[S390] rework smp code

Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.

The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.

Overall the code is now simpler and there are ~380 lines less code.

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

4 files changed, 75 insertions, 224 deletions

diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 0831449e87a..4e69563bc95 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -1,5 +1,5 @@
 /*
- *    Copyright IBM Corp. 1999,2010
+ *    Copyright IBM Corp. 1999,2012
  *    Author(s): Hartmut Penner <hp@de.ibm.com>,
  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
  *		 Denis Joseph Barrow,
@@ -12,14 +12,6 @@
 #include <asm/ptrace.h>
 #include <asm/cpu.h>
 
-void restart_int_handler(void);
-void ext_int_handler(void);
-void system_call(void);
-void pgm_check_handler(void);
-void mcck_int_handler(void);
-void io_int_handler(void);
-void psw_restart_int_handler(void);
-
 #ifdef CONFIG_32BIT
 
 #define LC_ORDER 0
@@ -117,32 +109,37 @@ struct _lowcore {
 	__u64	steal_timer;			/* 0x0288 */
 	__u64	last_update_timer;		/* 0x0290 */
 	__u64	last_update_clock;		/* 0x0298 */
+	__u64	int_clock;			/* 0x02a0 */
+	__u64	mcck_clock;			/* 0x02a8 */
+	__u64	clock_comparator;		/* 0x02b0 */
 
 	/* Current process. */
-	__u32	current_task;			/* 0x02a0 */
-	__u32	thread_info;			/* 0x02a4 */
-	__u32	kernel_stack;			/* 0x02a8 */
+	__u32	current_task;			/* 0x02b8 */
+	__u32	thread_info;			/* 0x02bc */
+	__u32	kernel_stack;			/* 0x02c0 */
+
+	/* Interrupt, panic and restart stack. */
+	__u32	async_stack;			/* 0x02c4 */
+	__u32	panic_stack;			/* 0x02c8 */
+	__u32	restart_stack;			/* 0x02cc */
 
-	/* Interrupt and panic stack. */
-	__u32	async_stack;			/* 0x02ac */
-	__u32	panic_stack;			/* 0x02b0 */
+	/* Restart function and parameter. */
+	__u32	restart_fn;			/* 0x02d0 */
+	__u32	restart_data;			/* 0x02d4 */
+	__u32	restart_source;			/* 0x02d8 */
 
 	/* Address space pointer. */
-	__u32	kernel_asce;			/* 0x02b4 */
-	__u32	user_asce;			/* 0x02b8 */
-	__u32	current_pid;			/* 0x02bc */
+	__u32	kernel_asce;			/* 0x02dc */
+	__u32	user_asce;			/* 0x02e0 */
+	__u32	current_pid;			/* 0x02e4 */
 
 	/* SMP info area */
-	__u32	cpu_nr;				/* 0x02c0 */
-	__u32	softirq_pending;		/* 0x02c4 */
-	__u32	percpu_offset;			/* 0x02c8 */
-	__u32	ext_call_fast;			/* 0x02cc */
-	__u64	int_clock;			/* 0x02d0 */
-	__u64	mcck_clock;			/* 0x02d8 */
-	__u64	clock_comparator;		/* 0x02e0 */
-	__u32	machine_flags;			/* 0x02e8 */
-	__u32	ftrace_func;			/* 0x02ec */
-	__u8	pad_0x02f8[0x0300-0x02f0];	/* 0x02f0 */
+	__u32	cpu_nr;				/* 0x02e8 */
+	__u32	softirq_pending;		/* 0x02ec */
+	__u32	percpu_offset;			/* 0x02f0 */
+	__u32	machine_flags;			/* 0x02f4 */
+	__u32	ftrace_func;			/* 0x02f8 */
+	__u8	pad_0x02fc[0x0300-0x02fc];	/* 0x02fc */
 
 	/* Interrupt response block */
 	__u8	irb[64];			/* 0x0300 */
@@ -254,34 +251,39 @@ struct _lowcore {
 	__u64	steal_timer;			/* 0x02e0 */
 	__u64	last_update_timer;		/* 0x02e8 */
 	__u64	last_update_clock;		/* 0x02f0 */
+	__u64	int_clock;			/* 0x02f8 */
+	__u64	mcck_clock;			/* 0x0300 */
+	__u64	clock_comparator;		/* 0x0308 */
 
 	/* Current process. */
-	__u64	current_task;			/* 0x02f8 */
-	__u64	thread_info;			/* 0x0300 */
-	__u64	kernel_stack;			/* 0x0308 */
+	__u64	current_task;			/* 0x0310 */
+	__u64	thread_info;			/* 0x0318 */
+	__u64	kernel_stack;			/* 0x0320 */
+
+	/* Interrupt, panic and restart stack. */
+	__u64	async_stack;			/* 0x0328 */
+	__u64	panic_stack;			/* 0x0330 */
+	__u64	restart_stack;			/* 0x0338 */
 
