Merge tag 's390-5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:
 "This is mainly to decouple udelay() and arch_cpu_idle() and simplify
  both of them.

  Summary:

   - Always initialize kernel stack backchain when entering the kernel,
     so that unwinding works properly.

   - Fix stack unwinder test case to avoid rare interrupt stack
     corruption.

   - Simplify udelay() and just let it busy loop instead of implementing
     a complex logic.

   - arch_cpu_idle() cleanup.

   - Some other minor improvements"

* tag 's390-5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: convert comma to semicolon
  s390/idle: allow arch_cpu_idle() to be kprobed
  s390/idle: remove raw_local_irq_save()/restore() from arch_cpu_idle()
  s390/idle: merge enabled_wait() and arch_cpu_idle()
  s390/delay: remove udelay_simple()
  s390/irq: select HAVE_IRQ_EXIT_ON_IRQ_STACK
  s390/delay: simplify udelay
  s390/test_unwind: use timer instead of udelay
  s390/test_unwind: fix CALL_ON_STACK tests
  s390: make calls to TRACE_IRQS_OFF/TRACE_IRQS_ON balanced
  s390: always clear kernel stack backchain before calling functions

4 files changed, 11 insertions, 26 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 1f4659203f8c..f1ba197b10c0 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -414,6 +414,7 @@ ENTRY(system_call)
 	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
 	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
 	stg	%r14,__PT_FLAGS(%r11)
+	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	ENABLE_INTS
 .Lsysc_do_svc:
 	# clear user controlled register to prevent speculative use
@@ -430,7 +431,6 @@ ENTRY(system_call)
 	jnl	.Lsysc_nr_ok
 	slag	%r8,%r1,3
 .Lsysc_nr_ok:
-	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	stg	%r2,__PT_ORIG_GPR2(%r11)
 	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
 	lg	%r9,0(%r8,%r10)			# get system call add.
@@ -699,8 +699,8 @@ ENTRY(pgm_check_handler)
 	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
 	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
 	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
-6:	RESTORE_SM_CLEAR_PER
-	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+6:	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+	RESTORE_SM_CLEAR_PER
 	larl	%r1,pgm_check_table
 	llgh	%r10,__PT_INT_CODE+2(%r11)
 	nill	%r10,0x007f
@@ -731,8 +731,8 @@ ENTRY(pgm_check_handler)
 # PER event in supervisor state, must be kprobes
 #
 .Lpgm_kprobe:
-	RESTORE_SM_CLEAR_PER
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+	RESTORE_SM_CLEAR_PER
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	brasl	%r14,do_per_trap
 	j	.Lpgm_return
@@ -778,10 +778,8 @@ ENTRY(io_int_handler)
 .Lio_skip_asce:
 	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
 	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
-	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
-	jo	.Lio_restore
-	TRACE_IRQS_OFF
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+	TRACE_IRQS_OFF
 .Lio_loop:
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	lghi	%r3,IO_INTERRUPT
@@ -966,10 +964,8 @@ ENTRY(ext_int_handler)
 	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
 	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
 	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
-	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
-	jo	.Lio_restore
-	TRACE_IRQS_OFF
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+	TRACE_IRQS_OFF
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	lghi	%r3,EXT_INTERRUPT
 	brasl	%r14,do_IRQ
diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 2b85096964f8..a5d4d80d6ede 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -9,7 +9,6 @@
 
 #include <linux/kernel.h>
 #include <linux/kernel_stat.h>
-#include <linux/kprobes.h>
 #include <linux/notifier.h>
 #include <linux/init.h>
 #include <linux/cpu.h>
@@ -21,22 +20,19 @@
 
 static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
 
-void enabled_wait(void)
+void arch_cpu_idle(void)
 {
 	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
 	unsigned long long idle_time;
-	unsigned long psw_mask, flags;
-
+	unsigned long psw_mask;
 
 	/* Wait for external, I/O or machine check interrupt. */
 	psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT | PSW_MASK_DAT |
 		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 	clear_cpu_flag(CIF_NOHZ_DELAY);
 
-	raw_local_irq_save(flags);
-	/* Call the assembler magic in entry.S */
+	/* psw_idle() returns with interrupts disabled. */
 	psw_idle(idle, psw_mask);
-	raw_local_irq_restore(flags);
 
 	/* Account time spent with enabled wait psw loaded as idle time. */
 	raw_write_seqcount_begin(&idle->seqcount);
@@ -46,8 +42,8 @@ void enabled_wait(void)
 	idle->idle_count++;
 	account_idle_time(cputime_to_nsecs(idle_time));
 	raw_write_seqcount_end(&idle->seqcount);
+	raw_local_irq_enable();
 }
-NOKPROBE_SYMBOL(enabled_wait);
 
 static ssize_t show_idle_count(struct device *dev,
 				struct device_attribute *attr, char *buf)
@@ -120,12 +116,6 @@ void arch_cpu_idle_enter(void)
 {
 }
 
-void arch_cpu_idle(void)
-{
-	enabled_wait();
-	raw_local_irq_enable();
-}
-
 void arch_cpu_idle_exit(void)
 {
 }
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 98b3aca1de8e..7a21eca498aa 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -1512,7 +1512,7 @@ static void diag308_dump(void *dump_block)
 	while (1) {
 		if (diag308(DIAG308_LOAD_NORMAL_DUMP, NULL) != 0x302)
 			break;
-		udelay_simple(USEC_PER_SEC);
+		udelay(USEC_PER_SEC);
 	}
 }
 
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 1f16a03be995..1fbed91c73bc 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -335,7 +335,6 @@ int __init arch_early_irq_init(void)
 	if (!stack)
 		panic("Couldn't allocate async stack");
 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
-	udelay_enable();
 	return 0;
 }