[PATCH] lockdep: irqtrace subsystem, s390 support

irqtrace support for s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/s390/Kconfig.debug

 menu "Kernel hacking"
 
+config TRACE_IRQFLAGS_SUPPORT
+	bool
+	default y
+
 source "lib/Kconfig.debug"
 
 endmenu

arch/s390/kernel/entry.S

@@ -58,6 +58,21 @@ STACK_SIZE  = 1 << STACK_SHIFT
 
 #define BASED(name) name-system_call(%r13)
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+	.macro	TRACE_IRQS_ON
+	l	%r1,BASED(.Ltrace_irq_on)
+	basr	%r14,%r1
+	.endm
+
+	.macro	TRACE_IRQS_OFF
+	l	%r1,BASED(.Ltrace_irq_off)
+	basr	%r14,%r1
+	.endm
+#else
+#define TRACE_IRQS_ON
+#define TRACE_IRQS_OFF
+#endif
+
 /*
  * Register usage in interrupt handlers:
  *    R9  - pointer to current task structure
@@ -361,6 +376,7 @@ ret_from_fork:
 	st	%r15,SP_R15(%r15)	# store stack pointer for new kthread
 0:	l       %r1,BASED(.Lschedtail)
 	basr    %r14,%r1
+	TRACE_IRQS_ON
         stosm   __SF_EMPTY(%r15),0x03     # reenable interrupts
 	b	BASED(sysc_return)
 
@@ -516,6 +532,7 @@ pgm_no_vtime3:
 	mvc	__THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
 	mvc	__THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
 	oi	__TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+	TRACE_IRQS_ON
 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts
 	b	BASED(sysc_do_svc)
 
@@ -539,9 +556,11 @@ io_int_handler:
 io_no_vtime:
 #endif
 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	TRACE_IRQS_OFF
         l       %r1,BASED(.Ldo_IRQ)        # load address of do_IRQ
         la      %r2,SP_PTREGS(%r15) # address of register-save area
         basr    %r14,%r1          # branch to standard irq handler
+	TRACE_IRQS_ON
 
 io_return:
         tm      SP_PSW+1(%r15),0x01    # returning to user ?
@@ -651,10 +670,12 @@ ext_int_handler:
 ext_no_vtime:
 #endif
 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	TRACE_IRQS_OFF
 	la	%r2,SP_PTREGS(%r15)    # address of register-save area
 	lh	%r3,__LC_EXT_INT_CODE  # get interruption code
 	l	%r1,BASED(.Ldo_extint)
 	basr	%r14,%r1
+	TRACE_IRQS_ON
 	b	BASED(io_return)
 
 __critical_end:
@@ -731,8 +752,10 @@ mcck_no_vtime:
 	stosm	__SF_EMPTY(%r15),0x04	# turn dat on
 	tm	__TI_flags+3(%r9),_TIF_MCCK_PENDING
 	bno	BASED(mcck_return)
+	TRACE_IRQS_OFF
 	l	%r1,BASED(.Ls390_handle_mcck)
 	basr	%r14,%r1		# call machine check handler
+	TRACE_IRQS_ON
 mcck_return:
 	mvc	__LC_RETURN_MCCK_PSW(8),SP_PSW(%r15) # move return PSW
 	ni	__LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit
@@ -1012,7 +1035,11 @@ cleanup_io_leave_insn:
 .Lvfork:       .long  sys_vfork
 .Lschedtail:   .long  schedule_tail
 .Lsysc_table:  .long  sys_call_table
-
+#ifdef CONFIG_TRACE_IRQFLAGS
+.Ltrace_irq_on:.long  trace_hardirqs_on
+.Ltrace_irq_off:
+	       .long  trace_hardirqs_off
+#endif
 .Lcritical_start:
                .long  __critical_start + 0x80000000
 .Lcritical_end:

arch/s390/kernel/entry64.S

@@ -58,6 +58,19 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NEED_RESCHED | \
 
