s390/nmi: remove casts

Remove all the casts to and from the machine check interruption code.
This patch changes struct mci to a union, which contains an anonymous
structure with the already known bits and in addition an unsigned
long field, which contains the raw machine check interruption code.

This allows to simply assign and decoce the interruption code value
without the need for all those casts we had all the time.

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

arch/s390/include/asm/nmi.h

@@ -21,49 +21,52 @@
 
 #ifndef __ASSEMBLY__
 
-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 vr :  1; /* 25 vector register validity */
-	__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 */
+union mci {
+	unsigned long val;
+	struct {
+		u64 sd :  1; /* 00 system damage */
+		u64 pd :  1; /* 01 instruction-processing damage */
+		u64 sr :  1; /* 02 system recovery */
+		u64    :  1; /* 03 */
+		u64 cd :  1; /* 04 timing-facility damage */
+		u64 ed :  1; /* 05 external damage */
+		u64    :  1; /* 06 */
+		u64 dg :  1; /* 07 degradation */
+		u64 w  :  1; /* 08 warning pending */
+		u64 cp :  1; /* 09 channel-report pending */
+		u64 sp :  1; /* 10 service-processor damage */
+		u64 ck :  1; /* 11 channel-subsystem damage */
+		u64    :  2; /* 12-13 */
+		u64 b  :  1; /* 14 backed up */
+		u64    :  1; /* 15 */
+		u64 se :  1; /* 16 storage error uncorrected */
+		u64 sc :  1; /* 17 storage error corrected */
+		u64 ke :  1; /* 18 storage-key error uncorrected */
+		u64 ds :  1; /* 19 storage degradation */
+		u64 wp :  1; /* 20 psw mwp validity */
+		u64 ms :  1; /* 21 psw mask and key validity */
+		u64 pm :  1; /* 22 psw program mask and cc validity */
+		u64 ia :  1; /* 23 psw instruction address validity */
+		u64 fa :  1; /* 24 failing storage address validity */
+		u64 vr :  1; /* 25 vector register validity */
+		u64 ec :  1; /* 26 external damage code validity */
+		u64 fp :  1; /* 27 floating point register validity */
+		u64 gr :  1; /* 28 general register validity */
+		u64 cr :  1; /* 29 control register validity */
+		u64    :  1; /* 30 */
+		u64 st :  1; /* 31 storage logical validity */
+		u64 ie :  1; /* 32 indirect storage error */
+		u64 ar :  1; /* 33 access register validity */
+		u64 da :  1; /* 34 delayed access exception */
+		u64    :  7; /* 35-41 */
+		u64 pr :  1; /* 42 tod programmable register validity */
+		u64 fc :  1; /* 43 fp control register validity */
+		u64 ap :  1; /* 44 ancillary report */
+		u64    :  1; /* 45 */
+		u64 ct :  1; /* 46 cpu timer validity */
+		u64 cc :  1; /* 47 clock comparator validity */
+		u64    : 16; /* 47-63 */
+	};
 };
 
 struct pt_regs;

arch/s390/kernel/nmi.c

@@ -29,7 +29,7 @@ struct mcck_struct {
 	int warning;
 	unsigned int etr_queue : 1;
 	unsigned int stp_queue : 1;
-	unsigned long long mcck_code;
+	unsigned long mcck_code;
 };
 
 static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
@@ -89,7 +89,7 @@ void s390_handle_mcck(void)
 	if (mcck.kill_task) {
 		local_irq_enable();
 		printk(KERN_EMERG "mcck: Terminating task because of machine "
-		       "malfunction (code 0x%016llx).\n", mcck.mcck_code);
+		       "malfunction (code 0x%016lx).\n", mcck.mcck_code);
 		printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
 		       current->comm, current->pid);
 		do_exit(SIGSEGV);
@@ -101,7 +101,7 @@ 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)
+static int notrace s390_revalidate_registers(union mci mci)
 {
 	int kill_task;
 	u64 zero;
@@ -110,14 +110,14 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 	kill_task = 0;
 	zero = 0;
 
-	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;
 	}
-	if (!mci->fp) {
+	if (!mci.fp) {
 		/*
 		 * Floating point registers can't be restored and
 		 * therefore the process needs to be terminated.
@@ -126,7 +126,7 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 	}
 	fpt_save_area = &S390_lowcore.floating_pt_save_area;
 	fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
-	if (!mci->fc) {
+	if (!mci.fc) {
 		/*
 		 * Floating point control register can't be restored.
 		 * Task will be terminated.
@@ -160,7 +160,7 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 		/* Revalidate vector registers */
 		union ctlreg0 cr0;
 
