BIT
 	/*
 	 * See if we can revalidate the TOD programmable register with its
···
 			: : "a" (&S390_lowcore.tod_progreg_save_area)
 			: "0", "cc");
 #endif
-
 	/* Revalidate clock comparator register */
 	asm volatile(
 		"	stck	0(%1)\n"
···
 #define MAX_IPD_COUNT	29
 #define MAX_IPD_TIME	(5 * 60 * USEC_PER_SEC) /* 5 minutes */
 
+#define ED_STP_ISLAND	6	/* External damage STP island check */
+#define ED_STP_SYNC	7	/* External damage STP sync check */
+#define ED_ETR_SYNC	12	/* External damage ETR sync check */
+#define ED_ETR_SWITCH	13	/* External damage ETR switch to local */
+
 /*
  * machine check handler.
  */
 void notrace s390_do_machine_check(struct pt_regs *regs)
 {
+	static int ipd_count;
 	static DEFINE_SPINLOCK(ipd_lock);
 	static unsigned long long last_ipd;
-	static int ipd_count;
+	struct mcck_struct *mcck;
 	unsigned long long tmp;
 	struct mci *mci;
-	struct mcck_struct *mcck;
 	int umode;
 
 	lockdep_off();
-
 	s390_idle_check();
 
 	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
 	mcck = &__get_cpu_var(cpu_mcck);
 	umode = user_mode(regs);
 
-	if (mci->sd)
+	if (mci->sd) {
 		/* System damage -> stopping machine */
 		s390_handle_damage("received system damage machine check.");
-
+	}
 	if (mci->pd) {
 		if (mci->b) {
 			/* Processing backup -> verify if we can survive this */
···
 			 * Nullifying exigent condition, therefore we might
 			 * retry this instruction.
 			 */
-
 			spin_lock(&ipd_lock);
-
 			tmp = get_clock();
-
 			if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
 				ipd_count++;
 			else
 				ipd_count = 1;
-
 			last_ipd = tmp;
-
 			if (ipd_count == MAX_IPD_COUNT)
 				s390_handle_damage("too many ipd retries.");
-
 			spin_unlock(&ipd_lock);
-		}
-		else {
+		} else {
 			/* Processing damage -> stopping machine */
 			s390_handle_damage("received instruction processing "
 					   "damage machine check.");
···
 			mcck->kill_task = 1;
 			mcck->mcck_code = *(unsigned long long *) mci;
 			set_thread_flag(TIF_MCCK_PENDING);
-		}
-		else
+		} else {
 			/*
 			 * Couldn't restore all register contents while in
 			 * kernel mode -> stopping machine.
 			 */
 			s390_handle_damage("unable to revalidate registers.");
+		}
 	}
-
 	if (mci->cd) {
 		/* Timing facility damage */
 		s390_handle_damage("TOD clock damaged");
 	}
-
 	if (mci->ed && mci->ec) {
 		/* External damage */
 		if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
···
 		if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
 			stp_island_check();
 	}
-
 	if (mci->se)
 		/* Storage error uncorrected */
 		s390_handle_damage("received storage error uncorrected "
 				   "machine check.");
-
 	if (mci->ke)
 		/* Storage key-error uncorrected */
 		s390_handle_damage("received storage key-error uncorrected "
 				   "machine check.");
-
 	if (mci->ds && mci->fa)
 		/* Storage degradation */
 		s390_handle_damage("received storage degradation machine "
 				   "check.");
-
 	if (mci->cp) {
 		/* Channel report word pending */
 		mcck->channel_report = 1;
 		set_thread_flag(TIF_MCCK_PENDING);
 	}
-
 	if (mci->w) {
 		/* Warning pending */
 		mcck->warning = 1;
···
 	lockdep_on();
 }
 
-/*
- * s390_init_machine_check
- *
- * initialize machine check handling
- */
-static int
-machine_check_init(void)
+static int __init machine_check_init(void)
 {
-	init_MUTEX_LOCKED(&m_sem);
 	ctl_set_bit(14, 25);	/* enable external damage MCH */
-	ctl_set_bit(14, 27);    /* enable system recovery MCH */
+	ctl_set_bit(14, 27);	/* enable system recovery MCH */
 #ifdef CONFIG_MACHCHK_WARNING
 	ctl_set_bit(14, 24);	/* enable warning MCH */
 #endif
 	return 0;
 }
-
-/*
- * Initialize the machine check handler really early to be able to
- * catch all machine checks that happen during boot
- */
 arch_initcall(machine_check_init);
-
-/*
- * Machine checks for the channel subsystem must be enabled
- * after the channel subsystem is initialized
- */
-static int __init
-machine_check_crw_init (void)
-{
-	struct task_struct *task;
-
-	task = kthread_run(s390_collect_crw_info, &m_sem, "kmcheck");
-	if (IS_ERR(task))
-		return PTR_ERR(task);
-	ctl_set_bit(14, 28);	/* enable channel report MCH */
-	return 0;
-}
-
-device_initcall (machine_check_crw_init);

