[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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

6 files changed, 520 insertions, 5 deletions

diff --git a/arch/s390/include/asm/crw.h b/arch/s390/include/asm/crw.h
new file mode 100644
index 0000000..2185a6d
--- /dev/null
+++ b/arch/s390/include/asm/crw.h
@@ -0,0 +1,68 @@
+/*
+ *   Data definitions for channel report processing
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <adlung@de.ibm.com>,
+ *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Cornelia Huck <cornelia.huck@de.ibm.com>,
+ *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
+ */
+
+#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 */
diff --git a/arch/s390/include/asm/nmi.h b/arch/s390/include/asm/nmi.h
new file mode 100644
index 0000000..f4b6044
--- /dev/null
+++ b/arch/s390/include/asm/nmi.h
@@ -0,0 +1,66 @@
+/*
+ *   Machine check handler definitions
+ *
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <adlung@de.ibm.com>,
+ *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Cornelia Huck <cornelia.huck@de.ibm.com>,
+ *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
+ */
+
+#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 */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 33e7aee..228e310 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -22,7 +22,7 @@ CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w
 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)
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
new file mode 100644
index 0000000..8d50eaf
--- /dev/null
+++ b/arch/s390/kernel/nmi.c
@@ -0,0 +1,383 @@
+/*
+ *   Machine check handler
+ *
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Ingo Adlung <adlung@de.ibm.com>,
+ *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Cornelia Huck <cornelia.huck@de.ibm.com>,
+ *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/module.h>
+#include <asm/lowcore.h>
+#include <asm/smp.h>
+#include <asm/etr.h>
+#include <asm/cpu.h>
+#include <asm/nmi.h>
+#include <asm/crw.h>
+
+struct mcck_struct {
+	int kill_task;
+	int channel_report;
+	int warning;
+	unsigned long long mcck_code;
+};
+
+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)
+{
+	unsigned long flags;
+	struct mcck_struct mcck;
+
+	/*
+	 * Disable machine checks and get the current state of accumulated
+	 * machine checks. Afterwards delete the old state and enable machine
+	 * checks again.
+	 */
+	local_irq_save(flags);
+	local_mcck_disable();
+	mcck = __get_cpu_var(cpu_mcck);
+	memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
+	clear_thread_flag(TIF_MCCK_PENDING);
+	local_mcck_enable();
+	local_irq_restore(flags);
+
+	if (mcck.channel_report)
+		crw_handle_channel_report();
+
+#ifdef CONFIG_MACHCHK_WARNING
+/*
+ * The warning may remain for a prolonged period on the bare iron.
+ * (actually till the machine is powered off, or until the problem is gone)
+ * So we just stop listening for the WARNING MCH and prevent continuously
+ * being interrupted.  One caveat is however, that we must do this per
+ * processor and cannot use the smp version of ctl_clear_bit().
+ * On VM we only get one interrupt per virtally presented machinecheck.
+ * Though one suffices, we may get one interrupt per (virtual) processor.
+ */
+	if (mcck.warning) {	/* WARNING pending ? */
+		static int mchchk_wng_posted = 0;
+		/*
+		 * Use single machine clear, as we cannot handle smp right now
+		 */
+		__ctl_clear_bit(14, 24);	/* Disable WARNING MCH */
+		if (xchg(&mchchk_wng_posted, 1) == 0)
+			kill_cad_pid(SIGPWR, 1);
+	}
+#endif
+
+	if (mcck.kill_task) {
+		local_irq_enable();
+		printk(KERN_EMERG "mcck: Terminating task because of machine "
+		       "malfunction (code 0x%016llx).\n", mcck.mcck_code);
+		printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
+		       current->comm, current->pid);
+		do_exit(SIGSEGV);
+	}
+}
+EXPORT_SYMBOL_GPL(s390_handle_mcck);
+
+/*
+ * returns 0 if all registers could be validated
+ * returns 1 otherwise
+ */
+static int notrace s390_revalidate_registers(struct mci *mci)
+{
+	int kill_task;
+	u64 tmpclock;
+	u64 zero;
+	void *fpt_save_area, *fpt_creg_save_area;
+
+	kill_task = 0;
+	zero = 0;
+
+	if (!mci->gr) {
+		/*
+		 * General purpose registers couldn't be restored and have
+		 * unknown contents. Process needs to be terminated.
+		 */
+		kill_task = 1;
+	}
+	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"
+		"	ld	2,8(%0)\n"
+		"	ld	4,16(%0)\n"
+		"	ld	6,24(%0)"
+		: : "a" (&S390_lowcore.floating_pt_save_area));
+#endif
+
+	if (MACHINE_HAS_IEEE) {
+#ifdef CONFIG_64BIT
+		fpt_save_area = &S390_lowcore.floating_pt_save_area;
+		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;
+#endif
+		if (!mci->fc) {
+			/*
+			 * Floating point control register can't be restored.
+			 * Task will be terminated.
+			 */