-	/* Interrupt and panic stack. */
-	__u64	async_stack;			/* 0x0310 */
-	__u64	panic_stack;			/* 0x0318 */
+	/* Restart function and parameter. */
+	__u64	restart_fn;			/* 0x0340 */
+	__u64	restart_data;			/* 0x0348 */
+	__u64	restart_source;			/* 0x0350 */
 
 	/* Address space pointer. */
-	__u64	kernel_asce;			/* 0x0320 */
-	__u64	user_asce;			/* 0x0328 */
-	__u64	current_pid;			/* 0x0330 */
+	__u64	kernel_asce;			/* 0x0358 */
+	__u64	user_asce;			/* 0x0360 */
+	__u64	current_pid;			/* 0x0368 */
 
 	/* SMP info area */
-	__u32	cpu_nr;				/* 0x0338 */
-	__u32	softirq_pending;		/* 0x033c */
-	__u64	percpu_offset;			/* 0x0340 */
-	__u64	ext_call_fast;			/* 0x0348 */
-	__u64	int_clock;			/* 0x0350 */
-	__u64	mcck_clock;			/* 0x0358 */
-	__u64	clock_comparator;		/* 0x0360 */
-	__u64	vdso_per_cpu_data;		/* 0x0368 */
-	__u64	machine_flags;			/* 0x0370 */
-	__u64	ftrace_func;			/* 0x0378 */
-	__u64	gmap;				/* 0x0380 */
-	__u8	pad_0x0388[0x0400-0x0388];	/* 0x0388 */
+	__u32	cpu_nr;				/* 0x0370 */
+	__u32	softirq_pending;		/* 0x0374 */
+	__u64	percpu_offset;			/* 0x0378 */
+	__u64	vdso_per_cpu_data;		/* 0x0380 */
+	__u64	machine_flags;			/* 0x0388 */
+	__u64	ftrace_func;			/* 0x0390 */
+	__u64	gmap;				/* 0x0398 */
+	__u8	pad_0x03a0[0x0400-0x03a0];	/* 0x03a0 */
 
 	/* Interrupt response block. */
 	__u8	irb[64];			/* 0x0400 */
diff --git a/arch/s390/include/asm/sigp.h b/arch/s390/include/asm/sigp.h
deleted file mode 100644
index 7040b8567cd..00000000000
--- a/arch/s390/include/asm/sigp.h
+++ /dev/null
@@ -1,132 +0,0 @@
-/*
- *  Routines and structures for signalling other processors.
- *
- *    Copyright IBM Corp. 1999,2010
- *    Author(s): Denis Joseph Barrow,
- *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
- *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
- */
-
-#ifndef __ASM_SIGP_H
-#define __ASM_SIGP_H
-
-#include <asm/system.h>
-
-/* Get real cpu address from logical cpu number. */
-extern unsigned short __cpu_logical_map[];
-
-static inline int cpu_logical_map(int cpu)
-{
-#ifdef CONFIG_SMP
-	return __cpu_logical_map[cpu];
-#else
-	return stap();
-#endif
-}
-
-enum {
-	sigp_sense = 1,
-	sigp_external_call = 2,
-	sigp_emergency_signal = 3,
-	sigp_start = 4,
-	sigp_stop = 5,
-	sigp_restart = 6,
-	sigp_stop_and_store_status = 9,
-	sigp_initial_cpu_reset = 11,
-	sigp_cpu_reset = 12,
-	sigp_set_prefix = 13,
-	sigp_store_status_at_address = 14,
-	sigp_store_extended_status_at_address = 15,
-	sigp_set_architecture = 18,
-	sigp_conditional_emergency_signal = 19,
-	sigp_sense_running = 21,
-};
-
-enum {
-	sigp_order_code_accepted = 0,
-	sigp_status_stored = 1,
-	sigp_busy = 2,
-	sigp_not_operational = 3,
-};
-
-/*
- * Definitions for external call.
- */
-enum {
-	ec_schedule = 0,
-	ec_call_function,
-	ec_call_function_single,
-	ec_stop_cpu,
-};
-
-/*
- * Signal processor.
- */
-static inline int raw_sigp(u16 cpu, int order)
-{
-	register unsigned long reg1 asm ("1") = 0;
-	int ccode;
-
-	asm volatile(
-		"	sigp	%1,%2,0(%3)\n"
-		"	ipm	%0\n"
-		"	srl	%0,28\n"
-		:	"=d"	(ccode)
-		: "d" (reg1), "d" (cpu),
-		  "a" (order) : "cc" , "memory");
-	return ccode;
-}
-
-/*
- * Signal processor with parameter.
- */
-static inline int raw_sigp_p(u32 parameter, u16 cpu, int order)
-{
-	register unsigned int reg1 asm ("1") = parameter;
-	int ccode;
-
-	asm volatile(
-		"	sigp	%1,%2,0(%3)\n"
-		"	ipm	%0\n"
-		"	srl	%0,28\n"
-		: "=d" (ccode)
-		: "d" (reg1), "d" (cpu),
-		  "a" (order) : "cc" , "memory");
-	return ccode;
-}
-
-/*
- * Signal processor with parameter and return status.
- */
-static inline int raw_sigp_ps(u32 *status, u32 parm, u16 cpu, int order)
-{
-	register unsigned int reg1 asm ("1") = parm;
-	int ccode;
-
-	asm volatile(
-		"	sigp	%1,%2,0(%3)\n"
-		"	ipm	%0\n"
-		"	srl	%0,28\n"
-		: "=d" (ccode), "+d" (reg1)
-		: "d" (cpu), "a" (order)
-		: "cc" , "memory");
-	*status = reg1;
-	return ccode;
-}
-
-static inline int sigp(int cpu, int order)
-{
-	return raw_sigp(cpu_logical_map(cpu), order);
-}
-
-static inline int sigp_p(u32 parameter, int cpu, int order)
-{
-	return raw_sigp_p(parameter, cpu_logical_map(cpu), order);
-}
-
-static inline int sigp_ps(u32 *status, u32 parm, int cpu, int order)
-{
-	return raw_sigp_ps(status, parm, cpu_logical_map(cpu), order);
-}
-
-#endif /* __ASM_SIGP_H */
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index c32e9123b40..797f7872968 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -1,5 +1,5 @@
 /*
- *    Copyright IBM Corp. 1999,2009
+ *    Copyright IBM Corp. 1999,2012
  *    Author(s): Denis Joseph Barrow,
  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
  *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
@@ -10,71 +10,52 @@
 #ifdef CONFIG_SMP
 