-		if (!mci->vr) {
+		if (!mci.vr) {
 			/*
 			 * Vector registers can't be restored and therefore
 			 * the process needs to be terminated.
@@ -182,7 +182,7 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 	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.
@@ -190,7 +190,7 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 		kill_task = 1;
 	}
 	/* Revalidate control registers */
-	if (!mci->cr) {
+	if (!mci.cr) {
 		/*
 		 * Control registers have unknown contents.
 		 * Can't recover and therefore stopping machine.
@@ -209,7 +209,7 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 	 * See if we can revalidate the TOD programmable register with its
 	 * old contents (should be zero) otherwise set it to zero.
 	 */
-	if (!mci->pr)
+	if (!mci.pr)
 		asm volatile(
 			"	sr	0,0\n"
 			"	sckpf"
@@ -223,14 +223,14 @@ static int notrace s390_revalidate_registers(struct mci *mci)
 	/* Revalidate clock comparator register */
 	set_clock_comparator(S390_lowcore.clock_comparator);
 	/* Check if old PSW is valid */
-	if (!mci->wp)
+	if (!mci.wp)
 		/*
 		 * Can't tell if we come from user or kernel mode
 		 * -> stopping machine.
 		 */
 		s390_handle_damage();
 
-	if (!mci->ms || !mci->pm || !mci->ia)
+	if (!mci.ms || !mci.pm || !mci.ia)
 		kill_task = 1;
 
 	return kill_task;
@@ -254,21 +254,21 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
 	static unsigned long long last_ipd;
 	struct mcck_struct *mcck;
 	unsigned long long tmp;
-	struct mci *mci;
+	union mci mci;
 	int umode;
 
 	nmi_enter();
 	inc_irq_stat(NMI_NMI);
-	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
+	mci.val = S390_lowcore.mcck_interruption_code;
 	mcck = this_cpu_ptr(&cpu_mcck);
 	umode = user_mode(regs);
 
-	if (mci->sd) {
+	if (mci.sd) {
 		/* System damage -> stopping machine */
 		s390_handle_damage();
 	}
-	if (mci->pd) {
-		if (mci->b) {
+	if (mci.pd) {
+		if (mci.b) {
 			/* Processing backup -> verify if we can survive this */
 			u64 z_mcic, o_mcic, t_mcic;
 			z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
@@ -276,7 +276,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
 				  1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
 				  1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
 				  1ULL<<16);
-			t_mcic = *(u64 *)mci;
+			t_mcic = mci.val;
 
 			if (((t_mcic & z_mcic) != 0) ||
 			    ((t_mcic & o_mcic) != o_mcic)) {
@@ -309,7 +309,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
 			 * user mode -> mark task for termination.
 			 */
 			mcck->kill_task = 1;
-			mcck->mcck_code = *(unsigned long long *) mci;
+			mcck->mcck_code = mci.val;
 			set_cpu_flag(CIF_MCCK_PENDING);
 		} else {
 			/*
@@ -319,11 +319,11 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
 			s390_handle_damage();
 		}
 	}
-	if (mci->cd) {
+	if (mci.cd) {
 		/* Timing facility damage */
 		s390_handle_damage();
 	}
-	if (mci->ed && mci->ec) {
+	if (mci.ed && mci.ec) {
 		/* External damage */
 		if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
 			mcck->etr_queue |= etr_sync_check();
@@ -336,21 +336,21 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
 		if (mcck->etr_queue || mcck->stp_queue)
 			set_cpu_flag(CIF_MCCK_PENDING);
 	}
-	if (mci->se)
+	if (mci.se)
 		/* Storage error uncorrected */
 		s390_handle_damage();
-	if (mci->ke)
+	if (mci.ke)
 		/* Storage key-error uncorrected */
 		s390_handle_damage();
-	if (mci->ds && mci->fa)
+	if (mci.ds && mci.fa)
 		/* Storage degradation */
 		s390_handle_damage();
-	if (mci->cp) {
+	if (mci.cp) {
 		/* Channel report word pending */
 		mcck->channel_report = 1;
 		set_cpu_flag(CIF_MCCK_PENDING);
 	}
-	if (mci->w) {
+	if (mci.w) {
 		/* Warning pending */
 		mcck->warning = 1;
 		set_cpu_flag(CIF_MCCK_PENDING);

drivers/s390/cio/cio.c

@@ -826,11 +826,11 @@ static atomic_t chpid_reset_count;
 static void s390_reset_chpids_mcck_handler(void)
 {
 	struct crw crw;
-	struct mci *mci;
+	union mci mci;
 
 	/* Check for pending channel report word. */
-	mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
-	if (!mci->cp)
+	mci.val = S390_lowcore.mcck_interruption_code;
+	if (!mci.cp)
 		return;
 	/* Process channel report words. */
 	while (stcrw(&crw) == 0) {