 #define BASED(name) name-system_call(%r13)
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+	.macro	TRACE_IRQS_ON
+	 brasl	%r14,trace_hardirqs_on
+	.endm
+
+	.macro	TRACE_IRQS_OFF
+	 brasl	%r14,trace_hardirqs_off
+	.endm
+#else
+#define TRACE_IRQS_ON
+#define TRACE_IRQS_OFF
+#endif
+
 	.macro  STORE_TIMER lc_offset
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 	stpt	\lc_offset
@@ -354,6 +367,7 @@ ret_from_fork:
 	jo	0f
 	stg	%r15,SP_R15(%r15)	# store stack pointer for new kthread
 0:	brasl   %r14,schedule_tail
+	TRACE_IRQS_ON
         stosm   24(%r15),0x03     # reenable interrupts
 	j	sysc_return
 
@@ -535,6 +549,7 @@ pgm_no_vtime3:
 	mvc	__THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
 	mvc	__THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
 	oi	__TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+	TRACE_IRQS_ON
 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts
 	j	sysc_do_svc
 
@@ -557,8 +572,10 @@ io_int_handler:
 io_no_vtime:
 #endif
 	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	TRACE_IRQS_OFF
         la      %r2,SP_PTREGS(%r15)    # address of register-save area
 	brasl   %r14,do_IRQ            # call standard irq handler
+	TRACE_IRQS_ON
 
 io_return:
         tm      SP_PSW+1(%r15),0x01    # returning to user ?
@@ -665,9 +682,11 @@ ext_int_handler:
 ext_no_vtime:
 #endif
 	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
+	TRACE_IRQS_OFF
 	la	%r2,SP_PTREGS(%r15)    # address of register-save area
 	llgh	%r3,__LC_EXT_INT_CODE  # get interruption code
 	brasl   %r14,do_extint
+	TRACE_IRQS_ON
 	j	io_return
 
 __critical_end:
@@ -743,7 +762,9 @@ mcck_no_vtime:
 	stosm	__SF_EMPTY(%r15),0x04	# turn dat on
 	tm	__TI_flags+7(%r9),_TIF_MCCK_PENDING
 	jno	mcck_return
+	TRACE_IRQS_OFF
 	brasl	%r14,s390_handle_mcck
+	TRACE_IRQS_ON
 mcck_return:
 	mvc	__LC_RETURN_MCCK_PSW(16),SP_PSW(%r15) # move return PSW
 	ni	__LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit

arch/s390/kernel/irq.c

@@ -97,7 +97,7 @@ asmlinkage void do_softirq(void)
 
 	account_system_vtime(current);
 
-	__local_bh_enable();
+	_local_bh_enable();
 
 	local_irq_restore(flags);
 }

arch/s390/kernel/process.c

@@ -142,6 +142,7 @@ static void default_idle(void)
 		return;
 	}
 
+	trace_hardirqs_on();
 	/* Wait for external, I/O or machine check interrupt. */
 	__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_WAIT |
 			PSW_MASK_IO | PSW_MASK_EXT);

drivers/s390/char/sclp.c

@@ -383,6 +383,7 @@ void
 sclp_sync_wait(void)
 {
 	unsigned long psw_mask;
+	unsigned long flags;
 	unsigned long cr0, cr0_sync;
 	u64 timeout;
 
@@ -395,9 +396,11 @@ sclp_sync_wait(void)
 			  sclp_tod_from_jiffies(sclp_request_timer.expires -
 						jiffies);
 	}
+	local_irq_save(flags);
 	/* Prevent bottom half from executing once we force interrupts open */
 	local_bh_disable();
 	/* Enable service-signal interruption, disable timer interrupts */
+	trace_hardirqs_on();
 	__ctl_store(cr0, 0, 0);
 	cr0_sync = cr0;
 	cr0_sync |= 0x00000200;
@@ -415,11 +418,10 @@ sclp_sync_wait(void)
 		barrier();
 		cpu_relax();
 	}
-	/* Restore interrupt settings */
-	asm volatile ("SSM 0(%0)"
-		      : : "a" (&psw_mask) : "memory");
+	local_irq_disable();
 	__ctl_load(cr0, 0, 0);
-	__local_bh_enable();
+	_local_bh_enable();
+	local_irq_restore(flags);
 }
 
