Revert "s390: add ppa to kernel entry / exit"

BugLink: http://bugs.launchpad.net/bugs/1768474

This reverts commit b226be50 to be
replaced by the upstream patch set from 4.4.130.
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/s390/include/asm/processor.h

@@ -69,7 +69,6 @@ extern void s390_adjust_jiffies(void);
 extern const struct seq_operations cpuinfo_op;
 extern int sysctl_ieee_emulation_warnings;
 extern void execve_tail(void);
-extern void __bpon(void);
 
 /*
  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.

arch/s390/kernel/alternative.c

@@ -14,19 +14,6 @@ static int __init disable_alternative_instructions(char *str)
 
 early_param("noaltinstr", disable_alternative_instructions);
 
-extern struct alt_instr __alt_nobp[], __alt_nobp_end[];
-static int __init nobp_setup(char *str)
-{
-	bool enabled;
-	int rc;
-
-	rc = strtobool(str, &enabled);
-	if (!rc && enabled)
-		apply_alternatives(__alt_nobp, __alt_nobp_end);
-	return rc;
-}
-__setup("nobp=", nobp_setup);
-
 struct brcl_insn {
 	u16 opc;
 	s32 disp;

arch/s390/kernel/entry.S

@@ -162,41 +162,8 @@ _PIF_WORK	= (_PIF_PER_TRAP)
 		tm	off+\addr, \mask
 	.endm
 
-	.macro BPOFF
-	.pushsection .altinstr_replacement, "ax"
-660:	.long	0xb2e8c000
-	.popsection
-661:	.long	0x47000000
-	.pushsection .altnobp, "a"
-	.long 661b - .
-	.long 660b - .
-	.word 82
-	.byte 4
-	.byte 4
-	.popsection
-	.endm
-
-	.macro BPON
-	.pushsection .altinstr_replacement, "ax"
-662:	.long	0xb2e8d000
-	.popsection
-663:	.long	0x47000000
-	.pushsection .altnobp, "a"
-	.long 663b - .
-	.long 662b - .
-	.word 82
-	.byte 4
-	.byte 4
-	.popsection
-	.endm
-
 	.section .kprobes.text, "ax"
 
-ENTRY(__bpon)
-	.globl __bpon
-	BPON
-	br	%r14
-
 /*
  * Scheduler resume function, called by switch_to
  *  gpr2 = (task_struct *) prev
@@ -256,9 +223,7 @@ ENTRY(sie64a)
 	jnz	.Lsie_skip
 	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
 	jo	.Lsie_skip			# exit if fp/vx regs changed
-	BPON
 	sie	0(%r14)
-	BPOFF
 .Lsie_skip:
 	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
 	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
@@ -302,7 +267,6 @@ ENTRY(system_call)
 	stpt	__LC_SYNC_ENTER_TIMER
 .Lsysc_stmg:
 	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
-	BPOFF
 	lg	%r10,__LC_LAST_BREAK
 	lg	%r12,__LC_THREAD_INFO
 	lghi	%r14,_PIF_SYSCALL
@@ -347,7 +311,6 @@ ENTRY(system_call)
 	jnz	.Lsysc_work			# check for work
 	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
 	jnz	.Lsysc_work
-	BPON
 .Lsysc_restore:
 	lg	%r14,__LC_VDSO_PER_CPU
 	lmg	%r0,%r10,__PT_R0(%r11)
@@ -508,7 +471,6 @@ ENTRY(kernel_thread_starter)
 
 ENTRY(pgm_check_handler)
 	stpt	__LC_SYNC_ENTER_TIMER
-	BPOFF
 	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
 	lg	%r10,__LC_LAST_BREAK
 	lg	%r12,__LC_THREAD_INFO
@@ -598,7 +560,6 @@ ENTRY(pgm_check_handler)
 ENTRY(io_int_handler)
 	STCK	__LC_INT_CLOCK
 	stpt	__LC_ASYNC_ENTER_TIMER
-	BPOFF
 	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
 	lg	%r10,__LC_LAST_BREAK
 	lg	%r12,__LC_THREAD_INFO
@@ -640,13 +601,9 @@ ENTRY(io_int_handler)
 	lg	%r14,__LC_VDSO_PER_CPU
 	lmg	%r0,%r10,__PT_R0(%r11)
 	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
-	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
-	jno	.Lio_exit_kernel
-	BPON
 .Lio_exit_timer:
 	stpt	__LC_EXIT_TIMER
 	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
-.Lio_exit_kernel:
 	lmg	%r11,%r15,__PT_R11(%r11)
 	lpswe	__LC_RETURN_PSW
 .Lio_done:
@@ -778,7 +735,6 @@ ENTRY(io_int_handler)
 ENTRY(ext_int_handler)
 	STCK	__LC_INT_CLOCK
 	stpt	__LC_ASYNC_ENTER_TIMER
-	BPOFF
 	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC
 	lg	%r10,__LC_LAST_BREAK
 	lg	%r12,__LC_THREAD_INFO
@@ -817,7 +773,6 @@ ENTRY(psw_idle)
 	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
 .Lpsw_idle_stcctm:
 #endif
-	BPON
 	STCK	__CLOCK_IDLE_ENTER(%r2)
 	stpt	__TIMER_IDLE_ENTER(%r2)
 .Lpsw_idle_lpsw:
@@ -922,7 +877,6 @@ load_fpu_regs:
  */
 ENTRY(mcck_int_handler)
 	STCK	__LC_MCCK_CLOCK
-	BPOFF
 	la	%r1,4095		# revalidate r1
 	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# revalidate cpu timer
 	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
@@ -979,7 +933,6 @@ ENTRY(mcck_int_handler)
 	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
 	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
 	jno	0f
-	BPON
 	stpt	__LC_EXIT_TIMER
 	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
 0:	lmg	%r11,%r15,__PT_R11(%r11)

arch/s390/kernel/ipl.c

@@ -563,7 +563,6 @@ static struct kset *ipl_kset;
 
 static void __ipl_run(void *unused)
 {
-	__bpon();
 	diag308(DIAG308_IPL, NULL);
 	if (MACHINE_IS_VM)
 		__cpcmd("IPL", NULL, 0, NULL);

arch/s390/kernel/smp.c

@@ -299,7 +299,6 @@ static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
 	mem_assign_absolute(lc->restart_fn, (unsigned long) func);
 	mem_assign_absolute(lc->restart_data, (unsigned long) data);
 	mem_assign_absolute(lc->restart_source, source_cpu);
-	__bpon();
 	asm volatile(
 		"0:	sigp	0,%0,%2	# sigp restart to target cpu\n"
 		"	brc	2,0b	# busy, try again\n"
@@ -889,7 +888,6 @@ void __cpu_die(unsigned int cpu)
 void __noreturn cpu_die(void)
 {
 	idle_task_exit();
-	__bpon();
 	pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
 	for (;;) ;
 }

arch/s390/kernel/vmlinux.lds.S

@@ -89,9 +89,6 @@ SECTIONS
 		__alt_instructions = .;
 		*(.altinstructions)
 		__alt_instructions_end = .;
-		__alt_nobp = .;
-		*(.altnobp)
-		__alt_nobp_end = .;
 	}
 
 	/*