drivers/s390/s390mach.h

···
-/*
- *  drivers/s390/s390mach.h
- *   S/390 data definitions for machine check processing
- *
- *  S390 version
- *    Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
- *    Author(s): Ingo Adlung ([e-mail])
- */
-
-#ifndef __s390mach_h
-#define __s390mach_h
-
-#include <asm/types.h>
-
-struct mci {
-	__u32   sd              :  1; /* 00 system damage */
-	__u32   pd              :  1; /* 01 instruction-processing damage */
-	__u32   sr              :  1; /* 02 system recovery */
-	__u32   to_be_defined_1 :  1; /* 03 */
-	__u32   cd              :  1; /* 04 timing-facility damage */
-	__u32   ed              :  1; /* 05 external damage */
-	__u32   to_be_defined_2 :  1; /* 06 */
-	__u32   dg              :  1; /* 07 degradation */
-	__u32   w               :  1; /* 08 warning pending */
-	__u32   cp              :  1; /* 09 channel-report pending */
-	__u32   sp              :  1; /* 10 service-processor damage */
-	__u32   ck              :  1; /* 11 channel-subsystem damage */
-	__u32   to_be_defined_3 :  2; /* 12-13 */
-	__u32   b               :  1; /* 14 backed up */
-	__u32   to_be_defined_4 :  1; /* 15 */
-	__u32   se              :  1; /* 16 storage error uncorrected */
-	__u32   sc              :  1; /* 17 storage error corrected */
-	__u32   ke              :  1; /* 18 storage-key error uncorrected */
-	__u32   ds              :  1; /* 19 storage degradation */
-	__u32   wp              :  1; /* 20 psw mwp validity */
-	__u32   ms              :  1; /* 21 psw mask and key validity */
-	__u32   pm              :  1; /* 22 psw program mask and cc validity */
-	__u32   ia              :  1; /* 23 psw instruction address validity */
-	__u32   fa              :  1; /* 24 failing storage address validity */
-	__u32   to_be_defined_5 :  1; /* 25 */
-	__u32   ec              :  1; /* 26 external damage code validity */
-	__u32   fp              :  1; /* 27 floating point register validity */
-	__u32   gr              :  1; /* 28 general register validity */
-	__u32   cr              :  1; /* 29 control register validity */
-	__u32   to_be_defined_6 :  1; /* 30 */
-	__u32   st              :  1; /* 31 storage logical validity */
-	__u32   ie              :  1; /* 32 indirect storage error */
-	__u32   ar              :  1; /* 33 access register validity */
-	__u32   da              :  1; /* 34 delayed access exception */
-	__u32   to_be_defined_7 :  7; /* 35-41 */
-	__u32   pr              :  1; /* 42 tod programmable register validity */
-	__u32   fc              :  1; /* 43 fp control register validity */
-	__u32   ap              :  1; /* 44 ancillary report */
-	__u32   to_be_defined_8 :  1; /* 45 */
-	__u32   ct              :  1; /* 46 cpu timer validity */
-	__u32   cc              :  1; /* 47 clock comparator validity */
-	__u32	to_be_defined_9 : 16; /* 47-63 */
-};
-
-/*
- * Channel Report Word
- */
-struct crw {
-	__u32 res1    :  1;   /* reserved zero */
-	__u32 slct    :  1;   /* solicited */
-	__u32 oflw    :  1;   /* overflow */
-	__u32 chn     :  1;   /* chained */
-	__u32 rsc     :  4;   /* reporting source code */
-	__u32 anc     :  1;   /* ancillary report */
-	__u32 res2    :  1;   /* reserved zero */
-	__u32 erc     :  6;   /* error-recovery code */
-	__u32 rsid    : 16;   /* reporting-source ID */
-} __attribute__ ((packed));
-
-typedef void (*crw_handler_t)(struct crw *, struct crw *, int);
-
-extern int s390_register_crw_handler(int rsc, crw_handler_t handler);
-extern void s390_unregister_crw_handler(int rsc);
-
-#define NR_RSCS 16
-
-#define CRW_RSC_MONITOR  0x2  /* monitoring facility */
-#define CRW_RSC_SCH      0x3  /* subchannel */
-#define CRW_RSC_CPATH    0x4  /* channel path */
-#define CRW_RSC_CONFIG   0x9  /* configuration-alert facility */
-#define CRW_RSC_CSS      0xB  /* channel subsystem */
-
-#define CRW_ERC_EVENT    0x00 /* event information pending */
-#define CRW_ERC_AVAIL    0x01 /* available */
-#define CRW_ERC_INIT     0x02 /* initialized */
-#define CRW_ERC_TERROR   0x03 /* temporary error */
-#define CRW_ERC_IPARM    0x04 /* installed parm initialized */
-#define CRW_ERC_TERM     0x05 /* terminal */
-#define CRW_ERC_PERRN    0x06 /* perm. error, fac. not init */
-#define CRW_ERC_PERRI    0x07 /* perm. error, facility init */
-#define CRW_ERC_PMOD     0x08 /* installed parameters modified */
-
-static inline int stcrw(struct crw *pcrw )
-{
-	int ccode;
-
-	__asm__ __volatile__(
-		"stcrw 0(%2)\n\t"
-		"ipm %0\n\t"
-		"srl %0,28\n\t"
-		: "=d" (ccode), "=m" (*pcrw)
-		: "a" (pcrw)
-		: "cc" );
-	return ccode;
-}
-
-#define ED_ETR_SYNC	12	/* External damage ETR sync check */
-#define ED_ETR_SWITCH	13	/* External damage ETR switch to local */
-
-#define ED_STP_SYNC	7	/* External damage STP sync check */
-#define ED_STP_ISLAND	6	/* External damage STP island check */
-
-struct pt_regs;
-
-void s390_handle_mcck(void);
-void s390_do_machine_check(struct pt_regs *regs);
-#endif /* __s390mach */