+			asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
+			kill_task = 1;
+
+		} else
+			asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
+
+		asm volatile(
+			"	ld	0,0(%0)\n"
+			"	ld	1,8(%0)\n"
+			"	ld	2,16(%0)\n"
+			"	ld	3,24(%0)\n"
+			"	ld	4,32(%0)\n"
+			"	ld	5,40(%0)\n"
+			"	ld	6,48(%0)\n"
+			"	ld	7,56(%0)\n"
+			"	ld	8,64(%0)\n"
+			"	ld	9,72(%0)\n"
+			"	ld	10,80(%0)\n"
+			"	ld	11,88(%0)\n"
+			"	ld	12,96(%0)\n"
+			"	ld	13,104(%0)\n"
+			"	ld	14,112(%0)\n"
+			"	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) {
+		/*
+		 * Access registers have unknown contents.
+		 * Terminating task.
+		 */
+		kill_task = 1;
+	}
+	/* Revalidate control registers */
+	if (!mci->cr) {
+		/*
+		 * Control registers have unknown contents.
+		 * Can't recover and therefore stopping machine.
+		 */
+		s390_handle_damage("invalid control registers.");
+	} else {
+#ifdef CONFIG_64BIT
+		asm volatile(
+			"	lctlg	0,15,0(%0)"
+			: : "a" (&S390_lowcore.cregs_save_area));
+#else
+		asm volatile(
+			"	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
+	 * old contents (should be zero) otherwise set it to zero.
+	 */
+	if (!mci->pr)
+		asm volatile(
+			"	sr	0,0\n"
+			"	sckpf"
+			: : : "0", "cc");
+	else
+		asm volatile(
+			"	l	0,0(%0)\n"
+			"	sckpf"
+			: : "a" (&S390_lowcore.tod_progreg_save_area)
+			: "0", "cc");
+#endif
+	/* Revalidate clock comparator register */
+	asm volatile(
+		"	stck	0(%1)\n"
+		"	sckc	0(%1)"
+		: "=m" (tmpclock) : "a" (&(tmpclock)) : "cc", "memory");
+
+	/* Check if old PSW is valid */
+	if (!mci->wp)
+		/*
+		 * Can't tell if we come from user or kernel mode
+		 * -> stopping machine.
+		 */
+		s390_handle_damage("old psw invalid.");
+
+	if (!mci->ms || !mci->pm || !mci->ia)
+		kill_task = 1;
+
+	return kill_task;
+}
+
+#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;
+	struct mcck_struct *mcck;
+	unsigned long long tmp;
+	struct mci *mci;
+	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) {
+		/* 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 */
+			u64 z_mcic, o_mcic, t_mcic;
+#ifdef CONFIG_64BIT
+			z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
+			o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
+				  1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
+				  1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
+				  1ULL<<16);
+#else
+			z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
+				  1ULL<<29);
+			o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
+				  1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
+				  1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
+#endif
+			t_mcic = *(u64 *)mci;
+
+			if (((t_mcic & z_mcic) != 0) ||
+			    ((t_mcic & o_mcic) != o_mcic)) {
+				s390_handle_damage("processing backup machine "
+						   "check with damage.");
+			}
+
+			/*
+			 * 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 {
+			/* Processing damage -> stopping machine */
+			s390_handle_damage("received instruction processing "
+					   "damage machine check.");
+		}
+	}
+	if (s390_revalidate_registers(mci)) {
+		if (umode) {
+			/*
+			 * Couldn't restore all register contents while in
+			 * user mode -> mark task for termination.
+			 */
+			mcck->kill_task = 1;
+			mcck->mcck_code = *(unsigned long long *) mci;
+			set_thread_flag(TIF_MCCK_PENDING);
+		} 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))
+			etr_sync_check();
+		if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH))
+			etr_switch_to_local();
+		if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
+			stp_sync_check();
+		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;
+		set_thread_flag(TIF_MCCK_PENDING);
+	}
+	lockdep_on();
+}
+
+static int __init machine_check_init(void)
+{
+	ctl_set_bit(14, 25);	/* enable external damage 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;
+}
+arch_initcall(machine_check_init);
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index e6b4806..bd616fb 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -39,6 +39,7 @@
 #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");
@@ -68,7 +69,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 	return sf->gprs[8];
 }
 
-extern void s390_handle_mcck(void);
 /*
  * The idle loop on a S390...
  */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c55a4b9..caa4d28 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -23,7 +23,7 @@
 #include <linux/timer.h>
 #include <asm/lowcore.h>
 #include <asm/pgtable.h>
-
+#include <asm/nmi.h>
 #include "kvm-s390.h"
 #include "gaccess.h"
 
@@ -440,8 +440,6 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 	return -EINVAL; /* not implemented yet */
 }
 
-extern void s390_handle_mcck(void);
-
 static void __vcpu_run(struct kvm_vcpu *vcpu)
 {
 	memcpy(&vcpu->arch.sie_block->gg14, &vcpu->arch.guest_gprs[14], 16);