 EXPORT_SYMBOL(sclp_sync_wait);

drivers/s390/cio/cio.c

@@ -147,7 +147,7 @@ cio_tpi(void)
 		sch->driver->irq(&sch->dev);
 	spin_unlock(&sch->lock);
 	irq_exit ();
-	__local_bh_enable();
+	_local_bh_enable();
 	return 1;
 }
 

include/asm-s390/irqflags.h

+/*
+ *  include/asm-s390/irqflags.h
+ *
+ *    Copyright (C) IBM Corp. 2006
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#ifndef __ASM_IRQFLAGS_H
+#define __ASM_IRQFLAGS_H
+
+#ifdef __KERNEL__
+
+/* interrupt control.. */
+#define raw_local_irq_enable() ({ \
+	unsigned long  __dummy; \
+	__asm__ __volatile__ ( \
+		"stosm 0(%1),0x03" \
+		: "=m" (__dummy) : "a" (&__dummy) : "memory" ); \
+	})
+
+#define raw_local_irq_disable() ({ \
+	unsigned long __flags; \
+	__asm__ __volatile__ ( \
+		"stnsm 0(%1),0xfc" : "=m" (__flags) : "a" (&__flags) ); \
+	__flags; \
+	})
+
+#define raw_local_save_flags(x) \
+	__asm__ __volatile__("stosm 0(%1),0" : "=m" (x) : "a" (&x), "m" (x) )
+
+#define raw_local_irq_restore(x) \
+	__asm__ __volatile__("ssm   0(%0)" : : "a" (&x), "m" (x) : "memory")
+
+#define raw_irqs_disabled()		\
+({					\
+	unsigned long flags;		\
+	local_save_flags(flags);	\
+	!((flags >> __FLAG_SHIFT) & 3);	\
+})
+
+static inline int raw_irqs_disabled_flags(unsigned long flags)
+{
+	return !((flags >> __FLAG_SHIFT) & 3);
+}
+
+/* For spinlocks etc */
+#define raw_local_irq_save(x)	((x) = raw_local_irq_disable())
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_IRQFLAGS_H */

include/asm-s390/system.h

@@ -301,34 +301,6 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 #define set_mb(var, value)      do { var = value; mb(); } while (0)
 #define set_wmb(var, value)     do { var = value; wmb(); } while (0)
 
-/* interrupt control.. */
-#define local_irq_enable() ({ \
-        unsigned long  __dummy; \
-        __asm__ __volatile__ ( \
-                "stosm 0(%1),0x03" \
-		: "=m" (__dummy) : "a" (&__dummy) : "memory" ); \
-        })
-
-#define local_irq_disable() ({ \
-        unsigned long __flags; \
-        __asm__ __volatile__ ( \
-                "stnsm 0(%1),0xfc" : "=m" (__flags) : "a" (&__flags) ); \
-        __flags; \
-        })
-
-#define local_save_flags(x) \
-        __asm__ __volatile__("stosm 0(%1),0" : "=m" (x) : "a" (&x), "m" (x) )
-
-#define local_irq_restore(x) \
-        __asm__ __volatile__("ssm   0(%0)" : : "a" (&x), "m" (x) : "memory")
-
-#define irqs_disabled()			\
-({					\
-	unsigned long flags;		\
-	local_save_flags(flags);	\
-        !((flags >> __FLAG_SHIFT) & 3);	\
-})
-
 #ifdef __s390x__
 
 #define __ctl_load(array, low, high) ({ \
@@ -442,8 +414,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
         })
 #endif /* __s390x__ */
 
-/* For spinlocks etc */
-#define local_irq_save(x)	((x) = local_irq_disable())
+#include <linux/irqflags.h>
 
 /*
  * Use to set psw mask except for the first byte which
@@ -482,4 +453,3 @@ extern void (*_machine_power_off)(void);
 #endif /* __KERNEL__ */
 
 #endif
-