Commit fa2ae4a3 authored by Sven Schnelle's avatar Sven Schnelle Committed by Alexander Gordeev
Browse files

s390/idle: Rewrite psw_idle() in C 



To ease maintenance and further enhancements, convert
the psw_idle() function to C.

Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent 62b672c4

arch/s390/include/asm/processor.h

+14 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include <asm/setup.h>

#include <asm/runtime_instr.h>

#include <asm/irqflags.h>

#include <asm/alternative.h>



typedef long (*sys_call_ptr_t)(struct pt_regs *regs);
@@ -92,6 +93,14 @@ static inline void get_cpu_id(struct cpuid *ptr) 
	asm volatile("stidp %0" : "=Q" (*ptr));

}



static __always_inline unsigned long get_cpu_timer(void)

{

	unsigned long timer;



	asm volatile("stpt	%[timer]" : [timer] "=Q" (timer));

	return timer;

}



void s390_adjust_jiffies(void);

void s390_update_cpu_mhz(void);

void cpu_detect_mhz_feature(void);
@@ -394,6 +403,11 @@ static __always_inline bool regs_irqs_disabled(struct pt_regs *regs) 
	return arch_irqs_disabled_flags(regs->psw.mask);

}



static __always_inline void bpon(void)

{

	asm volatile(ALTERNATIVE("nop", ".insn	rrf,0xb2e80000,0,0,13,0", 82));

}



#endif /* __ASSEMBLY__ */



#endif /* __ASM_S390_PROCESSOR_H */

arch/s390/kernel/asm-offsets.c

+0 −6
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ 
#include <linux/purgatory.h>

#include <linux/pgtable.h>

#include <linux/ftrace.h>

#include <asm/idle.h>

#include <asm/gmap.h>

#include <asm/stacktrace.h>
@@ -71,11 +70,6 @@ int main(void) 
	OFFSET(__SFVDSO_RETURN_ADDRESS, stack_frame_vdso_wrapper, return_address);

	DEFINE(STACK_FRAME_VDSO_OVERHEAD, sizeof(struct stack_frame_vdso_wrapper));

	BLANK();

	/* idle data offsets */

	OFFSET(__CLOCK_IDLE_ENTER, s390_idle_data, clock_idle_enter);

	OFFSET(__TIMER_IDLE_ENTER, s390_idle_data, timer_idle_enter);

	OFFSET(__MT_CYCLES_ENTER, s390_idle_data, mt_cycles_enter);

	BLANK();

	/* hardware defined lowcore locations 0x000 - 0x1ff */

	OFFSET(__LC_EXT_PARAMS, lowcore, ext_params);

	OFFSET(__LC_EXT_CPU_ADDR, lowcore, ext_cpu_addr);

arch/s390/kernel/entry.S

+0 −23
Original line number Diff line number Diff line
@@ -440,29 +440,6 @@ SYM_CODE_END(\name) 
INT_HANDLER ext_int_handler,__LC_EXT_OLD_PSW,do_ext_irq

INT_HANDLER io_int_handler,__LC_IO_OLD_PSW,do_io_irq



/*

 * Load idle PSW.

 */

SYM_FUNC_START(psw_idle)

	stg	%r14,(__SF_GPRS+8*8)(%r15)

	stg	%r3,__SF_EMPTY(%r15)

	larl	%r1,psw_idle_exit

	stg	%r1,__SF_EMPTY+8(%r15)

	larl	%r1,smp_cpu_mtid

	llgf	%r1,0(%r1)

	ltgr	%r1,%r1

	jz	.Lpsw_idle_stcctm

	.insn	rsy,0xeb0000000017,%r1,5,__MT_CYCLES_ENTER(%r2)

.Lpsw_idle_stcctm:

	oi	__LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT

	BPON

	stckf	__CLOCK_IDLE_ENTER(%r2)

	stpt	__TIMER_IDLE_ENTER(%r2)

	lpswe	__SF_EMPTY(%r15)

SYM_INNER_LABEL(psw_idle_exit, SYM_L_GLOBAL)

	BR_EX	%r14

SYM_FUNC_END(psw_idle)



/*

 * Machine check handler routines

 */

arch/s390/kernel/idle.c

+7 −3
Original line number Diff line number Diff line
@@ -57,9 +57,13 @@ void noinstr arch_cpu_idle(void) 
	psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT |

		   PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;

	clear_cpu_flag(CIF_NOHZ_DELAY);



	/* psw_idle() returns with interrupts disabled. */

	psw_idle(idle, psw_mask);

	set_cpu_flag(CIF_ENABLED_WAIT);

	if (smp_cpu_mtid)

		stcctm(MT_DIAG, smp_cpu_mtid, (u64 *)&idle->mt_cycles_enter);

	idle->clock_idle_enter = get_tod_clock_fast();

	idle->timer_idle_enter = get_cpu_timer();

	bpon();

	__load_psw_mask(psw_mask);

}



static ssize_t show_idle_count(struct device *dev,