s390/irq: store interrupt information in pt_regs

Copy the interrupt parameters from the lowcore to the pt_regs structure
in entry[64].S and reduce the arguments of the low level interrupt handler
to the pt_regs pointer only. In addition move the test-pending-interrupt
loop from do_IRQ to entry[64].S to make sure that interrupt information
is always delivered via pt_regs.

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

6 files changed, 30 insertions, 10 deletions

diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 559512a455d..52b56533c57 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -24,6 +24,7 @@ struct pt_regs
 	unsigned long gprs[NUM_GPRS];
 	unsigned long orig_gpr2;
 	unsigned int int_code;
+	unsigned int int_parm;
 	unsigned long int_parm_long;
 };
 
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 7a82f9f7010..d6de844bc30 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -47,6 +47,7 @@ int main(void)
 	DEFINE(__PT_GPRS, offsetof(struct pt_regs, gprs));
 	DEFINE(__PT_ORIG_GPR2, offsetof(struct pt_regs, orig_gpr2));
 	DEFINE(__PT_INT_CODE, offsetof(struct pt_regs, int_code));
+	DEFINE(__PT_INT_PARM, offsetof(struct pt_regs, int_parm));
 	DEFINE(__PT_INT_PARM_LONG, offsetof(struct pt_regs, int_parm_long));
 	DEFINE(__PT_SIZE, sizeof(struct pt_regs));
 	BLANK();
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 4d5e6f8a797..be7a408be7a 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -429,11 +429,19 @@ io_skip:
 	stm	%r0,%r7,__PT_R0(%r11)
 	mvc	__PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
 	stm	%r8,%r9,__PT_PSW(%r11)
+	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
 	TRACE_IRQS_OFF
 	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
+io_loop:
 	l	%r1,BASED(.Ldo_IRQ)
 	lr	%r2,%r11		# pass pointer to pt_regs
 	basr	%r14,%r1		# call do_IRQ
+	tm	__LC_MACHINE_FLAGS+2,0x10	# MACHINE_FLAG_LPAR
+	jz	io_return
+	tpi	0
+	jz	io_return
+	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
+	j	io_loop
 io_return:
 	LOCKDEP_SYS_EXIT
 	TRACE_IRQS_ON
@@ -573,10 +581,10 @@ ext_skip:
 	stm	%r0,%r7,__PT_R0(%r11)
 	mvc	__PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
 	stm	%r8,%r9,__PT_PSW(%r11)
+	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
+	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
 	TRACE_IRQS_OFF
 	lr	%r2,%r11		# pass pointer to pt_regs
-	l	%r3,__LC_EXT_CPU_ADDR	# get cpu address + interruption code
-	l	%r4,__LC_EXT_PARAMS	# get external parameters
 	l	%r1,BASED(.Ldo_extint)
 	basr	%r14,%r1		# call do_extint
 	j	io_return
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index aa0ab02e959..3ddbc26d246 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -54,7 +54,7 @@ void handle_signal32(unsigned long sig, struct k_sigaction *ka,
 void do_notify_resume(struct pt_regs *regs);
 
 struct ext_code;
-void do_extint(struct pt_regs *regs, struct ext_code, unsigned int, unsigned long);
+void do_extint(struct pt_regs *regs);
 void do_restart(void);
 void __init startup_init(void);
 void die(struct pt_regs *regs, const char *str);
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 4c17eece707..bc5864c5148 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -460,10 +460,18 @@ io_skip:
 	stmg	%r0,%r7,__PT_R0(%r11)
 	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
 	stmg	%r8,%r9,__PT_PSW(%r11)
+	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
 	TRACE_IRQS_OFF
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+io_loop:
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	brasl	%r14,do_IRQ
+	tm	__LC_MACHINE_FLAGS+6,0x10	# MACHINE_FLAG_LPAR
+	jz	io_return
+	tpi	0
+	jz	io_return
+	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
+	j	io_loop
 io_return:
 	LOCKDEP_SYS_EXIT
 	TRACE_IRQS_ON
@@ -605,13 +613,13 @@ ext_skip:
 	stmg	%r0,%r7,__PT_R0(%r11)
 	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
 	stmg	%r8,%r9,__PT_PSW(%r11)
+	lghi	%r1,__LC_EXT_PARAMS2
+	mvc	__PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
+	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
+	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
 	TRACE_IRQS_OFF
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
-	lghi	%r1,4096
 	lgr	%r2,%r11		# pass pointer to pt_regs
-	llgf	%r3,__LC_EXT_CPU_ADDR	# get cpu address + interruption code
-	llgf	%r4,__LC_EXT_PARAMS	# get external parameter
-	lg	%r5,__LC_EXT_PARAMS2-4096(%r1)	# get 64 bit external parameter
 	brasl	%r14,do_extint
 	j	io_return
 
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index dd3c1994b8b..54b0995514e 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -234,9 +234,9 @@ int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
 }
 EXPORT_SYMBOL(unregister_external_interrupt);
 
-void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
-			   unsigned int param32, unsigned long param64)
+void __irq_entry do_extint(struct pt_regs *regs)
 {
+	struct ext_code ext_code;
 	struct pt_regs *old_regs;
 	struct ext_int_info *p;
 	int index;
@@ -248,6 +248,7 @@ void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
 		clock_comparator_work();
 	}
 	kstat_incr_irqs_this_cpu(EXTERNAL_INTERRUPT, NULL);
+	ext_code = *(struct ext_code *) &regs->int_code;
 	if (ext_code.code != 0x1004)
 		__get_cpu_var(s390_idle).nohz_delay = 1;
 
@@ -255,7 +256,8 @@ void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
 	rcu_read_lock();
 	list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
 		if (likely(p->code == ext_code.code))
-			p->handler(ext_code, param32, param64);
+			p->handler(ext_code, regs->int_parm,
+				   regs->int_parm_long);
 	rcu_read_unlock();
 	irq_exit();
 	set_irq_regs(old_regs);