 #include <asm/system.h>
-#include <asm/sigp.h>
-
-extern void machine_restart_smp(char *);
-extern void machine_halt_smp(void);
-extern void machine_power_off_smp(void);
 
 #define raw_smp_processor_id()	(S390_lowcore.cpu_nr)
 
-extern int __cpu_disable (void);
-extern void __cpu_die (unsigned int cpu);
-extern int __cpu_up (unsigned int cpu);
-
 extern struct mutex smp_cpu_state_mutex;
+extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
+
+extern int __cpu_up(unsigned int cpu);
 
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
-extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
-
-extern void smp_switch_to_ipl_cpu(void (*func)(void *), void *);
-extern void smp_switch_to_cpu(void (*)(void *), void *, unsigned long sp,
-			      int from, int to);
-extern void smp_restart_with_online_cpu(void);
-extern void smp_restart_cpu(void);
+extern void smp_call_online_cpu(void (*func)(void *), void *);
+extern void smp_call_ipl_cpu(void (*func)(void *), void *);
 
-/*
- * returns 1 if (virtual) cpu is scheduled
- * returns 0 otherwise
- */
-static inline int smp_vcpu_scheduled(int cpu)
-{
-	u32 status;
-
-	switch (sigp_ps(&status, 0, cpu, sigp_sense_running)) {
-	case sigp_status_stored:
-		/* Check for running status */
-		if (status & 0x400)
-			return 0;
-		break;
-	case sigp_not_operational:
-		return 0;
-	default:
-		break;
-	}
-	return 1;
-}
+extern int smp_find_processor_id(u16 address);
+extern int smp_store_status(int cpu);
+extern int smp_vcpu_scheduled(int cpu);
+extern void smp_yield_cpu(int cpu);
+extern void smp_yield(void);
+extern void smp_stop_cpu(void);
 
 #else /* CONFIG_SMP */
 
-static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
+static inline void smp_call_ipl_cpu(void (*func)(void *), void *data)
 {
 	func(data);
 }
 
-static inline void smp_restart_with_online_cpu(void)
+static inline void smp_call_online_cpu(void (*func)(void *), void *data)
 {
+	func(data);
 }
 
-#define smp_vcpu_scheduled	(1)
+static inline int smp_find_processor_id(int address) { return 0; }
+static inline int smp_vcpu_scheduled(int cpu) { return 1; }
+static inline void smp_yield_cpu(int cpu) { }
+static inline void smp_yield(void) { }
+static inline void smp_stop_cpu(void) { }
 
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_HOTPLUG_CPU
 extern int smp_rescan_cpus(void);
 extern void __noreturn cpu_die(void);
+extern void __cpu_die(unsigned int cpu);
+extern int __cpu_disable(void);
 #else
 static inline int smp_rescan_cpus(void) { return 0; }
 static inline void cpu_die(void) { }
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index 533f35751ae..c4a11cfad3c 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -40,8 +40,8 @@ struct vdso_per_cpu_data {
 extern struct vdso_data *vdso_data;
 
 #ifdef CONFIG_64BIT
-int vdso_alloc_per_cpu(int cpu, struct _lowcore *lowcore);
-void vdso_free_per_cpu(int cpu, struct _lowcore *lowcore);
+int vdso_alloc_per_cpu(struct _lowcore *lowcore);
+void vdso_free_per_cpu(struct _lowcore *lowcore);
 #endif
 
 #endif /* __ASSEMBLY__ */